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Diffstat (limited to 'TAO/docs')
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diff --git a/TAO/docs/DIFFERENCES b/TAO/docs/DIFFERENCES deleted file mode 100644 index 0a8dd343d4d..00000000000 --- a/TAO/docs/DIFFERENCES +++ /dev/null @@ -1,360 +0,0 @@ -@(#)DIFFERENCES 1.1 95/09/13 - -[ NOTE that the CORBA 2.0 specifications have now been published, but are -not yet sufficiently available that this document can usefully just list -any differences between that specification and this software. As a rule, -there are no differences between this software and CORBA 2.0 in areas -where CORBA 2.0 has specified an interface. ] - - -This document summarizes known differences between what is implemented in -this software and currently available OMG specifications. As a rule, these -establish compatibility with revised specifications that are currently being -prepared for publication. However, in some cases the differences resolve -problems that are currently being addressed by ORB taskforces. When those -revised CORBA specifications are published, this document will be updated to -reflect any remaining differences from them. - -The reason for those changes is that different specifications were adopted -at the same time and there were in some cases subtle differences which need -to be resolved. Minor errata have also been fixed. None of these changes -are substantial, with the exception of the TypeCode interpreter API which -was added to the C++ mapping. - -Also, note that the goal of this software is fidelity to the IIOP, so that -issues relating (in particular) to the C++ language mapping or other OMG -specifications were judged to be of less importance at this time. - - -DIFFERENCES from IIOP in UNO Spec (95-3-10) -------------------------------------------- -Some changes to the original specification (94-9-32) for the IIOP protocol -were found to be necessary; most related to the subsequently adopted Interface -Repository (IFR) specification (94-11-7). Others resulted from correction -of minor editorial errors, and experience gained as multiple teams implement -to that specification. - -The bulk of those changes have been incorporated into the 95-3-10 document, -but these few have not. - - -CDR TYPECODE INDIRECTION - -An additional constraint on the use of typecode indirection has been -identified. Specifically, the typecode to which an indirection points -be "self-sufficient", and may not point "outside of itself" for any -further indirections. For example, always indirections occur within -encapsulations, so it's OK for the indirection to point anywhere in -that encapsulation, or at the encoded TCKind enum value immediately -before the encapsulation's length. For typecode encapsulations nested -inside other typecode encapsulations, the indirection may point no -further than the outermost encapsulation. - -Also, when an indirection points to another typecode, the byte order -of that other typecode must be deduced from the encoded value found -there. This is straightforward for encoded TCKind values, all of which -fit into a single byte: if the first byte of the word is zero, then -the encoding is big-endian, else it's little-endian. - -Indirecting to another indirection is not allowed, since the byte order -of the encoded offset can't consistently be deduced. - - -MISCELLANY - -The type GIOP::Version is assumed to be identical to IIOP::Version. -As part of the editorial separation of GIOP from its Internet version -IIOP, this typedef was accidentally omitted. - -This implementation of IIOP supports the OMG-IDL Primitive Data Types as -defined in Appendix A of 94-9-32, but with TCKind numbers following the new -tk_exception and tk_alias codes. (That is, rather than using range 21-25, -these TCKind values are in the range 23-27.) - -These data types are currently the topic of an RFP in process in the OMG, -and are not currently defined as part of a current OMG specification. -Clients and servers using these extended data types are relying on CORBA -extensions that are not yet standardized; and should be prepared to change. - - -CORBA 2.0/CORE Differences --------------------------- -As of this writing, the new CORBA 2.0/CORE document has not yet been made -available. This is a modification of the CORBA 1.2 document, with the -addition of (mandatory) extensions from the UNO (94-9-32) specification: -notably DSI and some new object reference operations. This summarizes -differences between the as-yet-unpublished CORBA 2.0/CORE document and -the original text in the UNO specification. - - -DYNAMIC SKELETON INTERFACE - -Since the new "tk_except" typecodes now include the exception ID (this is -the repository ID describing the exception's type) the "exception" operation -used to report an exception through a ServerRequest no longer includes the -exception ID. - -Since the OperationDef entries for attributes are no longer found in the -interface repositories, the ServerRequest convenience operation to return -this has been removed. Application programs (such as bridges) must compare -the operation name string with the prefixes "_get_" and "_set_" to see if -any given operation applies to an attribute. If an operation is one of the -two for which an OMG-IDL "attribute" declaration is shorthand, then the -application must search the interface repository for that attribute. - -(There are in fact three categories of operations on which an object adapter -and implementation collaborate to handle: user defined operations, user -defined attributes, and operations defined by CORBA such as "is_a" and -"get_implementation". Some object adapters, like the BOA, handle this last -category directly, rather than exposing it to applications.) - -The "non_existent" objref operation accidentally used attribute syntax; this -has been corrected. All operations on CORBA::Object references now use -normal operation syntax in their (pseudo) IDL definitions, and are uniformly -prefixed with underscores as part of their C++ mapping. - - -DIFFERENCES from IDL C++ Mapping (94-9-14) ------------------------------------------- -There are four basic ways in which the IIOP framework does not comply -with the OMG's IDL C++ mapping specification, beyond the use of the CORBA2 -module/namespace rather than the CORBA module/namespace. (CORBA2 is used -so that this software can be linked with existing ORBs, which should be -using the CORBA module/namespace already.) - -These ways are beyond the portability-derived use of the "class" construct -(instead of the C++ namespace construct), and the use of CORBA2::Environment -(rather than C++ exceptions), both of which are accomodated by the mapping: - - (1) This framework does not attempt to be complete. - - Completeness is not required to implement the Internet IOP, - so time was not spent in providing a complete mapping. - - (2) In some cases the API provided is not the one in the mapping. - For example CORBA2::Environment is not always passed in all - operations. This was done to promote ease of implementation - and coding. - - (3) Implementation details are generally exposed. - - This isn't so much a noncompliance issue (it's not specified - that such details must be hidden) as an issue of allowing - noncompliant applications. The effort required to actively - prevent use of implementation details by higher level code - would be nontrivial, and could slow down IIOP code, so no - time was applied to hiding such details. - - (However, note that when the software was modified to use COM, - standard C++ techniques were used to hide most such details.) - - (4) The C++ mapping needs completion in some areas. - - Notably, 94-9-14 does not satisfy requirements to provide - support for for all data types in an "Any" or exception without - needing any precompiled data type support routines. The - TypeCode interpreter addresses this issue. - - Some additional operations were not adopted at the time 94-9-14 - was defined; both 94-9-32 and 94-11-7 added new ORB interfaces - which are not found in the initial C++ mapping document. - -With respect to this fourth issue, descriptions of the API extensions -used is provided later in this file. The additional CORBA operations -are not described since their mapping is straightforward if it isn't given -in those documents. - - -ACCESS TO ALL DATA IN "ANY" AND EXCEPTIONS - -The "void *" value in an "Any", and any "CORBA2::Exception *" value, may -always be passed to the TypeCode interpreter (see next). This allows access -to all data held within an "Any" and an Exception. The "void *" value in an -Any with an exception TypeCode is of type CORBA2::Exception *". Due to -the way CORBA is specified, it is not possible to tell whether an "Any" -holding an exception denotes a user or standard (system-defined) exception -except by exhaustive comparison against exception IDs. - -Also, _all_ legal OMG-IDL data types may be held in an "Any", and may be -manipulated using the TypeCode interpreter. This satisfies a language -mapping requirement that DII (and DSI) be able to manipulate all OMG-IDL -data types without requiring compiler generated support for them. - - -TYPECODE INTERPRETER - -In any given C/C++ execution environment there is a binary standard for how -data is represented. While that standard will differ between execution -environments, there are a very limited number of ways in which those -representations differ. Those differences are encapsulated only in the -TypeCode interpreter, so that portable applications using the dynamic -typing infrastructure in the ORB can completely ignore how it's done in -any particular environment. - -The APIs in this software distribution have been suggested for adoption as -part of the OMG specification suite. The two APIs are nonstatic member -functions in the C++ mapping's TypeCode pseudo-object, and are augmented -by a single new enumeration type. - - unsigned long size() - - This returns the size of an instance of the type that is - described by the TypeCode. - - For example, when invoked on the typecode constant CORBA::_tc_Short, - the value returned is sizeof(CORBA::Short); and when invoked on the - typecode for a structure, it is the size of that structure (including - any internal and tail padding needed). When invoked on a sequence - typecode, it returns a value that does not include the size for - any embedded buffer. - - enum traverse_status {TRAVERSE_STOP, TRAVERSE_CONTINUE }; - - This is a data type used in the traverse() member function. - It allows data type traversal to be terminated early for - non-exceptional conditions, and eliminates the confusion - that some similar APIs have created when they use a single - boolean value (does TRUE mean to stop, or to continue?). - - traverse_status traverse ( - const void *value1; - const void *value2 - traverse_status visit ( - TypeCode_ptr tc, - const void *visit_value1, - const void *visit_value2, - void *visit_context - ), - void *context - ); - - (In the current language mapping, CORBA2::Environment references - are passed as the final parameter to the 'traverse' and 'visit' - routines for use when reporting exceptions.) - - The pointers "value1" and "value2" point to instances of the - data type described by the typecode (or are null pointers). - - For each constituent of that data type (e.g. structure member) - the visit() routine is called once. The constituent's type - is described by "tc"; "visit_value1" points to the constituent - of that type in "value1" (assuming the traverse routine was - not passed a null pointer) and similarly for "visit_value2". - The "visit_context" parameter is the context parameter passed - to the traverse() routine, and can point to whatever data is - needed by the visit() routine. - - Members are traversed in first-to-last order, as defined in the - IDL specification for the data type. So for example, the - visit routine for a structure could print out each element - on a IO stream passed through the context parameter, perhaps in - a neatly formatted form intended for human consumption. - - The visit() function may choose to recursively traverse() each - element. So for example if "tc->kind()" in a visit routine - returned CORBA::tk_struct, the contents of that struct would - be ignored unless the visit routine invoked traverse() using - the typecode and values passed to it. - - If the visit() routine returns TRAVERSE_CONTINUE, succeeding - constituents of the data type are visited in turn; if it - returns TRAVERSE_STOP, the traverse() routine returns that - value to its caller. Of course, if a visit() routine calls - traverse() itself, it may choose to ignore TRAVERSE_STOP. - -The traverse() routine is a powerful tool. It is used in the IIOP code -itself in several ways; look at such use for tutorial details. You could -implement data value comparison and "debug" data dumping as simple exercises -in the use of these APIs. - -The "marshaling interpreter" (marshal.cc) uses it to encode and decode -values according to the IIOP protocol specification. The "Any" code -(any.cc) uses traverse() both to free embedded pointers, and to make "deep" -copies of any data structure given its TypeCode. - -Only that "deep copy" visit routine uses "value2" as anything other than a -null pointer; it allows efficient construction of "deep copies" without -needing extra space for temporary values or coroutine stacks. (A general -purpose two-value comparison could also use "value2".) Most uses of the API -only manipulate a single data value at a time; no realistic need has yet -been seen for manipulating more than two data values at once. - -With respect to the OMG C and C++ mappings, it is clear that this style API -must be provided for the C mapping, but some people have noted that a -"purer" object oriented style API could also be provided in C++. That style -would use another internal visit routine, performing the requisite "switch" -over the fixed number of TCKind values, and then make a virtual function -call to an instance of a C++ class whose private state was the "context" and -whose member functions matched the arms of the switch. - - -MEMORY ALLOCATION - -In order to dynamically manipulate instances of arbitrary data types, -applications need to be able to allocate and free memory. The OMG C++ -mapping only says how to do this for data types which have static C++ -interfaces defined, which is clearly inadequate for using constructed -types with the DII/DSI/Any family of interfaces. - -This infrastructure requires the standard "malloc" and "free" primitives to -be used, and cast to the appropriate type. Data allocated using malloc -will normally be sized according to TypeCode::size(), and then be stored -inside an Any. When the Any is deleted, if the ORB deallocates the memory -it always uses "free" (including for any nested pointers, and correctly -handling cases such as arrays and sequences). - -Note that to support implementations where C and C++ language bindings -share the same ORB infrastructure, this solution is inadequate. This is -because the C binding's CORBA_free() interface would have no way to -determine the type of the data being freed. Instead, typed allocation -APIs will need to be used even when using the dynamically typed CORBA -subsystem ... a TypeCode::malloc() routine would suffice, if it returned -memory that was internally tagged with that TypeCode. In such a case, -the CORBA_free() routine could use that TypeCode to "deep free" data as -required, and C++ "new" and "delete" operators would need to know about -the internal tagging for all those data types. Such tagged allocation -would need to be used for all data that was to be freed by the ORB. - -(Having the C mapping require use of "typed free" routines, instead of the -CORBA_free interface, is sufficient to eliminate this problem.) - - -PASSING EXCEPTIONS THROUGH THE DII - -The C++ mapping's Dynamic Invocation Interface (DII) has key omissions -in that it doesn't say how to access to user-defined exception values, -and implicitly requires ORBs either to pass "excess" data on the wire -or else to consult an interface repository to deal with exceptions or -(deprecated) "context" strings. - -This software changes the DII specification in two ways to support the -requirement for DII users to be able to see user-defined exceptions, yet -not to violate the OMG-IDL type model by reporting illegal exceptions: - - * The Object::_create_request() member function, through which DII - users provide all the information included in an IDL operation's - signature, has an additional parameter. - - That parameter is a sequence of exception typecodes, describing - the user-defined exceptions that the operation can return. (The - standard exceptions defined in CORBA may always be returned.) - When any other exception is returned, the client's ORB reports that - the object's type definition has been violated by the server's ORB. - - * The TypeCode interpreter (see above) may be used to examine all - exception values reported through a CORBA::Environment. A new - Exception::id() operation may be used to determine which typecode - should be used. - -Note that a number of portability and specification problems have been -identified in the current C++ mapping for DII, e.g. for details of memory -management. Later versions of this code may attempt to closely comply -with an improved mapping for DII, to the extent that the interpretation -used here differs from that more unambiguous specification. - -Since there is no efficient way to distinguish typecodes for user defined -exceptions from ones for system-defined ("standard") exceptions (comparing -the exception ID against all the system defined ones is inefficient :-) -a new enum type "ExceptionType" is defined. (An analogous type is already -defined for the C language mapping.) This is used to report exceptions -through DII and DSI. diff --git a/TAO/docs/HISTORY b/TAO/docs/HISTORY deleted file mode 100644 index d97a8e35b2e..00000000000 --- a/TAO/docs/HISTORY +++ /dev/null @@ -1,44 +0,0 @@ -@(#)HISTORY 1.1 95/09/13 - -Mmmmmmmm DD, 1995 -- RELEASE 1.3: ---------------------------------- -Release 1.3 includes bugfixes, and support for the COM binary interface -model, both on UNIX and on MS-Windows platforms. The source tree has -been considerably restructured, with the goal of enabling addition of -other components at both the binary and source levels. - - -September 1, 1995 -- RELEASE 1.2: ---------------------------------- -Release 1.2 includes fixes for problems noted in the recent multivendor -interoperability testing at Object World, and as reported by other users on -the Internet. The most notable of these is that in some cases, when using -multiple connections to IIOP servers and clients, the connection management -code previously would get confused about which connection was which. (One -consequence of fixing this is that an old test has been removed.) Also, -there was no simple way to use Solaris 2.4 threads; see the Makefile for -details. A few other minor features were added to facilitate use of this -code for more than just protocol testing. - - -June 28, 1995 -- RELEASE 1.1: ------------------------------ -Release 1.1 includes support for several new platforms. Particular thanks -go to the team at APM, which contributed the bulk of the new "autoconf" -support (substantially enhancing portability), support for DEC Alpha and -HP 9000 platforms, runtime initialization of the size and alignment table -used to drive the typecode interpreter, and more; see README.apm for details. - -Release 1.1 includes POSIX.1c threading support; on platforms which provide -POSIX.1c threads, applications will be able to take advantage of them. - -Union and indirection support has been added to the TypeCode interpreter, -and more typecode utility APIs have been implemented. Various bugfixes and -cleanup have also been provided. Unfinished stubs for the COS Naming service -are included; these rely on C++ exception support. - - -March 21, 1995 -- RELEASE 1.0: ------------------------------- -The original release ran on a set of UNIX platforms (including Solaris, -SunOS, Linux, and NEXTSTEP) as well as with 16-bit and 32-bit MS-Windows. diff --git a/TAO/docs/Options.html b/TAO/docs/Options.html deleted file mode 100644 index 4db3ac62af9..00000000000 --- a/TAO/docs/Options.html +++ /dev/null @@ -1,363 +0,0 @@ -<HTML> -<HEAD> - <META NAME="GENERATOR" CONTENT="Adobe PageMill 2.0 Mac"> - <TITLE>Options for TAO Components</TITLE> -</HEAD> - -<BODY text = "#000000" -link="#000fff" -vlink="#ff0f0f" -bgcolor="#ffffff"> - -<HR><P> -<H3 ALIGN=CENTER>Options for TAO Components</H3> - -<H3>Overview</H3> -<blockquote> - -<P>Certain components in TAO such as the ORB Core or Object Adapter -can be tuned by users by providing value for options or environment -variables to them. These options are commonly specified as (1) -environment variables or (2) strings passed on the command-line. They -are generally passed to component initialization methods for -consumption.</P> - -<P><EM>Programmer's Note:</EM> the internal structure for options is -the traditional <CODE>argc</CODE>/<CODE>argv</CODE> vector of strings -style popularized by C and Unix. By convention, an initialization -method will consume, <EM>i.e.</EM>, remove from the vector, any -options that it recognizes.</P> </blockquote> - -<HR><P> -<H3>Environment Variables</H3> - -The following environment variables are supported by TAO: - -<BLOCKQUOTE> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING="0" > -<TR> -<TH>Environment Variable</TH> -<TH>Description</TH></TR> -<TR> -<TD><CODE>NameServiceIOR</CODE> <EM>which</EM></TD> -<TD> -Specifies which IOR the Naming Service is listening on. -</TD></TR> -<TR> -<TD><CODE>NameServicePort</CODE> <EM>which</EM></TD> -<TD> -Specifies which port the Naming Service is listening on. -</TD></TR> -<TR> -<TD><CODE>TradingServiceIOR</CODE> <EM>which</EM></TD> -<TD> -Specifies which IOR the Trading Service is listening on. -</TD></TR> -<TR> -<TD><CODE>TradingServicePort</CODE> <EM>which</EM></TD> -<TD> -Specifies which port the Trading Service is listening on. -</TD></TR> -<TR> -<TD><CODE>TAO_ORB_DEBUG</CODE> <EM>which</EM></TD> -<TD> -Enables TAO debugging mode. -</TD></TR> -</TABLE> -</P> -</BLOCKQUOTE> - -<HR><P> - -<H3>Types of Options</H3> - -<blockquote> -<P>The following components can be tuned via options:</P> - -<UL> - <LI><A HREF="#ORB"><CODE>CORBA::ORB</CODE></A> - <LI><A HREF="#POA"><CODE>CORBA::POA</CODE></A> - <LI><A HREF="#ResourceFactory"><CODE>TAO_Resource_Factory</CODE></A> - <LI><A HREF="#DefaultServer"><CODE>TAO_Default_Server_Strategy_Factory</CODE></A> - <LI><A HREF="#DefaultClient" TARGET="_top"><CODE>TAO_Default_Client_Strategy_Factory</CODE></A> -</UL> - -Typically, CORBA::ORB options are set via command line parameters, -while the rest of the options are set via the service configurator -(svc.conf) file. - -</blockquote> - -<blockquote> -<H3><CODE>CORBA::ORB</CODE><A NAME="ORB"></A></H3> - -<blockquote> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING= -"0"> -<TR> -<TH>Option</TH> -<TH>Description</TH></TR> -<!-- <TR NAME="ORBsvcconf"> --> -<TD><CODE>-ORBsvcconf</CODE> <EM>config file name</EM></TD> -<TD>Specifies the name of the file from which it will read dynamic service configuration -directives <EM>ala</EM> ACE's Service Configurator.</TD></TR> -<TD><CODE>-ORBsvcconfdirective</CODE> <EM>directivestring</EM></TD> -<TD>Specifies a service configuration -directive, which is passed to ACE's Service Configurator.</TD></TR> -<TR> -<TD><CODE>-ORBdaemon</CODE></TD> -<TD>Specifies that the ORB should <I>daemonize</I> itself.</TD></TR> -<TR> -<TD><CODE>-ORBdebug</CODE></TD> -<TD>Turns on the output of debugging messages within ACE's Service Configurator -componentry.</TD></TR> -<TR> -<TD><CODE>-ORBhost</CODE> <EM>hostname</EM></TD> -<TD><a name="-ORBhost"></a>Tells the Object Adapter to listen for requests on the interface associated -with the host named <I><EM>hostname</EM></I>.</TD></TR> -<TR> -<TD><CODE>-ORBport</CODE> <EM>portspec</EM></TD> -<TD>Tells the Object Adapter to listen for requests on the port specified by -<I><EM>portspec</EM></I>, which can be a name as found in <TT>/etc/services</TT> -or a number. The default is <TT>10013</TT>.</TD></TR> -<TR> -<TD><CODE>-ORBobjrefstyle</CODE> <EM>which</EM></TD> -<TD>Specifies the user-visible style of object references. The range of values -is <CODE>IOR</CODE>, which is the traditional nonsensical object reference, -or <CODE>URL</CODE>, which looks more like a URL.</TD></TR> -<TR> -<TD><CODE>-ORBtablesize</CODE> <EM>object table size</EM></TD> -<TD>Specifies the size of the object table as a positive, non-zero integer. -If not specified, the default is <TT>64</TT>.</TD></TR> -<TR> -<TD><CODE>-ORBrcvsock</CODE> <EM>receive buffer size</EM></TD> -<TD><A NAME="-ORBrcvsock"></a>Specify the size of the socket receive buffer as a positive, non-zero integer. -If not specified, the system-dependent default is used.</TD></TR> -<TR> -<TD><CODE>-ORBsndsock</CODE> <EM>send buffer size</EM></TD> -<TD><A NAME="-ORBsndsock"></a>Specify the size of the socket send buffer as a positive, non-zero integer. -If not specified, the system-dependent default is used.</TD></TR> -<TR> -<TD><CODE>-ORBnameserviceport</CODE> <EM>portspec</EM></TD> -<TD>Specifies which port the Naming Service is listening on.</TD></TR> -<TR> -<TD><CODE>-ORBnameserviceior</CODE> <EM>ior</EM></TD> -<TD>Specifies the IOR for the Naming Service.</TD></TR> -<TR> -<TD><CODE>-ORBtradingserviceior"</CODE> <EM>ior</EM></TD> -<TD>Specifiles the IOR for the Trading Service.</TD></TR> -<TR> -<TD><CODE>-ORBtradingserviceport"</CODE> <EM>portspec</EM></TD> -<TD>Specifies to which port the tradingservice is listening - on.</TD></TR> -<TR> -<TD><CODE>-ORBcollocation</CODE> <EM>yes/no</EM></TD> -<TD>Specifies the use of collocation object optimization. Default is yes.</TD></TR> -<TR> -<TD><CODE>-ORBpreconnect</CODE> <EM>host</EM><STRONG>:</STRONG><EM>port</em>[<STRONG>,</STRONG><EM>host</EM><STRONG>:</STRONG><EM>port</em>...]</TD> -<TD><A name="-ORBpreconnect"></a>Pre-establishes a blocking connection to each listed -<em>host</em>:<em>port</em> combination. If a connection cannot -be established, a warning is announced and it continues with the -next listed. Listing the same combination multiple times will -properly establish multiple connections to that endpoint.</TD></TR> -<TR> -<TD><CODE>-ORBcdrtradeoff</CODE> <EM>maxsize</EM></TD> -<TD><A name="-ORBCDRtradeoff"></a>Control the strategy to tradeoff -between copy vs no copy marshalling of octet sequences. -If an octet sequence is smaller than <EM>maxsize</EM> and the current -message block contains enough space for it the octet sequence is -copied instead of appended to the CDR stream.</TD></TR> -<TR> -<TD><CODE>-ORBgioplite</CODE></TD> -<TD><A name="-ORBgioplite"></a>Enable a lightweight version of the - GIOP protocol. This protocol removes some of the fields in - the GIOP and the Request header. It only works on - homogenous environments..</TD></TR> -<TR> -<TD><CODE>-ORBdotteddecimaladdresses</CODE> <EM>boolean (0 / 1)</EM></TD> -<TD><A name="-ORBdotteddecimaladdresses"></a> Use the dotted decimal - notation for addresses.</TD></TR> -<TR> -<TD><CODE>-ORBInitRef</CODE> <EM>ObjectId=IOR</EM></TD> -<TD><A name="-ORBInitRef"></a> Allows specification of an arbitrary object reference for an initial service. The IOR could be in the one of the following formats : OMG IOR, URL, iiopname or the iioploc form. The iiopname and iioploc are multiple end-point IORs understood by the string_to_object () and used as a boot-strapping mechanism by the resolve_initial_references (). The mappings specified through this argument override the orb-install-time defaults.</TD></TR> - -<TR> -<TD><CODE>-ORBDefaultInitRef</CODE> <EM>IOR prefix</EM></TD> -<TD><A name="-ORBDefaultInitRef"></a> This argument allows resolution of initial references not explicitly specified with -ORBInitRef. It requires a URL prefix that, after appending a slash '/' and a stringified object key, forms a new URL to identify an initial object reference. The URL prefix formats currently supported are iiopname and iioploc.</TD></TR> - -</TABLE> -</P> -</blockquote> - -<H3><CODE>CORBA::POA</CODE><A NAME="POA"></A></H3> - -<blockquote> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING="0"> -<TR> -<TH>Option</TH> -<TH>Description</TH></TR> -<TR> -<TD><CODE>-OAid</CODE> <EM>OA Identifier</EM></TD> -<TD>Associates <I><EM>OA Identifier</EM></I> with the Object Adapter.</TD></TR> -</TABLE> -</P> -</blockquote> - -<H3><CODE>TAO_Resource_Factory</CODE><A NAME="ResourceFactory"></A></H3> - -<blockquote> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING="0"> -<TR> -<TH>Option</TH> -<TH>Description</TH></TR> -<TR> -<TD><CODE>-ORBresources</CODE> <EM>which</EM></TD> -<TD>Specify whether each thread uses a global -(<em>which</em> = <code>global</code>) or a thread-specific -(<em>which</em> = <code>tss</code>) instance for the resources it returns.</TD></TR> -<TR> -<TD><CODE>-ORBpoa</CODE> <EM>which</EM></TD> -<TD><a name="-ORBpoa"></a>Specify whether each thread uses a global -(<em>which</em> = <code>global</code>) or a thread-specific -(<em>which</em> = <code>tss</code>) instance for the Root POA.</TD></TR> -<TR> -<TD><CODE>-ORBreactorlock</CODE> <EM>which</EM></TD> -<TD><a name="-ORBcoltable"></a>Specify whether the ORB reactor is thread-safe -(<em>which</em> = <code>token</code>) or not -(<em>which</em> = <code>null</code>). Default is <code>token</code></TD></TR> -<TR> -<TD><CODE>-ORBcoltable</CODE> <EM>which</EM></TD> -<TD><a name="-ORBcoltable"></a>Specify whether each ORB uses a global -(<em>which</em> = <code>global</code>) or a per-ORB -(<em>which</em> = <code>orb</code>) collocation table.</TD></TR> -<TR> -<TD><CODE>-ORBinputcdrallocator</CODE> <EM>which</EM></TD> -<TD><a name="-ORBinputcdrallocator"></a> - Specify whether the ORB uses a global - (<em>which</em> = <code>global</code>) - or a per-thread (<em>which</em> = <code>tss</code>) - allocator for the incoming CDR buffers. - The default is <CODE>tss</CODE> and should give the - optimal performance; - unless the user takes advantage of the features in TAO - to keep the CDR stream buffer after the upcall. - </TD></TR> -</TABLE> -</P> -</blockquote> - -<H3><CODE>TAO_Default_Server_Strategy_Factory</CODE><A NAME="DefaultServer"></A></H3> - -<p><em>Note:</em> <code>-ORBdemuxstrategy</code> flag has been changed to <code>-ORBsystemidpolicydemuxstrategy</code>. - -<blockquote> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING="0" > -<TR> -<TH>Option</TH> -<TH>Description</TH></TR> -<TR> -<TD><CODE>-ORBconcurrency</CODE> <EM>which</EM></TD> -<TD>Specify which concurrency strategy to use. Range of values is <code>reactive</code> -for a purely Reactor-driven concurrency strategy or -<code>thread-per-connection</code> for creating a new thread to service each connection.</TD></TR> -<TR> -<TD><CODE>-ORBtablesize</CODE> <EM>object table size</EM></TD> -<TD>Specify the size of the object table. If not specified, the default value -is 64.</TD></TR> -<TR> - -<TD><CODE>-ORBuseridpolicydemuxstrategy</CODE> <EM>user id policy -based demultiplexing strategy</EM></TD> <TD>Specify the demultiplexing -lookup strategy to be used with the user id policy. The -<EM>demultiplexing strategy</EM> can be one of <CODE>dynamic</CODE>, -<CODE>linear</CODE>, or <CODE>user</CODE>. This option defaults to -use the <CODE>dynamic</CODE> strategy. </TD></TR> <TR> - -<TD><CODE>-ORBsystemidpolicydemuxstrategy</CODE> <EM>system id policy -based demultiplexing strategy</EM></TD> <TD>Specify the demultiplexing -lookup strategy to be used with the system id policy. The -<EM>demultiplexing strategy</EM> can be one of <CODE>dynamic</CODE>, -<CODE>linear</CODE>, <CODE>active</CODE>, or <CODE>user</CODE>. This -option defaults to use the <CODE>active</CODE> strategy. </TD></TR> -<TR> - -<TD><CODE>-ORBuniqueidpolicyreversedemuxstrategy</CODE> <EM>unique id -policy based reverse demultiplexing strategy</EM></TD> <TD>Specify the -reverse demultiplexing lookup strategy to be used with the unique id -policy. The <EM>reverse demultiplexing strategy</EM> can be one of -<CODE>dynamic</CODE> or <CODE>user</CODE>. This option defaults to use -the <CODE>dynamic</CODE> strategy. </TD></TR> <TR> - -<TD><CODE>-ORBthreadflags</CODE> <EM>thread flags</EM></TD> -<TD>Specify the flags used for thread creation. Flags can be any -logical-OR combination of <CODE>THR_DETACHED</CODE>, -<CODE>THR_BOUND</CODE>, <CODE>THR_NEW_LWP</CODE>, -<CODE>THE_SUSPENDED</CODE>.</TD></TR> <TR> - -<TD><CODE>-ORBpoalock</CODE> <EM>lock type</EM></TD> <TD><a -name="-ORBpoalock"></a>Specify the type of lock to be used for POA -accesses. Possible values for <em>lock type</em> are -<code>thread</code>, which specifies that an inter-thread mutex is -used to guarantee exclusive acccess, and <code>null</code>, which -specifies that no locking be performed. The default is -<code>thread</code>.</TD></TR> <TR> - -<TD><CODE>-ORBcoltbllock</CODE> <EM>lock type</EM></TD> <TD><a -name="-ORBcoltbllock"></a>Specify the type of lock to be used for the -global collocation table. Possible values for <em>lock type</em> are -<code>thread</code>, which specifies that an inter-thread mutex is -used to guarantee exclusive acccess, and <code>null</code>, which -specifies that no locking be performed. The default is -<code>thread</code>.</TD></TR> <TR> - -<TD><CODE>-ORBconnectorlock</CODE> <EM>lock type</EM></TD> <TD><a -name="-ORBconnectorlock"></a>Specify the type of lock to be used by -the connector. Possible values for <em>lock type</em> are -<code>thread</code>, which specifies that an inter-thread mutex is -used to guarantee exclusive acccess, and <code>null</code>, which -specifies that no locking be performed. The default is -<code>thread</code>.</TD></TR> <TR> - -<TD><CODE>-ORBpoamgrlock</CODE> <EM>lock type</EM></TD> <TD><a -name="-ORBpoamgrlock"></a>Specify the type of lock to be used for POA -Manager accesses. Possible values for <em>lock type</em> are -<code>thread</code>, which specifies that an inter-thread mutex is -used to guarantee exclusive acccess, and <code>null</code>, which -specifies that no locking be performed. The default is -<code>null</code>.</TD></TR> - -</TABLE> -</P> -</blockquote> - -<H3><CODE>TAO_Default_Client_Strategy_Factory</CODE><A NAME="DefaultClient"></A></H3> - -<BLOCKQUOTE> -<P><TABLE BORDER="2" CELLSPACING="2" CELLPADDING="0" > -<TR> -<TH>Option</TH> -<TH>Description</TH></TR> -<TR> -<TD><CODE>-ORBiiopprofilelock</CODE> <EM>which</EM></TD> -<TD> -Specify, whether to use a lock for accessing the IIOP Profile or not. -Default is <code>thread</code>, which means that a lock is used. The -second option is <code>null</code>, which means a null lock is used. -This makes sense in case of optiziations and is allowed when -no forwarding is used or only a single threaded client. -</TD></TR> -<TR> -<TD><CODE>-ORBclientconnectionhandler</CODE> <EM>MT / ST</EM></TD> -<TD><A name="-ORBclientconnectionhandler"></a> ST means use the -single-threaded client connection handler and MT means use the -multi-threaded client connection handler .</TD></TR> -</TABLE> -</P> -</BLOCKQUOTE> -</blockquote> - -<P><HR><P> -Back to the TAO <A HREF="components.html">components documentation</A>. - -<!--#include virtual="/~schmidt/cgi-sig.html" --> -</HTML> diff --git a/TAO/docs/REFERENCES b/TAO/docs/REFERENCES deleted file mode 100644 index a44ef31c16e..00000000000 --- a/TAO/docs/REFERENCES +++ /dev/null @@ -1,91 +0,0 @@ -@(#)REFERENCES 1.2 95/11/08 - -REFERENCES -========== -Most of the relevant references here are to OMG documents, however there -are a few external references of some note: - - * http://www.uci.agh.edu.pl/research/cs/TOCOOS/COPERNICUS.html - - -OMG REFERENCES --------------- -As of this writing, OMG is in the process of publishing new versions of the -base CORBA specifications, merging specifications as needed into single -documents and splitting out the C mapping from the CORBA/CORE specification. - -This software has made every effort to track both the base documents and the -agreed corrections and revisions. Since those documents have not yet been -published, there will inevitably be areas in which it does not reflect the -versions yet to be published. See the "DIFFERENCES" file for information -about where this software differs from these current base documents: - -* CORBA 2.0/Interoperability: Universal Networked Objects (UNO), OMG - TC Document 95-3-10. This includes the mandatory IIOP and bridging - support, as well as the optional DCE-CIOP protocol. - -* CORBA 1.2 specification, OMG TC Document 93-12-43. This is the - base document on which the CORBA 2.0 CORE specifications build. - -* Universal Networked Objects (UNO), OMG TC Document 94-9-32. Until - the CORBA 2.0/CORE document is published, replacing the CORBA 1.2, - initialisation, and IFR specifications, you must use this earlier - version of UNO to see (only!) the specification for DSI and several - other CORBA CORE extensions (for bridging) adopted by the OMG. - [ NOTE: use the IIOP specification in 95-3-10, not the one here; - 95-3-10 has changes required by the IFR specification, 95-11-7. ] - -* Initialisation, OMG TC Document 94-10-24. This defines the portable - APIs for initialising ORBs. - -* Interface Repository, OMG TC Document 94-11-7. This updates the - CORBA specifications above and is referenced by the UNO document. - -* IDL C++ Language Mapping Specification, OMG TC Document 94-9-14. - This defines the mapping of CORBA 1.2, including OMG-IDL, onto C++. - -There are a few inconsistencies between these documents, which are in the -process of being resolved. The inconsistencies arose because different -groups worked on different parts of the system, at different times and -with some different goals. Contact the various revision committees to -find out how these differences are being resolved: - - - interop@omg.org ... the interop revision task force (RTF) - - cxx_revision@omg.org ... the C++ RTF - - orb_revision@omg.org ... the general ORB RTF - -Also, note that these ORB specifications correspond to only the lowest levels -of OMG's Object Management Architecture. In particular, the "Object Services" -define object interfaces for naming, events, persistence, relationships, -lifecycle, externalization, transactions, and concurrency control. Also, -"Common Facilities" objects will address such things as compound document -architecture. If you intend to develop software based on ORBs, these -specifications are likely to be of interest. The OMA is available in -technical bookstores: - - Richard Soley (ed.), Object Management Architecture Guide, - Second Edition, John Wiley & Sons, New York, 1992. - - -ACQUIRING REFERENCE DOCUMENTS ------------------------------ -To acquire those reference documents, use the OMG document server through -Internet email. Send a message to "server@omg.org", with content lines -such as - - send help - -to get directions about how to use the server, or - - send docs/95-3-10.ps - -to get a PostScript copy of any particular document. (OMG specifications -are available only in PostScript.) - -The OMG document server is maintained for use by OMG members, but is also -available for general Internet access. Only members will be supported in -the case of problems. - -To find out more about the OMG, send email to "omg@omg.org", or look -at the Web page at "http://www.omg.org". - diff --git a/TAO/docs/compiler.html b/TAO/docs/compiler.html deleted file mode 100644 index 67cab6a4023..00000000000 --- a/TAO/docs/compiler.html +++ /dev/null @@ -1,341 +0,0 @@ -<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> -<html> -<head> - <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> - <meta name="GENERATOR" content="Mozilla/4.5 [en] (X11; I; SunOS 5.5.1 sun4u) [Netscape]"> - <title>TAO IDL compiler User's Guide</title> -<!-- $Id$ --> -</head> -<body text="#000000" bgcolor="#FFFFFF" link="#0000FF" vlink="#CC0000"> - -<hr> -<h3> -TAO IDL compiler User's Guide</h3> - -<h2> -Scope</h2> -This document describes the options and features of TAO IDL compiler, it -is not a reference manual or tutorial on IDL. -<h2> -Generated Files</h2> -The IDL compiler generates 6 files from each <tt>.idl</tt> file, the file -names are obtained by taking the IDL basename and appending <tt>C.h</tt>, -<tt>C.i</tt>, -<tt>C.cpp</tt>, -<tt>S.h</tt>, -<tt>S.i</tt> -and <tt>S.cpp</tt>; the client stubs are declared in the <tt>C.h</tt> file, -the skeletons in the <tt>S.h</tt> file. Please see the Options list on -how to get different suffixes for these files. -<p>Both clients and servers should link against the object files for the -stubs and skeletons, this is needed to transparently support collocated -objects. -<h2> -Operation Lookup Strategies</h2> -The server skeleton can make use of different lookup strategies to match -the incoming operation with the correct operation at the servant. -<br>Dynamic Hashing and Perfect Hashing are the two different operation -lookup strategies that are currently supported in tao_idl. -<br>By default, tao_idl tries to use Perfect Hashing strategy. <a href="http://www.cs.wustl.edu/~schmidt/gperf.ps.gz">gperf -</a>generates -the lookup methods for this strategy. -<br>ACE_HAS_GPERF has been defined for the platforms where gperf works. -This includes Solaris and NT. -<p>To make use of Perfect Hashing: -<ul> -<li> -Build the gperf program at $ACE_ROOT/apps/gperf. (This build also leaves -a copy/link of the gperf program at the $ACE_ROOT/bin directory).</li> - -<li> -Set the environment variable $ACE_ROOT appropriately or add $ACE_ROOT/bin -to the PATH.</li> - -<li> -Use -g option for the tao_idl or set the PATH accordingly to use gperf -located at other places other than $ACE_ROOT/bin.</li> -</ul> - -<h2> -Options</h2> -The IDL compiler invokes your <tt>C</tt> (or <tt>C++</tt>) preprocessor -to resolve included IDL files, it receives the common options for preprocessors -(such as <tt>-D</tt> or <tt>-I</tt>); but also receives other options that -are specific to it. -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 > -<tr> -<th>Option</th> - -<th>Description</th> -</tr> - -<tr NAME="V"> -<td><tt>-V</tt></td> - -<td>The compiler printouts its version and exits</td> -</tr> - -<tr NAME="Wb"> -<td><tt>-Wb,</tt><i>option_list</i></EM</TD></td> - -<td>Pass options to the backend.</td> -</tr> - -<tr NAME="export_macro"> -<td></td> - -<td><tt>export_macro=</tt><i>macro_name</i></td> - -<td>The compiler will emit <i>macro_name</i> right after each <tt>class</tt> -or <tt>extern</tt> keyword, this is needed for Windows/NT that requires -special directives to export symbols from DLLs, usually the definition -is just a space on unix platforms. </td> -</tr> - -<tr NAME="export_include"> -<td></td> - -<td><tt>export_include=</tt><i>include_path</i></td> - -<td>The compiler will generate code to include <i>include_path</i> at the -top of the client header, this is usually a good place to define the export -macro. </td> -</tr> - -<tr NAME="E"> -<td><tt>-E</tt></td> - -<td>Only invoke the preprocessor</td> -</tr> - -<tr NAME="Wp"> -<td><tt>-Wp,</tt><i>option_list</i></EM</TD></td> - -<td>Pass options to the preprocessor.</td> -</tr> - -<tr NAME="D"> -<td><tt>-D</tt><i>macro_definition</i></td> - -<td>It is passed to the preprocessor</td> -</tr> - -<tr NAME="U"> -<td><tt>-U</tt><i>macro_name</i></td> - -<td>It is passed to the preprocessor</td> -</tr> - -<tr NAME="I"> -<td><tt>-I</tt><i>include_path</i></td> - -<td>It is passed to the preprocessor</td> -</tr> - -<tr NAME="A"> -<td><tt>-A</tt><i>assertion</i></td> - -<td>It is passed to the preprocessor</td> -</tr> - -<tr NAME="Y"> -<td><tt>-Y</tt></td> - -<td>It is passed to the preprocessor</td> -</tr> - -<tr NAME="H perfect_hash"> -<td><tt>-H perfect_hash</tt></td> - -<td>To specify the IDL compiler to generate skelton code that uses perfect -hashed operation lookup strategy, which is the default strategy. Perfect -hashing uses <a href="http://www.cs.wustl.edu/~schmidt/gperf.ps.gz">gperf -</a>program, -to generate lookup methods. </td> -</tr> - -<tr NAME="H dynamic_hash"> -<td><tt>-H dynamic_hash</tt></td> - -<td>To specify the IDL compiler to generate skelton code that uses dynamic -hashed operation lookup strategy. </td> -</tr> - -<tr NAME="H binary_search"> -<td><tt>-H binary_search</tt></td> - -<td>To specify the IDL compiler to generate skelton code that uses binary -search based operation lookup strategy. </td> -</tr> - -<tr NAME="H linear_search"> -<td><tt>-H linear_search</tt></td> - -<td>To specify the IDL compiler to generate skelton code that uses linear -search based operation lookup strategy.</td> -</tr> - - -<tr NAME="in"> -<TD><TT>-in</TT></TD> -<TD> To generate #include statements with <>'s for the standard - include files (e.g. tao/corba.h) indicating them as non-changing - files</TD> -</TR> - - -<TR NAME="ic"> -<TD><TT>-ic</TT></TD> -<TD> To generate #include statements with ""s for changing - standard include files (e.g. tao/corba.h). </TD> -</TR> - -<tr NAME="g"> -<td><tt>-g</tt></td> - -<td>To specify the path for the perfect hasing program (GPERF). Default -is $ACE_ROOT/bin/gperf. </td> -</tr> - -<tr NAME="o"> -<td><tt>-o</tt></td> - -<td>To specify the output directory to IDL compiler as to where all the -IDL-compiler-generated files are to be put. By default, all the files are -put in the current directory from where <tao_idl>is called. </td> -</tr> - -<tr NAME="hc"> -<td><tt>-hc</tt></td> - -<td>Client's header file name ending. Default is "C.h".</td> -</tr> - -<tr NAME="hs"> -<td><tt>-hs</tt></td> - -<td>Server's header file name ending. Default is "S.h".</td> -</tr> - -<tr NAME="hT"> -<td><tt>-hT</tt></td> - -<td>Server's template header file name ending. Default is "S_T.h".</td> -</tr> - -<tr NAME="cs"> -<td><tt>-cs</tt></td> - -<td>Client stub's file name ending. Default is "C.cpp".</td> -</tr> - -<tr NAME="ci"> -<td><tt>-ci</tt></td> - -<td>Client inline file name ending. Default is "C.i".</td> -</tr> - -<tr NAME="ss"> -<td><tt>-ss</tt></td> - -<td>Server skeleton file name ending. Default is "S.cpp".</td> -</tr> - -<tr NAME="sT"> -<td><tt>-sT</tt></td> - -<td>Server template skeleton file name ending. Default is "S_T.cpp".</td> -</tr> - -<tr NAME="si"> -<td><tt>-si</tt></td> - -<td>Server inline skeleton file name ending. Default is "S.i".</td> -</tr> - -<tr NAME="st"> -<td><tt>-st</tt></td> - -<td>Server's template inline file name ending. Default is "S_T.i".</td> -</tr> - -<tr NAME="Gc"> -<td><tt>-Gc</tt></td> - -<td>Generate stubs and skeletons using compiled marshaling </td> -</tr> - -<tr NAME="Gi"> -<td><tt>-Gi</tt></td> - -<td>Generate stubs and skeletons using interpretive marshaling (default -for now) </td> -</tr> - -<tr NAME="Ge"> -<td><tt>-Ge</tt></td> - -<td>Generate code that uses C++ exceptions (unimplemented as yet)</td> -</tr> - -<tr NAME="Gt"> -<td><tt>-Gt</tt></td> - -<td>Generate optimized TypeCodes (unimplemented as yet)</td> -</tr> - -<tr> -<td>-<tt>GI</tt></td> - -<td>Generate templates files for the servant implementation </td> -</tr> - -<tr> -<td><tt>-GIh </tt><i>arg</i></td> - -<td>Servant implemenation header file name ending</td> -</tr> - -<tr> -<td><tt>-GIs </tt><i>arg</i></td> - -<td>Servant implemenation skeleton file name ending</td> -</tr> - -<tr> -<td><tt>-GIb </tt><i>arg</i></td> - -<td>Prefix to the implementation class names</td> -</tr> - -<tr> -<td><tt>-GIe </tt><i>arg</i></td> - -<td>Suffix to the implementation class names</td> -</tr> - -<tr> -<td><tt>-GIc </tt><i>arg</i></td> - -<td>Generate copy constructors in the servant implementation template files</td> -</tr> - -<tr NAME="Sa"> -<td><tt>-Sa</tt></td> - -<td>Suppress generation of the Any operators</td> -</tr> - -<tr NAME="St"> -<td><tt>-St</tt></td> - -<td>Suppress generation of the TypeCodes</td> -</tr> -</table> - -<hr> -<address> -<i><a href="mailto:coryan@cs.wustl.edu">Carlos O'Ryan</a></i></address> - -</body> -</html> diff --git a/TAO/docs/components.html b/TAO/docs/components.html deleted file mode 100644 index 5a1d34631d0..00000000000 --- a/TAO/docs/components.html +++ /dev/null @@ -1,44 +0,0 @@ -<HTML> - <HEAD> - <META NAME="GENERATOR" CONTENT="Adobe PageMill 2.0 Mac"> - <TITLE>TAO Component Documentation</TITLE> - </HEAD> - -<BODY text = "#000000" -link="#000fff" -vlink="#ff0f0f" -bgcolor="#ffffff"> - -<HR> - <H3 ALIGN=CENTER>Component Documentation</H3> - - <P>The following documentation is available on certain TAO components:</P> - - <UL> - <LI><A HREF="Options.html">Options</A> ­ describes the - options available to customize various components within TAO. - These customizations can be done by an end-user and do not - require C++ programming.<P> - - <li><a href="configurations.html">Configuration</a> ­ - describes how to mix and match component <a - href="Options.html">options</a> to customize - how TAO processes requests. For example, this - document explains how to configure TAO to process - all request in one thread, each request in a separate thread, or each connection - in a separate thread, <em>etc.</em><P> - - <LI> Mapping of all <A - HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/">TAO files</A> - into a manageable set of <A -HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/TAO-inheritance.ps.gz">inheritance -hierarchies</A>. <P> - </UL> - </BODY> - -<P><HR><P> -Back to the TAO <A HREF="index.html">documentation index</A>. - -<!--#include virtual="/~schmidt/cgi-sig.html" --> - -</HTML> diff --git a/TAO/docs/configurations.html b/TAO/docs/configurations.html deleted file mode 100644 index f3b55578c83..00000000000 --- a/TAO/docs/configurations.html +++ /dev/null @@ -1,681 +0,0 @@ -<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> -<html> -<head> - <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> - <meta name="GENERATOR" content="Mozilla/4.5 [en] (WinNT; I) [Netscape]"> - <title>Configuring TAO's Components</title> -<!-- $Id$ --> -</head> -<body text="#000000" bgcolor="#FFFFFF" link="#000FFF" vlink="#FF0F0F"> - -<hr> -<center> -<h3> -Configuring TAO's Components</h3></center> - -<h3> -Overview</h3> -As described in the <a href="Options.html">options</a> documentation, various -components in TAO can be customized by specifying options for those components. -This document illustrates how to combine these options in order to affect -ORB behavior and performance, particularly its <a href="http://www.cs.wustl.edu/~schmidt/CACM-arch.ps.gz">concurrency -model</a>. -<p>TAO configures itself using the <a href="http://www.cs.wustl.edu/~schmidt/O-Service-Configurator.ps.gz">ACE -Service Configurator</a> framework. Thus, options are specified in the -familiar <tt>svc.conf</tt> file (if you want to use a different file name, -use the <tt><a href="Options.html#svcfonf">-ORBsvcconf</a></tt> option). -<br> -<hr> -<h3> -Roadmap</h3> - -<blockquote>Details for the following configurations are provided. -<ul> -<li> -<b><a href="#comp">Configurating key components</a>:</b></li> - -<ul> -<li> -<a href="#concurrency">Server Concurrency Strategy.</a></li> - -<li> -<a href="#orb">ORB and other resources.</a></li> - -<li> -<a href="#poa">POA.</a></li> - -<li> -<a href="#coltbl">Collocation Table.</a></li> - -<li> -<a href="#iiopprofile">Forwarding IIOP Profile</a></li> - -<li> -<a href="#orbsvcs">orbsvcs Library</a></li> -</ul> - -<li> -<b><a href="#examples">Configuration examples</a></b></li> - -<ul> -<li> -<a href="#reactive">Single-threaded, reactive model.</a></li> - -<li> -<a href="#tpc">Multiple threads, thread-per-connection model.</a></li> - -<li> -<a href="#multiorb">Multiple threads, ORB-per-Reactor-thread model.</a></li> - -<li> -<a href="#multiorb-tpc">Multiple threads, ORB-per-thread, thread-per-connection -model.</a></li> - -<li> -<a href="#tpool">Multiple threads, thread-pool model.</a> (Not yet implemented.)</li> - -<li> -<a href="#multiorb-tpool">Multiple threads, ORB-per-thread, thread-pool -model.</a> (Not yet implemented.)</li> - -<li> -Each configuration has the following information:</li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="70%" > -<tr ALIGN=LEFT> -<th>Typical Use </th> - -<td>A brief description of the scenario and its typical use. </td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>The number of threads used by ORB-related activities.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>Identifies the creator of the threads discussed above.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Where information on various resources is stored.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>Describes what task is undertaken for each thread.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Options</th> - -<td>Specifies the options for each service in order to utilize this configuration.</td> -</tr> -</table> -</ul> - -<li> -<b><a href="#homogenous">Configuration for homogenous systems</a></b></li> - -<ul> -<li> -<a href="#homogenous_compile">Compile time options</a></li> - -<li> -<a href="#homogenous_runtime">Runtime time</a></li> -</ul> -</ul> -</blockquote> - -<hr> -<h3> -<a NAME="comp"></a>Configuring key components</h3> - -<ul> -<li> -<a NAME="concurrency"></a><b>Server concurrency strategy</b> specifies -the concurrency strategy an ORB uses. It says nothing about how many ORBs -(or, threads) are there in a process.</li> - -<br> -<p> -<ul> -<li> -<tt>reactive</tt>: The ORB handles requests reactively, i.e., the ORB runs -in one thread and service multiple requests/connections simultaneously -using "<tt>select</tt>" call. You can have multiple ORBs accepting requests -reactively and running in separate threads.</li> - -<br> -<p> -<li> -<tt>thread-per-connection</tt>: The ORB handles new connections by spawning -a new thread whose job is to service requests coming from the connection. -The new threads inherits all properties from the ORB threads (see below.)</li> - -<li> -<tt>thread-pool</tt> (not yet implemented): ... to be continued ...</li> - -<br> -<p> </ul> - -<li> -<a NAME="orb"></a><b>ORB and other resources.</b></li> - -<br> -<p> -<ul> -<li> -<tt>global</tt>: There's only one ORB process-wide. <tt>ORB_init () </tt>must -be called only once. Every thread accesses the same ORB.</li> - -<li> -<tt>tss</tt>: When using <tt>tss</tt> ORB, the programmer is responsible -for spawning the ORB threads and setting up the ORB by calling <tt>ORB_init -()</tt> for each ORB threads. Any ORB spawned thread (i.e., thru thread-per-connection) -shares the same resource the spawning ORB uses.</li> - -<br> -<p> </ul> - -<li> -<a NAME="poa"></a><b>POA.</b></li> - -<br> -<p> -<ul> -<li> -<tt>global</tt>: All ORBs share the same POA. The advantage of using a -global POA is that once an object is registered to the POA under an ORB, -it can be externalized from other ORB.</li> - -<br> -<p> -<li> -per ORB (<tt>tss</tt>): Each ORB has its own POA, which means, the programmer -should also instantiate the POA for each ORB (otherwise, a default RootPOA -gets created, which might not be what you what and thus, is discouraged.)</li> - -<br> -<p> </ul> - -<li> -<a NAME="coltbl"></a><b>Collocation Table:</b> <sup>*</sup>Care must be -taken when using CORBA objects to control the ORB directly. For you are -actually executing the collocated object, not in the object's ORB context, -but in the calling ORB's context.</li> - -<br> -<p> -<ul> -<li> -<tt>global</tt>: Process keeps a global collocation table which contains -tuples of listening endpoint and its corresponding RootPOA.</li> - -<li> -per ORB (<tt>tss</tt>): At this moment, since TAO only supports one listening -endpoint per ORB, there is no per-ORB collocation Table. Checking of collocated -objects is done by comparing object's IIOP profile and the calling ORB's -listening endpoint.</li> - -<br> -<p> </ul> - -<li> -<a NAME="iiopprofile"></a><b>Forwarding IIOP Profile:</b> In the case of -multiple threads using the same <tt>CORBA::Object</tt> and using forwarding, -it is necessary to protect the forwarding <tt>IIOP_Profile</tt>, which -is part of the <tt>IIOP_Object</tt>, which is part of the CORBA::Object -against multiple access. Therefore a mutex lock is used by default to ensure -proper access. Using the switch <tt>-ORBiiopprofilelock</tt> this policy -can be deactivated specifying <tt>-ORBiiopprofilelock null</tt>. A motivation -to do this might be performance reasons in cases, where no forwarding is -used or no multithreading with access to shared <tt>CORBA::Object</tt>'s. -Deactivating forces the ORB to use a null mutex, which does introduce only -a very small overhead, compared with overhead introduced by a regular mutex -lock.</li> - -<li> -<a NAME="orbsvcs"></a><b>orbsvcs Library:</b> By default, the TAO orbsvcs -library contains all of the services that TAO currently supports. To reduce -build time and library size, you can exclude unused services. To do that, -define a <tt>TAO_ORBSVCS</tt> variable using one of these approaches:</li> - -<br> -<p> -<ol> -<li> -In your <tt>$(ACE_ROOT)/include/makeinclude/platform_macros.GNU</tt> file,</li> - -<br> -<p> -<li> -On the make command line, <i>e.g.</i>,</li> - -<br> -<p> -<pre> -<tt> make TAO_ORBSVCS=Naming -</tt></pre> -or -<br> -<br> -<li> -Set (and export) a <tt>TAO_ORBSVCS</tt> environment variable.</li> - -<br> -<p> </ol> -Please see <tt><a href="../rules.tao.GNU">rules.tao.GNU</a></tt> for the -default setting of <tt>TAO_ORBSVCS</tt>. -<p> Please note the current limitations: -<br> -<br> -<ol> -<li> -We currently don't check for interdependencies between services. For example, -if you build the CosEvent service, you must also explicitly specify the -Sched and Event services, at least.</li> - -<br> -<p> -<li> -We currently don't check this macro in each of the orbsvcs Makefiles, or -in their tests. We'll add those checks soon.</li> - -<br> -<p> </ol> -</ul> - -<hr> -<h3> -<a NAME="examples"></a>Configuration Example</h3> - -<ul> -<li> -<a NAME="reactive"></a>Single-threaded, reactive model.</li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr> -<th ALIGN=LEFT>Typical Use</th> - -<td>This is the default configuration of TAO, where one thread handles -requests from multiple clients via a single Reactor. It is appropriate -when the requests (1) take a fixed, relatively uniform amount of time and -(2) are largely compute bound. </td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>1</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>OS or whomever creates the main ORB thread in a process.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Resources are stored process-wide.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>The single thread processes all connection requests and CORBA messages.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Options</th> - -<td><tt>TAO_Resource_Manager</tt>: <tt>-ORBresources global</tt> -<br><tt>TAO_Server_Strategy_Factory</tt>: <tt>-ORBconcurrency reactive</tt></td> -</tr> -</table> -Check out the <tt><a href="../tests/Param_Test/">Param_Test</a></tt>for -an example of this configuration. -<br> -<br> -<li> -<a NAME="tpc"></a>Multiple threads, thread-per-connection model.</li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr ALIGN=LEFT> -<th>Typical Use</th> - -<td>This configuration spawns a new thread to serve requests from a new -connection. This approach works well when there are multiple connections -active simultaneously and each request-per-connection may take a fair amount -of time to execute.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>1 plus the number of connections.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>Programmer must set up the main thread which is responsible to create -new threads for new connections.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Process-wise.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>The main thread handles new connections and spawns new threads for -them. Other threads handle requests for established connections.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Options</th> - -<td><tt>TAO_Resource_Manager</tt>: <tt>-ORBresources global</tt> -<br><tt>TAO_Server_Strategy_Factory</tt>: <tt>-ORBconcurrency thread-per-connection</tt></td> -</tr> -</table> -<tt><a href="../performance-tests/Cubit/TAO/IDL_Cubit/">IDL_Cubit</a></tt> -is a good example on using <i>multiple threads, thread-per-connection</i> -configuration. -<br> -<br> -<li> -Multiple threads, ORB-per-thread model.<a NAME="multiorb"></a></li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr ALIGN=LEFT> -<th>Typical Use</th> - -<td>In this configuration, there multiple ORBs per process each running -in its own thread. Each thread handles requests reactively. It's good for -hard real-time applications that require different thread priorities for -the various ORBs.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>The number of ORBs.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>The main process (thread).</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Thread specific.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>Service the requests from associating ORB.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Options</th> - -<td><tt>TAO_Resource_Manager</tt>: <tt>-ORBresources tss</tt> -<br><tt>TAO_Server_Strategy_Factory</tt>: <tt>-ORBconcurrency reactive</tt></td> -</tr> -</table> - -<li> -Multiple threads, ORB-per-thread, thread-per-connection model.<a NAME="multiorb-tpc"></a></li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr ALIGN=LEFT> -<th>Typical Use</th> - -<td>This approach provides a range of thread priorities plus connections -that don't interfere with each others.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>Number of ORBs plus number of connections.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>Main threads creates threads running ORBs. They, in turns, create connection -handling threads.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Thread specific.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>There are ORB threads which handle connection requests and handler -threads which service requests form establiched connections.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Options</th> - -<td><tt>TAO_Resource_Manager</tt>: <tt>-ORBresources tss</tt> -<br><tt>TAO_Server_Strategy_Factory</tt>: <tt>-ORBconcurrency thread-per-connection</tt></td> -</tr> -</table> -<tt><a href="../performance-tests/Cubit/TAO/MT_Cubit/">MT_Cubit</a></tt> -is a good example on using <i>multiple threads, ORB-per-thread, and thread-per-connection</i> -configuration. -<br> -<br> -<li> -<a NAME="tpool"></a>Multiple threads, thread-pool model. (Not yet implemented.)</li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr ALIGN=LEFT> -<th>Typical Use</th> - -<td>This model implements a highly optimized thread pool that minimizes -context switching, synchronization, dynamic memory allocations, and data -movement between threads.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>The number of threads used by ORB-related activities.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>Identifies the creator of the threads discussed above.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Where information on various resources is stored.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>Describes what task is undertaken for each thread.</td> -</tr> -</table> - -<li> -Multiple threads, ORB-per-thread, thread-pool model.<a NAME="multiorb-tpool"></a> -(Not yet implemented.)</li> - -<table BORDER=2 CELLSPACING=2 CELLPADDING=0 WIDTH="90%" > -<tr ALIGN=LEFT> -<th>Typical Use</th> - -<td>A brief description of the scenario and its typical use.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Number of Threads</th> - -<td>The number of threads used by ORB-related activities.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread Creator</th> - -<td>Identifies the creator of the threads discussed above.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Resource Location</th> - -<td>Where information on various resources is stored.</td> -</tr> - -<tr ALIGN=LEFT> -<th>Thread task</th> - -<td>Describes what task is undertaken for each thread.</td> -</tr> -</table> -</ul> - -<hr> -<h3> -Configuration for homogenous systems<a NAME="homogenous"></a></h3> - -<ul><b>Compile time options</b><a NAME="homogenous_compile"></a> -<p>Many real-time applications run on homogenous environments, TAO (and -ACE) can take advantage of this fact by simplifying the server side demarshaling; -to enable this feature you have to edit the <tt>$ACE_ROOT/ace/OS.h</tt> -file and enable the macro <font size=-1>ACE</font><tt>_DISABLE_SWAP_ON_READ</tt>. -<p>In this systems it is also common that server and the client startup -and shutdown simultaneously, in those circumstances there is no need to -check the timestamps in the POA, another macro (<tt>POA_NO_TIMESTAMP</tt>) -can be used for this purpose. -<p>Users running in embebbed systems may also need to modify the default -options for TAO, the macros <tt>TAO_DEFAULT_RESOURCE_FACTORY_ARGS</tt>, -<tt>TAO_DEFAULT_CLIENT_STRATEGY_FACTORY_ARGS</tt> and <tt>TAO_DEFAULT_SERVER_STRATEGY_FACTORY_ARGS</tt> -can be used for those purposes. If the footprint size is an issue users -may consider writing custom strategy factories that only create the right -strategies, this eliminates the parsing code for the different options. -<p><b>Runtime options</b><a NAME="homogenous_runtime"></a> -<p>If the only ORB running is TAO and there is no need to be IIOP interoperable -the option <tt>-ORBgioplite</tt> can be used to reduce the message size -and the processing time. -<p>Some embedded systems run without the benefit of a DNS server, in that -case they can use the <tt>-ORBdotteddecimaladdresses</tt> option; the ORB -will avoid the use of hostnames in the profiles it generates, thus clients -don't need to do any name resolution. The compile-time define <tt>TAO_USES_DOTTED_DECIMAL_ADDRESSES</tt> -in <tt>$TAO_ROOT/tao/orbconf.h</tt> to make this the default behavior.</ul> - -<hr> -<center> -<h3> -Hints</h3></center> -Choosing the right configuration is hard and, of course, depends on your -application. In the following section we will attempt to describe some -motivations for features in TAO, hopefully that can guide you through the -choice of your configuration options. -<ul><b>ORB-per-thread</b> The main motivation behind this options is to -minimize priority invertion, since threads share no ORB resources no locking -is required and thus, priority is preserved in most cases (assuming proper -support from the OS). If you are not too concerned about priority inversion -try to use a global ORB, using ORB-per-thread has some tradeoffs (like -calling ORB_init on each thread, activation of a servant is more complicated, -etc.) Some of the problems, can be minimized, but they require even more -careful analysis. For example, object activation can be simplified by using -a global POA; the careful reader will wonder how could global POA be useful -in anyway since it will require locks and thus introduce priority inversions -again; some applications activate all their objects beforehand so locks -in the POA are not always needed; other applications only activate a few -objects after startup, so they can use a child POA with the right locking -policy for the dynamic servants and the root poa (with no locking) for -the majority of the servants. -<p>As the reader will note this is a delicate configuration option, the -rule of thumb should be <b>not</b> to use ORB-per-thread unless it is really -required. -<li> -<b>Collocation tables</b> Why could the application what a non-global collocation -table? If objects are to serve requests only at a well known priority the -application can be configured with the ORB-per-thread option, and the object -is activated only in the thread (ORB) corresponding to the desired priority. -But using a global table would subert the priority assignment (because -calls would run at the priority of the client).</li> - -<li> -<b>Single-threaded vs. Multi-threaded Connection Handlers</b> The <tt>Client_Connection_Handler</tt> -is the component in TAO that writes the requests to the underlying transport -socket; this is also the component that reads the response back from the -server.</li> - -<p><br>While waiting for this response new requests to the local ORB can -arrive, this is the so-called nested upcall support. TAO supports two mechanisms -for handling nested upcalls, the default uses the leader-follower model -to allow multiple threads to wait on a single reactor for several concurrent -requests; sometimes this configuration can be an overkill, if only one -thread is using a reactor at the same time a lighter weight implementation -can be used. -<p>This configuration is controled by the <tt>-ORBclientconnectionhandler</tt> -option, good opportunities to use this option are: -<ul> -<li> -Single threaded servers</li> - -<li> -Servers running in ORB-per-thread mode</li> - -<li> -Pure clients that will never receive a request</li> -</ul> - -<li> -<b>Allocator for input CDR streams</b> Normally the application has no -access to this buffer, and it is only used on the demarshaling of arguments -(or results). It is almost always better to use the "<tt>-ORBinputcdrallocator -tss</tt>" option since it will allocate memory from a thread specific allocator -and it will not need locks to manage that memory.</li> - -<p><br>In some cases the user <i>may</i> gain access to the CDR stream -buffer: TAO makes no copies when demarshaling octet sequences, instead -the octet sequence simply points to the CDR buffer, since the octet sequence -does not own this buffer a copy must be made if the user wants to keep -the buffer after the upcall. -<p>The user can, however, increase the reference count on the CDR stream -buffer, thus allowing her to extend the lifetime of this buffer. Still -passing this buffer to another thread and attempting to release it in that -thread will result in some memory leak or corruption. Users willing to -use this feature of TAO can still do so, <b>if</b> they use a global allocator -for their input CDR stream, but that will introduce extra locking on the -critical path. -<p>As the reader can see this is an option that has limited applicability -and requires careful consideration of the tradeoffs involved.</ul> - -<hr> -<p>Back to the TAO <a href="components.html">components documentation</a>. <!--#include virtual="/~schmidt/cgi-sig.html" --> -</body> -</html> diff --git a/TAO/docs/events_tutorial.html b/TAO/docs/events_tutorial.html deleted file mode 100644 index c07ae139d88..00000000000 --- a/TAO/docs/events_tutorial.html +++ /dev/null @@ -1,1819 +0,0 @@ -<html> -<head> -<title>Using the Real-Time Event Service</title> -</head> - -<BODY text = "#000000" -link="#000fff" -vlink="#ff0f0f" -bgcolor="#ffffff"> - -<br> -<br> - -<center> -<h1>Using the Real-Time Event Service</h1><P> - -<A HREF="http://www.cs.wustl.edu/~cdgill/">Chris Gill</a>, -<A HREF="http://www.cs.wustl.edu/~harrison/">Tim Harrison</a>, and -<A HREF="http://www.cs.wustl.edu/~coryan/">Carlos O'Ryan</a><br><br> - -<A HREF="mailto:cdgill@cs.wustl.edu">cdgill@cs.wustl.edu</a>, -<A HREF="mailto:harrison@cs.wustl.edu">harrison@cs.wustl.edu</a>, and -<A HREF="mailto:coryan@cs.wustl.edu">coryan@cs.wustl.edu</a><br> -</center> - -<br> -<br> - -<P><HR><P> -<!-- ************************************************************ --> - -<center> -<table cellpadding=10 border=0 cellspacing=4> -<tr><td> -<h2><a name="Section0">Overview</a></h2> -<BR> -<BR> -<tr><td> -<h3>Contents</h3> -<BR> -<ol> - <li> <a href="events_tutorial.html#Section0">Overview</a> - <li> <a href="events_tutorial.html#Section1">The COS Event Model</a> - <li> <a href="events_tutorial.html#Section2">Real-Time Event Service Enhancements</a> - <li> <a href="events_tutorial.html#Section3">The Real-Time Event Service</a> - <li> <a href="events_tutorial.html#Section4">Developing Consumers</a> - <li> <a href="events_tutorial.html#Section5">Developing Suppliers</a> - <li> <a href="events_tutorial.html#Section6">Caring For Your Event Channel</a> - <li> <a href="events_tutorial.html#Section7">Sample Applications</a> - <li> <a href="events_tutorial.html#Section8">Reference Materials</a> -</ol> - -<P><HR><P> -<tr><td> -<h3>Introduction</h3> -<BR> -This material is intended to provide an introduction to the COS Event Model, -the Real-Time extensions to that model in TAO, and a set of examples that -illustrate the techniques used to build systems using these models. The CORBA -Event Service provides a flexible model for asynchronous communication among -objects. However, the standard CORBAEvent Service specification lacks -important features required by real-time applications. These features include -event filtering, event correlation, and periodic event processing.<P> - -The standard CORBA operation invocation model supports twoway, oneway, -and deferred synchronous interactions between clients and servers. -The primary strength of the twoway model is its intuitive mapping onto -the <code>object->operation()</code> paradigm supported by OO languages. -In principle, twoway invocations simplify the development of -distributed applications by supporting an implicit request/response -protocol that makes remote operation invocations transparent to the -client. <P> - -In practice, however, the standard CORBA operation invocation models -are too restrictive for real-time applications. In particular, these -models lack asynchronous message delivery, do not support timed -invocations or group communication, and can lead to excessive polling -by clients. Moreover, standard oneway invocations might not implement -reliable delivery and deferred synchronous invocations require the use -of the CORBA Dynamic Invocation Interface (DII), which yields -<A HREF="http://www.cs.wustl.edu/~schmidt/GLOBECOM-96.ps.gz">excessive -overhead</A> for most real-time applications. <P> - -The Event Service is a CORBA Object Service (COS) that is designed to -alleviate some of the restrictions with standard CORBA invocation -models. In particular, the COS Event Service supports asynchronous -message delivery and allows one or more suppliers to send messages to -one or more consumers. Event data can be delivered from suppliers to -consumers without requiring these participants to know about each -other explicitly. <P> - -There are two models (<EM>i.e.</EM>, <EM>push</EM> vs. <EM>pull</EM>) -of participant collaborations in the COS Event Service architecture. -This material focuses on real-time enhancements to the push model, which -allows suppliers of events to initiate the transfer of event data to -consumers. Suppliers push events to the Event Channel, which in turn -pushes the events to consumers. <P> - -Suppliers use Event Channels to push data to consumers. Likewise, -consumers can explicitly pull data from suppliers. The push and pull -semantics of event propagation help to free consumers and suppliers -from the overly restrictive synchronous semantics of the standard -CORBA twoway communication model. In addition, Event Channels can -implement group communication by serving as a replicator, broadcaster, -or multicaster that forward events from one or more suppliers to -multiple consumers.<p> - -</table> -</center> - -<hr><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td align=center> -<center><h2><a name="Section1">The COS Event Model</a></h2></center> -</table></center> - -<table cellpadding=1 border=0 cellspacing=4> -<h3>Relationships Between Modules</h3> - -The role of each component in the COS Event Model is outlined -below:<P> - -<ul> - <li> <b><i>EventChannel</i></b> -- The EventChannel interface provides - two factory methods, which allow applications to obtain consumer and - supplier administration objects, respectively, and use them to create - the other objects described below, to connect to the event channel. <P> - - <li> <b><i>SupplierAdmin</i></b> -- The SupplierAdmin interface provides - factory methods which create the appropriate supplier proxy objects. <P> - - <li> <b><i>ConsumerAdmin</i></b> -- The ConsumerAdmin interface provides - factory methods which create the appropriate consumer proxy objects. <P> - - <li> <b><i>ProxyPullSupplier</i></b> -- The ProxyPullSupplier - interface is used by consumers in the pull model to connect and - disconnect from the channel. This interface inherits from the - PullSupplier interface, and acts as a proxy for the suppliers - from which the channel will pull events. <P> - - <li> <b><i>ProxyPushSupplier</i></b> -- The ProxyPushSupplier - interface is used by consumers in the push model to connect and - disconnect from the channel. This interface inherits from the - PushSupplier interface, and acts as a proxy for the suppliers - which will push events to the channel. <P> - - <li> <b><i>ProxyPullConsumer</i></b> -- The ProxyPullConsumer - interface is used by suppliers in the pull model to connect and - disconnect from the channel. This interface inherits from the - PullConsumer interface, and acts as a proxy for the consumers - on whose behalf the channel will pull events. <P> - - <li> <b><i>ProxyPushConsumer</i></b> -- The ProxyPushConsumer - interface is used by suppliers in the push model to connect and - disconnect from the channel. This interface inherits from the - PushConsumer interface, and acts as a proxy for the consumers - to which the channel will push events. <P> - - <li> <b><i>PullSupplier</i></b> -- The PullSupplier interface provides - the necessary methods of a supplier of events in the pull model. <P> - - <li> <b><i>PushSupplier</i></b> -- The PushSupplier interface provides - the necessary methods of a supplier of events in the push model. <P> - - <li> <b><i>PullConsumer</i></b> -- The PullConsumer interface provides - the necessary methods of a consumer of events in the pull model. <P> - - <li> <b><i>PushConsumer</i></b> -- The PushConsumer interface provides - the necessary methods of a consumer of events in the push model. <P> -</ul> - -<tr><td> -</table> -<br> -<br> -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td align=center> -<center><IMG SRC="http://www.cs.wustl.edu/~schmidt/gifs/ec_participants2.gif"></center> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3>The Push Model</h3> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~schmidt/gifs/ec_push.gif"></center> - -<tr><td> -<UL> - <LI> Consumers - Ultimate targets of events - <LI> Suppliers - Generate events - <LI> Event Channel - Decouple consumers and suppliers by propagating - events to consumers on behalf of suppliers -</UL> -</table></center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> - -<h2><a name="Section2">Real-Time Event Service Enhancements</a></h2> - -<tr><td> -<ul> - <li> <b><i>Prioritized dispatching within preemption - classes</i></b> -- The current implementation can dispatch - events in the same queue by their order of importance, which is - necessary to support priorities within a rate group. <p> - - <li> <b><i>Suspend/resume</i></b> -- If a consumer's event - dependencies change at run-time, it can utilize the - suspend/resume functionality through the new - <code>ProxyPushSupplier::suspend</code> and - <code>ProxyPushSupplier::resume</code> methods. When a - consumer invokes <code>ProxyPushSupplier::suspend</code>, the - dependencies registered with that proxy will be disabled until - the <code>resume</code> methods is called. These enhancements - allow run-time flexibility of event dependencies, but maintains - the determinism required by the system scheduling policy (i.e., - consumers can not add and remove dependencies at run-time - - just suspend and resume them).<p> - - <LI> <B><I>Event data model</I></B> -- The data model may use - unions, untyped buffers, or type anys.<P> - -<LI> <B><I>Event filtering</I></B> -- Consumers may register for -events based on event type, or supplier id. The event channel filters events -based on these registrations, to ensure efficient event delivery.<P> - -<LI> <B><I>Event correlation</I></B> -- Consumers may register -for event delivery based on conjunctive or disjunctive sets of events. Conjunctive -registrations cause the event channel to notify the consumer when <I>all</I> -events in the set have arrived. Disjunctive registrations cause the event channel -to notify the consumer when <I>any</I> event in the set has arrived.<P> - -<LI> <B><I>Periodic event processing</I></B> -- Consumers -may register for suppliers based on timed events. Periodic suppliers push events -into the channel at well defined intervals.<P> - - <LI> <B><I>Active consumers and suppliers</I></B> -- See - <a href="events_tutorial.html#Section3">The Real-Time Event Service</a><P>. - -</ul> -</table> -</center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td align=center> -<h2><a name="Section3">The Real-Time Event Service</a></h2> -</table></center> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3>Real-Time ORB and Services</h3> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~schmidt/gifs/corbaopt10.gif"></center> - -<br> -<center><tr><td> -<ul> - <li> Real-time event dispatching<P> - <UL> - <LI> Priority-based queueing and preemption mechanisms<P> - </UL> - <li> Centralized event filtering and correlation<P> - <ul> - <LI> Source/type-based filtering<P> - <LI> Conjunction/Disjunction (AND/OR) correlations<P> - </ul> - - <li> Periodic and Aperiodic processing <P> - <UL> - <LI> Canonical timeouts<P> - <LI> Dependency timeouts - </UL> -</ul> -</center> -</table></center> -<br> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td align=center> -<h3>Real-Time Event Service Internals</h3> -<BR> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~schmidt/gifs/ec_dispatching.gif"></center> -</table></center> -<br> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3>Characteristics of Real-Time Push Event Service Participants</h3> - -<tr><td> -Two major roles are played by the participants in a real-time push event -service.<P> - -<tr><td> -The first role is that of an event consumer, which receives events from the -event channel. A consumer specifies the type and/or source id for each event -it is interested in receiving.<P> - -In hard real-time applications, a consumer must also specify RT_Info data for -each event it is interested in receiving, and any other events on which that -event depends. The RT_Info structure resides in the Scheduler, and is -accessed through the scheduler interface. A unique handle is returned to the -consumer when an RT_Info is created, which can then be used to set the -information in the RT_Info. An RT_Info handle may also be obtained via the -Scheduler's lookup method.<P> - -<tr><td> -The second role is that of an event supplier, which generates events and -passes them into the event channel. A supplier must specify its source id, -and the type of each event it will generate. - -<tr><td> -In hard real-time applications, a supplier must also specify RT_Info data for -the events it will generate. In particular, it must specify the maximum rate -at which it will generate each event. This information is used by a real-time -scheduler to assign appropriate dispatch priorities.<P> - -<tr><td> -Note that the event channel may also be configured to use a null scheduling service. This will -cause all operations to be dispatched at the same priority, and will not require the application -to specify worst case execution times, periods, etc. - -<tr><td> -The consumer and supplier roles may be combined, as illustrated in the tables below. There are -two main cases in which the roles are combined: a passive one termed Consumer/Supplier which -borrows a thread of execution to produce events, and an active one termed Supplier/Consumer -which produces events in its own thread. Both consume events and produce events.<P> -</table></center> - -<br> -<br> -<center><table cellpadding=4 border=1 cellspacing=4> -<h4>EC Roles and Specified RT_Info Contents</h4> - -<tr> -<th>EC Roles -<th>RT_Info Contents -<th>Domain Examples -</tr> - -<tr> -<td> Consumer -<td> dependencies (and optionally, importance) -<td> Display, Exception & Maintenance Logs -</tr> - -<tr> -<td> Consumer/Supplier -<td> dependencies (and optionally, importance) -<td> Navigation Component (NAV) -</tr> - -<tr> -<td> Supplier/Consumer -<td> rate, dependencies (and optionally, importance) -<td> Kalman Filter -</tr> - -<tr> -<td> Supplier -<td> rate -<td> Operator Control Panel, EC Reactor Threads -</tr> - -</table></center> -<BR> -<BR> - - -<center><table cellpadding=1 border=1 cellspacing=4> -<h4>EC Roles and Scheduler Dependency Chain</h4> - -<tr> -<th> EC Roles -<th> Scheduler Dependency Chain -</tr> - -<tr> -<td> Pure Consumer -<td> root node -</tr> - -<tr> -<td> Consumer/Supplier -<td> internal node -</tr> - -<tr> -<td> Supplier/Consumer -<td> internal node -</tr> - -<tr> -<td> Pure Supplier -<td> leaf node -</tr> - -</table></center> -<BR> -<BR> - -<center><table cellpadding=1 border=1 cellspacing=4> -<h4>EC Roles, Threading, and CORBA Roles</h4> - -<tr> -<th> EC Roles -<th> Activity -<th> Thread Behavior -<th> CORBA Roles -</tr> - -<tr> -<td> Pure Consumer -<td> Passive -<td> Threads optional, "internal", wait for an event to occur -<td> Servant -</tr> - -<tr> -<td> Consumer/Supplier -<td> Passive -<td> Threads optional, "internal", wait for an event to occur -<td> Client and/or Servant -</tr> - -<tr> -<td> Supplier/Consumer -<td> Active -<td> Threads required and visible to EC: consume events and actively produce other events -<td> Client and/or Servant -</tr> - -<tr> -<td> Pure Supplier -<td> Active -<td> Threads required and visible to EC: actively produce events -<td> Client -</tr> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~cdgill/ec_roles.GIF"></center> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~cdgill/ec_roles2.GIF"></center> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~cdgill/ec_backbone.GIF"></center> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~cdgill/distributed_ec_roles.GIF"></center> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><IMG SRC="http://www.cs.wustl.edu/~cdgill/ec_orb_view.GIF"></center> -</table></center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<center><h2><a name="Section4">Developing Consumers</a></h2></center> -<br> -<ul> - <li> <a href="events_tutorial.html#Section4_1">Providing QoS Information</a> - <li> <a href="events_tutorial.html#Section4_2">Connecting Consumers to the Event Channel</a> - <li> <a href="events_tutorial.html#Section4_3">Receiving Events</a> - <li> <a href="events_tutorial.html#Section4_4">Disconnecting Consumers from the Event Channel</a> -</ul> -</table></center> - -<P><hr width="75%"><P> <!-- intra-section separator --> -<center><table cellpadding=1 border=0 cellspacing=4> -<center><h3><a name="Section4_1">Providing QoS Information</a><h3></center><p> - -<tr><td> -The following steps are only necessary for applications that make use of the -Event Service's hard real-time features. Applications that do not need these -features and are configured with a null scheduler may skip the following -operations on the scheduling server. - -<tr><td> -For each operation, a Consumer should provide the worst case, expected, and -cached execution time for that operation. It must also specify criticality and -importance values for each operation. A real-time scheduler uses this information -to order dispatches within a set of operations whose dependencies have been met. - -<tr><td> -If it is a Consumer/Supplier (one which consumes an event and passively generates -one or more events from the thread in which it was called, as illustrated in the -tables above), it must provide dependencies on one or more other events to the -scheduler. - -<tr><td> -If it is a Supplier/Consumer (one which consumes an event and actively generates -one or more events from its own thread, as illustrated in the tables above), it -must also specify the rate at which it will generate the new events by passing a -positive value in the period argument to the scheduler set method. It may also -indicate a positive number of threads in which the dispatch will be made. If the -number of threads given is zero, but a period is specified, the number of threads -defaults to 1. - -</table> -</center> - - -<center><table cellpadding=1 border=0 cellspacing=4> - -<tr><td> -<pre> - - // Obtain a reference to the scheduler server. - RtecScheduler::Scheduler_ptr server = - ACE_Scheduler_Factory::server (); - - // Create new RT_Info descriptors for three events. - - RtecScheduler::handle_t handle1 = - server->create ("event_1", // Name of entry point - TAO_TRY_ENV // Environment - ); - - RtecScheduler::handle_t handle2 = - server->create ("event_2", // Name of entry point - TAO_TRY_ENV // Environment - ); - - RtecScheduler::handle_t handle3 = - server->create ("event_3", // Name of entry point - TAO_TRY_ENV // Environment - ); - - - // Register as a consumer/supplier: act as a supplier of event_1 but with - // a consumer dependency on event_3. Therefore, the actual period and - // number of threads for event_1 depends on the characteristics of event_3. - server->set (handle1, // RT_Info handle - RtecScheduler::HIGH_CRITICALITY, // Criticality - 500, // Worst case time (in 100 nanosecs) - 500, // Typical time (in 100 nanosecs) - 500, // Cached time (in 100 nanosecs) - 0, // Period - will depend on event_3 - RtecScheduler::LOW_IMPORTANCE, // Importance - 0, // Quantum (unused) - 0, // Threads - will depend on event_3 - RtecScheduler::OPERATION, // Info type - TAO_TRY_ENV); - - // Register as a producer of event_2. - server->set (handle2, // RT_Info handle - RtecScheduler::HIGH_CRITICALITY, // Criticality - 500, // Worst case time (in 100 nanosecs) - 500, // Typical time (in 100 nanosecs) - 500, // Cached time (in 100 nanosecs) - 50000 * 10, // Period in 100 nsec (= 20 Hz) - RtecScheduler::LOW_IMPORTANCE, // Importance - 0, // Quantum (unused) - 1, // Threads - RtecScheduler::OPERATION, // Info type - TAO_TRY_ENV); - - // Register as a consumer of event_3. - server->set (handle3, // RT_Info handle - RtecScheduler::HIGH_CRITICALITY, // Criticality - 500, // Worst case time (in 100 nanosecs) - 500, // Typical time (in 100 nanosecs) - 500, // Cached time (in 100 nanosecs) - 0, // Period - will depend on supplier - RtecScheduler::LOW_IMPORTANCE, // Importance - 0, // Quantum (unused) - 0, // Threads - will depend on supplier - RtecScheduler::OPERATION, // Info type - TAO_TRY_ENV); - - - // Establish a dependency of event_1 on event_3. - server->add_dependency (handle1, // handle that depends - handle3, // handle that is depended on - 1, // number of calls per event occurance - TAO_TRY_ENV // environment - ); - - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3> -<a name="Section4_2">Connecting Consumers to the Event Channel</a> -</h3> - -<tr><td> -The following code is derived from the EC_Throughput consumer code, which can be -found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp</a> - -<tr><td> -<pre> - -void -Test_Consumer::connect (const char* name, - int event_a, int event_b, - RtecEventChannelAdmin::EventChannel_ptr ec, - CORBA::Environment& _env) -{ - - // Register operations with the scheduling service. The following steps are - // only necessary for applications that make use of the Event Service's hard - // real-time features. Applications that do not need these features and are - // configured with a null scheduler may skip the following operations on the - // scheduling server. - - // Obtain a reference to the scheduler from the ACE_Scheduler_Factory. - RtecScheduler::Scheduler_ptr server = - ACE_Scheduler_Factory::server (); - - // Create a new RT_Info entry for the function identifier - // we were passed, and hang onto the handle to the RT_Info. - RtecScheduler::handle_t rt_info = - server->create (name, _env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Set the attributes for the RT_Info. - ACE_Time_Value tv (0, 2000); - TimeBase::TimeT time; - ORBSVCS_Time::Time_Value_to_TimeT (time, tv); - server->set (rt_info, - RtecScheduler::VERY_HIGH_CRITICALITY, - time, time, time, - 0, - RtecScheduler::VERY_LOW_IMPORTANCE, - time, - 0, - RtecScheduler::OPERATION, - _env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Specify a disjunctive dependency on the arrival of event_a, the arrival - // of event b, OR the arrival of an event service shutdown event. Note that - // the same RT_Info is used for each event. This can be used to simplify - // code in applications using a null scheduler, or to consolidate events - // with identical characteristics in hard real-time applications. - ACE_ConsumerQOS_Factory qos; - qos.start_disjunction_group (); - qos.insert_type (ACE_ES_EVENT_SHUTDOWN, rt_info); - qos.insert_type (event_a, rt_info); - qos.insert_type (event_b, rt_info); - - // = Connect as a consumer. - - // Obtain a reference to the consumer administration object. - RtecEventChannelAdmin::ConsumerAdmin_var consumer_admin = - ec->for_consumers (_env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Obtain a reference to the push supplier proxy. - this->supplier_proxy_ = - consumer_admin->obtain_push_supplier (_env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Obtain a reference to this object. - RtecEventComm::PushConsumer_var objref = this->_this (_env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Connect as a consumer. - this->supplier_proxy_->connect_push_consumer (objref.in (), - qos.get_ConsumerQOS (), - _env); - TAO_CHECK_ENV_RETURN_VOID(_env); -} - -</pre> - -<tr><td> -The following code is derived from the EC_Throughput consumer driver code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Consumer_Driver.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Consumer_Driver.cpp</a> - -<tr><td> -<pre> - -int -ECT_Consumer_Driver::run (int argc, char* argv[]) -{ - // argc/argv are used to initialize the ORB and the options - // for this particular test. Other applications may hard-code - // the ORB options, obtain them from another source, etc. - - TAO_TRY - { - // The use of TAO_TRY macros isolate us from the differences - // between platforms with and without native C++ exceptions. - // This is work in progress and may change in the future! - - // Below is some boiler plate code to initialize the ORB and - // the POA. Notice that applications that connect to the Event - // Channel play the server role in some instances, because - // they receive push() requests (as Consumers) or - // disconnect_push_supplier() requests (as Suppliers). - - // Initialize the ORB reference. - this->orb_ = - CORBA::ORB_init (argc, argv, "", TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Initialize the root POA reference. - CORBA::Object_var poa_object = - this->orb_->resolve_initial_references("RootPOA"); - if (CORBA::is_nil (poa_object.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to initialize the POA.\n"), - 1); - - // Obtain the narrowed root POA reference. - PortableServer::POA_var root_poa = - PortableServer::POA::_narrow (poa_object.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Obtain a reference to the POA manager. - PortableServer::POAManager_var poa_manager = - root_poa->the_POAManager (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Now some boiler plate code to obtain a reference to the - // naming service..... - - // Resolve a reference to the naming service. - CORBA::Object_var naming_obj = - this->orb_->resolve_initial_references ("NameService"); - if (CORBA::is_nil (naming_obj.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to get the Naming Service.\n"), - 1); - - // Narrow the naming service reference. - CosNaming::NamingContext_var naming_context = - CosNaming::NamingContext::_narrow (naming_obj.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Use the Naming Service to locate the Scheduling Service and - // use the Scheduler_Factory to keep a global pointer to the - // latter. - - // Initialize the scheduler factory to operate in configuration mode. - if (ACE_Scheduler_Factory::use_config (naming_context.in ()) == -1) - return -1; - - // Use the Naming Service to locate the Event Service.... - - // Set up the event service lookup name. - CosNaming::Name name (1); - name.length (1); - name[0].id = CORBA::string_dup ("EventService"); - - // Resolve a reference to the event service. - CORBA::Object_var ec_obj = - naming_context->resolve (name, TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Narrow the reference to the event service. - RtecEventChannelAdmin::EventChannel_var channel; - if (CORBA::is_nil (ec_obj.in ())) - channel = RtecEventChannelAdmin::EventChannel::_nil (); - else - channel = RtecEventChannelAdmin::EventChannel::_narrow (ec_obj.in (), - TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Activate the POA so we can start receiving requests... - - // Activate the POA manager. - poa_manager->activate (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Connect consumers to the event service. - this->connect_consumers (channel.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - ACE_DEBUG ((LM_DEBUG, "connected consumer(s)\n")); - ACE_DEBUG ((LM_DEBUG, "running the test\n")); - - // Run the event loop. - if (this->orb_->run () == -1) - ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "orb->run"), -1); - ACE_DEBUG ((LM_DEBUG, "event loop finished\n")); - - this->dump_results (); - - // Disconnect consumers from the event service. - this->disconnect_consumers (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Destroy the event service. - channel->destroy (TAO_TRY_ENV); - TAO_CHECK_ENV; - } - TAO_CATCH (CORBA::SystemException, sys_ex) - { - TAO_TRY_ENV.print_exception ("SYS_EX"); - } - TAO_CATCHANY - { - TAO_TRY_ENV.print_exception ("NON SYS EX"); - } - TAO_ENDTRY; - return 0; -} - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<!-- Must be after suppliers connect. --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3><a name="Section4_3">Receiving Events</a></h3><p> - -<tr><td> -The following code is derived from the EC_Throughput consumer code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp</a> - -<tr><td> -<pre> - -void -Test_Consumer::push (const RtecEventComm::EventSet& events, - CORBA::Environment &_env) -{ - // Make sure at least one event was pushed. - if (events.length () == 0) - { - // ACE_DEBUG ((LM_DEBUG, "no events\n")); - return; - } - - // Make sure only one thread has access. - ACE_GUARD (ACE_SYNCH_MUTEX, ace_mon, this->lock_); - - // We start the timer as soon as we receive the first event. - if (this->recv_count_ == 0) - this->timer_.start (); - - // Update the count of received events. - this->recv_count_ += events.length (); - - if (TAO_debug_level > 0 - && this->recv_count_ % 1000 == 0) - { - ACE_DEBUG ((LM_DEBUG, - "ECT_Consumer (%P|%t): %d events received\n", - this->recv_count_)); - } - - // Loop through the events, looking for shutdown events. - for (u_int i = 0; i < events.length (); ++i) - { - if (events[i].header.type == ACE_ES_EVENT_SHUTDOWN) - { - this->shutdown_count_++; - if (this->shutdown_count_ >= this->n_suppliers_) - { - // We stop the timer as soon as we realize it is time to - // do so. - this->timer_.stop (); - this->driver_->shutdown_consumer (this->cookie_, _env); - } - } - } -} - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3> -<a name="Section4_4">Disconnecting Consumers from the Event Channel</a> -</h3> - -<tr><td> -The following code is derived from the EC_Throughput consumer code, which can be -found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Consumer.cpp</a> - -<tr><td> -<pre> - -void -Test_Consumer::disconnect (CORBA::Environment &_env) -{ - // Make sure the supplier proxy reference is valid. - if (CORBA::is_nil (this->supplier_proxy_.in ())) - return; - - // Disconnect from further communication with the push - // supplier(s). Each consumer is represented by a unique - // ACE_ES_ConsumerModule instance. Which connection to - // disconnect is determined by the instance for the consumer. - this->supplier_proxy_->disconnect_push_supplier (_env); - TAO_CHECK_ENV_RETURN_VOID(_env); - - // Mark the supplier proxy reference invalid. - this->supplier_proxy_ = - RtecEventChannelAdmin::ProxyPushSupplier::_nil (); - - // We want to stop processing events for this consumer. Above, - // we disconnected the consumer from the Event Channel, so no - // more events will be sent, but we could have some events in - // transit. - - // Without a flushing protocol we need to deactivate the - // servant to stop accepting push () requests for any - // incoming events. - - // Deactivate the servant - PortableServer::POA_var poa = - this->_default_POA (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - PortableServer::ObjectId_var id = - poa->servant_to_id (this, _env); - TAO_CHECK_ENV_RETURN_VOID (_env); - poa->deactivate_object (id.in (), _env); - TAO_CHECK_ENV_RETURN_VOID (_env); -} - -</pre> -</table> -</center> - - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<td> -<h2><a name="Section5">Developing Suppliers</a></h2> - -<ul> - <li> <a href="events_tutorial.html#Section5_1">Providing QoS Information</a> - <li> <a href="events_tutorial.html#Section5_2">Connecting Suppliers to the Event Channel</a> - <li> <a href="events_tutorial.html#Section5_3">Generating Events</a> - <li> <a href="events_tutorial.html#Section5_4">Disconnecting Suppliers from the Event Channel</a> -</ul> -</table> -</center> - - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3><a name="Section5_1">Providing QoS Information</a></h3><p> -<tr><td> -In applications that use hard real-time scheduling, a Supplier should provide -the worst case, expected, and cached execution time for each operation on the -supplier side. Even if these values are small and highly deterministic, it is -generally better to specify them in the supplier's RT_Info rather than folding -them into the RT_Info of each consumer. - -<tr><td> -Such a supplier must also specify criticality and importance values, a period, -and the number of threads for each operation. A real-time scheduler propagates -this information to consumer RT_Infos along the graph of dependencies. The -scheduler then uses the propagated information to order dispatches within a -set of operations whose dependencies have been met. - -<tr><td> -The Event Service matches supplier publications with consumer subscriptions to -provide efficient event filtering. Providing incorrect publications or -subscriptions will result in missed events. The Event Service also uses the -subscription information to create additional dependencies between registered -RT_Infos. Thus, providing correct supplier publication and consumer -subscription information is also critical for correct scheduling in hard -real-time applications. - - -<tr><td> -As noted before in the discussion of consumers, the following steps are only -necessary for applications that make use of the Event Service's hard real-time -features. Applications that do not need these features and are configured -with a null scheduler may skip the following operations on the scheduling -server. - -</table> -</center> - -<center><table cellpadding=1 border=0 cellspacing=4> - -<tr><td> -<pre> - - // Obtain a reference to the scheduler server. - RtecScheduler::Scheduler_ptr server = - ACE_Scheduler_Factory::server (); - - // Create new RT_Info descriptors for two events. - - RtecScheduler::handle_t handle0 = - server->create ("event_0", // Name of entry point - TAO_TRY_ENV // Environment - ); - - RtecScheduler::handle_t handle1 = - server->create ("event_1", // Name of entry point - TAO_TRY_ENV // Environment - ); - - // Register as a producer of event_0. - server->set (handle0, // RT_Info handle - RtecScheduler::HIGH_CRITICALITY, // Criticality - 10, // Worst case time (in 100 nanosecs) - 10, // Typical time (in 100 nanosecs) - 10, // Cached time (in 100 nanosecs) - 50000 * 10, // Period in 100 nanosecs (= 20 Hz) - RtecScheduler::LOW_IMPORTANCE, // Importance - 0, // Quantum (unused) - 1, // Threads - RtecScheduler::OPERATION, // Info type - TAO_TRY_ENV); - - // Register as a producer of event_1. - server->set (handle1, // RT_Info handle - RtecScheduler::HIGH_CRITICALITY, // Criticality - 10, // Worst case time (in 100 nanosecs) - 10, // Typical time (in 100 nanosecs) - 10, // Cached time (in 100 nanosecs) - 50000 * 10, // Period in 100 nanosecs (= 20 Hz) - RtecScheduler::LOW_IMPORTANCE, // Importance - 0, // Quantum (unused) - 1, // Threads - RtecScheduler::OPERATION, // Info type - TAO_TRY_ENV); - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<td> -<h3><a name="Section5_2">Connecting Suppliers to Event Channel</a></h3><P> -<p> - -<tr><td> -The following code is derived from the EC_Throughput supplier code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp</a> - - -<tr><td> -<pre> - -void -Test_Supplier::connect (const char* name, - int burst_count, - int burst_size, - int event_size, - int burst_pause, - int event_a, - int event_b, - RtecEventChannelAdmin::EventChannel_ptr ec, - CORBA::Environment &_env) -{ - // Some application-specific setup code. - - // Store the passed parameters in the object. - this->burst_count_ = burst_count; - this->burst_size_ = burst_size; - this->event_size_ = event_size; - this->burst_pause_ = burst_pause; - this->event_a_ = event_a; - this->event_b_ = event_b; - - // Register operations with the scheduling service. The following steps are - // only necessary for applications that make use of the Event Service's hard - // real-time features. Applications that do not need these features and are - // configured with a null scheduler may skip the following operations on the - // scheduling server. - - // Obtain a reference to the scheduling service. - RtecScheduler::Scheduler_ptr server = - ACE_Scheduler_Factory::server (); - - // Create an RT_Info descriptor for the passed operation name. - RtecScheduler::handle_t rt_info = - server->create (name, _env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Calculate the period at which to supply events. - ACE_Time_Value tv (0, burst_pause); - RtecScheduler::Period_t rate = tv.usec () * 10; - - // Set the information in the RT_Info descriptor. - tv.set (0, 2000); - TimeBase::TimeT time; - ORBSVCS_Time::Time_Value_to_TimeT (time, tv); - server->set (rt_info, - RtecScheduler::VERY_HIGH_CRITICALITY, - time, time, time, - rate, - RtecScheduler::VERY_LOW_IMPORTANCE, - time, - 1, - RtecScheduler::OPERATION, - _env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Now, create a supplier id, and publish the events - // that will be supplied under this id. - - // Create a supplier id from the passed name - this->supplier_id_ = ACE::crc32 (name); - ACE_DEBUG ((LM_DEBUG, "ID for <%s> is %04.4x\n", name, - this->supplier_id_)); - - // Publish the events the supplier provides. - ACE_SupplierQOS_Factory qos; - qos.insert (this->supplier_id_, - event_a, - rt_info, 1); - qos.insert (this->supplier_id_, - event_b, - rt_info, 1); - qos.insert (this->supplier_id_, - ACE_ES_EVENT_SHUTDOWN, - rt_info, 1); - - // And finally, some boiler plate code to connect a supplier - // to the Event Service. This is where the connection is - // actually made. - - // Obtain a reference to the supplier administration object. - RtecEventChannelAdmin::SupplierAdmin_var supplier_admin = - ec->for_suppliers (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Obtain a reference to the consumer proxy object. - this->consumer_proxy_ = - supplier_admin->obtain_push_consumer (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Obtain a reference to this supplier object. - RtecEventComm::PushSupplier_var objref = - this->supplier_._this (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Connect as a supplier of the published events. - this->consumer_proxy_->connect_push_supplier (objref.in (), - qos.get_SupplierQOS (), - _env); - TAO_CHECK_ENV_RETURN_VOID (_env); -} - -</pre> - - -<tr><td> -The following code is derived from the EC_Throughput supplier driver code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Supplier_Driver.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Supplier_Driver.cpp</a> - -<tr><td> -<pre> - -int -ECT_Supplier_Driver::run (int argc, char* argv[]) -{ - // argc/argv are used to initialize the ORB and the options - // for this particular test. Other applications may hard-code - // the ORB options, obtain them from another source, etc. - - TAO_TRY - { - // The use of TAO_TRY macros isolate us from the differences - // between platforms with and without native C++ exceptions. - // This is work in progress and may change in the future! - - // Below is some boiler plate code to initialize the ORB and - // the POA. Notice that applications that connect to the Event - // Channel play the server role in some instances, because - // they receive push() requests (as Consumers) or - // disconnect_push_supplier() requests (as Suppliers). - - // Initialize the ORB reference. - CORBA::ORB_var orb = - CORBA::ORB_init (argc, argv, "", TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Initialize the root POA reference. - CORBA::Object_var poa_object = - orb->resolve_initial_references("RootPOA"); - if (CORBA::is_nil (poa_object.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to initialize the POA.\n"), - 1); - - // Obtain the narrowed root POA reference. - PortableServer::POA_var root_poa = - PortableServer::POA::_narrow (poa_object.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Obtain a reference to the POA manager. - PortableServer::POAManager_var poa_manager = - root_poa->the_POAManager (TAO_TRY_ENV); - TAO_CHECK_ENV; - - - // Now some boiler plate code to obtain a reference to the - // naming service..... - - // Resolve a reference to the naming service. - CORBA::Object_var naming_obj = - orb->resolve_initial_references ("NameService"); - if (CORBA::is_nil (naming_obj.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to get the Naming Service.\n"), - 1); - - // Narrow the naming service reference. - CosNaming::NamingContext_var naming_context = - CosNaming::NamingContext::_narrow (naming_obj.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Use the Naming Service to locate the Scheduling Service and - // use the Scheduler_Factory to keep a global pointer to the - // latter. - - // Initialize the scheduler factory to operate in configuration mode. - if (ACE_Scheduler_Factory::use_config (naming_context.in ()) == -1) - return -1; - - // Use the Naming Service to locate the Event Service.... - - // Set up the event service lookup name. - CosNaming::Name name (1); - name.length (1); - name[0].id = CORBA::string_dup ("EventService"); - - // Resolve a reference to the event service. - CORBA::Object_var ec_obj = - naming_context->resolve (name, TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Narrow the reference to the event service. - RtecEventChannelAdmin::EventChannel_var channel; - if (CORBA::is_nil (ec_obj.in ())) - channel = RtecEventChannelAdmin::EventChannel::_nil (); - else - channel = RtecEventChannelAdmin::EventChannel::_narrow (ec_obj.in (), - TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Activate the POA so we can start receiving requests... - - // Activate the POA manager. - poa_manager->activate (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Connect suppliers to the event service. - this->connect_suppliers (channel.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - ACE_DEBUG ((LM_DEBUG, "connected supplier(s)\n")); - - // Activate the supplier objects - this->activate_suppliers (TAO_TRY_ENV); - TAO_CHECK_ENV; - - ACE_DEBUG ((LM_DEBUG, "suppliers are active\n")); - - // Wait for the supplier threads. - if (ACE_Thread_Manager::instance ()->wait () == -1) - { - ACE_ERROR ((LM_ERROR, "Thread_Manager wait failed\n")); - return 1; - } - - ACE_DEBUG ((LM_DEBUG, "suppliers finished\n")); - - this->dump_results (); - - // Disconnect suppliers from the event service. - this->disconnect_suppliers (TAO_TRY_ENV); - TAO_CHECK_ENV; - } - TAO_CATCH (CORBA::SystemException, sys_ex) - { - TAO_TRY_ENV.print_exception ("SYS_EX"); - } - TAO_CATCHANY - { - TAO_TRY_ENV.print_exception ("NON SYS EX"); - } - TAO_ENDTRY; - return 0; -} - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3><a name="Section5_3">Generating Events</a></h3><P><p> - -<tr><td> -The following code is derived from the EC_Throughput supplier code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp</a> - -<tr><td> -<pre> - -int -Test_Supplier::svc () -{ - TAO_TRY - { - // First, a bunch of code that is specific to this test. - - // Set pause (sleep) value between message bursts. - ACE_Time_Value tv (0, this->burst_pause_); - - // Set up message block for event data. - ACE_Message_Block mb (this->event_size_); - mb.wr_ptr (this->event_size_); - - // Create an event set for one event, initialize event header. - RtecEventComm::EventSet event (1); - event.length (1); - event[0].header.source = this->supplier_id (); - event[0].header.ttl = 1; - - // Set up time stamps in event header. This is for performance - // measurements, so this step can be omitted at will. - ACE_hrtime_t t = ACE_OS::gethrtime (); - ORBSVCS_Time::hrtime_to_TimeT (event[0].header.creation_time, t); - event[0].header.ec_recv_time = ORBSVCS_Time::zero; - event[0].header.ec_send_time = ORBSVCS_Time::zero; - - // Initialize data fields in event. - event[0].data.x = 0; - event[0].data.y = 0; - - // We use replace to minimize the copies. This should result - // in just one memory allocation; - event[0].data.payload.replace (this->event_size_, - &mb); - - // This is where the events are actually pushed into - // the event channel. The test pushes bursts of events, - // pausing a specified interval between bursts. - - // Start the timer, and begin pushing events. - this->timer_.start (); - for (int i = 0; i < this->burst_count_; ++i) - { - // Send a burst of events. - for (int j = 0; j < this->burst_size_; ++j) - { - if (j % 2 == 0) - event[0].header.type = this->event_a_; - else - event[0].header.type = this->event_b_; - - // ACE_DEBUG ((LM_DEBUG, "(%t) supplier push event\n")); - this->consumer_proxy ()->push (event, TAO_TRY_ENV); - - TAO_CHECK_ENV; - } - - // Sleep until it's time to send the next burst. - ACE_OS::sleep (tv); - } - - // Send a "magic" type of event to inform the consumer that we are - // not sending anything else... - - // Send one event shutdown from each supplier - event[0].header.type = ACE_ES_EVENT_SHUTDOWN; - this->consumer_proxy ()->push(event, TAO_TRY_ENV); - TAO_CHECK_ENV; - this->timer_.stop (); - - } - TAO_CATCH (CORBA::SystemException, sys_ex) - { - TAO_TRY_ENV.print_exception ("SYS_EX"); - } - TAO_CATCHANY - { - TAO_TRY_ENV.print_exception ("NON SYS EX"); - } - TAO_ENDTRY; - return 0; -} - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<td> -<h3><a name="Section5_4">Disconnecting Suppliers from the Event Channel</a></h3><P> -<p> - -<tr><td> -The following code is derived from the EC_Throughput supplier code, which -can be found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp"> -$TAO_ROOT/orbsvcs/tests/EC_Throughput/ECT_Supplier.cpp</a> - - -<tr><td> -<pre> - -void -Test_Supplier::disconnect (CORBA::Environment &_env) -{ - // Make sure the consumer proxy reference is valid. - if (CORBA::is_nil (this->consumer_proxy_.in ())) - return; - - // Disconnect communication with the push consumer(s). - this->consumer_proxy_->disconnect_push_consumer (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - - // Mark the consumer proxy reference invalid. - this->consumer_proxy_ = - RtecEventChannelAdmin::ProxyPushConsumer::_nil (); - - // We need to stop accepting disconnect_push_supplier () requests - // for this supplier, before it is safe to destroy the supplier. - // As required by the CORBA spec, you must explicitly deactivate - // a servant before destroying it. - - // Deactivate the servant - PortableServer::POA_var poa = - this->supplier_._default_POA (_env); - TAO_CHECK_ENV_RETURN_VOID (_env); - PortableServer::ObjectId_var id = - poa->servant_to_id (&this->supplier_, _env); - TAO_CHECK_ENV_RETURN_VOID (_env); - poa->deactivate_object (id.in (), _env); - TAO_CHECK_ENV_RETURN_VOID (_env); - RtecEventChannelAdmin::ProxyPushConsumer::_nil (); -} - -</pre> - -</table> -</center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<td> -<h2><a name="Section6">Caring for your Event Channel</a></h2> - - -<BR> - -<ul> - <li> <a href="events_tutorial.html#Section6_1">Creation and Name Service Registration</a> - <li> <a href="events_tutorial.html#Section6_2">Register Suppliers Before Consumers</a> -</ul> -</table> -</center> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3><a name="Section6_1">Creation and Name Service Registration</a><h3><p> - -<tr><td> -The following code is derived from the Event_Service executable, which can be -found in TAO in the file: -<A HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/Event_Service/Event_Service.cpp"> -$TAO_ROOT/orbsvcs/Event_Service/Event_Service.cpp</a> - -<tr><td> -<pre> - -int main (int argc, char *argv[]) -{ - TAO_TRY - { - // argc/argv are used to initialize the ORB and the options - // for the Event Service executable. Other applications may - // hard code the ORB options, obtain them from another source, etc. - - // Again the boiler plate code for ORB and POA initialization. - - // Initialize ORB. - CORBA::ORB_var orb = - CORBA::ORB_init (argc, argv, "internet", TAO_TRY_ENV); - TAO_CHECK_ENV; - - if (parse_args (argc, argv) == -1) - return 1; - - CORBA::Object_var poa_object = - orb->resolve_initial_references("RootPOA"); - if (CORBA::is_nil (poa_object.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to initialize the POA.\n"), - 1); - - PortableServer::POA_var root_poa = - PortableServer::POA::_narrow (poa_object.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - PortableServer::POAManager_var poa_manager = - root_poa->the_POAManager (TAO_TRY_ENV); - TAO_CHECK_ENV; - - CORBA::Object_var naming_obj = - orb->resolve_initial_references ("NameService"); - if (CORBA::is_nil (naming_obj.in ())) - ACE_ERROR_RETURN ((LM_ERROR, - " (%P|%t) Unable to initialize the Naming Service.\n"), - 1); - - CosNaming::NamingContext_var naming_context = - CosNaming::NamingContext::_narrow (naming_obj.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Notice the use of auto_ptr<> to automagically manage the - // destruction of the servant. When the auto_ptr goes out - // of scope, its destructor is called, which in turn destroys - // the servant. - - auto_ptr<POA_RtecScheduler::Scheduler> scheduler_impl; - RtecScheduler::Scheduler_var scheduler; - - - // Create a new servant to implement the Scheduling Service, - // register it with the Naming Service, and use the - // Scheduler_Factory to keep a global pointer to the new - // Scheduling Service. - - // This is the name we (potentially) use to register the Scheduling - // Service in the Naming Service. - CosNaming::Name schedule_name (1); - schedule_name.length (1); - schedule_name[0].id = CORBA::string_dup ("ScheduleService"); - - if (global_scheduler == 0) - { - scheduler_impl = - auto_ptr<POA_RtecScheduler::Scheduler>(new ACE_Config_Scheduler); - if (scheduler_impl.get () == 0) - return 1; - scheduler = scheduler_impl->_this (TAO_TRY_ENV); - TAO_CHECK_ENV; - - CORBA::String_var str = - orb->object_to_string (scheduler.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - ACE_DEBUG ((LM_DEBUG, "The (local) scheduler IOR is <%s>\n", - str.in ())); - - // Register the servant with the Naming Context.... - naming_context->bind (schedule_name, scheduler.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - } - - ACE_Scheduler_Factory::use_config (naming_context.in ()); - - // The Event Service can be configured to support priority based - // dispatching (the "default_Module_Factory") or best effort (the - // "Reactive_Module_Factory"). We pick the right module factory - // according to the command line options processed above. - - TAO_Default_Module_Factory default_module_factory; - TAO_Reactive_Module_Factory reactive_module_factory; - - TAO_Module_Factory* module_factory = &default_module_factory; - if (reactive) - module_factory = &reactive_module_factory; - - // Now, create a new event channel servant to implement the - // Event Service, and register it with Naming Service. - - // Construct the event channel using the given module factory. - ACE_EventChannel ec_impl (1, - ACE_DEFAULT_EVENT_CHANNEL_TYPE, - module_factory); - - // Obtain an object reference to the new channel. - RtecEventChannelAdmin::EventChannel_var ec = - ec_impl._this (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Convert the EC object reference to a string. - CORBA::String_var str = - orb->object_to_string (ec.in (), TAO_TRY_ENV); - - // Output the EC object reference string (debug only). - ACE_DEBUG ((LM_DEBUG, - "The EC IOR is <%s>\n", str.in ())); - - // Register the EC with the Naming Service. - CosNaming::Name channel_name (1); - channel_name.length (1); - channel_name[0].id = CORBA::string_dup (service_name); - naming_context->bind (channel_name, ec.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Activate the POA so we can start receiving requests... - - // Activate the POA manager. - poa_manager->activate (TAO_TRY_ENV); - TAO_CHECK_ENV; - - // Run the ORB event loop - ACE_DEBUG ((LM_DEBUG, "%s; running event service\n", __FILE__)); - if (orb->run () == -1) - ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "run"), 1); - - // Now the Event Service is finished. We could deactivate the - // EC and SS here, but we don't need to, as the server is - // going down anyway. - - - // Remove the event service and the scheduling service from - // the Naming Service. - - naming_context->unbind (channel_name, TAO_TRY_ENV); - TAO_CHECK_ENV; - - if (global_scheduler == 0) - { - naming_context->unbind (schedule_name, TAO_TRY_ENV); - TAO_CHECK_ENV; - } - - } - TAO_CATCHANY - { - TAO_TRY_ENV.print_exception ("EC"); - } - TAO_ENDTRY; - - - return 0; -} - -</pre> -</table> -</center> - -<P><hr width="75%"><P> <!-- intra-section separator --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<h3><a name="Section6_2">Register Suppliers before Consumers</a></h3><p> -<BR> -<BR> -<tr><td> -<center> -<IMG SRC="http://www.cs.wustl.edu/~schmidt/gifs/ec_registration.gif"> -</center> -</table></center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<h2><a name="Section7">Sample Applications</a></h2> - -<tr><td> -A number of sample applications are available in the directories under -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/"> -TAO's ORB Services tests</a>. - -<tr><td> -In particular, much of the code shown in this tutorial was drawn from the -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Throughput/"> -EC_Throughput</a> test. This test exercises the Event Service and measures its -throughput capabilities. - -<tr><td> -A similar test, -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/Event_Latency/"> -Event_Latency</a>, measures the latency of events through the Event Service. - -<tr><td> -The -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Basic/"> -EC_Basic</a> test demonstrates the basic use the Event Service. - -<tr><td> -The -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/tests/EC_Multiple/"> -EC_Multiple</a> test shows a number of ways to connect multiple Event Channels. - - -<tr><td> -For the IDL source for the various interfaces, please see -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/orbsvcs/RtecScheduler.idl">RtecScheduler.idl</a>, -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/orbsvcs/CosEventChannelAdmin.idl">CosEventChannelAdmin.idl</a>, -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/orbsvcs/CosEventComm.idl">CosEventComm.idl</a> -and -<a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/orbsvcs/orbsvcs/CosNaming.idl">CosNaming.idl</a>. - - -</table> -</center> - -<P><HR><P> -<!-- ************************************************************ --> - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -<h2><a name="Section8">Reference Materials</a></h2> - -<tr><td> -The following materials were used in developing this tutorial: please refer to them for further information. - -<tr><td> -<br> -<tr><td> -<h3>Books</h3> - -<tr><td> -Mowbray, T. and Zahavi, R. The Essential CORBA, Systems Integration Using Distributed Objects. Wiley, 1995. -ISBN 0-471-10611-9 - -<tr><td> -<br> - -<tr><td> -Baker, S. CORBA Distributed Objects Using Orbix. Addison-Wesley, 1997. ISBN 0-201-92475-7 - -<tr><td> -<br> -<tr><td> -<h3>Papers</h3> - -<tr><td> -<ul> - -<li><a href="http://www.cs.wustl.edu/~schmidt/Arch.ps.gz"> -Architectural Considerations for Deterministic Real-Time ORB -Endsystems and Applications</a> - -<li><a href="http://www.cs.wustl.edu/~schmidt/JSAC-98.ps.gz"> The -Design and Performance of a Real-Time CORBA Object Event Service</a> - -<li><a href="http://www.cs.wustl.edu/~schmidt/RT-ORB.ps.gz"> The -Design of the TAO Real-Time Object Request Broker</a> - -</ul> - - -<tr><td> - -</table> -</center> - -<P><HR><P> -<!-- ************************************************************ --> - - -<center><table cellpadding=1 border=0 cellspacing=4> -<tr><td> -Last modified 10:50:30 CST 22 December 1998 by Chris Gill -</table></center> - -</body></html> - diff --git a/TAO/docs/exceptions.html b/TAO/docs/exceptions.html deleted file mode 100644 index 8999b2f4aba..00000000000 --- a/TAO/docs/exceptions.html +++ /dev/null @@ -1,22 +0,0 @@ -<!DOCTYPE HTML SYSTEM -"http://www.w3.org/pub/WWW/MarkUp/Cougar/Cougar.dtd"> -<!-- $Id$ --> -<html> <head> -<title>Exception handling</title> -</head> - -<body> -<h1>Exception Handling</h1> - -Since the exception handling macros in TAO can be used with any ORB, -it has been generalized and moved to ACE. - -<h3>Notice that ACE's try macros are now prefered over the original -TAO try macros. You should avoid using them in your applications. -They might be removed completely one day.</h3> - -The new document about exception handling has been moved to -<a href="../../docs/exceptions.html">here</a>. - -<!--#include virtual="/~schmidt/cgi-sig.html" --> -</body></HTML> diff --git a/TAO/docs/forwarding.html b/TAO/docs/forwarding.html deleted file mode 100644 index 16b3406a733..00000000000 --- a/TAO/docs/forwarding.html +++ /dev/null @@ -1,111 +0,0 @@ -<html> - <!-- $Id$ --> - <head> - <title>Implementation of location forwarding</title> - </head> - - <BODY text = "#000000" - link="#0000ff" - vlink="#cc0000" - bgcolor="#ffffff"> - - <body> - <HR> - <h1>Location forwarding</h1> - <HR> - <h2>Context</h2> - The motivation to support location forwarding for objects is - to allow objects to move or forward certain requests to other objects. - Moving of objects is very important for the Common Object Services - LifeCycle Service. An objet complying to the LifeCycleObject interface, - defined by the LifeCycle Service should support the move operation. The move - operation allows the client to keep its object reference to the object, - but the object is going to be relocated on the same or a different server. - Making location forwarding transparent to the client is the most important - issue. - - <h2>Communication between server and client</h2> - GIOP defines a message named "LOCATION_FORWARD", which should be used to - inform the client stub, that the object has been moved. The message body - has to contain an object reference to the new location of the forwarded - object. - - - <h2>Server side implementation</h2> - Two approaches are possible, one is that the POA replaces the object with - a forwarding servant, which knows the new location. This servant will then - raise an exception each it time it is called, as supposed to be the - actual object. The exception will be a user exception and will be caught - in the marshalling code of the server request "IIOP_ServerRequest". The involved - methods are "set_exception", "marshall" and "init_reply". "set_exception" will - check the user exceptions for the special one, only raised by the forwarding - servant and will extract the new location. "init_reply" will then create - the proper GIOP Reply message with the message type set to LOCATION_FORWARD. - The message is encoded into a CDR (Common Data Representation) stream. - - The second approach is to use a POA servant locator for the child POA, where - the object resides on. The servant locator will be used each time the object - will be accessed. Basically two methods, named "preinvoke" and "postinvoke" - are called each time before and after the actual upcall to the object. - Forwarding using the servant locator works in the following way. The object - tells its servant locator that it has moved and supports the servant locator - with the new object reference. The object locator then raises a special system - exception "forward_request" in "preinvoke" each time the object is called from now on. - The exception is then caught by the lowest possible level, when the - system exceptions are going to be marshalled. Which is in "TAO_Server_Connection_Handler", - the involved methods are "handle_input" and "send_error". "handle_input" - checks for errors (involving exceptions) and calls "send_error" to create - the proper GIOP Reply containing either the system exception or - the location forwarding in case the system exception was the - "forward_request" exception. - - <h2>Client side implementation</h2> - The client has to expect the location forwarding GIOP message and should - respond to it in setting the IIOP_Profile of its IIOP_Object right. - The IIOP_Object is a low level object, to which CORBA::Object has a - pointer to. The reply type is determined by "TAO_GIOP_Invocation::invoke" - which then calls "TAO_GIOP_Invocation::location_forward". "location_forward" - sets the changes the IIOP_Profile of the object. The call is then - reissued by "TAO_IIOP_Object::do_static_call". - - - <h2>Conclusion</h2> - Changing the IIOP_Profile is transparent to the client. So the - client gets no idea, that the object now resides somewhere else. - - The result of the above mentioned solution is that - if an object moves the client will notice it with the next call to the - object. If the object moves again, the original location is not - bothered at all again. Say if the original location was A, then - it moved to B and finally to C. First location A responeded with - a GIOP Location Forward to the client, then B gets used and finally - after moving the object to C, B will send a GIOP Location - Forward and location C gets used. - - There is "no" concept of a home location. If the object moves - very often and old servers die it might be a problem, because - clients, which did not call on the object lately will not know - where to search. Though in the situation of a home location, there - is also the risk that this server might die and the object - is not reachable any more. - - <h2>Optimization</h2> - In the case, when the object moves several times, a chain - of forwarding servers is created. But this chain might be - easily disturbed by just one server failing. A good idea - is to give the servant locator more intelligence to - tell all the oter/previous servers where the object is now. - This will of course increase the communication overhead - in the case of a move, but we get a high reliability - against dying hosts. - - <HR> - For more details and questions, - <p> - - <address><a href="mailto:mk1@cs.wustl.edu">Michael Kircher</a></address> - <p> - <address><a href="mailto:irfan1@cs.wustl.edu">Irfan Pyarali</a></address> - </body> -</html> - diff --git a/TAO/docs/implrepo.html b/TAO/docs/implrepo.html deleted file mode 100644 index 8263bff6d4c..00000000000 --- a/TAO/docs/implrepo.html +++ /dev/null @@ -1,12 +0,0 @@ -<HTML> -<!-- $Id$ --> -<HEAD> -<TITLE>IR docs have moved</TITLE> -<META HTTP-EQUIV="Refresh" CONTENT="1; URL=implrepo/index.html"> -</HEAD> -<BODY> -<P>The IR docs have moved to <A HREF="implrepo/index.html">here</A>.</P> -<P>This page should automatically redirect you there, if not, click on -the link above.</P> -</BODY> -</HTML>
\ No newline at end of file diff --git a/TAO/docs/implrepo/index.html b/TAO/docs/implrepo/index.html deleted file mode 100644 index 03def3ac7e2..00000000000 --- a/TAO/docs/implrepo/index.html +++ /dev/null @@ -1,73 +0,0 @@ -<html> - -<head> -<meta http-equiv="Content-Type" -content="text/html; charset=iso-8859-1"> -<meta name="GENERATOR" content="Microsoft FrontPage Express 2.0"> -<title>Implementation Repository</title> -<!-- $Id$ --> -</head> - -<body bgcolor="#FFFFFF" text="#000000"> - -<hr> - -<h2>Impementation Repository</h2> - -<p>The Implementation Repository (often shortened to IR or -ImplRepo) in TAO is an activation/reactivation service. Its -purpose is to maintain a registry of servers so that it can -restart servers upond demand. The IR redirect requests from -clients to the correct server so that servers can shutdown and -restart without sacrificing the functionality of persistent IORs. -Our work has been largely based on an excellent paper by <a -href="http://www.triodia.com/staff/michi-henning.html">Michi -Henning</a>, <a -href="http://www.triodia.com/staff/michi/cacm.pdf">Binding, -Migration, and Scalability in CORBA</a>. </p> - -<hr> - -<h3>Other IR Documents</h3> - -<DL> -<DT> <img alt="o" src="http://www.cs.wustl.edu/~schmidt/gifs/misc/redball.gif"> -<a href="status.html">Status Page</a> - This page details a -checklist of short-term and long-term goals for the development -of the IR. <P> - -<DT> <img alt="o" src="http://www.cs.wustl.edu/~schmidt/gifs/misc/redball.gif"> -<a href="usersguide.html">Users Guide</a> - Overall documentation on - how to use the IR in your programs. <P> - -<DT> <img alt="o" src="http://www.cs.wustl.edu/~schmidt/gifs/misc/redball.gif"> -<a href="paper.html">The Paper</a> - A paper that has a -general description of the IR. This is also where to look to -find information on the inner working of the IR. <P> - -<DT> <img alt="o" src="http://www.cs.wustl.edu/~schmidt/gifs/misc/redball.gif"> -<a href="http://tao.cs.wustl.edu/~brunsch/implrepo.html">Discussion -Page</a> - Notes that I've made while working on the -IR. -</DL> - -<hr> - -<h3>Who's Responsible?</h3> - -<p>The person responsible is Darrell Brunsch <<a -href="mailto:brunsch@cs.wustl.edu">brunsch@cs.wustl.edu</a>>. -You can reach me by either email, through the <a -href="http://www.cs.wustl.edu/~schmidt/ACE-mail.html">ACE mailing -list</a> <<a href="mailto:ace-useres@cs.wustl.edu">ace-users@cs.wustl.edu</a>>, -or through the <a href="news:comp.soft-sys.ace">comp.soft-sys.ace</a> -newsgroup. The newsgroup mirrors the mailing list, but not the -other way. Also, if you use the mailing list, it is best if you -join it before sending a question, since responses are usually -just replied back to the group.</p> - -<hr> - -<p>Back to the <a href="../index.html">TAO Documentation</a>.</p> -</body> -</html> diff --git a/TAO/docs/implrepo/paper.html b/TAO/docs/implrepo/paper.html deleted file mode 100644 index 22f8e233512..00000000000 --- a/TAO/docs/implrepo/paper.html +++ /dev/null @@ -1,820 +0,0 @@ -<html> - -<head> -<meta http-equiv="Content-Type" -content="text/html; charset=iso-8859-1"> -<meta name="GENERATOR" content="Microsoft FrontPage Express 2.0"> -<title>TAO Implementation Repository</title> -<!-- $Id$ --> -</head> - -<body bgcolor="#FFFFFF" text="#000000" link="#0000FF" -vlink="#CC0000"> - -<hr> - -<h1>TAO Implementation Repository </h1> - -<p>Revision 3.05</p> - -<hr> - -<h2>Table of Contents</h2> - -<ul> - <li><a href="#Changes">Recent Changes</a> </li> - <li><a href="#Overview">Overview</a> <ul> - <li><a href="#PersistentandTransientIORs">Persistent - and Transient IORs</a> </li> - <li><a href="#TheImplementationRepository">The - Implementation Repository</a> </li> - </ul> - </li> - <li><a href="#TAOsImplementationRepository">TAO's - Implementation Repository</a> <ul> - <li><a href="#VirtualServers">Virtual Servers</a> </li> - <li><a href="#PingObject">Ping Object</a></li> - <li><a href="#NewIORs">New IORs</a> <ul> - <li><a href="#WhatwaswrongwiththeoldIOR">What - was wrong with the old IOR?</a> </li> - <li><a href="#WhydoesImplRepocontainanOBJKey">Why - does the Implementation Repository - profile contain an Object Key?</a> </li> - </ul> - </li> - <li><a href="#POAExtensions">POA Extensions</a> </li> - <li><a href="#PossibleFutureGoals">Possible Future - Goals</a> </li> - <li><a href="#ServerRestrictions">Server Restrictions</a> - </li> - <li><a href="#PreliminaryInterface">Preliminary - Interface</a> </li> - </ul> - </li> - <li><a href="#AlternateImplementations">Alternate - Implementations</a> </li> - <li><a href="#AccessingtheImplementationRepository">Accessing - the Implementation Repository</a> <ul> - <li><a href="#HelperApplication">Helper Application</a> - </li> - <li><a href="#LocatinganinstanceofImplRepo">Locating - an instance of the Implementation Repository</a> <ul> - <li><a href="#Serverside">Server Side</a> </li> - <li><a href="#Clientside">Client Side</a> </li> - </ul> - </li> - </ul> - </li> - <li><a href="#Howitworks">How It Works</a> <ul> - <li><a href="#HowServerProducesPersistentIORdefault">How - a server produces a Persistent IOR (in the - default case)</a> </li> - <li><a href="#HowServerProducesPersistentIORcomplex">How - a server produces a Persistent IOR (in the - complex case)</a> </li> - <li><a href="#HowClientUsesPersistentIOR">How a - client uses a Persistent IOR</a> </li> - </ul> - </li> -</ul> - -<hr> - -<h2><a name="Changes">Recent Changes</a></h2> - -<p>Since 3.04</p> - -<ul> - <li>Moved it to the same directory as all the new</li> - <li>After a long delay (too long, if you ask me) addressed - the comments that John Mulhern <<a - href="mailto:9107@mn3.lawson.lawson.com">9107@mn3.lawson.lawson.com</a>> - sent me. </li> -</ul> - -<p>Since 3.03 </p> - -<ul> - <li>Added information on the new POA policy where the format - of the persistent IOR can be changed from that of both - the last-known-server-IOR and Implementation Repository - to that just of the Implementation Repository</li> - <li>TAO is now fork-safe, with the introduction of the - CLOEXEC flag through ACE_CLOEXEC.</li> -</ul> - -<p>Since 3.02 </p> - -<ul> - <li>Added a section to give more detailed information on how - Ping Objects work.</li> - <li>Rewrote the Virtual Server section</li> -</ul> - -<hr> - -<h2><a name="Overview">Overview</a></h2> - -<p>This document describes the proposed design of the TAO -Implementation Repository, which was originally known as the -reactivator/activation service. If you have any questions or -comments on our design, please post them to the <a -href="http://www.cs.wustl.edu/~schmidt/ACE-mail.html">ACE</a> -mailing list <<a href="mailto:ace-useres@cs.wustl.edu">ace-users@cs.wustl.edu</a>> -or send email to Darrell Brunsch <<a -href="mailto:brunsch@cs.wustl.edu">brunsch@cs.wustl.edu</a>>.</p> - -<h3><a name="PersistentandTransientIORs">Persistent and Transient -IORs</a></h3> - -<p>CORBA defines two types of object references: <a -href="http://www.cs.wustl.edu/~schmidt/C++-report-col12.ps.gz">persistent -and transient</a>. The difference between the two stems from the -lifetime of the reference in relation to the lifetime of the -server process that created it. The lifetime of a transient -object reference is limited to the lifetime of its server -process. Once the server process exits the transient object -reference no longer exists. All references to this object should -now be invalid, even if the server is restarted. In contrast, -persistent object references can outlive their originating server -process. Therefore, the server can exit and be restarted without -invalidating its persistent object references. This enables the -implementation of features like automatic server activation and -object migration.</p> - -<p>Note that both persistent and transient object references can -refer to objects that reside in <em>manually activated</em> -servers, <em>i.e.</em>, the so-called ``persistent servers.'' A -persistent server is a server that is launched manually, <em>i.e.</em>, -it is always running. A persistent server can generate transient -references and/or persistent references. </p> - -<p>Developers should be aware that persistence of the object -reference does not imply any persistence on the object -implementation state. It is certainly possible to provide -persistent object references for objects whose state is not -persistent. Therefore, servant implementors are responsible for -preserving the state of their servants, <em>e.g.</em>, using a -database or file. </p> - -<h3><a name="TheImplementationRepository">The Implementation -Repository</a></h3> - -<p>According to the CORBA specification, "The Implementation -Repository contains information that allows the ORB to locate and -activate implementations of objects" [CORBA Spec Rev. 2.2: -2.1.14] In earlier revisions of the specification, there was a -method <code>get_implementation</code> in the CORBA Object -interface. This has been deprecated as of the CORBA 2.2 -specification, leaving both the interface and implementation of -the Implementation Repository to the ORB vendor.</p> - -<p>A good paper describing the functionality of the CORBA -Implementation Repository is "<a -href="http://www.triodia.com/staff/michi/cacm.pdf">Binding, -Migration, and Scalability in CORBA</a>" [Michi Henning]. -This paper describes the following three functions of the -Implementation Repository: </p> - -<ol> - <li>Maintain a registry of known servers.</li> - <li>Record which server is currently running, and which port - and host it uses.</li> - <li>Starts servers on demand if they are registered with the - Implementation Repository.</li> -</ol> - -<p>The TAO Implementation Repository is based on the design in -this paper. He also wrote an earlier <a -href="http://www.triodia.com/staff/michi/binding.txt">email</a> -that may be useful to see the issues involved. The next section -details our goals and plans for the implementation.</p> - -<hr> - -<h2><a name="TAOsImplementationRepository">TAO's Implementation -Repository</a></h2> - -<p>The following is an brief outline of TAO'S Implementation -Repository. </p> - -<ul> - <li>Use of TAO's Implementation Repository will be optional. - Real-time applications can choose not to use the - Implementation Repository according to their - performance/predictability/footprint requirements.</li> - <li>Use of TAO's Implementation Repository will be invisible - to clients and servers for common use-case. For more - complicated behavior, programs can use Implementation - Repository extensions of the POA.</li> - <li>TAO's Implementation Repository will work with any CORBA - client that supports <code>LOCATION_FORWARD</code> IIOP - messages and multiple profiles in IORs, even if the - client is not implemented using TAO.</li> - <li>TAO's Implementation Repository will know if one of the - servers registered with it is running by the use of a - "ping"-like service in the server. This service - allows the Implementation Repository to know when it - should restart the server.</li> - <li>TAO will be fork-safe. Since there will be an open - connection to the client while the server is restarted - (via fork or CreateProcess) then care will be needed to - make sure that the open sockets will be closed in the - client process. The addition of CLOEXEC feature to TAO - will cover this problem.</li> - <li>TAO will exploit features of IIOP 1.1 to safely and - efficiently verify if an IOR was generated by TAO itself - on the client side. The server will still determine this - through the object key, since that is all that is passed - in a request.</li> - <li>TAO will support multiple profiles in IORs. A profile - contains the host/port and object key of a CORBA Object. - An optimization that will be possible is to have a last - known profile of the object as the first profile and an - Implementation Repository as the second profile in an - IOR. The client will first try the object to see if it - still active at the host/port before it contacts the - Implementation Repository. This strategy will reduce - latency. </li> -</ul> - -<h3><a name="VirtualServers">Virtual Servers</a></h3> - -<p>TAO's Implementation Repository must keep track of whether an -object's implementation is currently running or is stopped. To -have a record for every object would require too much overhead, -but having a record for every executable server would be -inflexible and prevent the migration of objects. In the Henning -paper, he mentions the use of a <em>server name</em> as the index -for the table maintained by the Implementation Repository. </p> - -<p>A virtual server does not refer to the executable but instead -to a group of objects. An executable may have one or more virtual -servers within it. This allows one virtual server to be moved off -the executable to another executable (for instance, onto another -machine) without affecting the objects in other virtual servers -on the original executable. </p> - -<p>Each virtual server will be indexed in the Implementation -Repository by a name that is given to it by the user. It is the -users responsibility to make sure that each virtual server name -is unique. By default, this name is the name of the executable -(since by default there is only one virtual server per -executable). However, this default behavior can be overridden. </p> - -<h3><a name="PingObject">Ping Object</a></h3> - -<p>Ping objects are simple objects that reside in the server, one -for every virtual server. It is contacted by the Implementation -Repository to determine if the virtual server is still running -and responding. At certain intervals the Implementation -Repository will invoke a one-way method on the ping object, and -then will expect a "pong" message to be sent back. -Different strategies for pinging (which will depend on a TAO -option) will be used by the implementation repository. If a -server is expected to be responsive, the Implementation -Repository will not wait long for a response before considering -the server to be gone. Other servers may be -computationally-intensive and need to be held under less -stringent expectations.</p> - -<p>We chose the ping method to be a one-way (instead of two-way) -because if the server became unresponsive, it would not return -from the method invocation. The Implementation Repository needs -some form of a timeout with the ping to be able to determine if -the server is unresponsive or not.</p> - -<h3><a name="NewIORs">New IORs</a></h3> - -<p>Standard CORBA IORs contain the following two sections:</p> - -<table border="1"> - <tr> - <td>Type ID</td> - <td>Sequence of Tagged Profiles</td> - </tr> -</table> - -<p>The Type ID is an indicator for the most derived type known at -the time of the reference creation. It is used as a hint for the -client in determining what interfaces the object can support. The -Sequence of Tagged Profiles consist of one or more profiles that -encapsulate information used by the associated protocol in order -to communicate with the object (host, port, object id, etc.).</p> - -<p>Currently, TAO uses only one IIOP 1.0 Tagged Profile, which is -defined as follows:</p> - -<table border="1"> - <tr> - <td>Version</td> - <td>Host</td> - <td>Port</td> - <td>Object Key</td> - </tr> -</table> - -<table border="0"> - <tr> - <td>Object Key: </td> - <td><table border="1"> - <tr> - <td>Transient/Persistent Flag</td> - <td>TimeStamp</td> - <td>POA ID</td> - <td>OBJ ID</td> - </tr> - </table> - </td> - </tr> -</table> - -<p>To accomodate the Implementation Repository and IIOP 1.1, the -Profile was changed according to the CORBA specification as -follows:</p> - -<table border="1"> - <tr> - <td>Version</td> - <td>Host</td> - <td>Port</td> - <td>Object Key</td> - <td>Components</td> - </tr> -</table> - -<table border="0"> - <tr> - <td>Object Key: </td> - <td><table border="1"> - <tr> - <td>TAO</td> - <td>TAO version</td> - <td>TimeStamp/Server Name</td> - <td>POA ID</td> - <td>OBJ ID</td> - </tr> - </table> - </td> - </tr> -</table> - -<p>The two main changes is the addition of the Components field -(which is a IIOP 1.1 thing) and the addition of TAO with its -version. Transient object references will still have a TimeStamp -to ensure uniqueness, but persistent object references will have -a server name to identify themselves to the Implementation -Repository. </p> - -<p>For servers that move around or need to be restarted often, -the IOR will contain a reference to the Implementation Repository -with the object key of the server and the server name imbedded. - Once the client contacts the Implementation Repository, it -will be forwarded to the correct object. This IOR will look like -the following:</p> - -<table border="1"> - <tr> - <td>Version</td> - <td>Host</td> - <td>Port</td> - <td>Object Key</td> - <td>Components</td> - </tr> -</table> - -<table border="0"> - <tr> - <td>Object Key: </td> - <td><table border="1"> - <tr> - <td>TAO</td> - <td>TAO version</td> - <td>Server Name</td> - <td>POA ID</td> - <td>OBJ ID (actually the OBJ Key of the Server)</td> - </tr> - </table> - </td> - </tr> -</table> - -<p>For servers that expect to remain in the same host/port for a -long time, the above IOR can be optimized by placing the server -profile in the IOR before the Implementation Repository -profile. TAO clients will first try the server, and if that -fails, then try the Implementation Repository. Clients from -other ORBs may behave the same way, but this isn't guaranteed -since the handling of multiple profiles is not yet in the CORBA -spec. There will be an option to only generate the IR-only IORs -for ORBs that do not support multiple profiles in the needed -manner. </p> - -<p>There will be a POA policy to determine which type of -Persistent IOR to use. By default, the Implementation -Repository alone version will be used.</p> - -<h4><a name="WhatwaswrongwiththeoldIOR">What was wrong with the -old IOR?</a></h4> - -<p>We need a place to put a TAO marker in the IOR so TAO servers -can differentiate TAO IORs from IORs of other vendors. In the -original scheme used in TAO, Persistent IORs had a null -timestamp. To support virtual servers, we will use that slot to -store the server name so the Implementation Repository knows -which server to launch.</p> - -<h4><a name="WhydoesImplRepocontainanOBJKey">Why does the -Implementation Repository profile contain an Object Key?</a></h4> - -<p>It needs to know what the object key of the object when -forwarding is used. A server may contain more than one object, so -the object key is needed to forward to the correct object on the -server. </p> - -<h3><a name="POAExtensions">POA Extensions</a></h3> - -<p>TAO's POA will contain a new TAO-specific method called <code>create_reference_with_virtual_server[_and_id] -(...)</code>. This method takes additional arguments for a -virtual server name and a sequence of Implementation Repository -IORs. The POA will register the virtual server name with each of -the Implementation Repositories in the sequence passed in. -Several Implementation Repositories can be specified to enhance -availability through redundancy. </p> - -<p>TAO's POA will also contain a policy for the type of IOR -created with <code>create_reference</code>. It can either -produce the standard type, with just a reference to the -Implementation Repository, or it can produce one also containing -a reference to the current server.</p> - -<h3><a name="PossibleFutureGoals">Possible Future Goals</a></h3> - -<p>The following are features that may be added to support TAO's -Implementation Repository: </p> - -<ul> - <li>Optimization on TAO clients to recognize when a server is - restarted, and change all other IORs that contain the - server instead of going through the Implementation - Repository</li> - <li>Some sort of server security that checks the executable - to make sure it is the correct executable (checksum, - signatures, etc).</li> - <li>Add the ability to put servers into DLLs or Shared Object - files so the Implementation Repository can load it via - those methods.</li> - <li>GUI interface for such things as the helper application.</li> - <li>Federations of Implementation Repositories.</li> - <li>The ability to start a remote server (possibly with rsh, - ssh, rexec, etc)</li> -</ul> - -<h3><a name="ServerRestrictions">Server Restrictions</a></h3> - -<p>Most often servers that have Persistent IORs will save their -state to secondary storage. Databases are a good example of this, -where the server can be stopped and restarted with all the -information remaining on disk. </p> - -<p>The server must also make sure it creates the POA and Object -in a way that does not change the POA ID and Object ID. The -Implementation Repository forwards requests based on the -information in the IOR; if the POA ID or Object ID changes, then -the Implementation Repository will be unable to sucessfully -forward requests. If the server implements dynamic servants and -dynamic POA activations, then this is not an issue since the -necessary POAs and servants will be created on demand.</p> - -<h3><a name="PreliminaryInterface">Preliminary Interface</a></h3> - -<p>The following is a proposed IDL interface for the TAO -Implementation Repository: </p> - -<pre>module TAO -{ - // .... - - exception Already_Registered {}; - // Object already bound in the Implementation Repository - - exception Cannot_Activate - { - string reason_; - }; - - exception Not_Found {}; - // Object not found in the Implementation Repository - - struct Environment_Variable - { - string name_; - string value_; - }; - // One environment variable - - struct INET_Addr - { - unsigned short port_; - unsigned long host_; - }; - // The location of a server - - typedef sequence<Environment_Variable> Environment; - // Complete environment - - typedef sequence<string> Command_Line_Options; - // Command line options - - struct Process_Options - { - string executable_name_; - // Executable name - - Command_Line_Options command_line_options_; - // Command line options - - Environment environment_; - // Environment - - string working_directory_; - // Working directory - - unsigned long creation_flags_; - // Creation flags - }; - - interface Ping_Object - { - oneway void ping (); - // Used for checking for liveness of a server. When the server receives - // this, it should send back a response indicating it is sill alive. - // Depending on the policy specified, a timeout can be reached where the - // Implementation Repository will restart the server. - }; - - interface Implementation_Repository - { - Object activate_object (in Object obj) - raises (Not_Found, - Cannot_Activate); - // Restart server that will contain this persistent object and return the - // new Object reference. - // - // The <Not_Found> exception is raised when <obj> is not found - // in the Implementation Repository. The <Cannot_Activate> exception - // is raised when <obj> is found in the Repository but could not be - // activated. - - INET_Addr activate_server (in string server) - raises (Not_Found, - Cannot_Activate); - // Restart server that is named <server> and return the host/port - // - // - // The <Not_Found> exception is raised when <server> is not found - // in the Implementation Repository. The <Cannot_Activate> exception - // is raised when <server> is found in the Repository but could not be - // activated. - - void register_server (in string server, - in Process_Options options) - raises (Already_Registered); - // Restart server process when client is looking for <server>. - // - // The <Already_Registered> exception is raised when <server> has - // already been registered with the Implementation Repository. - // - // The <Object_Not_Persistent> exception is raised when <server> is - // not a Persistent Object Reference. - - void reregister_server (in string server, - in Process_Options options) - raises (Already_Registered); - // Restart server process when client is looking for <server>. - // - // The <Already_Registered> exception is raised when <server> has - // already been registered with the Implementation Repository. - // - // The <Object_Not_Persistent> exception is raised when <server> is - // not a Persistent Object Reference. - - void remove_server (in string server) - raises (Not_Found); - // Remove <server> from the Implementation Repository. - // - // The <Not_Found> exception is raised when <server> is not found - // in the Implementation Repository. - - Profile server_is_running (in string server, - in INET_Addr addr, - in Ping_Object ping); - // Used to notify the Implementation Repository that <server> is alive and - // well at <addr>. - - void server_is_shutting_down (in string server); - // Used to tell the Implementation Repository that <server> is shutting - // down. - }; -};</pre> - -<hr> - -<h2><a name="AlternateImplementations">Alternate Implementations</a></h2> - -<p>Other ORB vendors use alternative techniques for their -Implementation Repositories. These techniques usually require new -naming techniques to access persistent object references and new -client-side APIs to bind to persistent object references. TAO's -Implementation Repository will not require such extensions. </p> - -<p>A possible design alternative for the IR might use an Object -Reference that points to the Implementation Repository instead of -pointing directly to the persistent object. This extra level of -indirection would be used by the Implementation Repository to -start the server, if needed. The Location Forwarding mechanism -would then be used to forward the client request to the server. -The difference between this design and TAO's design is that the -persistent IOR in TAO will contain a profile pointing to a -location of the server (where it still might be running) to try -first, and then only if that fails does the client contact the -Implementation Repository. This is an optimization for case where -the server does not shut down often, and most requests do not -need to be forwarded to a new address.</p> - -<p>In cases where most requests will require a forward, TAO can -support a policy that is just like this alternative, where the -Implmentation Repository will be contacted first.</p> - -<hr> - -<h2><a name="AccessingtheImplementationRepository">Accessing the -Implementation Repository</a> </h2> - -<p>The Implementation Repository will be transparent to the -clients and the servers. Clients will only deal with IIOP 1.1 -IORs, and in the default case all the Implementation Repository -logic on the server side will be handled internally by the ORB -and the POA. </p> - -<h3><a name="HelperApplication">Helper Application</a></h3> - -<p>A helper application will be included with the Implementation -Repository. It will be a command-line utility that will assist -users with adding and removing server records (containing virtual -server names and executable name/options) from the Implementation -Repository. </p> - -<h3><a name="LocatinganinstanceofImplRepo">Locating an Instance -of the Implementation Repository </a></h3> - -<h4><a name="Serverside">Server-side</a></h4> - -<p>In the default case, the Implementation Repository will be -found via the command-line, environment variables, and multicast -(in that order). This location strategy is consistent with that -used by TAO to local its default Naming Service instance. Using -the POA extensions, other Implementation Repositories can be -specified in the call to <code>POA::create_reference_with_virtual_server</code>. -The default port of the Implementation Repository can be -overridden through command-line options or environment variables. -</p> - -<h4><a name="Clientside">Client-side</a></h4> - -<p>One or more Implementation Repositories will be stored in -additional profiles in the IOR. Other Implementation Repositories -can also be located by multicasting (on a default multicast -group) the server name of the Persistent Object the client is -interested in. The default multicast group and default port of -the Implementation Repository can be overridden through command -line options or environment variables. </p> - -<p>In most cases, one Implementation Repository will be enough. -For redundancy, several Implementation Repositories can be -specified.</p> - -<hr> - -<h2><a name="Howitworks">How It Works</a></h2> - -<h3><a name="HowServerProducesPersistentIORdefault">How a server -produces a Persistent IOR (in the default case)</a></h3> - -<p>Before a server starts, it must be registered (via a -command-line utility) with an implementation repository. On -platforms that don't support multicast, the Implementation -Repository must be specified on the command line or in an -environment variable. </p> - -<ol> - <li>When the server starts up it calls <code>ORB_init</code>. - <code>ORB_init</code>, if not passed a server name, will - take argv[0] and use that as a default server name (TAO - expects this to be the executable name). </li> - <li><code>ORB_init</code> will create a ping object.</li> - <li><code>ORB_init</code> will look for Implementation - Repositories on the command-line, environmental - variables, and then through multicast (in that order). - Once it finds one it registers itself and passes the ping - object to the implementation repository with <code>server_is_running</code> - operation. </li> - <li>The profile returned by registration will be stored for - later use.</li> - <li>Client later can call the <code>POA::create_reference</code> - operation.</li> - <li>The <code>create_reference</code> operation will create - the local profile.</li> - <li>The stored Implementation Repository profile will have - its object id changed to be the object key just created.</li> - <li>Both profiles will be joined together if the multiple - profile IOR policy is set, and then returned.</li> -</ol> - -<h3><a name="HowServerProducesPersistentIORcomplex">How a server -produces a Persistent IOR (in complex cases)</a></h3> - -<p>As with the default case, the server must be registered with -an Implementation Repository, although it does not need to be -multicast aware since the IORs will be passed to the POA by the -program. </p> - -<ol> - <li><code>ORB_init</code> is called and does the default work - (if it has Implementation Repositories to contact).</li> - <li><code>POA::create_reference_with_virtual_server[_and_id]</code> - will be called with a server name and list of - Implementation Repositories. </li> - <li>The profile for the object is created.</li> - <li>The ping object created in <code>ORB_init</code> and the - object key is passed to the Implementation Repositories, - and their profiles are returned.</li> - <li>Both profiles will be joined together if the multiple - profile IOR policy is set, and then returned.</li> -</ol> - -<h3><a name="HowClientUsesPersistentIOR">How a client uses a -Persistent IOR</a></h3> - -<p>For all Clients: </p> - -<ul> - <li>Client obtains a Persistent Object Reference, which - contains multiple profiles to both regular objects and - Implementation Repositories.</li> - <li>It will now make a request on the first profile.</li> - <li>If the first profile if the server profile, and the - server is still there, then it will be successful. - If the server has moved (or shut down), then the next - profile will be tried.</li> - <li>If the first profile is the Implementation Repository, or - if the server profile failed, then it will be - contacted. The Implemenation Repository will then - return NOT_FOUND or will start up the server and return a - Location Forward message.</li> -</ul> - -<p>If everything fails, then most clients will return failure for -the request. TAO clients will attempt to contact other -Implementation Repositories that are specified on the -command-line, in environment variables, or found through -multicast. </p> - -<ul> - <li>If all of the profiles fail, then contact the other - Implementation Repositories. First get those specified on - the command line or in environment variables.</li> - <li>Then, if multicast is available: <ul> - <li>Multicast the Object Reference to a group of - Implementation Repositories </li> - <li>Wait until response or a timeout. The response - will contain the Object Reference of a - Implementation Repository that knows about the - Object Reference </li> - </ul> - </li> - <li>Connect to the Implementation Repository that responds - first.</li> - <li>Call <i>activate</i> passing the Persistent Object - Reference.</li> - <li>If a new Object Reference was sent back then retry the - request using the it. If this request fails, then fail - (no more retries).</li> - <li>If a null reference was sent back, then fail.</li> -</ul> - -<p>TAO clients will have an optimization where if there are -several IORs that have the same server name, and one of them gets -forwarded, then the client will be able to change its other IORs -without going through the overhead of contacting Implementation -Repository.</p> - -<hr> - -<p>Last update to this document: $Date$</p> - -<p>Back to <a href="../releasenotes/">TAO Release Notes</a></p> - -<p>Back to <a href="index.html">Implementation Repository</a></p> -</body> -</html> diff --git a/TAO/docs/implrepo/status.html b/TAO/docs/implrepo/status.html deleted file mode 100644 index 1397e8c1a89..00000000000 --- a/TAO/docs/implrepo/status.html +++ /dev/null @@ -1,70 +0,0 @@ -<html> -<!-- $Id$ --> - -<head> -<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> -<meta name="GENERATOR" content="Microsoft FrontPage 3.0"> -<title>Implementation Repository Status</title> -</head> - -<body bgcolor="#FFFFFF" text="#000000"> - -<hr> - -<h3>Implementation Repository Status</h3> - -<p>Point of contact: <a href="mailto:brunsch@cs.wustl.edu">Darrell Brunsch</a> </p> - -<p>Here is a brief list of my goals (and the dates completed).</p> - -<p>Immediate goals: - -<ul> - <li>[7/17] Create the base test client and server programs</li> - <li>[7/23] Add an IR that forwards server requests</li> - <li>[7/23] Persistence</li> - <li>[8/10] Have the server register its IOR with the IR</li> - <li>[8/14] Have the server exit after every call, so it is restarted each time</li> - <li>[9/10] Make the IR forward any request</li> - <li>[9/10] Add the ping object to the server</li> - <li>[9/10] Add in shutdown calls to test ping objects</li> - <li>[9/15] Implement the full IDL Interface for the IR</li> - <li>Add more Documentation</li> - <li>Fix a problem</li> - <li>Add another test server</li> -</ul> - -<p>Longer term goals: - -<ul> - <li>Change IOR format</li> - <li>Add in support for virtual server names</li> - <li>Integration with POA and ORB</li> -</ul> - -<p>Other goals: - -<ul> - <li>Multiple Profiles</li> - <li>POA extension</li> -</ul> - -<p>Future Goals (might or might not happen): - -<ul> - <li>TAO client-side optimization with restarted servers</li> - <li>Server security (checksums)</li> - <li>Helper Application</li> - <li>Federation of IRs</li> - <li>DLLs</li> -</ul> - -<hr> - -<p>Last update to this document: $Date$</p> - -<p>Back to <a href="../releasenotes/">TAO Release Notes</a></p> - -<p>Back to <a href="index.html">Implementation Repository</a></p> -</body> -</html> diff --git a/TAO/docs/implrepo/usersguide.html b/TAO/docs/implrepo/usersguide.html deleted file mode 100644 index 12b0f1de771..00000000000 --- a/TAO/docs/implrepo/usersguide.html +++ /dev/null @@ -1,101 +0,0 @@ -<html> - -<head> -<meta http-equiv="Content-Type" -content="text/html; charset=iso-8859-1"> -<meta name="GENERATOR" content="Microsoft FrontPage Express 2.0"> -<title>Implementation Repository User's Guide</title> -</head> - -<body bgcolor="#FFFFFF"> - -<hr> - -<h3>User's Guide</h3> - -<p>The Implementation Repository is still kind of in a state of -flux and will probably change quite a bit this semester. Right -now it works, although it is still a bit inflexible. Most of this -document will change, so make sure to get the version of this -document that is paired with the version of the IR that you are -using.</p> - -<hr> - -<h4>What does the server need to do.</h4> - -<p>The IR needs information about the server to be able to direct -to the right place. The current scheme uses a regular persistent -IOR and replaces the host and port with that of the IR. Then when -the call comes into the IR, it sends back a LOCATION_FORWARD to -the client and directs it to the correct server (after starting -it if necessary).</p> - -<p>So the server needs to know the IOR of the IR in order to -change the host and port in it to that of the IR. The information -the IR needs to receive from the server is its poa name (which it -uses as an identifier) and commands used to restart the server.</p> - -<hr> - -<h4>The IR_Helper class</h4> - -<p>Most of the work on the server is done in the IR_Helper class. -The first thing it expects is to have the implrepo.ior file in -the current directory. This file contains the IOR of the IR. -IR_Helper then uses this to register itself. </p> - -<p>Here is the small checklist I went through when I used the -IR_Helper class in Airplane Test. The Cubit-style references are -just refering to any server that has used the structure of the -IDL_Cubit test (a lot of TAO's examples are like this).</p> - -<dir> - <li>Make yourself an IR_Helper object. (If you follow - the Cubit-style architecture, this will be a pointer in - the Server_i class). </li> - <li>After you create the POA, construct the IR_Helper and - pass it the relevant information. (Cubit-style: assign a - new object within Server_i::init) </li> - <li>If you need to register, call register_server () - (Cubit-style: add another option "-r" and have - it set a flag. Within Server_i::init call - register_server ()) </li> - <li>After you create and register your objects, call - change_object to redo the references. Then you can - output the new IOR. (Cubit-style: still within - Server_i::init) </li> - <li>Right before ORB::run call notify_startup and afterwards, - call notify shutdown (Cubit-style: within Server_i::run) </li> -</dir> - -<hr> - -<h4>To use, or not to use the IR</h4> - -<p>If you look at the tests, they use -r and -i flags to -determine how to use the IR. The -i flag turns on the use of the -Implementation Repository (so the server can be tested without -the IR). The -r flag is used to register the entry in the IR for -the server. Note that -r will not work in the example without -i. -This does require some more work on the server side, so if you -choose you can just use the IR all the time and only worry about --r.</p> - -<hr> - -<h4>The implrepo.conf file</h4> - -<p>Because with the way it is set up, and the current -over-restrictiveness of the POA locks, the IR requires a special -configuration file, implrepo.conf, which you need to pass to the -IR via <font face="Times New Roman"><code>-ORBsvcconf -implrepo.conf</code></font> flag</p> - -<hr> - -<p>Last update to this document: $Date$</p> - -<p>Back to <a href="index.html">Implementation Repository</a></p> -</body> -</html> diff --git a/TAO/docs/index.html b/TAO/docs/index.html deleted file mode 100644 index e1d1db679b4..00000000000 --- a/TAO/docs/index.html +++ /dev/null @@ -1,45 +0,0 @@ -<html> - -<head> -<meta NAME="GENERATOR" CONTENT="Microsoft FrontPage 3.0"> -<title>TAO Documentation</title> -</head> - -<body text="#000000" link="#0000ff" vlink="#cc0000" bgcolor="#ffffff"> - -<hr> - -<h3 ALIGN="CENTER">TAO Documentation</h3> -<div align="center"><center> - -<table cellpadding="10" cellspacing="8" border="10"> - <tr> - <td><font SIZE="+1"><dl> - <dt><a HREF="http://www.cs.wustl.edu/~schmidt/corba-research-realtime.html">Technical - Overview</a> </dt><P> - <dt><a HREF="http://www.omg.org/library/c2indx.html">OMG CORBA 2.x spec</a> </dt><P> - <dt><p><a href="../../docs/exceptions.html">Exception Handling</a></p> - <dt><a HREF="http://www.cs.wustl.edu/~schmidt/events_tutorial.html">Event Service Tutorial</a></dt><P> - <dt><a HREF="http://www.cs.wustl.edu/~schmidt/TAO/index.html">TAO Viewgraphs</a></dt><P> - <dt><a HREF="releasenotes/index.html">Release Notes</a> </dt><P> - </dl> - </td></font> - - <td><font SIZE="+1"><dl> - <dt><a HREF="components.html">ORB Configuration Options</a> </dt><P> - <dt><a HREF="compiler.html">TAO IDL Compiler Options</a> </dt><P> - <dt><a HREF="orbsvcs.html">ORB Services Directories</a> </dt><P> - <dt><a HREF="poa_migration.html">POA Migration Notes</a> </dt><P> - <dt><a HREF="implrepo/">Implementation Repository</a> </dt><P> - <dt><p> </dt></p> - </dl> - </td></font> - </tr> -</table> -</center></div> - -<P><hr> - -<p>Back to the <a HREF="http://www.cs.wustl.edu/~schmidt/TAO.html">TAO</a> home page. <!--#include virtual="/~schmidt/cgi-sig.html" --> </p> -</body> -</html> diff --git a/TAO/docs/leader_follower.html b/TAO/docs/leader_follower.html deleted file mode 100644 index beb09eb92b3..00000000000 --- a/TAO/docs/leader_follower.html +++ /dev/null @@ -1,60 +0,0 @@ -<html> - <!-- $Id $ --> - <head> - <title>Implementation of leader follower model for global resources</title> - </head> - - <BODY text = "#000000" - link="#0000ff" - vlink="#cc0000" - bgcolor="#ffffff"> - - <body> - <HR> - <h1>Leader follower model for global resources</h1> - <HR> - <h2>Context</h2> - Global resources in TAO mean one ORB and using the reactive strategy - one Reactor. TAO uses the ACE Select Reactor for this purpose. - One main problem with multithreading and only one Reactor is that - only one thread can wait in handle_events at a time. - Handle_events is called, when a thread expects input, meaning - it is blocking to wait for it. - - <h2>Idea</h2> - One solution to this problem is to use a leader-follower model, - which partitions the set of threads wanting to wait for input - into one leader and followers. Every thread is eligible to become - a leader. A thread wanting to wait while nobody else is waiting - becomes the leader. If the leader gets its input, which is in - this case its response, it will select a new leader out of the - set of followers. The followers wait on a condition variable they - own and register it with the ORB core. The ORB core is thereby - responsible for making this access thread-save by providing - a lock for the list of followers with some flags, like - leader_available. - - <h2>Implementation</h2> - The above mentioned condition variables are owned by the - connection handlers, because reponses are expected per connection, - not necessarily, thinking about other resource models, per thread. - <p> - The involved classes are TAO_ORB_Core, TAO_Client_Connection_Handler - and TAO_ORB. In the TAO_ORB_Core class the list of followers, a lock, - a leader reference counter and a leader thread ID were added. - The handle_input and send_request methods on the TAO_Client_Connection_Handler - contain 95% of the code used for implementing the leader-follower - model. Care has to be taken, that the connection handlers are - suspended and resumed, properly. A special concern is that - no deadlocking occurs. - - <HR> - For more details and questions, - <p> - - <address><a href="mailto:mk1@cs.wustl.edu">Michael Kircher</a></address> - <p> - <address><a href="mailto:irfan1@cs.wustl.edu">Irfan Pyarali</a></address> - </body> -</html> - diff --git a/TAO/docs/locate_request.html b/TAO/docs/locate_request.html deleted file mode 100644 index 1978b2f3336..00000000000 --- a/TAO/docs/locate_request.html +++ /dev/null @@ -1,56 +0,0 @@ -<html> - <!-- $Id $ --> - <head> - <title>Implementation of locate requests</title> - </head> - - <BODY text = "#000000" - link="#0000ff" - vlink="#cc0000" - bgcolor="#ffffff"> - - <body> - <HR> - <h1>Locate requests</h1> - <HR> - <h2>Context</h2> - The CORBA specification describes locate requests as a way to - find out if an object is available at the other end of the wire - or not without invoking an actual method on it. - This way expensive marshalling and demarshalling can be prohibited. - Locate requests are part of GIOP. - - <h2>Implementation</h2> - The main classes involved in locate requests are the Server_Connection_Handler - to do check for the object. This is done by invoking the non standard - "non_existent" method on it. If it fails an exception will be thrown, - if the exception is not the Forward_Request exception of the POA, - the object is not there. If it is this specific exception, the new - forwarded location can be extracted and returned in the locate reply. - If the call on "non_existent" succeeds, we know the object is there and - return that. - - The client part of the locate request is handled int Locate_Request_Invocation. - The response is checked on the answer. If there, we go on and invoke the - actual method on the distant object. If not there, we fail and throw the proper - exception and if we get forwarded we replace our IIOP profile acordingly. - - <h2>API</h2> - To activate the locate requests, please invoke the non standard method - "_use_locate_requests (CORBA::B_TRUE)" on your CORBA::Object or any - object which inherits form this object. This will activate the locate - request on the first call to the object. The second time and on all - following calls "no" locate request will be used any more. To switch - it on again use "_use_locate_requests (CORBA::B_TRUE)" again. - You can also switch it of by "_use_locate_requests (CORBA::B_FALSE)". - - <HR> - For more details and questions, - <p> - <address><a href="mailto:irfan1@cs.wustl.edu">Irfan Pyarali</a></address> - <p> - <address><a href="mailto:mk1@cs.wustl.edu">Michael Kircher</a></address> - <p> - </body> -</html> - diff --git a/TAO/docs/orbsvcs.html b/TAO/docs/orbsvcs.html deleted file mode 100644 index 12e0a8a990f..00000000000 --- a/TAO/docs/orbsvcs.html +++ /dev/null @@ -1,252 +0,0 @@ -<html> - <!-- $Id$ --> - <head> - <title>TAO's CORBA Object Services Documentation</title> - </head> - -<BODY text = "#000000" -link="#0000ff" -vlink="#cc0000" -bgcolor="#ffffff"> - - <body> -<HR> - <h3>TAO's CORBA Object Services Directory Hierarchy</h3> - - <P>The file and directory organization for TAO services can be - confusing at first glance (and even on subsequent ones to be - honest), - so we felt like some rationale and explanation of the directory - hierarchy was needed.</P> - - <P>For general sanity all TAO services files are located under - <CODE>$TAO_ROOT/orbsvcs</CODE>.</P> - - <P>It is expected that clients use more - than one service at the same time - (in fact some of the services already do, for instance the - <B>Event Service</B> uses the <B>Naming Service</B> and the - <B>Scheduling Service</B>). - For this reason all the services stubs are grouped in one - library. - This library is located in - <CODE>$TAO_ROOT/orbsvcs/orbsvcs</CODE>. - Usually the include path is only <CODE>$TAO_ROOT/orbsvcs</CODE>, - so files are included like this:</P> - -<P><CODE> -#include "orbsvcs/CosNamingC.h" -</CODE></P> - - <P>To simplify the IDL generation the skeletons are also on the - library, - this is not a problem for client programs and most services need - to link the library anyway - (since they use other services.) - Further, - the current support for collocation requires that clients link - the skeleton files anyway. - </P> - - <P>In the future we intend to use ACE Service Configurator to give - the users control over collocation of the services implementation. - As a first cut all the service implementations are included in the - orbsvcs library <CODE>$TAO_ROOT/orbsvcs/orbsvcs</CODE>. - Since there are serveral services and each one is implemented - using several files we have given a different directory to each - service. - This structure could also simplify a future split into several - libraries (if it proves necessary). - </P> - - <P>The complete list of directories is:</P> - - <P> - <TABLE BORDER="2" - CELLSPACING="2" - CELLPADDING= "0"> - <TR> - <TH>Service</TH> - <TH>Implementation Sub-directory</TH></TR> - <TR> - <TD>A/V Streams Service</TD><TD><CODE>orbsvcs/AV</CODE></TD></TR> - <TR> - <TD>Concurrency Service</TD><TD><CODE>orbsvcs/Concurrency</CODE></TD></TR> - <TR> - <TD>Event Service</TD><TD><CODE>orbsvcs/CosEvent</CODE></TD></TR> - <TR> - <TD>Real-time Event Service</TD><TD><CODE>orbsvcs/Event</CODE></TD></TR> - <TR> - <TD>LifeCycle Service</TD><TD><CODE>orbsvcs/LifeCycle</CODE></TD></TR> - <TR> - <TD>Logging Service</TD><TD><CODE>orbsvcs/Log</CODE></TD></TR> - <TR> - <TD>Naming Service</TD><TD><CODE>orbsvcs/Naming</CODE></TD></TR> - <TR> - <TD>Property Service</TD><TD><CODE>orbsvcs/Property</CODE></TD></TR> - <TR> - <TD>Scheduling Service</TD><TD><CODE>orbsvcs/Sched</CODE></TD></TR> - <TR> - <TD>Trading Service</TD><TD><CODE>orbsvcs/Trader</CODE></TD></TR> - <TR> - <TD>Time Service</TD><TD><CODE>orbsvcs/Time</CODE></TD></TR> - </TABLE> - </P> - - <P>Note that in the current version of TAO we still have standalone - binaries for some of the services. However, some applications - may want to control what process implements a particular service. - Therefore, it has proved useful for - debugging purposes to keep the most used services separated. - The binaries in question are located in - <CODE>$TAO_ROOT/orbsvcs</CODE>, and the list includes: - </P> - - <UL> - <LI>Concurrenty_Service</LI> - <LI>Dump_Schedule</LI> - <LI>LifeCycle_Service</LI> - <LI>CosEvent_Service</LI> - <LI>Event_Service</LI> - <LI>Naming_Service</LI> - <LI>Scheduling_Service</LI> - <LI>Trading_Service</LI> - <LI>Time_Service</LI> - <LI>ImplRepo_Service *(see below)*</LI> - </UL> - - <P>In the future we plan to use a single binary and ACE Service - Configurator and keep a single binary.</P> - - <P>The Implementation Repository is a unique service in that it - starts server executables, and it doesn't make sense to collocate - it in another server. Because of this, only the IDL files are - located in <CODE>$TAO_ROOT/orbsvcs/orbsvcs</CODE>. The other - files are all located in - <CODE>$TAO_ROOT/orbsvcs/ImplRepo_Service</code>.</P> - - <P>Finally the tests and example programs are located in - <CODE>$TAO_ROOT/orbsvcs/tests</CODE>; - once more each may involves more than a single binary, - so each one is kept in its own directory; - the following list describes the contents of each one: - </P> - - <P> - <TABLE BORDER="2" - CELLSPACING="2" - CELLPADDING= "0"> - <TR> - <TH>Test directory</TH> - <TH>Purpose</TH></TR> - <TR> - <TD><CODE>AVStreams</CODE></TD> - <TD>A complete A/V server and client.</TD></TR> - <TR> - <TD><CODE>Concurrency</CODE></TD> - <TD>Test the Concurrency Service.</TD></TR> - - <TR> - <TD><CODE>CosEC_Basic</CODE></TD> - <TD>Test the basic functionality of the standard Event - Service. - </TD> - </TR> - - <TR> - <TD><CODE>CosEC_Multiple</CODE></TD> - <TD>Simple example that connects multiple consumers and/or - suppliers to the standard event service. It can be used to - show how composing a standard event-service and the - real-time event service provides filtering capabilities. - </TD> - </TR> - - <TR> - <TD><CODE>EC_Basic</CODE></TD> - <TD>Test the basic functionality of the real-time Event - Service. - </TD> - </TR> - - <TR> - <TD><CODE>EC_Custom_Marshal</CODE></TD> - <TD>Show how the Real-time event service can send user - defined data using custom marshaling. - </TD> - </TR> - - <TR> - <TD><CODE>EC_Mcast</CODE></TD> - <TD>Multiple real-time event channels can communicate using - multicast, this example shows how to do it. - </TD> - </TR> - - <TR> - <TD><CODE>EC_Multiple</CODE></TD> - <TD>Connect two Real-time Event Channels using the - <CODE>EC_Gateway</CODE>, - measure latency, utilization and minimum spacing. - </TD> - </TR> - - <TR> - <TD><CODE>EC_Throughput</CODE></TD> - <TD>Measure throughput and latency for collocated and remote - real-time event services. - </TD> - </TR> - - <TR> - <TD><CODE>Event_Latency</CODE></TD> - <TD>Test the Real-time Event Service and measure end-to-end latency, - it also uses the Scheduling and Naming services.</TD></TR> - - <TR> - <TD><CODE>ImplRepo</CODE></TD> - <TD>Tests used to test the functionality of the - Implementation Repository Service.</TD></TR> - - <TR> - <TD><CODE>Logger</CODE></TD> - <TD>An example logging service using the Naming Service to - locate a factory.</TD></TR> - <TR> - <TD><CODE>Naming</CODE></TD> - <TD>An advanced test of the Naming Service.</TD></TR> - <TR> - <TD><CODE>Property</CODE></TD> - <TD>Testing for the Property Service.</TD></TR> - <TR> - <TD><CODE>Sched</CODE></TD> - <TD>A test of the Scheduling Service.</TD></TR> - <TR> - <TD><CODE>Simple_Naming</CODE></TD> - <TD>A very simple Naming Service test.</TD></TR> - <TR> - <TD><CODE>Simulator</CODE></TD> - <TD>Prototype implementation of DOVE (DOVE Agent, DOVE - Browser, DOVE MIB, DOVE Application). The DOVE Agent - consists of the Event Channel, which is then connected to - a DOVE Browser implemented in Java.</TD></TR> - <TR> - <TD><CODE>Trading</CODE></TD> - <TD>Tests for the Trading Service.</TD></TR> - <TR> - <TD><CODE>Time</CODE></TD> - <TD> A test for the Time Service.</TD></TR> - </TABLE> - </P> - - <H2>SEE ALSO</H2> - - <P>You may you to check TAO - <A HREF="releasenotes/index.html">release notes</A> - for up to date information on status, changes, future work, etc.</P> - - <hr> - - <address><a href="mailto:coryan@macarena.cs.wustl.edu">Carlos O'Ryan</a></address> - </body> -</html> diff --git a/TAO/docs/poa_migration.html b/TAO/docs/poa_migration.html deleted file mode 100644 index 5623a283698..00000000000 --- a/TAO/docs/poa_migration.html +++ /dev/null @@ -1,69 +0,0 @@ -<HTML> -<HEAD> - <META NAME="GENERATOR" CONTENT="Adobe PageMill 2.0 Mac"> - <TITLE>Migrating from the BOA to the POA</TITLE> -</HEAD> - -<BODY text = "#000000" -link="#0000ff" -vlink="#cc0000" -bgcolor="#ffffff"> - -<HR><P> -<H3>Migrating from BOA to POA</H3> - -<UL> -<LI><EM><B>Client side</b></EM><P> -<ul> -<li>Very little has changed, and some have not needed any changes.</li><P> -<li>You'll have to insure that the Makefile includes .o's for both the server -and client; this is necessary to support collocation.</li> <P> -</ul> - -<LI><EM><B>Server side</B></EM><P> -<UL> -<li>POA_init() is replaced with resolve_initial_references("RootPOA") followed -by a _narrow operation.</li><P> -<li>The implementation no longer inherits from the client-side stub; they -inherit from PortableServer::ServantBase. The implications of this are (a) if -you want a object reference for that, you must use the _this() method.</li><P> -<li>Object ID's are assigned by the POA unless you activate the servant with a -specific ID; IDL_Cubit has examples on how to do this.</li><P> -<li>Unlike the BOA, the POA explicitly addresses the temporal nature of servants -and declares that a POA can service either transient or persistent servants -(not both). The root POA's (mandated, unchangeable) policy is "transient". -The implications of this are that in order for a client to be able to -manufacture an object reference on its own and use that to access an object, -the servant for that object must be registered with a POA whose policy is -"persistent". Thus, you must create a child POA with that policy and register -the servant with that POA. NOTE: when the POA declares something as -"persistent", it is only stating that the key is valid between different runs -of the server; it makes no claims that state or anything else is persistent.</li><P> - -<ul> - <li> Servants are not automatically activated, hence you must register - them by calling some of the activate_object* methods on a POA or - calling _this() on the servant; with the latest you have no control on - the ObjectId (which sometimes is good), and the POA must support the - right policies (the RootPOA does).</li><P> - - <li>Servant constructors use to take a <const char*> parameter to set - they object id, this is not needed now, in fact in many cases they use - to pass this argument to the skeleton class: this will fail now.</li><P> -</ul> -This list is not intended to be exhaustive, but should give you a good -starting point. If you find things along the way which have to change and I -didn't note them, please send them to me. Perhaps we can work together on the -ultimate migration document. <P> -</UL> -</UL> - -<hr><P> - -Back to the <A -HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/docs/index.html">TAO -documentation</A> page. - -<!--#include virtual="/~schmidt/cgi-sig.html" --> -</BODY> -</html> diff --git a/TAO/docs/reactivator.html b/TAO/docs/reactivator.html deleted file mode 100644 index e4abd9788ae..00000000000 --- a/TAO/docs/reactivator.html +++ /dev/null @@ -1,21 +0,0 @@ -<html> - -<head> -<title> TAO Reactivation Service </title> -<meta HTTP-EQUIV="Refresh" CONTENT="1;URL=implrepo.html"> -</head> - -<body text="#000000" link="#0000ff" vlink="#cc0000" bgcolor="#ffffff"> - -<hr> - -<h1>TAO Reactivator </h1> - -<p>Has moved to <a href="implrepo.html">here</a> as the Implementation Repository</p> - -<hr> - -<p>Back to the <a HREF="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/docs/index.html">TAO -documentation</a> page. <!--#include virtual="/~schmidt/cgi-sig.html" --> </p> -</body> -</html> diff --git a/TAO/docs/releasenotes.html b/TAO/docs/releasenotes.html deleted file mode 100644 index 21854918af1..00000000000 --- a/TAO/docs/releasenotes.html +++ /dev/null @@ -1,26 +0,0 @@ -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.03 [en] (X11; I; Linux 2.0.30_SMP i686) [Netscape]"> - <META HTTP-EQUIV="Refresh" CONTENT="1;URL=releasenotes/index.html"> - <TITLE>TAO Release Information and TODO List</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> -<!-- $Id$ --> -<CENTER> -<H2> -Release Information for The ACE ORB (TAO)</H2></CENTER> - -<CENTER> -<H3> -Version 0.0.12</H3></CENTER> - -<CENTER> -<H3> -17-October-1997</H3></CENTER> - -<HR> - -This document has moved <a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/docs/releasenotes/index.html">here</a>. - -</HTML> diff --git a/TAO/docs/releasenotes/TODO.html b/TAO/docs/releasenotes/TODO.html deleted file mode 100644 index bfb4630a56a..00000000000 --- a/TAO/docs/releasenotes/TODO.html +++ /dev/null @@ -1,1613 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> -<HEAD> - <TITLE>TAO TO-DO List</TITLE> -</HEAD> - <BODY TEXT="#000000" BGCOLOR="#FFFFFF"> - <!-- $Id$ --> - <CENTER><HR></CENTER> - - <CENTER> - <H3>General TO-DO list for TAO</H3> - </CENTER> - - <P> - This document presents our TO-DO list for TAO. - Currently, the list is not very well organized or prioritized. - It started as a personal TODO list for Carlos, so it is biased - towards the Event Service and related components. - As more people get involved it will become more - organized. - </P> - <P> - Last Updated: $Date$ $Revision$ - </P> - - <HR> - <P> - <H3>Work in progress</H3> - </P> - - <OL> - <LI><P>Implement an Implementation Repository for TAO. - <BR>[ASSIGNED TO:] Darrell. - </P> - </LI> - - <LI><P>Support the thread pool reactor in the ORB. - <BR>[ASSIGNED TO:] Nanbor. - </P> - </LI> - - <LI><P>Add support for multiple Profiles in the ORB (completing - the IIOP 1.0 support) - <BR>[ASSIGNED TO:] Fred - </P> - </LI> - - <LI><P>Implement a nice example of the COS Event Channel, - showing how it can provide filtering when combined with the - real-time Event Channel. - <BR>[ASSIGNED TO:] Pradeep - </P> - </LI> - - </OL> - - <HR> - <P> - <H3>Pending Tasks</H3> - </P> - - <H4>Performance optimizations</H4> - - <OL> - <LI><P>Location forwarding should be strategized since some - applications don't need this feature. - </P> - </LI> - - <LI>Further optimize the outgoing memory allocation by adding - support for message blocks allocated from a pool (the - Message_Block class itself not the Data_Block or the buffer it - contains). - <P></LI> - - <LI>Optimize twoways by delaying memory allocation for the - incoming data buffer, thus improving interleaving between the - client and server (the client does something useful before - starting to wait for the server). - <P></LI> - - <LI>The data blocks and their buffers could be allocated in a - single operation, using the beginning of a buffer to contain - the data block and the rest of it to contain the actual buffer - <P></LI> - - <LI><P>Some applications cannot afford compiled marshaling for - all the stubs and skeletons, - the generated code size would be too big. - Yet some operations could be critical and require code as - efficient as possible; - a <CODE>#pragma</CODE> can be added to give users - fine-grained control over code generation. - </P> - </LI> - - <LI><P>For extremely low latency applications we could remove - some fields from the IIOP protocol, for instance: - <UL> - <LI>The first four bytes are always 'GIOP' - </LI> - <LI>In homogeneous environments sending the byte order is a - waste - </LI> - <LI>Fields like the <CODE>Principal</CODE>, the services - context list, the versions can also be removed - </LI> - </UL> - <BR>[STATUS] Most of this optimizations were implemented, - and can be enabled using the <CODE>-ORBiioplite</CODE> command - line option. - </P> - </LI> - - <LI><P>Once the memory for incoming data is taken from an - allocator we can implement different approaches to manage - that memory: - <UL> - <LI>The allocator is global, allowing applications to keep - the incoming buffer even after the upcall has finished. - </LI> - <LI>The allocator is TSS, giving maximum performance for - applications that do not wish to preserve the buffer - after the upcall. - </LI> - <LI>The allocator is a TSS cache for a global memory pool, - this tries to strike a balance, by practically eliminating - the locking on each allocator/deallocation. Some strategy - is required to return the memory to the global pool, - consider, for example, - an application that will always allocate memory from one - thread and deallocate it in another thread. - </LI> - </UL> - </P> - </LI> - - <LI><P>Optimize marshaling for <CODE>TypeCode</CODE>, by not - including the optional fields on the wire; - this fields are useful (in some cases), so they should be - present for the "on memory" representation. - </P> - </LI> - - <LI><P>In some cases it is possible to marshal a complete - structure in a single operation to allow this the structure - must have fixed size (in the CDR spec sense) and its memory - layout must match the CDR layout. - </P> - </LI> - - <LI><P>If all the arguments to an operation are fixed size then - the header can be sent before the rest of the data, if the - data is big enoug this can represent a performance - improvement (because we increase overlapping between client - and server); further if the arguments also have the proper - layout they can be sent without copying to a temporary - buffer. - </P> - <P>If the arguments are not fixed size the header could be - sent before, but two passes over the data will be required. - </P> - </LI> - - <LI><P>One GIOP 1.1 is implemented we could use fragments to - minimize the buffer allocations: - the buffer could be fixed size and we simply send fragments - for each buffer. - </P> - </LI> - - <LI><P>Demarshaling and managment of Anys could be optimized, - they esentially keep a copy of the CDR stream, - but they could just keep a reference (and increase the - reference count). - </P> - </LI> - - <LI><P>Some uses of DSI can optimized also, - for instance, - if the application is simply going to forward the request to - another object there is no need to parse the arguments in - the CDR stream and decompose them in the arguments, - a single *big* CDR stream can be kept. - </P> - </LI> - - <LI><P>In the collocated case the generated - <CODE>_narrow()</CODE> method calls the - <CODE>_create_stub()</CODE> method that allocates several - temporary objects. - </P> - </LI> - - <LI><P>For various projects, we need to produce a - minimal-footprint TAO ORB. One thing we could probably do - very easily would be to provide an #ifdef that will - conditionally omit the servant manager, POA manager, and - adapter activator features from TAO, along with all the - demuxing features that aren't active demuxing or perfect - hashing. - </P> - </LI> - - <LI><P>The CDR streaming classes compute the alignment on each - operation, but they could remember the alingment from the - previous insertion or extraction operation; saving a few - cycles but spending a little more memory. - </P> - </LI> - - </OL> - - <H4>New features and Bug fixes</H4> - <OL> - <LI><P><B>EC:</B>Complete the implementation of the new EC, - specially generate the strategies and changes required to - support hard real-time behavior. - </P> - </LI> - - <LI><P><B>EC:</B>Optimize the updates to the SupplierFiltering - module, specially when it is a singleton: currently it - receives a <CODE>connected</CODE> call for each supplier, - event though one would be enough. - </P> - </LI> - - <LI><P><B>EC:</B>The supplier filters could depend on the QoS - data, as consumer filters do. We should provide a factory - for them too. - </P> - </LI> - - <LI><P><B>EC:</B>We need to provide simple operations to update - the subscriptions of a consumer, as well as the publications - of a supplier, the current scheme (disconnecting and - connecting again) is inefficient. - </P> - </LI> - - <LI><P><B>EC:</B>We need some strategy in the EC to periodically - flush out mibehaving suppliers and consumers. Examples of - misbehavior include: suppliers flooding the EC; - consumers or suppliers that are destroyed, but were not - disconnected; - consumers that are not accepting events (risking a - dead-lock); - etc. - </P> - </LI> - - <LI><P><B>EC:</B>Sometimes the Event Channel dead-locks during - shutdown. According to Ulf Jährig <jaehrig@desys.com>>;, an - easy way to reproduce the problem is to run the - EC_Throughput test under windows NT. - </P> - </LI> - - <LI><P><B>IDL Compiler:</B>Support for the <CODE>version</CODE> - pragma, this also requires some changes in the - <CODE>_is_a()</CODE> implementation. - </P> - </LI> - - <LI><P>Support native C++ exceptions. - This entails the following subtasks:<P> - <OL> - <LI>Create exceptions with the right dynamic type on the - client side. - For SII this should be simple: - the stub give us a list of the - possible user exceptions together with the factory methods - to allocate an exception of each type; - if the exception is not on that list we throw a - <CODE>CORBA::UNKNOWN</CODE>. - For DII we have to throw a - <CODE>CORBA::UnknownUserException</CODE>; - the user will receive the real exception inside an - <CODE>Any</CODE> then and she will have to extract it - either using the >>= operator or using the - forthcoming <CODE>DynAny</CODE>. - System exceptions are even easier, we always know how - to create them. - <BR>[STATUS] SII is working OK, we still need to complete - the support for DII. - <BR>[STATUS] The DII support was completed, but remains - untested. - <P></LI> - - <LI>Add the _raise() method to the exceptions. - <BR>[DONE] - <P></LI> - - <LI>On the server side: catch any CORBA exceptions thrown by - the upcall, and then transform that into the - proper <CODE>Reply</CODE> to the client side. - In the case of another C++ exception should we do - something? - <BR>[DONE] - <P></LI> - - <LI>On the client side, after creating the exception with - the right dynamic type we must invoke - <CODE>_raise()</CODE> on it. - <BR>[DONE] - <P></LI> - - <LI>Provide a TSS default value for the CORBA_Environment, - all the methods in the ORB library should use this - default. - <BR>[DONE] - <P></LI> - - <LI><B>IDL Compiler:</B>The IDL compiler should be able to - generate the - alternative mapping, but with the TSS default for the env - argument. - <BR>[DONE] - <P></LI> - - <LI><B>IDL Compiler:</B>The IDL compiler should generate the - standard mapping, without the environment argument. - <P></LI> - - <LI>In general we will need to complete and debug the - <CODE>TAO_TRY</CODE> macros; - they have limitations when dealing with the - alternative mapping, but are very useful. - <BR>[STATUS] This seems to be OK now, the code seems to - compile and work correctly now. - <BR>[STATUS] We need a new macro (TAO_TRY_THROW) to use - inside the TAO_TRY blocks, because TAO_THROW will not go - into the TAO_CATCH blocks, even if the exceptions match. - <P></LI> - - <LI>We need to test the ORB for resource leaking in the - presence of exceptions. - <P></LI> - - <LI>We <EM>could</EM> write portable server side code with - any of the mappings above if we use a macro for the env - argument, but the results are ugly: - <PRE> -// IDL -interface Foo { - void bar (in long x); -}; - -// C++ -class Foo { - void bar (CORBA::Long x TAO_ENV_ARG) - TAO_THROW_SPEC ((CORBA::SystemException)); -}; - </PRE> - note the missing comma before the TAO_ENV_ARG parameter. - <P> - </P> A different alternative is to generate both - functions, and make the default implementation just invoke - the other: - <PRE> -// IDL -interface Foo { - void bar (in long x); -}; - -// C++ -class POA_Foo { - void bar (CORBA::Long x, CORBA::Environment& env) - TAO_THROW_SPEC ((CORBA::SystemException)) - { - this->bar (x); - } - void bar (CORBA::Long x) - TAO_THROW_SPEC ((CORBA::SystemException)) = 0; -}; - </PRE> - The problem is: which alternative should be the pure - virtual function? Which one is overriden by the user? - <P></LI> - - </OL> - <BR>[STATUS] The main task ahead is to generate the conforming - mapping for the server side, i.e. remove the - <CODE>CORBA::Environment</CODE> argument and generate the - throw specs. - We need to wait for the compiled marshaling support to - implement this feature, otherwise the number of conflicts, - visitors and factories will grow without limit. - </P> - </LI> - - <LI><P><B>EC:</B> Automate EC multicast group usage. This probably - requires some kind of server that mantains the relation - between event type/source and the mcast groups. - <BR>[STATUS] The multicast map server was defined, an - example implementation that hardcodes the port, and casts - the event type into the mcast address was implemented. - <BR>[STATUS] An advanced example that uses multiple mcast - groups per process was developed; this example would be used - To test the required features for general mcast support. - <BR>[STATUS] The example is able to automatically join and - leave multicast groups, as the consumer set on a local EC - changes. - The test has been constructed to minimize resources, it only - uses one socket for outgoing multicast messages; - currently it uses only one socket for each local group of - multicast UDP addresses sharing the same port; - eventually more sockets may be needed, - as sockets have limits on the number of multicast groups - they can join. - </P> - </LI> - - <LI><P><B>EC:</B>The <CODE>TAO_EC_Gateway_IIOP</CODE> can be - required to subscribe for events by source, but the source - can be local instead of remote. - This is not a problem since the Event Channel supports - multiple supplier IDs, - but we could check the local publications and remove those - events from the Gateway publication and subscription list. - </P> - </LI> - - <LI>Support IIOP 1.1 in the ORB - <P></LI> - - <LI>Use the IIOP 1.1 profile info to pass QoS info and use it to - preserve end-to-end QoS. - <P></LI> - - <LI>Support IIOP 1.2 in the ORB - <P></LI> - - <LI>Support GIOP 1.1 in the ORB (fragments) - <P></LI> - - <LI>The size of pre-allocated buffer for the outgoing CDR - streams is defined at compilation time; but if we use an - efficient enough allocator we could make its size configurable - via the svc.conf file. In any case the *second* (and - subsequent) buffers come out of the allocator, so their sizes - could be configured in the already mentioned file. - <BR>[NOTE] We have to be able to do this while minimizing the - number of calls to ORB_Core_instance() - <P></LI> - - <LI><B>IDL Compiler:</B> The IDL compiler front-end should be - case insensitive, - more precisely it should flag identifiers that only differ by - case as a conflict and verify that all uses of an identifier - have the same case. - <P></LI> - - <LI><B>IDL Compiler:</B> The operation tables do not need to be - statics, they could be created on creation of the first - servant of that type. - <P></LI> - - <LI><B>IDL Compiler:</B>Support for unions with default cases - (implicit or explicit) - in the IDL compiler is incomplete. - <P></LI> - - <LI>It seems that some memory is leaked from the ORB cached - connector. - <P></LI> - - <LI><B>IDL Compiler:</B>Support for the <CODE>fixed</CODE> data - type in the IDL compiler - <P></LI> - - <LI>CDR stream support for <CODE>wchar</CODE> is flaky or at - least untested. - <P></LI> - - <LI>Add a <CODE>corbafwd.h</CODE> header file to eliminate the - deep (and recursive) header dependencies in TAO. - <P></LI> - - <LI>Add << and >> operators to the - <CODE>CORBA::Request</CODE> class, to simplify DII invocations - (this is an Orbix-sism). - The IDL compiler has to generate them for the user defined - types. - <P></LI> - - <LI>Several helper structs for <CODE>Any</CODE> have to be - added, mainly: <CODE>to_object</CODE>, <CODE>to_wchar</CODE>, - <CODE>to_wstring</CODE> and their <CODE>from_</CODE> - <BR>[STATUS] Jeff added several of them, I need to check what - is missing. - <P></LI> - - <LI>Prepare the 1.0 release:<P> - <OL> - <LI>Integrate the compiled marshalling approach. - <BR>[STATUS] Andy has made great progress on this. - </LI> - <LI>Verify the GPERF is working in all the relevant - platforms. - <BR>[STATUS] As far as we know it is working correctly. - </LI> - <LI>Integrate active demux of operations? - </LI> - </OL> - <P></LI> - - <LI>Support the Sun bootstrapping mechanism for the Naming - Service - <P></LI> - - <LI>Add a -ORBlogfile flag so we can set the ACE_ERROR and - ACE_DEBUG output destination in all TAO applications - <P></LI> - - <LI>Support several calls to ORB_init() on the same thread. - <P></LI> - - <LI><B>EC:</B> Call ORB_init() in the EC threads? - [The dispatching threads for Boeing] - <P></LI> - - <LI><B>EC:</B> Build an EC example that uses all the cool features - (multiple endpoints on each process, collocated EC and - Scheduling Service, Naming, etc.) - <P></LI> - - <LI><B>EC:</B> Extend the Concurrency Service (or create a new - one) that allow us to have global "barriers" to synchronize EC - startup/shutdown. - <P></LI> - - <LI><B>EC:</B> Debug interval computation in Linux (and NT?) - <P></LI> - - <LI><P>Remove the uneeded methods from CORBA::Object - <BR>[STATUS] This task seems to be complete - </P> - </LI> - - <LI><B>IDL Compiler:</B> The IDL compiler could generate a static - method to access the interface repository ID of a class. - <P></LI> - - <LI><B>IDL Compiler:</B> The IDL compiler should support - <CODE>#include "orb.idl"</CODE> properly. - IMHO it should not - add any <CODE>#include</CODE> to the generated code and the - <CODE>orb.idl</CODE> file should contain all the declarations, - except for the pseudo objects that are should be hardcoded - into the compiler. - <P></LI> - - <LI>The current scheme for the orbsvcs leaves the user without - control over collocation of servants, we need to move to a scheme - similar to the one in $ACE_ROOT/netsvcs. - <BR>[STATUS] The user can control collocation, but we need a - dynamic way to do it (or an example) that exploits the Service - Configurator. We also may need to split the library. - <P></LI> - - <LI><B>EC:</B> Use the Service_Configurator to dynamically load - the EC Module_Factory thus making it really configurable. - <P></LI> - - <LI><B>EC:</B> Cleanup the IDL structures for subscriptions, - publications, etc. (in the EC). - <BR>[STATUS] Part of this was completed. The Header and - Payload of the events are clearly distinguished, now we need - to use only the Header in the Publication and Subscription - definitions. - <P></LI> - - <LI>Resolve the <CODE>Typecode::equal</CODE> dilemma: is it - structural or type equivalence? Or a mixin? - <BR>[STATUS] The correct interpretation seems to be: - <UL> - <LI>If the interface repository ID is not present and/or the - optional field name is not present then TypeCode::equal - should just test for structural equivalence. - <P></LI> - <LI>If the interface repository ID is present then type - structural equivalence is not enough - <P></LI> - <LI>The spec (2.2 or 2.3?) will add a - <CODE>equivalent</CODE> method to check for structural - equivalence modulo aliases - <P></LI> - </UL> - <P></LI> - - <LI><P><B>IDL Compiler:</B> The methods on the server side - <B>must</B> have a throw spec, check CORBA 2.2, 20.35 - </P> - </LI> - - <LI><P>According to Vinoski and Henning the - <CODE>CORBA::Policy</CODE> objects are also locality - constrained. - I could not find a references in the spec.</P> - </LI> - - <LI><P>Exercise the insertion and extraction operators for - <CODE>Any</CODE> in the <CODE>Param_Test</CODE>, - for example, provide a new <CODE>-i dii_any_op</CODE> - testing mode. - </P> - </LI> - - <LI><P>Test Any with variable sized types, such as structures - that contain a string inside. Jeff reports that there is a - problem when destroying Anys initialized with this types, - even if the IDL compiler generated <<= operator is used. - </P> - </LI> - - <LI><P>Include a regression test to verify that - <CODE>octet</CODE> is <B>not</B> a valid discriminator for - unions - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> CORBA 2.2 does not allow - <CODE>octets</CODE> as - constants, yet the IDL compiler does not complain about it. - </P> - </LI> - - <LI><P>Verify that the typecode for unions use a - <CODE>octet</CODE> with value <CODE>0</CODE> for the default - discriminator - </P> - </LI> - - <LI><P>Is the client side in TAO handling a - <CODE>CloseConnection</CODE> GIOP message properly? - </P> - </LI> - - <LI><P>If the connection to the server cannot be established the - right exception is <CODE>TRANSIENT</CODE>, not - <CODE>COMM_FAILURE</CODE>; this and other exception - inconsistencies have to be checked - </P> - </LI> - - <LI><P>The spec (CORBA 2.2, 20.17) defines accesor methods for the - fields of a <CODE>SystemException</CODE>. - </P> - </LI> - - <LI><P>In some platforms it may be necessary to add an extra - value to an enum to force it to be 32-bits wide. - </P> - </LI> - - <LI><P>The spec requires that strings as fields of structures be - initialized to the empty (not the null) string. - </P> - </LI> - - <LI><P>The <CODE>SINGLE_THREAD_MODEL</CODE> for the POA requires - that the execution for all request on that POA happen on the - same thread. - </P> - </LI> - - <LI><P><CODE>$TAO_ROOT/orbsvcs/tests</CODE> may require the same - hierarchy changes that were done in - <CODE>$TAO_ROOT/tests</CODE>. - </P> - </LI> - - <LI><P>The <CODE>_duplicate()</CODE> and <CODE>_narrow()</CODE> - functions can throw exceptions, yet our mapping does not - contain an <CODE>CORBA::Environment</CODE> argument. - A similar problem ocurs with - <CODE>ORB::resolve_initial_references</CODE>, the ORB can - throw the <CODE>InvalidName</CODE> exception. - </P> - </LI> - - <LI><P>Apparently the implementation for the leader-follower - model on the client side has bug: - it will add the current thread to the follower list every - time it returns from waiting in the condition variable, - assuming that it was signaled and removed every time. - </P> - </LI> - - <LI><P>By default TAO disables Nagle's algorithm, this should be - an optional feature, otherwise TAO will perform poorly over - WANs. - </P> - </LI> - - <LI><P>Improve the connection recycling strategies, for - instance, - several strategies are possible: limit the maximum number of - open sockets, probably with both HWM and LWM bounds, - with different policies to choose the socket to close (LFU, - MRU?); - or maybe be more aggresive and recycle a socket once - all the object references pointing to a server are closed. - The later approach could be easily implemented if each - IIOP_Object held a reference to the set of sockets opened to - a certain TCP/IP address. - </P> - </LI> - - <LI><P>Check that system calls like <CODE>recv()</CODE> and - <CODE>send()</CODE> are restarted if a signal is received by - the process while they are executing. - </P> - </LI> - - <LI><P>Update the collocated test in Cubit - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> The CORBA 2.3 spec clarifies the scope of a - <CODE>#pragma prefix</CODE>: - the prefix is supposed to get cleared after each - <CODE>#include</CODE>, - also the statement -<PRE> -#pragma prefix "" -</PRE> - should clear the prefix. - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> GPERF is generating a function for - each binary search table; - a generic function could be used, or at least we should add - an option to gperf to it receives that generic function as - an argument. - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> The TAO_IDL compiler does not handle - the following code sequence properly: -<PRE> - // IDL - interface Foo; - typedef sequence<Foo> FooSeq; - - interface Foo { - // anything here - }; -</PRE> - It may be necessary to have a multi-pass code generator to - solve this problem. - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> Tom Ziomek - <tomz@cc.comm.mot.com> reports that the IDL - compiler does not verify that <CODE>oneway</CODE> operations - cannot include a <CODE>raise</CODE> expression. - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> We must also check that oneways do - not contain any <CODE>out</CODE> or <CODE>inout</CODE> - parameters. - </P> - </LI> - - <LI><P>Currently we use blocking writes for the request, we need - to change this so we use the Reactor to send the data - instead of blocking directly on the <CODE>writev</CODE> call. - </P> - </LI> - - <LI><P><B>ORB:</B> - When handling a forward request we may get forwarded to a - collocated object. - The typical scenario is a server that register with the - Implementation Repository: - if it creates an object reference to a local object the - object reference will be pointing to the ImplRepo and - potentially none of its profiles will match the local ones. - Trying to contact the ImplRepo will result in a - LOCATION_FORWARD exceptions (and/or a LocateReply) pointing - to the local endpoints, but now we should use collocation. - </P> - </LI> - - <LI><P><B>ImplRepo:</B> - How do the ImplRepo and pluggable protocols interact? What - if the ImplRepo is using a protocol that is not implemented - in the server? Or vice-versa? - </P> - </LI> - - <HR> - - <!-- Things below this point are "big" tasks" that --> - <!-- could require major work --> - - <LI><P>Provide mechanisms to marshal arguments into a CDR - stream, Jon Biggar contributed his proposal to the CORBA 2.3 - RTF: -<PRE> -Issue 991: Operations to add to CORBA::ORB pseudo-object - -Proposal: - -[Note I have expanded the SerializedEncoding IDL type to include version -information, since we now have 3 versions of CDR!] - -The following operations should be added to the CORBA::ORB -pseudo-object: - -module CORBA { - interface ORB { - ... - typedef sequence<octet> SerializedData; - typedef unsigned long SerializedFormat; - - const SerializedFormat ENCODING_CDR = 0; - - struct SerializedEncoding { - SerializedFormat format; - octet major_version; - octet minor_version; - }; - - SerializedData serialize(in Any data, - in SerializedEncoding how); - Any unserialize(in SerializedData data, - in SerializedEncoding how); - SerializedData serialize_value(in Any data, - in SerializedEncoding how); - Any unserialize_value(in SerializedData data, - in SerializedEncoding how, - in TypeCode tc); - ... - }; -}; - -These operations provide a standard mechanism for serializing and -unserializing the data in an any, along with hooks to support new -encoding formats as they are needed. The type SerializedEncoding -indicates the encoding mechanism to use to serialize and unserialize the -data. The format field specifies what encoding rules to use when -serializing the data, and the major_version and minor_version indicate -what version of the encoding rules to use. - -The serialize and unserialize encode the TypeCode along with the value -so that the serialized data is self contained. The serialize_value and -unserialize_value version encodes the value without the TypeCode to save -space, but a TypeCode must be supplied to unserialize the data. - -Since the serialized data may contain no indication of machine dependent -issues such as byte order, the serialized data can only be guaranteed to -correctly be unserialized on the same ORB. The IDL any type should be -used to exchange information between ORBs. - -Data encoded using the ENCODING_CDR format will be encoded using CDR -encapsulation format. -</PRE> - - </P> - </LI> - - <LI><P>Add support for Smart Proxies to the ORB</P> - </LI> - - <LI><P>The ORB should support server side and client side - interceptors</P> - </LI> - - <LI><P>The ORB does not have an interface repository</P> - </LI> - - <LI><P>Once the interface repository is in place we could add - support for CORBA script - </P> - </LI> - - <LI>The current scheme for Typecode (keeping a CDR buffer with - their representation) is broken; we should use classes for - each variant of a TypeCode; but initialization would be - complicated then. - <P></LI> - - <LI><P>The CORBAlite RFP is very interesting IMHO we just need to - remove features from TAO to make it a CORBAlite - implementation. The problem is how to keep the full blown - CORBA implementation also, this is an idea: - Write the TAOlite version of a class (example TypeCode):</P> - - <PRE> - class TAO_CORBAlite_TypeCode { - // Just the CORBAlite methods are implemented. - }; - </PRE> - - <P>Derive the full blown implementation:</P> - - <PRE> - class TAO_CORBA_TypeCode : public TAO_CORBAlite_TypeCode { - // Declare all the other methods. - }; - </PRE> - - <P>create two namespaces:</P> - - <PRE> - // in tao/CORBAlite.h - class CORBA { - tyedef TAO_CORBAlite_TypeCode TypeCode; - }; - - // in tao/CORBAfull.h - class CORBA { - typedef TAO_CORBAfull_TypeCode TypeCode; - }; - </PRE> - - <P>then (at compile time) the users chooses between the CORBAlite - or CORBAfull implementations:</P> - - <PRE> - // In $TAO_ROOT/tao/corba.h - #if USERS_WANTS_FAT_FREE_CORBA - #include "tao/CORBAlite.h" - #else - #include "tao/CORBAfull.h" - #endif - </PRE> - - <P>We need to consider how to support even smaller profiles that - the CORBAlite RFP, like removing <CODE>Any</CODE> or - <CODE>fixed<></CODE> support. - We also need to come out with a scheme to support - interpretive marshalling in the CORBAlite framework (where - TypeCodes don't have enough methods as to traverse them). - </P> - <P> - </LI> - - <LI><P>Consider decompositions of the ORB that would allow - dynamically linked plug-ins, for example it should be easy to - dynamically load a pluggable protocol. - Other decompositions are harder, but still worthwhile looking - at: - <UL> - <LI>Dynamically load the support for costly features, as the - ImplRepo or Location Forwarding. - <P> - </LI> - <LI>Dynamically configure POA with or without support for - holding state. - <P> - </LI> - </UL> - </P> - </LI> - - <LI><P><B>IDL Compiler:</B> Currently the IDL compiler creates an - operation table that - includes all the base classes operations; this permits the - generation of efficient code that does not rely in - dynamic_cast or the _downcast() method for Servants (which - compare strings, hence it is slow). - It could be interesting to implement the alternative approach - were the class only looks its own operations and then tries - the parent. This will reduce code size, but will probably - decrease performance. - </P></LI> - - <LI>Server_Request objects in TAO are magical, the _duplicate() - method returns 0 and release() does nothing. - The problem starts because Server_Request is allocated from the - stack (to speed up things), hence reference counting would be - useless. Adding a clone() method will work better, but the - Server_Request holds pointers to several positions in the CDR - stream, we could clone the CDR stream, but a normal - Server_Request does not own it.... In our opinion (Carlos and - Irfan) we need not worry about this until we find a use case for - it. - <P></LI> - - <LI> - The current implementation of collocation is optimal for - hard-real-time - applications, but in some cases it may be desirable to follow - the normal execution path yet minize costs for collocated - calls. - An example would include an application that activates the - objects on demand. - It would be interesting to have a half-collocated stub - implementation, that will marshall the request and then - invokes the normal path on the "server" side, but without - crossing the kernel boundary. Ideally even the serialization - could be minimized or avoided. - <P></LI> - - </OL> - -<HR><P> - <H3>Completed Tasks</H3> - - <OL> - <LI><P><B>EC:</B> The current architecture of the real-time - Event Channel does not support some features, such as: - <UL> - <LI><P><B>EC:</B> Some applications are both suppliers and - consumers of events, - they may be interested in all the - events of type <B>T</B> unless the event is generated - by them. - </LI> - <LI><P><B>EC:</B> Can we factor out the scheduling service from - the EC? - </P> - </LI> - - <LI><P><B>EC:</B> The reactive event channel can eliminate - data copies because the data does not need to survive - after the <CODE>push()</CODE> call. - </P> - </LI> - - <LI><P><B>EC:</B> Many applications require to intercept - the EC event processing, for example to keep track of - the number of events received and sent. - This requires strategized factories for many (if not - all) of the Event Channel internal servants. - </P> - </LI> - - <LI><P><B>EC:</B> Some applications require ad-hoc - filters, such as "this events must arrive in - sequence", or "wait for all this events and then send - this other event". - </P> - </LI> - - <!-- This is Boeing specific --> - <LI><P><B>EC:</B> For some applications it is insteresting - to activate the EC servants (such as the - ConsumerProxys) in different POAs - </P> - </LI> - - </UL> - We have completed a new design for the real-time event - channel that will let us implement all this features (and - others). - <BR>[DONE] The new implementation is working, we have to add - several strategies and stress test it, but the architecture - seems sound. - <BR>[ASSIGNED TO:] Carlos - </P> - </LI> - - <LI><P><B>IDL Compiler:</B>The IDL compiler could generate files - with empty - implementation classes, just to make the life of implementors - a bit easier. - <BR>[DONE] - <BR>[ASSIGNED TO:] Yamuna - </P> - </LI> - - <LI><P><B>EC:</B> Build a COS Event Channel on top of the RTEC - Event Service. - <BR>[DONE] - <BR>[ASSIGNED TO:] Pradeep - </P> - </LI> - - <LI><P><B>EC:</B>Implement fragmentation and reassembly of UDP - messages. This is important for an effective implementation - of the multicast version of the EC. The classes affected - include <CODE>UDP_Receiver</CODE> and <CODE>UDP_Sender</CODE>. - <BR>[DONE] - </P> - </LI> - - <LI><P><B>EC:</B> The Event Channel must be profiled, - quantified, etc. - Now that we have a single threaded event channel this task - is much easier, the points to investigate are: - </P> - <P> - <UL> - <LI> How many data copies does the EC make? Can we reduce it - to zero? - </LI> - <LI> How many memory allocations? - <BR>[RESULT: 8] - <BR>Can they be replaced by memory pools? - </LI> - <LI>How many locks? - <BR>[RESULT: 29 (single threaded), 31 MT] - <BR>Can we strategize locks? - <BR>Can we share a single lock for the whole dispatch? - </LI> - </UL> - <BR>[ASSIGNED TO:] Carlos - </P> - </LI> - - <LI><P>The TypeCode internal (private) state needs locking, double - checked locking is needed to avoid excessive overhead, there - is potential for memory leaks if this locking is not used. - <BR>[DONE] - </P> - </LI> - - <LI><P><B>EC:</B>The <CODE>UDP_Receiver</CODE> class has some - problems on Win32 platforms because a - <CODE>recvfrom()</CODE> call fails if the buffer is to small - for the datagram, even if the <CODE>MSG_PEEK</CODE> flag is - used. We may need to modify the - <CODE>ACE_OS::recvfrom()</CODE> call to match the unix - semantics. - </P> - <BR>[DONE] Irfan fixed the <CODE>ACE_OS::recvfrom()</CODE> - function. - </LI> - - <LI><P><B>EC:</B> When shuting down a reactive Event Channel the - timeouts for the EC have to be cancelled. - It would seem like the proper way to do that is to do it in - the <CODE>shutdown()</CODE> method of the - <CODE>Timer_Module</CODE>. - <BR>[DONE] - </P> - </LI> - - <LI><B>EC:</B> Improve configuration support in the EC, give an - example of a single threaded EC, support different dispatching - strategies, etc. - <BR>[DONE] But there are a few bugs to remove. - <P></LI> - - <LI><B>EC:</B> Correlation in the EC has a bug [?] - <BR>[DONE] Added a correlation test into the EC_Basic test, - this does not mean that all bugs have been removed, but we - don't know of any remaining bugs. - <P></LI> - - <LI><P>The methods in <CODE>CORBA::TypeCode</CODE> should be - <CODE>const</CODE>. - </P> - <BR>[DONE] - </LI> - - <LI><P>Add the <CODE>CORBA::TypeCode::_tc_Bounds</CODE> and the - <CODE>CORBA::TypeCode::_tc_BadKind</CODE> type codes. - Currently they are in the wrong namespace (just - <CODE>CORBA::_tc_Bounds</CODE>). - </P> - <BR>[DONE] - </LI> - - - <LI><P>Add compiled marshalling - <BR>[STATUS] Andy is working on this. - <BR>[DONE] The compiled marshaling code works, we still have - to fine tune it a bit. - </P> - </LI> - - <LI><P>Implement the new DynAny types. - <BR>[STATUS] Jeff is working on this. - <BR>[DONE] More testing is needed, but the basics are - there. - </P> - </LI> - - <LI><P><B>EC:</B>The <CODE>TAO_EC_Gateway_IIOP</CODE> class - receives events from a "remote" EC and pushes them on the - local EC. - The subscription and publication list for the Gateway are - the disjunction of the local EC consumer subscriptions. - Unfortunately this can result in multiple supplier_IDs for - the Gateway, the current implementation is not prepared to - handle this. - The Gateway must keep a list of suppliers, each one with a - different supplier id, - when it receives a remote event it should push the event - only to the right supplier. - It must also keep another supplier used for the events that - are of interest by their event type, regardless of their - supplier ID. - <BR>[DONE] - </P> - </LI> - - <LI><P><B>EC:</B>The Event Channel must be able to accept more - than one supplier with a given supplier ID, or at least we - should be able to configure the EC to work in such a mode. - This is required for some applications that treat the - supplier ID as a "supplier type". - <BR>[DONE] - </P> - </LI> - - <LI><P><B>EC:</B>If a Supplier disconnects while it has - consumers registered for it's Supplier_ID, - the consumers are not connected again even if the supplier - reconnects. - <BR>[DONE] - </P> - </LI> - - <LI><P>Further optimize memory allocation by using a memory pool - for the incoming CDR stream. - <BR>[DONE] The pool is configurable for the users that may - want to steal the CDR buffer. - </P> - </LI> - - <LI><P>The nested upcall support must be strategized, - some applications don't need this feature, - other applications are single threaded or use an - ORB-per-thread concurrency policy, - so using a full-blown leader follower in all cases can - result in a significant slow down. - It seems like the right way to - strategize this by changing the Client_Connection_Handlers. - <BR>[DONE] Irfan and Carlos are finished this task. - </P> - </LI> - - <LI><P>Use active demuxing in the POA to locate servants in - constant time, as well as active demuxing - in the skeletons to locate operations in constant time. - <BR>[DONE] Irfan finished this task. - </P> - </LI> - - <LI><P>Sometimes the ORB picks up the wrong name on multi-homed - hosts, - the <CODE>ACE_INET_Addr</CODE> class uses - <CODE>gethostbyaddr_r</CODE> to convert from the address into - a hostname, but it only uses the first alias. - <BR>[DONE] The current implementation tries to use the - alias that more closely matches the address of the given - host. - </P> - </LI> - - <LI><P>Many of the test programs in the - <CODE>$TAO_ROOT/tests</CODE> hierarchy are actually sample - programs or performance tests. - </P> - <P>We need to re-organize this hierarchy, following the ACE - scheme: - <UL> - <LI><B>tests</B> for programs that do regression testing. - </LI> - <LI><B>examples</B> for programs that illustrate how to use - TAO, a service or a component - </LI> - <LI><B>performace-tests</B> for programs that are used in - performance measurements - </LI> - </UL> - the same hierarchy may be needed in - <CODE>$TAO_ROOT/orbsvcs</CODE>. - <BR>[DONE] Doug did this changes already, minor revisions - many be necessary, and orbsvcs is still pending. - </P> - </LI> - - <LI>Cleanup memory managment in some of the servers, for - instance: Naming still believes that controlling the memory - for a stub will control the servants, this is not true - anymore. - <BR>[DONE] Marina fixed the Naming Service, the other services - are working OK also. - <P></LI> - - <LI><P>The mapping for the CORBA <CODE>boolean</CODE> type does - not require the <CODE>CORBA::TRUE</CODE> constant, - but it never mentions the <CODE>CORBA::B_TRUE</CODE> constant - either; in fact it recommends the usage of the literals - <CODE>0</CODE> and <CODE>1</CODE>. - We should move to use the <CODE>CORBA::TRUE</CODE> style, - because other ORBs offer the same feature, - but only use the literals, - to show the "Right Way"[tm] of doing CORBA things. - </P> - <BR>[DONE] Irfan removed the <CODE>CORBA::B_TRUE</CODE> and - <CODE>CORBA::B_FALSE</CODE> constants and replaced them with - the compliant <CODE>0</CODE> and <CODE>1</CODE> - </LI> - - <LI><P>Add an option to the IDL-compiler (e.g. -rp) meaning - "generate relative include paths". - <BR>[STATUS] Alex is working on this. - <BR>[DONE] - </P> - </LI> - - <LI><P>Add the <<= and >>= operators for - <CODE>CORBA::TypeCode</CODE> - <BR>[DONE] Jeff added the operators</P> - </LI> - - <LI>The IDL compiler should generate the code locally (not in - the directory where the .idl resides) or at least give an - option to do so - <BR>[DONE] Alex completed this, he even added an option to - select the output directory. - <P></LI> - - <LI>Are nested upcalls in different concurrency models, like - thread-per-connection working? - <BR>[STATUS] Irfan reports that this works correctly with - <CODE>thread-per-connection</CODE> - <BR>[DONE] The <CODE>NestedUpcall/Reactor</CODE> test is - giving the same results with either - <CODE>thread-per-connection</CODE> or <CODE>reactive</CODE> - strategies. - <P></LI> - - <LI>Normalize the compiled marshalling interface: the IDL - compiler is going to generate a different interface than the - code I showed in the EC_Custom_Marshal example; we need to - make all the code consistent so users have easy access to it. - <BR>[DONE] - <P></LI> - - <LI>Object references inside structures or sequences are not - decoded properly, the problem starts because the interpreter - expects a CORBA::Object_ptr, but the real type is a T_var; - virtual inheritance adds the last ingredient to the poison. - <BR>[STATUS] A possible solution is to use a T_manager_var that - has two fields a Object_ptr and a T_ptr.... - <BR>[DONE] The solution was to use - <CODE>TAO_Object_Field_T<T></CODE>, that - behaves like the _var classes, but extends them to provide - virtual methods to <CODE>_upcast()</CODE> and - <CODE>_downcast()</CODE> to and from - <CODE>CORBA_Object_ptr</CODE>. - Similar methods were added to sequences of objects. - <P></LI> - - <LI>Add options to the IDL compiler to set the suffixes. - <BR>[DONE] Alex finished this. - <P></LI> - - <LI>Support for 64bit longs in the IDL compiler - <BR>[DONE] They were supported already, but we had to test - them, I added a test to Param_Test. - <P></LI> - - <LI>The do_static_call() and do_dynamic_call() methods should - use an array of <CODE>void*</CODE> - (in the first case static and generated by the IDL compiler); - this will remove the problems with g++ and probably work - faster. - <BR>[DONE] - <P></LI> - - <LI>The IDL compiler gets confused with paths in NT, this may be - due to my changes to report errors correctly (coryan). - <BR>[STATUS] Creating a Win32 workspace to try it. - <BR>[DONE] - <P></LI> - - <LI>The current implementation of octet sequences based on - message blocks has a few problems, it cannot marshall - chains of message blocks properly. - Notice that complete support for chains of message blocks will - complicate the sequence of octets implementation (like - operator[]) and will make others either hard or expensive - (like get_buffer ()). - <BR>[STATUS] It seems like the best tradeoff would be to - support the chain during marshalling, but disable or give no - warranties for operator[] and get_buffer(). - <BR>[DONE] - <P></LI> - - <LI>Debug Memory Pools in the EC there seem to be a problem when - sending multiple events in a row (a memory leak, limit or - corruption). - <BR>[DONE] - <P></LI> - - <LI>Add suspend and resume operations to the PushConsumerProxy - and PushSupplierProxy interfaces, following the Notification - Service spec. - <BR>[DONE] - <P></LI> - - <LI>Optimize connection lookup in the client side, using "hints" - from the previous lookup, or keeping smaller sets on each IIOP - profile or a combination of both. - <BR>[STATUS] Irfan is working on - this. - <BR>[DONE] - <P></LI> - - <LI>Optimize the outgoing CDR streams by using TSS memory pools - for both the data blocks and the buffers. - <BR>[DONE] But we may consider strategizing the kind of allocator - we use (like using a free list instead of a generic - ACE_Malloc). - <P></LI> - - <LI>Optimize Octet Sequences. - <BR>[DONE] - <P></LI> - - <LI>Obtain results for the EC_Multiple test. - <UL> - <LI>Latency seems OK. - <P></LI> - <LI> Overhead: need lower priority for scavenger thread. - <P></LI> - </UL> - <P></LI> - - <LI>Debug EC_Multiple. - <P></LI> - - <LI>Your next assignment: Regenerate all methods in - _tao_collocated to avoid "inherit via dominance" warnings. - <BR>[STATUS] The IDL compiler was modified to generate a - suitable - <CODE>#pragma</CODE> that removes the warning, it reenables - the warning when leaving the file - <P></LI> - - <LI>Remove the SOLARIS2 macro from the TAO_IDL compilation. - <BR>[DONE] - <P></LI> - - <LI>Remove the preemption_prio message from Scheduling_Service. - <P></LI> - - <LI>The ORB core should be able to choose the right port for us - (in other words -ORBport 0) should work. - <BR>[DONE] - <P></LI> - - <LI>Client side optimization for Octet Sequences. - <BR>[DONE] - <P></LI> - - <LI>Minimize memory allocation in TAO - <BR>[STATUS] Down to 3 on the client side and 4 on the server - side. - <BR>[STATUS] For oneways it is down to 0 (for the common case) - on the client side and 2 on the server side. For twoways it is - 2 on both sides. - <P></LI> - - <LI>Automate subscription and publication list generation in the - EC_Gateway. - [VERY important for Boeing] - <BR>[STATUS] Completed and debugged, but the EC is still - buggy. - <P></LI> - - <LI>Debug EC shutdown and startup.... - [Specially startup for Boeign, but shutdown is important for - Purify and Quantify] - <BR>[STATUS] Shutdown is clean and startup of threads can be - controlled by the user. - <P></LI> - - <LI>Support a chain of Message Blocks in Output CDRs and use - writev() to write them. - <BR>[DONE] - <P></LI> - - <LI>Memory managment in the demarshalling engine, it is not - clear that the current scheme works in all cases (like - sequences of unions of anys). - We also need to fix sequences of object references: how does - the demarshalling engine learn about the dynamic type of the - objects? - Closely related to this is the problem of memory alignment for - different architectures, we need to develop strategies for each - one (they should only be a few) and choose the right one. - <BR>[STATUS] This seems to be working for most of the cases, the - main idea is to delay demarshalling until enough information - is available, for instance, when decoding an Any just a - reference to the CDR stream is stored, decoding actually - happens when the user invokes >>= on the any (at that point - all the info is there). - <P></LI> - - <LI>Add a new Profile type that includes the QoS info and using - for end-to-end QoS preservation. - [DEPRECATED] The IIOP 1.1 Profiles can handle that. - <P></LI> - - <LI>Show an example of the - <CODE>sequence<octet></CODE> and CDR streams. - <BR>[DONE] But the example could also include the marshalling of - plain C++ types. - <BR>[DONE too] - <P></LI> - - <LI>Test anys in the EC. - <BR>[DONE] Michael reported that they work OK on NT. - <P></LI> - - <LI>UDP for event channel and Multicast support in the EC. - <BR>[STATUS] Manual configuration using Suppliers and Consumers is - possible, automation is under research. - <P></LI> - - <LI>Unbind the EC and scheduling service from the Naming - Service. - <BR>[DONE] For the Event_Service and the examples. - <P></LI> - - <LI>Optimize oneways by not allocating the memory for the return - buffers. - <BR>[DONE] Added different Invocation classes for each case. - <P></LI> - - <LI>Fix the _non_existent call. - <BR>[DONE] The client side semantics match the new clarifications - of the C++ RTF, the server side is implemented by the IDL - compiler, though t could be a good idea to put that in the - POA. - <P></LI> - - <LI>Simplify EC configuration, a Factory class must provide the - Dispatching, Supplier, Correlation and any other Modules that - are required. - This is the right spot to add trivial Dispatching or - Correlation Modules and to dynamically load and configure the - EC. - <BR>[DONE] A Factory class is used to create the modules, only the - default factory is implemented so far. - <P></LI> - - <LI>Fix the ACE_Thread_Condition madness. - <BR>[DONE] We changed ACE so ACE_SYNCH_CONDITION expands to - ACE_Condition_Thread_Mutex - <P></LI> - - <LI>Reference counting should have locks, but we should remove - all the QueryInterface madness to make that work. The policy - for references in multiple threads is: the reference count - must be >2 if that happens. - <BR>[STATUS] The QueryInterface method (all the COM stuff for that - matter) was removed... - <BR>[DONE] - <P></LI> - - <LI>Reference counting for Typecodes is completely broken. - <BR>[DONE] - <P></LI> - - <LI>Under g++(2.7.2) the use of multiple inheritance in IDL - triggers some compiler bug, if the IDL explictly generated the - copy constructor for the skeletons (the POA_ classes) the - problem would go away. - <BR>[DONE] Fixed, Seth is testing the fixes and will commit them - soon (Tue Jul 21 14:24:56 CDT 1998) - <P></LI> - - <LI>The octet sequence optimization causes problems when Anys - get into the game. - <BR>[DONE] Seth reported that the problem was not real. - <P></LI> - - <LI>The DEEP_FREE method is also broken, sometimes we need to - release the top-level memory, sometimes not. - <BR>[DONE] We always release the memory in the Any, it was failing - due to weird interactions between the Environment containing - an exception and the Any that also did. - <P></LI> - - <LI>Improve error messages in the IDL compiler. - <BR>[DONE] At least the filename is correct now. - <P></LI> - - <LI>Support for arrays in the IDL compiler is incomplete, - specially anonymous arrays. - <BR>[DONE] According to Andy this is properly supported by the IDL - compiler now. - <P></LI> - - <LI>Prepare the 0.2 release:<P> - <OL> - <LI>Execute all the tests in $TAO_ROOT/tests - </LI> - <LI>Run Param_Test (SII) and record what fails and what works. - </LI> - <LI>Run Param_test (DII) and record what fails and what works. - </LI> - <LI>Run Param_Test across Endian Borders. - </LI> - </OL> - <BR>[DONE] At last! - <P></LI> - - <LI>Move this list to the release notes. - <P></LI> - </OL> - -<HR> - -<P>Back to the TAO <A HREF="../index.html">documentation index</A>. <!--#include virtual="/~schmidt/cgi-sig.html" --> -</BODY> -</HTML> diff --git a/TAO/docs/releasenotes/ec.html b/TAO/docs/releasenotes/ec.html deleted file mode 100644 index 89c4fb506e8..00000000000 --- a/TAO/docs/releasenotes/ec.html +++ /dev/null @@ -1,214 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.06 [en] (X11; I; SunOS 5.5.1 sun4u) [Netscape]"> - <TITLE>Event Service Status</TITLE> -<!-- $Id$ --> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF"> - -<H3>TAO's Real-time Event Service</H3> -Point of contact: <A HREF="mailto:coryan@cs.wustl.edu">Carlos O'Ryan</A> -<H4> -Last Updated: $Date$</H4> - -<H3> -New on this release</H3> - -<UL> - <LI><P>Added fragmentation and reassembly support for the multicast - gateways</P> - </LI> -</UL> - -<H3> -Known issues:</H3> - -<DL> -<DT> -<I>The schedule cannot be downloaded</I></DT> - -<DD> -The Scheduling Service seems to compute proper schedules, but it is not -possible to download them, apparently there is a marshalling problem for -sequences of complex structures.</DD> - -<P>Due to this problem we have been unable to test the run-time scheduler -and performance it is impossible to complete performance measurements and -optimizations: the (global) scheduling service latency and overhead is -at least as large as the EC itself. -<P><B>Note:</B> This does not seem to be the case anymore, but the comment -will remain here until I can confirm that the problem dissapeared. -<DT> - -<P><I>Run-time scheduler requires re-link</I></DT> - -<DD> -During a normal execution of the system there is no need to use the a global -Real-time Scheduling Service, a faster, collocated implementation for the -service is available. Obviously the scheduling information is precomputed -in some config run.</DD> - -<P>Unfortunately the current scheme requires a relink of all the involved -applications against the generated tables for the run-time scheduling service. -<P>We should be able to download the schedule to the interested parties, -without need for a separate link phase. This will simplify and speed up -the developing cycle, but requires a (small and fixed) amount of dynamic -memory allocation. It could be interesting to "save" the schedule computation -in some persistent form, so startup cost are lower too. -<P>The current design contemplates a config run were a global consumer -accumulates the QoS requirements of all the objects, next an external utility -is used to force a computation and save of the schedule. In future executions -the global scheduler pre-loads this schedule and the clients simply download -the precomputed schedule, and all scheduling queries are to a local scheduling -service, without any further contact to the global instance. -<DT> -<P><I>Users have no control over service collocations</I></DT> - -<P>The user should have complete control of services collocation, using -ACE Service Configurator; currently the services must be explicitly instantiated -by the user. -<DT> - -<DT> -<P><I>Further details:</I></DT> - -<P>Many lower level issues and tasks can be found in the <A HREF="TODO.html">TODO -list</A>. - -</DL> - -<H3> -Examples</H3> - - -For general documentation on the Event Service please read <A HREF="http://www.cs.wustl.edu/~schmidt/oopsla.ps.gz">The -Design and Performance of a Real-time CORBA Event Service</A>. -<P>The simplest test for the Event Channel is <TT>Event_Latency</TT>, below -are the basic instructions to run it: -<OL> -<LI> -Compile everything under <TT>$TAO_ROOT/orbsvcs</TT>, this needs, obviously, -<TT>$TAO_ROOT/tao</TT> -and the IDL compiler in <TT>$TAO_ROOT/TAO_IDL</TT>.</LI> - -<P>Run the naming service, the scheduling service, the event service and -the test in <TT>$TAO_ROOT/TAO/orbsvcs/tests/Event_Latency</TT>; remember -to give a different port to each one, using the <TT>-ORBport</TT> option. -As in: -<P><TT>$ cd $TAO_ROOT/orbsvcs</TT> -<P><TT>$ cd Naming_Service ; ./Naming_Service -ORBport 10000 &</TT> -<P><TT>$ cd Event_Service ; ./Event_Service -ORBport 0 &</TT> -<P><TT>$ cd tests/Event_Latency ; ./Event_Latency -ORBport 0 -m 20 -j &</TT> -<P>You may want to run each program in a separate window. Try using a fixed -port number for the <TT>Naming Service</TT> so you can use the <TT>NameService</TT> -environment variable. -<P>The script <TT>start_services</TT> in <TT>$TAO_ROOT/orbsvcs/tests</TT> -can help with this. -<LI> -If you want real-time behavior on Solaris you may need to run these programs -as root; on the other hand, this particular example really has no priority -inversion, since only one thread runs at a time.</LI> -</OL> -Another example is <TT>EC_Multiple</TT>, numerous examples on how to run -this test can be found in the scripts located in <TT>$TAO_ROOT/orbsvcs/tests/EC_Multiple</TT>. - -<H3> -Features in previous releases</H3> - -<UL> - -<LI><P>Continued work on the multicast support for the EC, we added a new -server that maps the event types (and supplier ids) into the right mcast -group. Usually this server is collocated with the helper classes that send -the events through multicast, so using a CORBA interface for this mapping -is not expensive, further it adds the flexibility of using a global service -with complete knowledge of the traffic in the system, that could try to -optimize multicast group usage. -<P>The subscriptions and publications on a particular EC can be remotely -observed by instances of the <TT>RtecChannelAdmin::Observer</TT> class. -Once more using CORBA for this interface cost us little or nothing because -it is usually used by objects collocated with the EC. -<P><TT>TAO_EC_UDP_Receiver</TT> is a helper class that receives events -from multicast groups and dispatches them as a supplier to some event channel. -This class has to <B>join</B> the right multicast groups, using the <TT>Observer</TT> -described above and the <TT>RtecUDPAdmin</TT> to map the subscriptions -into multicast groups it can do this dynamically, as consumers join or -leave its Event Channel. -<P>When sending Events through multicast all the <TT>TAO_EC_UDP_Sender</TT> -objects can shared the same socket. -</P> -</LI> - -<LI><P>Added a prototype Consumer and Supplier that can send events though -multicast groups (or regular UDP sockets). -<P>The Event Channel can be configured using a Factory that constructs -the right modules (like changing the dispatching module), in the current -release only the default Factory is implemented. -<P>When several suppliers are consumers are distributed over the network -it could be nice to exploit locality and have a separate Event Channel -on each process (or host). Only when an event is required by some remote -consumer we need to send it through the network. -<P>The basic architecture to achieve this seems very simple, each Event -Channel has a proxy that connects to the EC peers, providing a "merge" -of its (local) consumer subscriptions as its own subscription list. -<P>Locally the proxy connects as a supplier, publishing all the events -it has register for. -<P>To avoid event looping the events carry a time-to-live field that is -decremented each time the event goes through a proxy, when the TTL gets -to zero the event is not propagated by the proxy. -<P>In the current release an experimental implementation is provided, it -basically hardcodes all the subscriptions and publications, we are researching -on how to automatically build the publication list. -<P>We use the COS Time Service types (not the services) to specify time -for the Event Service and Scheduling Service. -</P> -</LI> - -<LI> -<P>The <TT>Gateway</TT> to connect two event channels was moved from a test -to the library. The corresponding test (<TT>EC_Multiple</TT>) has been -expanded and improved. -</P> -</LI> - -<LI> -<P>The user can register a set of <TT>EC_Gateways</TT> with the <TT>EventChannel</TT> -implementation, the event channel will automatically update the subscription -list as consumers subscribe to the EC. -</P> -</LI> - -<LI> -<P>The code for consumer and supplier disconnection was improved and seems -to work without problems now -</P> -</LI> - -<LI> -<P>The <TT>Event_Service</TT> program creates a collocated <TT>Scheduling -Service</TT> this works around a problem in the ORB when running on -multiprocessor. -</P> -</LI> - -<LI> -<P>Startup and shutdown were revised, the event channel shutdown -cleanly now. -</P> -</LI> - -<LI> -<P>Added yet another example -(<TT>$TAO_ROOT/orbsvcs/tests/EC_Throughput</TT>), -this one ilustrate how to use the TAO extensions to create octet sequences -based on CDR streams, without incurring in extra copies. This is useful -to implement custom marshalling or late dermashalling of the event payload. -Future versions of the test will help measuring the EC throughput, hence -the name.</P> -</LI> -</UL> - -</BODY> -</HTML> diff --git a/TAO/docs/releasenotes/index.html b/TAO/docs/releasenotes/index.html deleted file mode 100644 index c2993c0bcfc..00000000000 --- a/TAO/docs/releasenotes/index.html +++ /dev/null @@ -1,1046 +0,0 @@ -<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> -<html> -<head> - - <title>TAO Release Information and TODO List</title> -</head> -<body text="#000000" bgcolor="#FFFFFF"> -<!-- $Id$ --> -<center> -<hr></center> - -<center> -<h3> -Release Information for The ACE ORB (TAO)</h3></center> -Information is available on the following topics related to the <a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/VERSION">current -release</a> of <a href="http://www.cs.wustl.edu/~schmidt/TAO.html">TAO</a>: -<ul> -<li> -<a href="#idl">IDL Compiler</a></li> - -<li> -<a href="orbcore.html">ORB Core</a></li> - -<li> -<a href="#pp">Pluggable Protocols</a></li> - -<li> -<a href="#poa">Portable Object Adapter</a></li> - -<li> -<a href="../implrepo/status.html">Implementation Repository</a></li> - -<li> -<a href="#interfrepo">Interface Repository</a></li> - -<li> -<a href="#nservices">CORBA Naming Service and Interoperable Naming Service</a></li> - -<li> -<a href="#tservices">CORBA Trading Service</a></li> - -<li> -<a href="#pservices">CORBA Property Service</a></li> - -<li> -<a href="#cservices">CORBA Concurrency Service</a></li> - -<li> -<a href="#av">CORBA Audio/Video Control Service</a></li> - -<li> -<a href="#ts">CORBA Time Service</a></li> - -<li> -<a href="#ec">CORBA Event Service</a></li> - -<li> -<a href="ec.html">TAO's Real-time Event Service</a></li> - -<li> -<a href="#scheduling">TAO's Scheduling Service</a></li> - -<li> -<a href="#logging">TAO's Logging Service</a></li> - -<li> -<a href="#apps">Test & Tests</a></li> - -<li> -<a href="#ace">ORB-related ACE Changes</a></li> - -<li> -<a href="#dove">The DOVE Demo</a></li> - -<li> -<a href="#forwarding">Location Forwarding</a></li> - -<li> -<a href="#leader">Global Resources and Leader-Follower Model</a></li> - -<li> -<a href="#locate">Locate requests</a></li> - -<li> -<a href="TODO.html">Our TODO list</a></li> -</ul> -A complete list of all modifications to TAO is available in the <a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/ChangeLog">ChangeLog</a>. -<p> -<hr> -<h3> -<a NAME="idl"></a>IDL Compiler</h3> -Point of contact: <a href="mailto:gokhale@research.bell-labs.com">Aniruddha -Gokhale</a> -<p>Current status: (As of Jan 22, 1999.) -<ul> -<li> -Generated code closely follows the C++ Mapping specified in the latest -C++ mapping for CORBA 2.3 (Document ptc/98-09-03).</li> - -<li> -Struct members of type strings and arrays of strings now use the managed -type instead of the _var type. This change was necessary to conform to -the IDL->C++ mapping.</li> - -<li> -Fixed a large number of problems with anonymous arrays and sequences inside -structs and unions. The name of anonymous sequence needs to be fixed as -per latest C++ mapping spec.</li> - -<li> -Compile problems with sequence of forward declared interfaces is fixed. -In addition, problems with sequence of CORBA::Objects is fixed. In this -specific case, we were not generating the _downcast and _upcast methods.</li> - -<li> -Some more problems with the front-end have been fixed. In particular, oneway -operations with a "raises" clause or having an "inout", "out", or "return" -mode is flagged as an error.</li> - -<li> -For platforms that support namespaces, we now allow reopening modules.</li> - -<li> -Support for generating compiled marshaling code is added. Use the -Gc option. -However, this needs thorough testing before we can claim success. Unions -are still a problme with compiled marshaling.</li> - -<li> -The problem of "#include"ing the relative path of the header files rather -than the paths of their corresponding IDL files has been fixed. tao_idl -now generates #include path names that are derived from the IDL files that -are #include'd in the main idl file.</li> - -<li> -Added options to IDL compiler to specify file name endings for the IDL-generated -stubs, skeletons and the various header files. Please refer to the <a href="http://www.cs.wustl.edu/~schmidt/ACE_wrappers/TAO/docs/compiler.html">IDL -compiler options</a> for details.</li> - -<li> -Added partial native C++ exception support:</li> - -<ul> -<li> -The ORB can be configured to catch native C++ exceptions thrown on the -server side and transmit them to the client side. On the client side exceptions -received from the wire are thrown using native C++ exceptions also.</li> - -<li> -To facilitate portability between the standard and alternative C++ mapping -the <tt>CORBA::Environment</tt> has a default value. The IDL compiler generates -code using that default value and the TAO library methods also have the -default.</li> - -<li> -Some macros are provided to facilitate portability between platforms with -and without macros.</li> -</ul> -There is still some work to do, mainly provide complete support for the -standard mapping, i.e. remove the <tt>CORBA::Environment</tt> argument -completely. -<li> -Verified support for the "long long" and "unsigned long long" datatypes. -On platforms that do not support 64 bit longs we provided <i>partial</i> -emulation through ACE_U_LongLong.</li> - -<li> Perfect Hashed Operation Lookup Strategy has been added to the -IDL Compiler. -P flag to <code>tao_idl</code> enables the perfect -hased lookup strategy. This strategy uses <a -href="http://www.cs.wustl.edu/~schmidt/gperf.ps.gz">GPERF</a>, the -GNU's Perfect Hash Function Generator written by Dr.Douglas -C. Schmidt. Right now, GPERF works only on Solaris. Any work on -porting GPERF to other platforms will be highly -appreciated.</L1></li> - -<li> -Significantly improved the support for unions. The default case is yet -to be handled.</li> - -<li> -Added support for TIE classes. If the interfaces are defined inside modules, -then the TIE class and its code gets generated inside a conditional macro. -For platforms that support namespaces, this macro will allow these TIE -classes else they get commented out. The reason to do this is because nested -templates have problems on most compilers.</li> - -<li> -The <<= and >>= operators for user-defined types are now generated.</li> - -<li> Completely redesigned the IDL compiler using the Visitor -patterns. Many incomplete issues have been resolved. These include -support for "sequence of typecodes", passing object references as in, -inout, and out parameters. Code generation for sequences is also -properly handled i.e., for a named sequence such as <CODE>typedef -sequence<char>CharSeq;</CODE>, we now generate a new class (and -hence a type) called "class CharSeq". Arrays are still being worked -out and will be done soon. An important difference in the generated -code is that the skeletons now use a table driven approach very -similar to the stubs.</li> - -<li> -Support for the "native" keyword added.</li> - -<li> -The problem of incorrect code generation for typedefs defined in an imported -file is resolved.</li> - -<li> -Problems when interfaces use single or multiple inheritance solved. The -problem was with the demultiplexing code, the generated operation tables, -and the dispatching mechanism. We are currently testing this with the Event -Channel code.</li> - -<li> -The problems arising due to public virtual inheritance when casting from -an interface class to CORBA::Object_ptr has been solved. We do this casting -inside the stubs/skeletons rather than first converting an interface class -pointer to a void*, storing it in an Any, and casting it to CORBA::Object_ptr -in the encode/decode methods. The casting inside the stubs/skeletons work -because the compiler has knowledge of both types.</li> - -<li> -Include files are handled properly. So are the definitions used inside -the include files that are used in the currently parsed files.</li> - -<li> -Generates C++ stubs and skeletons that use TAO's <a href="http://www.cs.wustl.edu/~schmidt/HICSS-97.ps.gz">interpretive -IIOP protocol engine</a>.</li> - -<li> -Support dynamic libraries on NT, i.e., marking classes for DLL export was -added. Two backend options control the name of the export macro, and the -name of an extra include file were the macro is defined; the options are -<tt>-Wp,export_macro=MACRO_NAME-Wp,export_include=INCLUDE_NAME</tt>.</li> - -<li> -The IDL compiler generates now source code for sequences. The user has -now the option to use these generated sequence classes or to use, as up -to now, the template instatiation. If TAO_LACKS_TEMPLATE_SPECIALIZATION -is defined, then template instantiation will be used, else not. The reason -for this was, that some C++ compilers did not support template instantiation -properly and sequences were based on templates. The generated source code -is mainly contained in the generated header file directly in the class -declaration.</li> - -<li> -The IDL Compiler generates templates for servant implementations. The options -are -GI [ h | s | b | e | c ]</li> -</ul> - -<p><br>Known bugs/unimplemented constructs: -<ul> -<li> -Generation of Managed types must somehow be moved to the ORB Core</li> - -<li> -We need support for ``TIEs'' (i.e., the object form of the Adapter pattern).</li> - -<li> -TypeCode generation for recursive types not implemented yet.</li> - -<li> -Unions with default cases yet to be handled</li> - -<li> -IDL is case-insensitive. However, it looks like our front-end is case-sensitive. -Thanks to Anil Gopinath (anil@ittc.ukans.edu) for pointing this out.</li> -</ul> -Future work: -<ul> -<li> -Need to relocate the various libraries used by the IDL compiler out of -the ACE directory. Having them here can cause problems when working with -multiple versions of TAO and a single version of ACE.</li> - -<li> -Fix bugs in the SunSoft IDL front-end we've uncovered. These primarily -include support for Unions.</li> - -<li> -Use <a href="http://www.cs.utah.edu/projects/flux/flick/">Flick</a> (from -the University of Utah) to generate compiled stubs.</li> - -<p>Goal is to measure the code size of the interpretive stubs generated -by TAO IDL compiler <i>vs</i> code size of compiled stubs. Then compare -the performance of each. We want to prove the thesis that TAO IDL compiler -generated interpretive stubs have a small code size, yet are comparable -in performance (or slightly less) than compiled stubs. Hence, it will be -useful for small distributed equipment such as handsets, PDAs, etc. -<p>In doing the above, improvements to the IIOP protocol engine in terms -of size/performance/determinism will be made. -<li> -Tweak the IDL compiler to generate code that's more easily integrated back -into the ORB Core, e.g., POA, etc. This will depend largely on our ability -to generalize the changes necessary to generated code.</li> - -<li> -The generated sequence classes should not be generated per sequence, but -per type and parent scope. Which means, that the overhead of having the -source code generated serveral times should be reduced. To do this, an -extra pass over the internal representation of the IDL file has to be done.<P> -</ul> - - -<hr></li> - -<br><!--#include virtual="orbcore.html" --> -<hr> -<h3> -<a NAME="pp"></a>Pluggable Protocols</h3> -Point of contact: <a href="mailto:fredk@cs.wustl.edu">Fred Kuhns</a> -<p>The goal of the pluggable protocol effort is to (1) identify logical -communication layers in the ORB, (2) abstract out common features, (3) -define general interfaces, and (4) provide necessary mechanisms for implementing -different concrete ORB and transport protocols. TAO's pluggable protocol -framework will allow disparate communication mechanisms to be supported -transparently, each with its own set of requirements and strategies. -<p>For example, if the ORB is communicating over a system bus, such as -PCI or VME, and not all the features of GIOP/IIOP are necessary and a simpler, -optimized ORB and transport protocol can be defined and implemented. Similarly, -it should be straightforward to add support for new transport protocols -that use native ATM or shared memory as the underlying communication mechanism. -In all cases the ORB's interface to the application will remain compliant -with the OMG CORBA standard. -<p>There will be several stages of the development proccess: (1) basic -pluggable transport protocols framework, (2) support for multiple profiles, -(4) add example transport protocols, such as ATM and VME, and refine/optimize -the transport protocols framework, and (4) add support for pluggable ORB -protocols, e.g., replacements for GIOP. Each of these steps is outlined -below: -<ul> -<li> -<b>Basic pluggable transport protocols framework</b>: We're currently adding -several Bridge classes that decouple the transport-specific details from -the rest of TAO's ORB Core. This allows us to isolate the details of how -messages are communicated at the transport layer in a few classes. This -design has led us to restructure how TAO's ORB Core sends and receives -requests. For instance, there is now the concept of communication layers: -Objects (e.g., references, method invocations, etc.), ORB Messaging, Transport, -and Network. The Object layer is just the usual stubs and skeletons.</li> - -<p>The common interfaces have been defined in the new abstract classes -that form the core of TAO's pluggable protocol framework, e.g., -<tt>TAO_Connector</tt>, -<tt>TAO_Acceptor</tt>, -<tt>TAO_Profile</tt> -and <tt>TAO_Transport</tt>. Two new mechanisms for keeping track of supported -transport protocols are the -<tt>TAO_Connector_Registry</tt> and -<tt>TAO_Acceptor_Registry</tt>, -which are essentially Abstract Factories that produce the right types of -connector, acceptors, and transports. <p> -<li> -<b>Multiple Profile</b> - Support for more than one profile per object. -This is important since there may be several different ways to access an -object. Each profile for an object may encode information pertaining to -QoS, network and transport protocols, addresses or routes.<p> - -<li> -<b>Example Transport protocols</b>- The first planned example aside from -IIOP will use UNIX domain sockets. Other interesting transport protocols -would be for ATM, Buses (VME or PCI), shared memory, TP4, GSMP, and - UDP/IP.</li> <p> - -<li> -<b>Pluggable ORB protocols</b> - This step will add support for ORB protocols -besides GIOP. In particular, we will explore lightweight protocols using -shared memory and system buses like PCI or VME.</li> -</ul> -Current Status: -<ul> -<li> - -The initial prototype of the basic framework to support pluggable transport -protocols has been compiled, linked and, tested against an older version -of TAO. The standard TAO regression tests -<tt>MT_Cubit</tt>, <tt>Multiple_Inheritance</tt>, -<tt>CDR</tt> -and <tt>EC_Throughput</tt> were run successfully.</li><P> - -<li> -The basic framework does not include support for multiple profiles and -the Acceptor registry. What it does do is separate the transport specific -processing from the rest of the ORB.</li> - -<p> -</ul> -Known Issues: - -<ul> -<li> -The ORB Core's resource factory needs to be enhanced to support the dynamic -allocation of resources for different transport protocols.</li><p> -</ul> -Critical Work: - -<ul> -<li> -Adding support for multiple profiles.</li><p> - -<p> -</ul> -Future Work: -<ul> -<li> -Immediate plans are to bring my workspace up to date with the repository -and verify all of TAO's regression tests still work. This will be followed -by performing a suite of tests to compare performance of with the unmodified -TAO distribution. Also, we'll extensively retest TAO using purify and quantify.</li><p> - -<li> -In parallel, we will add support for multiple profiles and an acceptor -registry class. The acceptor registry will both keep track of all acceptors -and be responsible for creating a list of profiles for new object references -(essentially the IOR).</li><p> - -<li> -Long term work will include adding support for pluggable ORB protocols, -as well as transport protocols. This way we can develop optimal messaging -and transport protocols for a given platform.</li> - -<p> -</ul> - -<hr> -<h3> -<a NAME="poa"></a>Portable Object Adapter (POA)</h3> -Point of contact: <a href="mailto:irfan@cs.wustl.edu">Irfan Pyarali</a> - -The POA associates servants with the ORB and demultiplexes incoming -requests to servants. <P> - -<p>Current Status: -<ul> -<li> -TAO supports the POA spec. This section will carry updates as available.</li> -</ul> -Known issues: -<ul> -<li> -The synchronization in the POA is broken. For example, the locks are held -across the invocation on the servant. The locks are also held across the -invocation on the AdapterActivator. This forces the use of recursive locks -inside the POA. However, the problem with recursive locks is that multiple -threads cannot dispatch requests on the same POA simultaneous.</li><P> - -<li> -Add the new RefCountServantBase class to TAO. This reference counted base -class was added to the CORBA specification to avoid race conditions for -servant deletion in threaded servers. <a href="ftp://ftp.omg.org/pub/docs/orbos/98-07-12.pdf">ftp://ftp.omg.org/pub/docs/orbos/98-07-12.pdf</a> -contains the relevant text.</li><P> - -<li> -Currently, the complete POA name is used as the POA identity. This scheme -is inefficient in many ways including: (a) the complete POA name can be -significantly large in size, and therefore, ineffient to pass with every -method call from the client to the server; (b) it is varible in size, and -therefore, does not lend itself to smart and effective parsing; (c) the -searching based on the complete POA name is very ineffient.</li> - -<p>The correct solution here is to use an active demux table, and flatten -the POA hierarchy. This will help in the searching since active demuxing -is fast and predictable. This will also help in the parsing since the demux -key will be fixed size. -<p>Note that for persistent ids, we have to pass the complete POA name -in addition to the demux key in order to handle POA creation on demand.<P> - -<li> -Timestamps in persistent IORs are not required. They should be removed.</li> <P> - -<li> -POA exceptions should be removed from the list of system - exceptions.</li> <P> - -<li> -We need to separate out the POA functionality required to support the full -CORBA spec from the POA functionality required to support the Minimal CORBA -spec.</li> <P> - -<li> -We need to investigate whether it feasible for us to provide active demuxing -for the USER_ID policy. Currently, the best we do with the USER_ID policy -is a hash table based demuxing.</li> <P> - -Note that we have to pass the user id in addition to the demux key in -order to handle servant creation on demand. <P> -<li> -We can potentially add active demuxing for method name lookup. The benefit -of this optimization is questionable since the current perfect hashing -scheme provide very good and predictable behavior.</li> <P> - -Also, note that this optimization will require many changes. We would -have to use the help of the IDL compiler to modify the object key that -is passed for every method call differently. Note that this scheme doesn't -work in the case of multiple inheritance or when the client stubs are not -TAO.<P> - -<li> -There are some POA objects in a typical server that are not freed up properly, -resulting in a memory leak. This is not very significant since the leak -does not grow. However, it still needs a fix.</li> <P> -</UL> - -Future work: -<ul> -<li> -Determine the degree to which we will support the full semantics of remote -objects on a collocated object. The spec mandates that collocated object -should behave <i>exactly</i> like remote objects, but that means that request -will have to be queued rather than calling a method directly, and this -could be hazardous to our quest for real-time ORB status.</li><P> - -<li> -Provide extensions of the specification to ensure real-time delivery of -messages.</li> <P> - -</ul> -Recently completed work:<P> -<ul> -<li> -Support for collocation should be much better now because the POA can tell -if we created the object reference.</li><P> - -<li> -The POA now supports active demultiplexing of servants in the SYSTEM_ID -policy. This should make the POA faster and more predictable since there -is no hashing involved and the index of the slot where the servant is registered -is in the Object Key.</li> <P> - -</UL> -<hr> -<h3> -<a NAME="interfrepo"></a>Interface Repository</h3> -Point of contact: <a href="mailto:parsons@cs.wustl.edu">Jeff Parsons</a><P> - -The Interface Repository provides run-time information about IDL -interfaces. Using this information, it is possible for a program to -encounter an object whose interface was not known when the program was -compiled, yet, be able to determine what operations are valid on the -object and make invocations on it using the DII. - -<p>Current Status: TDB -<p>Known Issues: TDB -<p>Recent Work: TDB -<p>Future Work: TDB -<p> -<hr> -<h3> -<a NAME="nservices"></a>CORBA Naming Service and Interoperable Naming Service</h3> -Points of contact: <a href="mailto:marina@cs.wustl.edu">Marina -Spivak</a> and <a href="mailto:vishal@cs.wustl.edu">Vishal Kachroo</a> -<p> - -The CORBA <a href="ftp://www.omg.org/pub/docs/formal/97-07-12.pdf">The -Naming Service</a> supports a hierarchical mapping between sequences -of strings and object references. The CORBA <A -HREF="ftp://ftp.omg.org/pub/docs/orbos/98-10-11.pdf">Interoperable -Naming Service</A> defines a standard way for clients and servers to -locate the Naming Service. <P> - -<p>Current status (as of 22nd Feb 1999): -<ul> -<li> -Implementation of the CORBA Naming Service spec is complete.</li> -</ul> -Recently completed work: -<ul> -<li> -The implementation of the Naming Service has been upgraded to use TAO's -exception macros, which allow it to work both with C++ exceptions and without.</li> -<li> -Destroy method has been updated.</li> -<li> -More test examples have been added to TAO/orbsvcs/tests/Simple_Naming.</li> -</ul> - -Work in progress: -<ul> -<li> -Currently the bindings are stored as a table in memory. Work is under way -to provide persistance option for the Naming Service.</li> - -<LI> Currently adding support for the Interoperable Naming Service, -which enables the ORB to support IORs in user-friendly URL formats -using the <CODE>iioploc</CODE> and <CODE>iiopname</CODE> formats. -These features allow the ORB to configured to return arbitrary object -references from <CODE>CORBA::ORB::resolve_initial_references</CODE> -for non-locality-constrained objects. In addition, two standard -<CODE>CORBA::ORB_init</CODE> arguments are being added to override the -TAO's initial reference configuration. The service provides an -extension to the existing Naming Service to include conversions to and -from URL-style IORs. - -<LI>The Naming Service is being used as an agent to understand IIOP -request messages from clients and respond with reply messages with a -LOCATION_FORWARD status. Work is in progress for the client-side -lookup tables built through commandline arguments to the ORB, -<CODE>-ORBInitRef</CODE> and <CODE>-ORBDefaultInitRef</CODE>.<P> -</ul> -Future work: -<ul> -<li> -Replication of the bindings to other Naming Service's currently running. -It will probably be modeled after the LDAP Multi-Master Replication Protocol.</li> -</ul> - -<p> -<hr> -<h3> -<a NAME="tservices"></a>CORBA Trading Service</h3> -Point of contact: <a href="mailto:sbw1@cs.wustl.edu">Seth Widoff</a> - -<p>The <a href="http://www.omg.org/corba/sectrans.htm#trader"> Trading -Service</a> is an implementation of the COS Trading Service -speficiation that meets the Linked Trader conformance criteria --- it -implements the <tt>Lookup</tt>, <tt>Register</tt>, <tt>Admin</tt>, and -<tt>Link</tt> interfaces, but not the <tt>Proxy</tt> -interface. Notably, the TAO trader supports the following features:<P> -<ul> <li> Multithreaded operation;</li> - -<li> -Trader federations and distributed queries;</li> - -<li> -Dynamic properties;</li> - -<li> -Modifiable properties;</li> - -<li> -All policies described in the specification;</li> - -<li> -Preference sorting;</li> - -<li> -Service type inheritance hierarchies and subtype searching.</li> -</ul> -<a href="trader.html">Trading Service documentation</a> is also available. -<p>Future Work: -<ul> -<li> -The Proxy Interface.</li> - -<li> -Persistent storage of service types and offers.</li> -</ul> -<p> -<hr> -<h3> -<a NAME="pservices"></a>CORBA Property Service</h3> -Point of contact: <a href="mailto:alex@cs.wustl.edu">Alexander Babu -Arulanthu</a> - -<p>Current status (as of Mar 9th, 1999): All the interfaces of this -service have been implemented. Please -go through the test examples at $TAO/orbsvcs/tests/CosPropertyService. -Property Service is has been used by the TAO's <a href="#av">Audio Video Streaming -Service</a>developed for TAO. For general documentation of the -Property Service, please read <a -href="http://www.omg.org/corba/sectrans.htm#prop">The Property Service -Specification.</a> - -<P>Recent Work: -<ul> - <li> - Changed the PropertyException from Exception to struct, according - to the OMG's changes. - </li> - <li> - Changed the implementation to allocate storage for the Sequence - out parameters, eventhough their length is 0. This is according - to the CORBA specification. - </li> -</ul> - -<p> -<hr> -<h3> -<a NAME="cservices"></a>CORBA Concurrency Service</h3> -Point of contact: <a href="mailto:tworm@cs.wustl.edu">Torben Worm</a> -<p>Current status (as of May 3rd): - -The <a href="http://www.omg.org/corba/sectrans.htm#concur"> -Concurrency Service</a> provides a mechanism that allows clients to -acquire and release various types of locks in a distributed system.<P> - -<ul> -<li> -A simple version of the Concurrency Service has been implemented, i.e. -a version without transactions. It is currently being tested.</li> -</ul> -Future Work: -<ul> -<li> -Implementation of the Concurrency Service with transactions</li> -</ul><P> -<hr WIDTH="100%"> -<h3> -<a NAME="av"></a>CORBA Audio/Video Control Service</h3> -Point of contact: <a href="mailto:naga@cs.wustl.edu">Nagarajan Surendran</a> -<p>This is an implementation of the OMG spec addressing the <a href="http://www.cs.wustl.edu/~sumedh/research/corbaav.pdf">Control -and Management of Audio/Video Streams</a>. -<p>The audio/video streaming service has been implemented in the light -profile. An MPEG-1 application which streams mpeg-1 video and mpeg-1 audio -separately has been developed using the service. This application currently -works only for Unix platforms. -<p>Work in progress: -<ul> -<li> -Implementing the SFP protocol</li> - -<li> -Integrating the mpeg-1 streaming application with the trading service.</li> -</ul> - -<hr> -<p><a NAME="ts"></a><b>CORBA Time Service</b> -<p>Point of contact: <a href="mailto:vishal@cs.wustl.edu">Vishal Kachroo</a> - -<p> The <a href="ftp://ftp.omg.org/pub/docs/formal/97-02-22.pdf">Time Service</a> - allows clients to connect to Time Service Clerks and obtain globally -synchronized time. This time is calculated from the time obtained from -one or more Time Servers running on multiple machines in the -network. The service uses the TAO Implementation Repository to -activate the time servers on demand. - -<p>Current status (as of 10th Jan 1999): -<ul> -<li> -Implementation of a Distributed CORBA Time Service is complete.</li> -</ul> -Future work: -<ul> -<li> -Currently the average of the time obtained from the various servers is -considered the global notion of time. A better distributed time synchronization -algorithm can be used in the future.</li> - -<li> -Implementation of the Timer Event Service.</li> -</ul> -<p> - -<hr WIDTH="100%"> -<h3> -<a NAME="ec"></a>CORBA Event Service</h3> - -<h4> -Last updated: Fri Mar 5 20:38:26 CST 1999</h4> -Point of contact: <a href="mailto:pradeep@cs.wustl.edu">Pradeep Gore</a> -<p>The COS compliant Event Service implements the Event Service Specification: -<a href="http://www.omg.org/docs/formal/97-12-11.pdf">(.pdf)</a>, -<a href="http://www.omg.org/docs/formal/97-12-11.ps">(.ps)</a> -<br>This implementation is based on the Real Time Event service. -<h3> -Features in this release:</h3> - -<ul> -<li> -The Event Channel (<tt>$TAO_ROOT/orbsvcs/orbsvcs/CosEvent</tt>) supports -the <tt>push </tt>style event communication.</li> - -<li> -A simple test (<tt>$TAO_ROOT/orbsvcs/tests/CosEC_Basic</tt>) demonstrates -how to create and use the event channel.</li> - -<li> -Event Service (<tt>$TAO_ROOT/orbsvcs/CosEvent_Service</tt>)The Event Service -creates a COS compliant event channel and registers it with the naming -service with the default name "CosEventChannel".</li> - -<br>Please read the associated README for more details. - -<li> -CosEC_Multiple: <tt>($TAO_ROOT/orbsvcs/tests/CosEC_Multiple)</tt>: -This test demonstrates how multiple CosEC's connect to one RtEC and how -multiple consumers and producers exchange events in this configuration.</li> -</ul> -<h3> -Known bugs:</h3> -<ul> -<li> -CosEC_Multiple: <tt>($TAO_ROOT/orbsvcs/tests/CosEC_Multiple)</tt>: -Once the tests are done, the control doesn't return to the shell, -you have to say CTRL-C to get back to the prompt. -</li> -</ul> - -<hr WIDTH="100%"> -<!--#include virtual="ec.html" --> -<p> -<hr> -<h3> -<a NAME="scheduling"></a>TAO's Scheduling Service</h3> -Point of contact: <a href="mailto:cdgill@cs.wustl.edu">Chris Gill</a> -and <a href="mailto:levine@cs.wustl.edu">David Levine</a> -<p>Currently Implemented Features: -<ul> -<li> -The scheduling service can be built to use either a null implementation -or a strategized implementation of the configuration scheduler.</li> - -<li> -The null scheduler implementation, which is built by default, allows the -configuration scheduler to be used with applications that require a scheduling -service interface, but do not (at least in the current stage of their development, -in certain configurations, etc.) make use of the real-time scheduling features -it provides.</li> - -<li> -The strategized scheduler implementation can be built by #defining TAO_USES_STRATEGY_SCHEDULER, -and the appropriate scheduling strategy macro (TAO_USES_RMS_SCHEDULING, -TAO_USES_EDF_SCHEDULING, TAO_USES_MUF_SCHEDULING, or TAO_USES_MUF_SCHEDULING) -in $ACE_ROOT/ace/config.h. This allows the configuration scheduler to be -used with applications that require a specific scheduling strategy. Each -scheduling strategy will produce a set of static scheduling priorities, -which it will assign to operations based on their RT_Infos. For each static -priority, a strategy will also determine the run-time (dynamic) scheduling -strategy to use for that priority level.</li> -</ul> -Future work: -<ul> -<li> -Implement heap-based dispatching queues.</li> - -<li> -Add support for additional configurability, especially in the type -of dispatching strategy (list vs. heap) that will be used to dispatch operations -at a given static priority level.</li> - -<li> -Benchmark the various alternative strategies to obtain performance -profiles across different operation loads and OS platforms.</li> - -<li> -Add increased functionality. Requests and suggestions are welcome.</li> -</ul> - -<hr> -<h3> -<a NAME="logging"></a>TAO's Logging Service</h3> -Point of contact: <a href="mailto:mjb2@cs.wustl.edu">Matt Braun</a> -<p>Current status (as of August 4'th): -<ul> -<li> -The basic logging service has been implemented. It can log basic messages -from multiple clients. It is currently in the testing stage.</li> -</ul> -Future work: -<ul> -<li> -Add increased functionality. Requests and suggestions are welcome.</li> -</ul> - -<hr> -<h3> -<a NAME="apps"></a>Test & Performance Tests</h3> -Point of contact: <a href="mailto:naga@cs.wustl.edu">Nagarajan Surendran</a> -<p>Current Status: -<p>The TAO IDL_Cubit test application makes use of the Naming Service and -the server holds a TAO_Naming_Server component.Just running server and -client is enough to test the application. -<p>The various tests in the tests/POA test the different features of the -Portable Object Adapter interface like Explicit Activation, On Demand Activation,etc.. -<p>MT_Cubit: -<p>Current status: -<p>The TAO MT_Cubit test application is meant to serve as a starting point -for real-time tests on the TAO system. It comprises the following parts: -<ul> -<li> -<i>Server.</i> The server creates multiple CORBA objects (servants), each -with different real-time priorities. This priority is implemented by using -real-time thread support provided by the operating system. Thus, requests -sent to a high-priority servant are handled by a high-priority real-time -thread, and those sent to a lower priority servant are handled by correspondingly -lower priority threads.</li> - -<li> -<i>Client.</i> The client component binds to the servants, and sends a -stream of CORBA requests to the servants. It measures the response time, -i.e. the time taken for the request to complete successfully. In particular, -it measures the time taken for requests sent to the high priority servant -to complete. The volume of lower priority requests is configurable. The -client is thus able to measure the performance of the high-priority servant -in the presence of competition from several lower-priority servants.</li> -</ul> -Clearly, if the ORB endsystem handles the priorities of the various requests -correctly, increasing the volume of lower priority requests should not -affect the performance seen by the higher priority requests. The application -thus serves as a tool to measure and confirm this behavior. -<p>Future work: -<ul> -<li> -Study the impacts of scheduling & concurrency strategies on performance.</li> - -<li> -Evolve into a testbed for discovering sources of performance non-determinism -& priority inversion.</li> -</ul> - -<p>Pluggable: -<p>Current status: -<p>The TAO Pluggable test utilizes ACE Timeprobes to time the latency at -various points in the ORB, especially that incurred by the Pluggable Protocols -implementation. Comparisons can be made not only between different layers of the -ORB, but also between different protocols as they become available. -<p>Future work: -<ul> -<li> -Add options to redirect the output to a file.</li> -<li> -Script or otherwise automate the piping of the output to a spreadsheet.</li> -</ul> - -<hr> -<h3> -<a NAME="ace"></a>ORB-related ACE Changes</h3> -Points of contact: <a href="mailto:nanbor@cs.wustl.edu">Nanbor Wang</a> -and <a href="mailto:irfan@cs.wustl.edu">Irfan Pyrarli</a> -<p>Recently Completed Work: -<ul> -<li> -Added special declaration to OS.h for <tt>inet_ntoa</tt> and other functions -because VxWorks doesn't provide full argument prototypes for these library -functions.</li> - -<li> -The current caching connector behaves properly in the face of a non-blocking -connect request. The "fix" is simply to not support non-blocking connects -through the cache. When the <tt>connect()</tt> fails with <tt>EWOULDBLOCK</tt>, -morph the error to -1 and clean up the request.</li> - -<li> -Service handlers obtained from the caching connector are now cleaned up. -The application needs to be able to signal that it's not using it any longer, -and, when the application encounters an error, needs to effectively close -down that connection for good so that a new connection can be initiated.</li> - -<br>Added the ability for a Svc_Handler to recycle itself. idle() can be -called when the Svc_Handler is done serving a particular connection and -can how be recycled. The Svc_Handler now also has a pointer to a recycler -that is responsible for managing the connections. The recycler is usually -a Cached_Connector. -<br>Added new class ACE_Recycling_Strategy. It defines the interface (and -default implementation) for specifying a recycling strategy for a Svc_Handler. -This strategy acts as a consular to the Svc_Handler, preparing it for the -tough times ahead when the Svc_Handler will be recycled. -<br>Added new class ACE_NOOP_Concurrency_Strategy. It implements a no-op -activation strategy in order to avoid calling open on a recycled svc_handler -multiple times. -<br>ACE_Cached_Connect_Strategy now implements the ACE_Connection_Recycling_Strategy -interface. This allows Svc_Handlers to cache themselves with ACE_Cached_Connect_Strategy -when they become idle. It also allows them to purge themselves from the -connection cache when the Svc_Handlers close down. -<br>Also added ~ACE_Cached_Connect_Strategy that will cleanup up the connection -cache.</ul> -Future work: -<blockquote><i>None currently scheduled.</i></blockquote> - -<hr> -<h3> -<a NAME="dove"></a>The DOVE Demo</h3> -Points of contact: <a href="mailto:mk1@cs.wustl.edu">Michael Kircher</a> -and <a href="mailto:cdgill@cs.wustl.edu">Chris Gill</a>. -<p><a href="http://www.cs.wustl.edu/~schmidt/dove.html">DOVE</a> is documented -in detail <a href="http://www.cs.wustl.edu/~schmidt/Dove.ps.gz">online</a>. -This discussion focuses on the following goals: -<ul> -<li> -Have a DOVE Browser running using Java Beans as vizualization components.</li> - -<li> -Have the Event Channel as DOVE Agent running with an Event Consumer in -the DOVE Browser.</li> - -<li> -Having a DOVE Management Information Base (MIB), which dumps all events -transfered on the Event Channel into a file on persistent storage for later -reuse.</li> -</ul> -The DOVE Browser uses independent visualization components (Java Beans) -and the Event Channel as DOVE Agent. Connections can be established between -monitored metrics and the visualization components. -<p>We have three major components: Observables (monitored metrics), Observers -(a Java Bean for displaying the metric) and a DataHandler (for demultiplexing -the monitored metrics to the appropriate Observables). Each component inherits -from a base class, so that a certain behavior of the components can be -assured for each component. Relationships between components are based -on these base classes. -<p>The used Java Beans are required to conform to some standards, as they -have to support a function called "getProperty" which allows the DOVE Browser -to determine if the vizualization capabilities of a specific Java Bean -are sufficient to display the metric. A JavaBean is for example a Java -Panel which shows a Graph of the delivered doubles. So all metrics can -be displayed by this visualization component which can be expressed by -a single double. -<p>The DataHandler is connected to the Event Push Consumer (PUSH, because -we use the push concept of the Event Service). The Event Push Consumer -does not know what kind of data is transported. The only component knowing -all the details about the dependencies of the metrics is the DataHandler. -This separation allows easy extension and change of the demo. -<p><a href="http://students.cec.wustl.edu/~mk1/dove.html">Object Diagrams</a> -are available about this new concept. -<p>Event Service events are used as communication between DOVE Applications -and the DOVE Browser. The DOVE MIB analyses the event data field of all -events and stores this information into a file. The event data filed is -of type CORBA::Any and the DOVE MIB has no notion of what is conveyed in -this field. So the DOVE MIB has to discover the content via the embedded -type code information. Future work includes: -<ul> -<li> -Enhancing MIB functionality</li> - -<li> -Monitoring the AV Streaming Service</li> -</ul> -For more information on the DOVE demo, please refer to: $TAO_ROOT/orbsvcs/tests/Simulator/README.<P> -<hr> -<h3> -<a NAME="forwarding"></a>Location Forwarding</h3> -Point of contact: <a href="mailto:irfan@cs.wustl.edu">Irfan Pyarali</a>, -<a href="mailto:mk1@mk1.wustl.edu">Michael -Kircher</a>. -<p>For more information see <a href="../forwarding.html">Location forwarding</a> -<p> -<hr> -<h3> -<a NAME="leader"></a>Global Resources and Leader-Follower Model</h3> -Point of contact: <a href="mailto:irfan@cs.wustl.edu">Irfan Pyarali</a>, -<a href="mailto:mk1@mk1.wustl.edu">Michael -Kircher</a>. -<p>For more information see <a href="../leader_follower.html">Leader-follower -model</a> -<p> -<hr> -<h3> -<a NAME="locate"></a>Implementation of locate request</h3> -Point of contact: <a href="mailto:irfan@cs.wustl.edu">Irfan Pyarali</a>, -<a href="mailto:mk1@mk1.wustl.edu">Michael -Kircher</a>. -<p>For more information see <a href="../locate_request.html">Locate request</a> -<p> -<hr> -<p>Back to the TAO <a href="../index.html">documentation index</a>.<!--#include virtual="/~schmidt/cgi-sig.html" --> -</body> -</html> diff --git a/TAO/docs/releasenotes/orbcore.html b/TAO/docs/releasenotes/orbcore.html deleted file mode 100644 index 3bbfe38e2a1..00000000000 --- a/TAO/docs/releasenotes/orbcore.html +++ /dev/null @@ -1,505 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.5b2 [en] (WinNT; I) [Netscape]"> - <TITLE>ORB Core Status</TITLE> -<!-- $Id$ --> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF"> - -<H3> -<A NAME="orb"></A>ORB & ORB Core</H3> -Point of contact: <A HREF="mailto:nanbor@cs.wustl.edu">Nanbor Wang</A> -<P>Last Update: $Date$ -<P><B>Current status:</B> -<UL> -<LI> -Provides dynamically linked wholesale assignment of ORB strategies for -communication, concurrency, demultiplexing, scheduling, and dispatching -using the ACE Service Configurator framework.</LI> - -<LI> -Supports several concurrency models out of the box: Reactive, Thread-per-Connection, -and ORB-per-thread. The ORB-per-thread design is optimized for real-time -I/O subsystems. (See: <A HREF="../configurations.html">Configuration Guide</A>.)</LI> - -<LI> -Supports <TT>resolve_initial_references("<CORBA Service>")</TT> using -ACE support for multicast.</LI> -</UL> -<B>Known issues:</B> -<UL> -<LI> - -Some CORBA objects need to have access to the ORB. We tend to use -<CODE>TAO_ORB_Core_instance()->orb()</CODE> to fetch the right ORB the -object is using. This is most often true when implementing the -shutdown method which allow other process to shutdown a remote -ORB. Althought this may be the "right" thing to do in TAO, it is not -CORBA compliant and hurts the portability of object implementation. A -common way of getting around this problem is to cache the ORB pointer -in the object when it is created and simply use the cached ORB when -needed. However, remember that there could be multiple ORBs in a -process and a POA may be shared by several ORBs. That means, we may -not handling the object with the same ORB it was created. Collocation -optimization further complicated the problem. <P> At the moment, using -<CODE>TAO_ORB_Core_instance()->orb()</CODE> is the only sane way to -get arond the problem. Though there may be a better way. <P> - -<LI> Object references for objects dynamically created within a server -may not have proper host. (See also <A HREF="#hostfix">recent -fix</A>.) When an object is dynamically created and its object -reference returned, it simply has to "guess" at the host information -that is returned in the IIOP Profile. Currently, it guesses using the -host name, which is a reasonable guess in most cases. However, if -there are multiple interfaces on a machine <I>and</I> they have -different host names, it is possible that the desired effect will not -be realized, i.e., the connection to that new object may use a -different interface from the original object. Currently the only way -to change this is to use the <A -HREF="../Options.html#-ORBhost"><B>-ORBhost</B> option</A> to manually -specify that dynamically-created objects bind to a specific interface -so that their IIOP Profile has the desired hostname. A more desirable -fix is being investigated.<P> </UL> - -<B>Recently Completed Work:</B> -<UL> -<LI> -The ORB Core is ready to throw exceptions received from the wire as a native -C++ exception. Similarly, on the server side, native C++ exceptions are -catched and sent over the wire to the client.</LI> - -<LI> -Added new option <TT>-ORBgioplite</TT> when this option is enabled the -ORB removes a few fields of the GIOP messages that are normally not used, -such as the version numbers, the magic 'GIOP' string, the service context, -the Principal object, etc. This option give us a slight performance improvement -but it is important for extremely low-latency systems (such as avionics), -that fortunately have tightly controlled environments so this kind of optimization -is safe to use.</LI> - -<LI> -The buffers for outgoing CDR streams are allocated from TSS memory pools, -reducing locking on the critical path.</LI> - -<LI> -Several optimizations on the critical path have been implemented, carefully -removing excesive locking, memory allocations and data copying. In some -cases special demarshaling and marshaling functions where written for the -request headers.</LI> - -<LI> -Adding a new option into TAO_Resource_Factory to control the internal lock -used by ORB's reacotr. With "<TT>-ORBreactorlock null</TT>" added into -<TT>svc.conf</TT>, you can eliminate the token inside the Select_Reactor -inside the ORB even on multi-threaded platforms. This eliminate some overheads -caused by synchronizing access to the Select_Reactor. Usually, if you have -TSS ORB and are using reactive concurrency startegy, the ORB are not accessed -by multiple threads, then, you can safely turn the lock off. - -<LI> -Strategized the connection management scheme so that we don't always have -to pay the price of a look up in the connection cache. Basically, we "hold" -a service handler for a string of requests.</LI> - -<LI> -There is no need to call ORB::open if the port is 0. It will automagically -be called when the first stub is created. - -<LI> The ORB now handles nested upcalls correctly. See <A -HREF="../leader_follower.html">this </A>for details on the design of -the solution. - -<LI> Making the collocation table configurable. We can either use a -global collocation table to share objects among ORBs, or use the -per-ORB collocation table. - -<LI> -Implement the inheritance mechanism in Default_Server_Connection_Handler -to access the parent's POA. This is necessary when we are using thread-per-connection -concurrency model. - -<LI> It is often desireable for a server to start up and not have to -specify the TCP port number on which the ORB will listen, i.e., let -the OS decide. While this works properly (by providing an argument -<TT>-ORBport 0</TT>), the actual port number used by the server won't -be available after the server starts listening. TAO now tries to bind -the address when <TT>-ORBport 0</TT> is issued so it can get the -actual address to publish the IOR for clients' use. - -<LI> Added optimization for collocated objects. This optimization -enables TAO to bypass communication layers and talks to collocated -objects directly. - -<LI> -Broke the tight coupling between <TT>CORBA_Object</TT> and <TT>IIOP_Object</TT> -so that multiple <TT>CORBA_Object</TT>s can share a single <TT>IIOP_Object</TT>. -This has a big win in <TT>_narrow</TT> operations. - -<LI> -Eliminated substantial memory leaks in servers. - -<LI> -Added documentation for <B><A HREF="../Options.html#-ORBpoa">-ORBpoa</A></B>, -which allows individual tweaking of the POA's locality (global vs. thread-specific) -independent of the locality of other ORB resources. Also, <B><A HREF="../Options.html#-ORBpoalock">-ORBpoalock</A></B> -and <B><A HREF="../Options.html#-ORBpoamgrlock">-ORBpoamgrlock</A></B> -control locking in the POA and POA manager, respectively, according to -application needs. - -<LI> -Began the process of changing the internals of TAO to use the "underbar" -namespace mapping. This should be completed soon. - -<LI> -The ORBs manipulation of object keys and object ids is now consistent. -Canonically, everything is managed as an opaque sequence of octets. Conversion -to/from strings is permitted, with non-printables turning into a trigraph -<B>\hl</B> where <B>h</B> is the high nibble digit in hex, and <B>l</B> -is the low nibble in hex.</LI> - -<LI> -<TT>CORBA_ORB::run()</TT> should be able to be called multiply in the same -execution path now.</LI> - -<LI> -Fixed the <B>LOCATION_FORWARD</B> capabilities to work as described in -the CORBA 2.1 and the POA specification.</LI> - -<LI> -Fixed problem in the IDL Cubit example which caused the server to dump -core when dealing with <TT>_out</TT> sequence types <I>ONLY</I> when compiled -with G++. It seems that G++ decided to interpret the expression <TT>output -== 0</TT> (where <TT>output</TT> is of type <TT>vector_out</TT>) differently -from Sun's C++ compiler.</LI> - -<LI> -Fixed a slight problem in <A HREF="#hostfix">other recent work</A> where -a servant listening on <TT>INADDR_ANY</TT> reported an IOR with address -<TT>0.0.0.0</TT>. It now reports the default hostname instead.</LI> - -<LI> -Working version of TAO on VxWorks with VME transport.</LI> - -<LI> -TAO now reacts gracefully in the face of a non-existent <TT>svc.conf</TT> -file or simply missing entries in the file. It logs a warning message and -uses default values versions of items which it would normally obtain from -the Service Repository.</LI> - -<LI> -<A NAME="hostfix"></A>Fixed problem where object references for objects -dynamically created within a server do not have proper host, at least if -the desired host was specified using <B><A HREF="../Options.html#-ORBhost">-ORBhost</A></B> -on the command line.</LI> - -<LI> -Added support for <B><A HREF="../Options.html#-ORBsndsock">-ORBsndsock</A></B> -and <B><A HREF="../Options.html#-ORBrcvsock">-ORBrcvsock</A></B> ORB options. -See <A HREF="../Options.html">options documentation</A> for details.</LI> - -<LI> -Added support for pre-established connections using the <B><A HREF="../Options.html#-ORBpreconnect">-ORBpreconnect</A></B> -option. This allows connections to be esablished before any CORBA requests -are made. See <A HREF="../Options.html">options documentation</A> for details.</LI> - -<LI> -Eliminated deprecated <B>-OAxxx</B> options parsed by the Object Adapter -<TT>init</TT> method but no longer used by part of the ORB.</LI> - -<LI> -Made argument parsing within the ORB and POA consume the arguments it parses.</LI> - -<LI> -Placed an optimization in IIOP::Profile that should speed up invocations -on the client side rather substantially. This was done by caching an instance -of <TT>ACE_INET_Addr</TT> in the private portion of <TT>Profile</TT> because -the cost of constructing one for every invocation (in <TT>TAO_GIOP_Invocation::start</TT>) -was simply enormous--the construction was something like 100 cycles on -Solaris. This is all because deep down this ends up calling <TT>gethostbyname()</TT>, -which can be very costly. Of course, this is platform-dependent, so the -improvements may not be as great on a different platform.</LI> - -<LI> -Got rid of need to have compile in TSS ORB Core (<TT>-DTAO_HAS_TSS_ORBCORE</TT>). -This is accomplished by having a Resource Factory (<TT>TAO_Resource_Factory</TT>) -singleton which the ORB Core consults in order to get pointers to resources. -The Resource Factory can be configured to return pointers from thread-specific -storage, or process-global storage. By doing this, the ORB Core is shielded -from ever having to know whether or not its resources are global or not.</LI> - -<LI> -Made all command-line like options look like the standard-professed options, -i.e., <B>-ORBxxx</B> or <B>-OAxxxx</B>.</LI> - -<LI> -Moved ORB option parsing into <TT>TAO_ORB_Core::init()</TT> rather than -in <TT>ORB_init()</TT>.</LI> - -<LI> -Define <TT>_FAR</TT> for all cases as an interim fix for LynxOS.</LI> - -<LI> -Fixed TAO so that the default port of 5001 is defined in <TT>orb_core.h</TT> -config header somewhere rather than in <TT>orbobj.cpp</TT>, and use <B>MAXHOSTNAMELEN</B> -ACE -constant for the hostname buffer.</LI> - -<LI> -Eliminated need for <TT>CORBA::Object</TT> to keep a pointer to its orb -sitting around anywhere.</LI> - -<LI> -Tested <TT>CORBA_ORB::shutdown()</TT> as a manner in which a thread of -control can request that <TT>CORBA_ORB::run()</TT> should return and no -longer service requests. It only honors a <I>wait_for_completion</I> argument -of <B>FALSE</B> right now because we haven't fully explored the issues -which surround doing all the completion.</LI> - -<LI> -Created a brief section in <TT><A HREF="../../TAO-INSTALL.html">$TAO_ROOT/TAO-INSTALL.html</A></TT> -that <I>briefly</I> documents installation on Unix platforms. There is -also a brief section which documents issues that apply across ALL platforms, -such as the fact that TAO and its application will likely not work well -if your ACE is linked through Orbix, VisiBroker, or another ORB. <A HREF="../../ChangeLog">ChangeLog</A> -discovery attribution for this should go to <I>Steve Wohlever <wohlever@mitre.org></I>.</LI> - -<LI> -Implemented <TT>CORBA_ORB::shutdown()</TT> as a manner in which a thread -of control can request that <TT>CORBA_ORB::run()</TT> should return and -no longer service requests.</LI> - -<LI> -Validated movement of Strategy Connector into ORB Core.</LI> - -<LI> -Tested and commited <TT>Connector::connect_n</TT> changes to ACE.</LI> - -<LI> -ACE & TAO compiling cleanly using Sun's CC on Solaris and G++ on Linux. -Also, the ACE tests run properly.</LI> - -<LI> -Use <TT>truss</TT> to verify for <A HREF="mailto:PAUL.G.WEHLAGE@cdev.com">Paul -Wehlage</A> that TAO really uses <TT>select</TT> vs. <TT>recv</TT> for -<B>-R</B> vs. <B>-T</B>.</LI> - -<LI> -Renamed <TT>boa.*</TT> to <TT>poa.*</TT>.</LI> - -<LI> -Renamed following files: Orb_Core.* ->orb_core.* & orbobj.* -> corba_orb.*.</LI> - -<LI> -The lock used in <TT>giop.cpp:626</TT> originally appeared in the IIOP-1.4 -code base. Its purpose was to protect access to the <TT>fwd_profile</TT> -data member. The original features are available, but they are currently -not used because none of our concurrency models present a thread-unsafe -condition. The <A HREF="../../ChangeLog">ChangeLog</A> presents more details -on the subject.</LI> - -<LI> -Fixed problems seen by <A HREF="mailto:brian.r.mendel@boeing.com">Brian -Mendel</A> of Boeing where the Cubit server application was crashing in -<TT>TAO_OA_Connection_Handler::handle_message</TT> when it was trying to -call <TT>CORBA::POA::handle_request</TT> through a NULL <TT>root_poa</TT> -pointer. The NULL pointer resulted from the inadvertent use of the Thread-per-Connection -concurrency model, which is currently incompatible with the ORB-per-thread -model. It was not caught because the change is normally done in configuration -files parsed by the Service Configurator, and VxWorks requires special -code in that area which was not tested until Boeing got hold of the code.</LI> - -<LI> -Clean up build under g++. All 'function used before declared inline' warnings -have been eliminated. Also, all other warnings (except for one that is -nearly unavoidable) have been eliminated.</LI> - -<LI> -Removed BOA and ROA names from the ORB.</LI> - -<LI> -Changed <TT>CORBA_ORB::open()</TT> to return an error status (first cut -at this already there--needs to be checked out).</LI> - -<LI> -Added README file to multiCubit test.</LI> - -<LI> -Added support for the -ORBInitRef option. This allows run-time specification of -an ObjectId:IOR mapping. It is used by resolve_initial_references () and -overrides the orb-install-time defaults.</LI> - -</UL> -<B>Ongoing Work:</B> -<UL> -<LI> -Verify ACE & TAO on Linux using g++, Solaris using CC, and Solaris -using g++.</LI> - -<LI> -Use Purify to eliminate straggling problems.</LI> - -<LI> -Clean up the internals and analyze for performance bottlenecks using Quantify.</LI> - -<LI> -Resolve <TT>// @@</TT> comment blocks. These are questions or comments -placed in the code by a reviewer (typically Doug).</LI> - -<LI> -Make more and better documentation on the internals of TAO.</LI> -</UL> -<B>Current Work:</B> -<UL>Verify that, in the ORB-per-thread concurrency model, it's possible -to have a factory in each thread that creates a client and returns an object -reference to that client within that thread. This is different from the -model that Sumedh originally had where the factory was trying to turn out -a client in a separate thread/ORB combination. -There is no application which attempts this at the moment, so both a -client and a server will need to be manufactured. Using existing Cubit-like -examples (that poor app is so weary) should reduce development time to -a couple of hours. -The real strategy/solution is to make <TT>CORBA::Object</TT> not keep -a pointer to its orb sitting around anywhere. It should only get it when -it needs it. This should not be difficult to change.</UL> - The interface Dynamic -Any (CORBA v.2.2) is being implemented. It will conform to and implement -all areas of the spec except for the following: -<UL> -<LI> -Interface DynFixed not implemented since TAO does not currently support -the IDL fixed data type.</LI> - -<LI> -Long double data type not supported in accessor and mutator functions.</LI> - -<LI> -Wstring (wide character string) data type not supported in accessor and -mutator functions.</LI> - -<LI> -DynUnion attribute set_as_default in treated as read only.</LI> -</UL> -<B>Critical Work:</B> -<UL> -<LI> -Identify/fix the problems in multithreaded client with TSS resources. This -could be done using the leader-follower model (thread-pool.)</LI> - -<LI> -Support new concurrency models, e.g., Thread-per-Request, thread pool, -etc..</LI> -</UL> -<B>Future work:</B> -<UL> -<LI> -Performance optimizations, such as:</LI> - -<OL> -<LI> -Replace all uses of <TT>new</TT> and <TT>delete</TT> with allocators that -can be put into TSS. The main motivation for this is to eliminate lock -contention when multiple threads need to allocate/deallocate memory, however -it might also be possible to substitute an allocator better-tuned to an -application's specific usage.</LI> -</OL> - -<LI> -Robustness improvements:</LI> - -<OL> -<LI> -Improve connection cache so that it won't crash when there are no more -slots or sockets.</LI> - -<LI> -Add an option to the ORB core, e.g., <B>-ORBnameservicetimeout</B>, to -allow specification of an upper bound on the itime-to-wait for a response -from the ORB's multicast "search" for a running name server.</LI> -</OL> - -<LI> -New features:</LI> - -<OL> -<LI> -Implement <TT>ORB::perform_work</TT> and <TT>ORB::work_pending</TT> so -that <TT>ORB::run</TT> <I>could</I> be implemented in terms of them.</LI> - -<LI> -Improve the <TT>Service Configurator</TT> service entry faking on VxWorks.</LI> - -<LI> -Integrate with realtime upcalls (RTUs).</LI> -</OL> - -<LI> -Internal restructuring:</LI> - -<OL> -<LI> -Create some sort of internal "request" object which carries enough context -to suport deferred method invocation such as one might find in the thread-pool -approach or wherever queuing might occur.</LI> -</OL> - -<LI> -Documentation:</LI> - -<OL> -<LI> -Update ORB Patterns paper to reflect the latest TAO has to offer. Specifically</LI> - -<UL> -<LI> -sections on the Abstract Factory and Concurrency strategies need to be -updated, and the entire paper needs to be reviewed for accuracy w.r.t the -current TAO.</LI> - -<LI> -Metrics must be re-computed.</LI> - -<LI> -Tighten existing discussions.</LI> - -<LI> -Add information on new patterns (such as TSS) which have been used since -initial work.</LI> -</UL> - -<LI> -Make the section in <TT><A HREF="../../TAO-Install.html">$TAO_ROOT/TAO-Install.html</A></TT> -that documents installation on Unix platforms more complete.</LI> -</OL> - -<LI> -Miscellany:</LI> - -<OL> -<LI> -Assist in porting higher level services (e.g., <A HREF="ec.html">Event -Channel</A>) to TAO.</LI> - -<LI> -Compile and verify ACE and TAO on Linux using the Kuck and Associates, -Inc. (KAI) compiler tools.</LI> -</OL> - -<LI> -Potential Optimizations:</LI> - -<OL> -<LI> -There is a certain amount of overhead introduced by the use of TSS Singletons. -TSS singletons are very convenient as the variable does not have to be -passed from function to function. Even though sort of access is generally -acceptable, the overhead of this approach maybe too high when used in code -which is executed frequently (e.g., during an upcall). This critical code -may have to be restructured not to use TSS Singletons because of the high -overhead associated with it.</LI> -</OL> -</UL> - -</BODY> -</HTML> diff --git a/TAO/docs/releasenotes/trader.html b/TAO/docs/releasenotes/trader.html deleted file mode 100644 index a8995ab1d81..00000000000 --- a/TAO/docs/releasenotes/trader.html +++ /dev/null @@ -1,1064 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> -<html> - -<head> -<title>TAO Trading Service Documentation</title> -</head> - -<body text="#000000" link="#0000FF" vlink="#CC0000" bgcolor="#FFFFFF"> - -<hr> - -<h1 align="center">TAO Trading Service Documentation</h1> - -<hr> - -<p>The TAO transient Trading Service implements the COS TradingObject Service -specification, and conforms to the Linked Trader conformance criteria. This document -details how to use the TAO Trading Service from the following perspectives: - -<ul> - <li>as an importer bootstrapping to the Trading Service;</li> - <li>as a service offer exporter;</li> - <li>as an administrator;</li> - <li>as an out-of-the-box server process; </li> - <li>as a collocated object. </li> -</ul> - -<p>In addition, it covers running the Trading Service tests and discusses known bugs and -workarounds.</p> - -<p>This document assumes you are familiar with Trading Service concepts, such as -"importer," "exporter", "service type", "service -offer," and "dynamic property", as well as the roles of each of the Trading -Service's interfaces --- <tt>Lookup</tt>, <tt>Register</tt>, <tt>Admin</tt>, and <tt>Link</tt> -(the TAO implementation doesn't currently support <tt>Proxy</tt>). I recommend reading the -first two sections of the <a href="ftp://www.omg.org/pub/docs/formal/97-12-23.pdf">Trading -Service specification</a>. This document has the following layout: - -<ol> - <li><a href="#TheClientRole">The Client Role</a> <ul> - <li><a href="#BootstrappingtotheTradingService">Bootstrapping to the Trading Service</a> </li> - <li><a href="#The ImporterRolePerformingaQuery">The Importer Role --- Performing a Query</a><ul> - <li><a href="#Constraints">Constraints</a></li> - <li><a href="#Preferences">Preferences</a></li> - <li><a href="#Policies">Policies</a></li> - <li><a href="#FilteringProperties">Filtering Properties</a> </li> - <li><a href="#OfferIterators">Offer Iterators</a></li> - <li><a href="#PropertyEvaluation">Property Evaluation</a></li> - </ul> - </li> - <li><a href="#TheExporterRole">The Exporter Role --- Registering a Service Type and Offer</a> - <ul> - <li><a href="#TheServiceTypeRepository">The Service Type Repository</a> </li> - <li><a href="#ExportingWithdrawingandModifying">Exporting, Withdrawing, and Modifying - Service Offers</a> </li> - <li><a href="#ImplementingDynamicProperties">Implementing Dynamic Properties</a></li> - </ul> - </li> - <li><a href="#TheAdministratorRole">The Administrator Role --- Tweaking Policies and - Adjusting Links</a></li> - </ul> - </li> - <li><a href="#TheServerRole">The Server Role</a><ul> - <li><a href="#TheTAOTradingServiceApplication">The TAO <tt>Trading_Service</tt> Application</a></li> - <li><a href="#ColocatingtheTradingServiceinaTAOApplication">Colocating the Trading Service - in a TAO Application</a></li> - </ul> - </li> - <li><a href="#RunningtheTradingServiceTests">Running the Trading Service Tests</a></li> - <li><a href="#KnownBugsandWorkarounds">Known Bugs and Workarounds</a></li> - <li><a href="#FutureWork">Future Work</a></li> -</ol> - -<hr> - -<h1><a name="TheClientRole">The Client Role</a></h1> - -<p align="left">There are three categories of operations that a client can perform on a -Trading Service instance: exporting a service offer to the Trading Service, importing a -list of Service Offers whose properties satisfy a constraint expression, and attending to -administrative duties --- tweaking policies or adjusting links. The first order of -business, of course, is obtaining a reference to a Trading Service instance, assuming that -instance is not colocated with the client. </p> - -<h2 align="left"><a name="BootstrappingtotheTradingService">Bootstrapping to the Trading -Service</a></h2> - -<p align="left">Like with the Naming Service, the ORB will obtain a reference to a Trading -Service instance's <tt>Lookup</tt> interface when a client invokes the <tt>CORBA::ORB::resolve_initial_references</tt> -method and passes to it the <tt>ObjectID</tt> "<tt>TradingService</tt>". The -following TAO code bootstraps to the Trading Service:</p> - -<table border="1" width="100%" cellpadding="6"> - <tr> - <td width="100%"><pre>TAO_TRY -{ - TAO_ORB_Manager orb_manager; - orb_manager.init (argc, argv, TAO_TRY_ENV); - TAO_CHECK_ENV; - CORBA::ORB_var orb = orb_manager.orb (); - CORBA::Object_var trading_obj = - orb->resolve_initial_references ("TradingService"); - CosTrading::Lookup_var lookup_if = - CosTrading::Lookup::_narrow (trading_obj.in (), TAO_TRY_ENV); - TAO_CHECK_ENV; -} -TAO_CATCHANY -{ - TAO_TRY_ENV.print_exception ("Failed to bootstrap to a trader"); -} -TAO_ENDTRY;</pre> - </td> - </tr> -</table> - -<p>The first time <tt>resolve_initial_references</tt> is called, the ORB uses a multicast -protocol to locate an existing trader. The ORB emits a multicast packet containing a field -identifying the desired service --- Naming or Trading --- and the port number that the -client is listening on for the response (the IP address can be inferred from the packet). -When the trader receives the packet and finds that the id contained within matches its -own, it opens a socket to the client on the designated port, and sends its IOR, which the -ORB converts to an object reference that it caches. </p> - -<p>If the trader IOR is known ahead of time, the string can be passed to the client in the -environment variable <tt>TradingService</tt>, or by the command line option <tt>-ORBtradingserviceior -<IOR></tt>. Likewise, if the multicast port is known ahead of time and differs from -the default port, the port number can be passed to the client in the environment variable <tt>TradingServicePort</tt>, -or by the command line option <tt>-ORBtradingserviceport <PORTNUM></tt>. </p> - -<h2><a name="The ImporterRolePerformingaQuery">The Importer Role --- Performing a Query</a></h2> - -<p>Once the importer has obtained a reference to a trader's <tt>Lookup</tt> interface, it -next needs to fire up a query. The query method takes nine parameters (aside from the <tt>CORBA::Environment</tt>):</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="39%"><tt>const CosTrading::ServiceTypeName</tt></td> - <td width="61%">The Trading Service will search Offers belonging to this subtype. If the <tt>exact_type_match</tt> - policy wasn't explicitly set to false, then offers belonging to subtypes of this type will - also be searched. </td> - </tr> - <tr> - <td width="39%"><tt>const CosTrading::Constraint</tt></td> - <td width="61%">An expression in the OMG standard constraint language, where each property - name is a property defined in the Service Type description of the type being searched.</td> - </tr> - <tr> - <td width="39%"><tt>const CosTrading::Lookup::Preference</tt></td> - <td width="61%">An expression in the OMG standard constraint language dictating how offers - in the <tt>returned_offers</tt> sequence should be ordered.</td> - </tr> - <tr> - <td width="39%"><tt>const CosTrading::PolicySeq</tt></td> - <td width="61%">Policies governing the breadth of search and the type of permissible - offers. A policy is a name/value pair --- a string and an <tt>Any</tt> --- that affect the - search algorithm. </td> - </tr> - <tr> - <td width="39%"><tt>const CosTrading::Lookup::SpecifiedProps</tt></td> - <td width="61%">A union specifying which properties should be returned in each offer. If - the descriminator is <tt>CosTrading::Lookup::some</tt>, the union contains the list - of designated property names. Other options are <tt>all</tt>or <tt>none</tt>. </td> - </tr> - <tr> - <td width="39%"><tt>CORBA::ULong how_many</tt></td> - <td width="61%">The number of offers that should be placed in the returned sequence.</td> - </tr> - <tr> - <td width="39%"><tt>CosTrading::OfferSeq_out</tt></td> - <td width="61%">A list of ordered offers whose properties meet the constraints.</td> - </tr> - <tr> - <td width="39%"><tt>CosTrading::OfferIterator_out</tt></td> - <td width="61%">Iterator over returned offers in excess of how_many --- unordered.</td> - </tr> - <tr> - <td width="39%"><tt>CosTrading::PolicyNameSeq_out</tt></td> - <td width="61%">A sequence of policy names for policies that limited the search.</td> - </tr> -</table> - -<h3><a name="Constraints">Constraints</a></h3> - -<p>A constraint is a string in the OMG standard constraint language (the BNF can be found -at the end of the specification). The trader iterates over applicable offers, and for each -offer determines if its properties meet the constraints, replacing property names in the -string with their values and computing the result. If the constraint evaluates to true, -the offer is placed in the pool of matched offers. If the constraint string is -syntactically invalid, contains property names not found in the service type description -for the listed service type, or has operators with mismatched operand types, the query -method will throw an <tt>InvalidConstraint</tt> exception. </p> - -<p>Operands can be of two types: property names or literals. A property name is an -unquoted string of alphanumeric characters and underscores that begins with a letter. The -service type describes the type of a property. A literal is an signed or unsigned integer, -floating point number --- scientific notation acceptable ---, single-quoted string, or -boolean --- written TRUE or FALSE. </p> - -<p>The constraint language supports the following operations:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="25%">Arithmetic (+, -, *, /)</td> - <td width="34%"><tt>Disk_Space*1000 - Amount_Used/10</tt></td> - <td width="41%">Accepts two numeric operands.</td> - </tr> - <tr> - <td width="25%">Inequality (<,>,<=,>=)</td> - <td width="34%"><tt>Amount_Used < Disk_Space</tt></td> - <td width="41%">Accepts two numeric or two string operands.</td> - </tr> - <tr> - <td width="25%">Equality (==, !=)</td> - <td width="34%"><tt>Amount_Used == Disk_Space</tt></td> - <td width="41%">Accepts two numeric, two string, or two boolean operands.</td> - </tr> - <tr> - <td width="25%">Substring (~)</td> - <td width="34%"><tt>'.wustl.edu' ~ Domain_Name</tt></td> - <td width="41%">Accept two string operands. Returns true if the right string contains the - left.</td> - </tr> - <tr> - <td width="25%">Sequence inclusion (in)</td> - <td width="34%"><tt>'sbw1' in User_Queue</tt></td> - <td width="41%">Accepts an operand of a primitive CORBA type on the left, and a sequence - of the same type on the right. Returns true when the sequence contains the value in the - left operand, false otherwise.</td> - </tr> - <tr> - <td width="25%">Property existence (exist)</td> - <td width="34%"><tt>exist User_Queue</tt></td> - <td width="41%">Accepts a property name. Returns true if the property is defined in the - offer.</td> - </tr> -</table> - -<h3><a name="Preferences">Preferences</a></h3> - -<p>A preference is a constraint language string that determines the order of offers in the -returned offer sequence. There are five types of preferences:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="18%"><tt>min</tt> <expression></td> - <td width="82%">Offers are ordered by ascending expression value. The expression must - return a number.</td> - </tr> - <tr> - <td width="18%"><tt>max</tt> <expression> </td> - <td width="82%">Offers are ordered by descending expression value. The expression must - return a number. </td> - </tr> - <tr> - <td width="18%"><tt>with</tt> <expression></td> - <td width="82%">Offers are partitioned into two parts: those offers for which the - expression returns true are placed in the front, the rest in the back. The expression must - return a boolean value.</td> - </tr> - <tr> - <td width="18%"><tt>random</tt></td> - <td width="82%">Offers in the sequence are shuffled.</td> - </tr> - <tr> - <td width="18%"><tt>first</tt></td> - <td width="82%">Offers are placed in the sequence in the order they're evaluated.</td> - </tr> -</table> - -<h3><a name="Policies">Policies</a></h3> - -<p>The following import policies are descibed in the specification and supported by the -TAO Trading Service:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="22%"><tt>exact_type_match</tt></td> - <td width="18%"><tt>CORBA::Boolean</tt></td> - <td width="60%">True --- Search only considers offers belonging to the given type.<br> - False --- Search considers offers belonging to the given type or any of its subtypes.</td> - </tr> - <tr> - <td width="22%"><tt>search_card</tt></td> - <td width="18%"><tt>CORBA::ULong</tt></td> - <td width="60%">Search ceases after <tt>search_card</tt> number of offers have been - evaluated.</td> - </tr> - <tr> - <td width="22%"><tt>match_card</tt></td> - <td width="18%"><tt>CORBA::ULong</tt></td> - <td width="60%">Search ceases after <tt>search_card</tt> number of offers have been - matched.</td> - </tr> - <tr> - <td width="22%"><tt>return_card</tt></td> - <td width="18%"><tt>CORBA::ULong</tt></td> - <td width="60%">Query returns at most <tt>return_card</tt> number of offers.</td> - </tr> - <tr> - <td width="22%"><tt>support_dynamic_properties</tt></td> - <td width="18%"><tt>CORBA::Boolean</tt></td> - <td width="60%">Search considers offers with dynamic properties.</td> - </tr> - <tr> - <td width="22%"><tt>support_modifiable_properties</tt></td> - <td width="18%"><tt>CORBA::Boolean</tt></td> - <td width="60%">Search considers offers with not readonly properties.</td> - </tr> - <tr> - <td width="22%"><tt>starting_trader</tt></td> - <td width="18%"><tt>CosTrading::TraderName</tt></td> - <td width="60%">Query is forwarded across all links in the policy, and search begins at - the final trader.</td> - </tr> - <tr> - <td width="22%"><tt>hop_count</tt></td> - <td width="18%"><tt>CORBA::ULong</tt></td> - <td width="60%">Maximum depth a query should be propagated in the trader federation.</td> - </tr> - <tr> - <td width="22%"><tt>link_follow_rule</tt></td> - <td width="18%"><tt>CosTrading::FollowOption</tt></td> - <td width="60%">Query propagates to other traders if the <tt>link_follow_rule</tt> permits - it.</td> - </tr> -</table> - -<p>The TAO Trading Service comes with a handy utility --- <tt>TAO_Policy_Manager</tt> --- -for creating a policy sequence to pass to the query method that won't incur any -exceptions. Use the <tt>TAO_Policy_Manager</tt> in the following way:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>TAO_Policy_Manager policies; -policies.exact_type_match (CORBA::B_FALSE); -policies.search_card (16*NUM_OFFERS); -policies.match_card (16*NUM_OFFERS); -policies.return_card (16*NUM_OFFERS); -policies.link_follow_rule (CosTrading::local_only); -const CosTrading::PolicySeq& policy_seq = policies.policy_seq ();</pre> - </td> - </tr> -</table> - -<h3><a name="FilteringProperties">Filtering Properties</a></h3> - -<p>If the client wants only a subset of the properties defined for a service type returned -in matching offers, it can specify those property names in the <tt>desired_properties</tt> -parameter of the query method. Pass the <tt>prop_names</tt> method of <tt>CosTrading::Lookup::SpecifiedProperties</tt> -a <tt>CosTrading::PropNameSeq</tt>:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>char* props[] = {"Name", "Description", "Location", "Host_Name" }; -CosTrading::Lookup::SpecifiedProps desired_props; -CosTrading::PropertyNameSeq prop_name_seq (4, 4, props, CORBA::B_FALSE); -desired_props.prop_names (prop_name_seq);</pre> - </td> - </tr> -</table> - -<h3><a name="OfferIterators">Offer Iterators</a></h3> - -<p>Those offers returned from the query in excess of <tt>how_many</tt> are placed in an -offer iterator for deferred retrieval. The <tt>CosTrading::OfferIterator::next_n</tt> -method will allocate a sequence and fill it with either n offers, or if it has fewer than <tt>n</tt> -offers, the remaining offers. The <tt>next_n</tt> method returns true if the iterator -contains more offers, and false if it's been depleted. After finishing with the iterator, -invoke its <tt>destroy</tt> method to release any server-side resources.</p> - -<p>The following code is an example of obtaining offers from a <tt>CosTrading::OfferIterator</tt>:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>CORBA::Boolean any_left = CORBA::B_FALSE; -CORBA::Environment _env;</pre> - <pre>do - { - CosTrading::OfferSeq_ptr iter_offers_ptr; - CosTrading::OfferSeq_out iter_offers_out (iter_offers_ptr); - - any_left = offer_iterator->next_n (length, - iter_offers_out, - _env); - TAO_CHECK_ENV_RETURN (_env, 0); - - CosTrading::OfferSeq_var iter_offers (iter_offers_ptr); - // Process offers... - - } while (any_left);</pre> - </td> - </tr> -</table> - -<h3><a name="PropertyEvaluation">Property Evaluation</a></h3> - -<p>After the client completes a query that used dynamic properties, to review the property -values of the returned offers, it has to distinguish between <tt>Anys</tt> containing -static properties and <tt>Anys</tt> containing dynamic property structures. The <tt>TAO_Property_Evaluator</tt> -class is a handy utility to obtain property values that hides how it evalutes properties -for the client --- by simple <tt>Any</tt> value extraction for static properties, or by -calling back to a dynamic property interface. The <tt>TAO_Property_Evaluator</tt> caches -the value of a dynamic property, and frees the allocated <tt>Anys</tt> during its -destruction. </p> - -<p>The following code demonstrates how to use the <tt>TAO_Property_Evaluator</tt> to dump -the properties of an offer to the screen. </p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>TAO_Property_Evaluator prop_eval (prop_seq); -for (int length = prop_seq.length (), k = 0; k < length; k++) - { - ACE_DEBUG ((LM_DEBUG, "%-15s: ", prop_seq[k].name.in ())); - TAO_TRY - { - CORBA::Boolean is_dynamic = prop_eval.is_dynamic_property (k); - TAO_CHECK_ENV; - - value = prop_eval.property_value(k, env); - TAO_CHECK_ENV; - - if (value != 0) - CORBA::Any::dump (*value); - } - TAO_CATCHANY - { - ACE_DEBUG ((LM_DEBUG, "Error retrieving property value.\n")); - } - TAO_ENDTRY; - }</pre> - </td> - </tr> -</table> - -<h2><a name="TheExporterRole">The Exporter Role --- Registering a Service Type and Offer</a></h2> - -<p>Before an exporting client can register a new service offer with the Trading Service, -it needs to ensure first that its service type is present in the service type repository -of the target trader. The most efficient way to do this is to first invoke the <tt>export</tt> -method on the <tt>Register</tt> interface, and if it raises an <tt>UnknownServiceType</tt> -exception, obtain a reference to the Repository, add the Service Type, and attempt the <tt>export</tt> -a second time. Here's the boilerplate code:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>CORBA::Object_var trading_obj = - orb_ptr->resolve_initial_references ("TradingService"); -CosTrading::Lookup_var lookup_if = - CosTrading::Lookup::_narrow (trading_obj.in (), _env); -TAO_CHECK_ENV_RETURN (_env, -1); -CosTrading::Register_var register_if = lookup_if->register_if (_env); -TAO_CHECK_ENV_RETURN (_env, -1); -CosTrading::TypeRepository_ptr obj = this->trader_->type_repos (_env); -CosTradingRepos::ServiceTypeRepository_var str = - CosTradingRepos::ServiceTypeRepository::_narrow (obj, _env); -TAO_CHECK_ENV_RETURN (_env, -1); - -TAO_TRY - { - // Attempt to export the offer. - offer_id = - register_id->export (object_ref, type, props, TAO_TRY_ENV); - TAO_CHECK_ENV; - } -TAO_CATCH (CosTrading::UnknownServiceType, excp) - { - // If the ServiceTypeName wasn't found, we'll have to add the - // type to the Service Type repository ourselves. - str->add_type (type, - object_ref->_interface_repository_id (), - prop_struct_seq, - super_type_name_seq, - _env); - TAO_CHECK_ENV_RETURN (_env, 0); - - // Now we'll try again to register the offer. - offer_id = reg->export (object_ref, type, this->tprops_, _env); - TAO_CHECK_ENV_RETURN (_env, 0); - - TAO_TRY_ENV.clear (); - } -TAO_CATCHANY - { - // Sigh, all our efforts were for naught. - TAO_RETHROW_RETURN (0); - } -TAO_ENDTRY;</pre> - </td> - </tr> -</table> - -<h3><a name="TheServiceTypeRepository">The Service Type Repository</a></h3> - -<p>Creating a service type description is simply a matter of filling in two sequences: a <tt>CosTradingRepos::ServiceTypeRepository::PropStructSeq</tt> -and a <tt>CosTradingRepos::ServiceTypeRepository::ServiceTypeNameSeq</tt>. When filling in -the <tt>value_type</tt> field, remember to up the reference count of the <tt>TypeCode</tt>, -since otherwise the <tt>TypeCode_var</tt> will sieze control of the memory and free it. -Here's a code excerpt taken from <tt>export_test</tt> showing how to build the first -couple elements of such sequences:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>this->type_structs_[TT_Info::PLOTTER].props.length (2); -this->type_structs_[TT_Info::PLOTTER].super_types.length (1); -this->type_structs_[TT_Info::PLOTTER].super_types[0] = -TT_Info::INTERFACE_NAMES[TT_Info::REMOTE_IO]; -this->type_structs_[TT_Info::PLOTTER].props[0].name = -TT_Info::PLOTTER_PROPERTY_NAMES[TT_Info::PLOTTER_NUM_COLORS]; -this->type_structs_[TT_Info::PLOTTER].props[0].value_type = -CORBA::TypeCode::_duplicate (CORBA::_tc_long); -this->type_structs_[TT_Info::PLOTTER].props[0].mode = -CosTradingRepos::ServiceTypeRepository::PROP_NORMAL; -this->type_structs_[TT_Info::PLOTTER].props[1].name = -TT_Info::PLOTTER_PROPERTY_NAMES[TT_Info::PLOTTER_AUTO_LOADING]; -this->type_structs_[TT_Info::PLOTTER].props[1].value_type = -CORBA::TypeCode::_duplicate (CORBA::_tc_boolean); -this->type_structs_[TT_Info::PLOTTER].props[1].mode = -CosTradingRepos::ServiceTypeRepository::PROP_READONLY;</pre> - </td> - </tr> -</table> - -<h3><a name="ExportingWithdrawingandModifying">Exporting, Withdrawing, and Modifying -Service Offers</a></h3> - -<p>Like with adding a Service Type, exporting an offer is just filling in the sequences. -For offers, of course, property values are passed, so this involves employing the <tt>Any</tt> -insertion operators. Here's a code exerpt from <tt>export_test</tt>:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>CosTrading::PropertySeq prop_seq (2); -prop_seq[0].name = - TT_Info::PLOTTER_PROPERTY_NAMES[TT_Info::PLOTTER_NUM_COLORS]; -prop_seq[0].value <<= ACE_static_cast (CORBA::Long, 256); -prop_seq[1].name = - TT_Info::PLOTTER_PROPERTY_NAMES[TT_Info::PLOTTER_AUTO_LOADING]; -prop_seq[1].value <<= CORBA::Any::from_boolean (CORBA::B_TRUE);</pre> - </td> - </tr> -</table> - -<p>The <tt>export_test</tt> returns a <tt>CosTrading::OfferId</tt> string, which is -required to perform the <tt>withdraw</tt> and <tt>modify</tt> operations on the exported -offer. <tt>withdraw</tt> requires that you simply pass the <tt>OfferId</tt> of the offer -to be withdrawn, while <tt>modify</tt> takes two additional sequences: a <tt>CosTrading::PropertyNameSeq</tt> -of property names to be removed from the offer, and a <tt>CosTrading::PropertySeq</tt> of -offers to be added or changed in the offer. </p> - -<h3><a name="ImplementingDynamicProperties">Implementing Dynamic Properties</a></h3> - -<p>To export an offer with a dynamic property: - -<ul> - <li>inherit from the <tt>TAO_Dynamic_Property</tt> class and implement its <tt>DP_Eval</tt> - method; </li> - <li>create a <tt>CosTradingDynamic::DynamicProperty</tt> structure using the <tt>TAO_Dynamic_Property::construct_dynamic_prop</tt> - method; </li> - <li>insert the <tt>CosTradingDynamic::DynamicProperty</tt> in the value field of the - property. </li> -</ul> - -<p>The following code, taken from the <tt>export_test</tt> example, illustrates this:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>// Step 1: Write the Dynamic Property callback handler. -class Simple_DP : public TAO_Dynamic_Property -{ -public: - - virtual CORBA::Any* evalDP (const char* name, - CORBA::TypeCode_ptr returned_type, - const CORBA::Any& extra_info, - CORBA::Environment& _env) - TAO_THROW_SPEC ((CosTradingDynamic::DPEvalFailure)); -}; - -CORBA::Any* -Simple_DP::evalDP (const char* name, - CORBA::TypeCode_ptr returned_type, - const CORBA::Any& extra_info, - CORBA::Environment& _env) - TAO_THROW_SPEC ((CosTradingDynamic::DPEvalFailure)) -{ - CORBA::Any* return_value = 0; - ACE_NEW_RETURN (return_value, CORBA::Any, 0); - - (*return_value) <<= ACE_static_cast (CORBA::ULong, ACE_OS::rand ()); - return return_value; -}</pre> - <pre>// Step 2: Create the Dynamic Property -Simple_DP dp; -CORBA::Any extra_info; -CosTrading::PropertySeq prop_seq (1); -CosTrading::DynamicProp* dp_struct = - dp.construct_dynamic_prop ("prop_name", - CORBA::_tc_ulong, - extra_info);</pre> - <pre>// Step 3: Turn over the dynamic property to the propery value Any. -CORBA::Environment env; -prop_seq[0].name = "prop_name"; -prop_seq[0].value.replace (CosTrading::_tc_DynamicProp, - dp_struct, - CORBA::B_TRUE, - env); -TAO_CHECK_ENV_RETURN (env, -1);</pre> - </td> - </tr> -</table> - -<h2><a name="TheAdministratorRole">The Administrator Role --- Tweaking Policies and -Adjusting Links</a></h2> - -<p>The trader can be configured remotely through two interfaces: the <tt>Admin</tt> -interface, for tweaking global policies, enabling and disabling interfaces, and dumping -the trader contents; and the <tt>Link</tt> interface, for attaching to and detaching from -other traders. </p> - -<p>Adjusting policies is straightforward. Here's an example of setting the <tt>max_search_card</tt> -policy:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>// lookup_if returned from resolve_initial_references. -CosTrading::Admin_var admin_if = - lookup_if->admin_if (TAO_TRY_ENV); -TAO_CHECK_ENV;</pre> - <pre>admin_if->set_max_match_card (200);</pre> - </td> - </tr> -</table> - -<p>Here's an example of using the list_offers method on the Admin interface to remove all -offers from the Trader:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>TAO_TRY -{ -CosTrading::OfferIdIterator_ptr offer_id_iter; -CosTrading::OfferIdSeq_ptr offer_id_seq; - -// lookup_if returned from resolve_initial_references. -CosTrading::Admin_var admin_if = - lookup_if->admin_if (TAO_TRY_ENV); -TAO_CHECK_ENV; - -CosTrading::Register_var register_if = - lookup_if->register_if (TAO_TRY_ENV); -TAO_CHECK_ENV; - -admin_if->list_offers (10, - CosTrading::OfferIdSeq_out (offer_id_seq), - CosTrading::OfferIdIterator_out (offer_id_iter), - TAO_TRY_ENV); -TAO_CHECK_ENV; - -if (offer_id_seq != 0) - { - CosTrading::OfferIdSeq_var offer_id_seq_var (offer_id_seq); - for (CORBA::ULong i = 0; i < offer_id_seq_var.length (); i++) - { - register_if->withdraw (offer_id_seq_var[i], TAO_TRY_ENV); - TAO_CHECK_ENV; - } - } - -if (offer_id_iter != CosTrading::OfferIdIterator::_nil ()) - { - CORBA::Boolean any_left = CORBA::B_FALSE; - CosTrading::OfferIdSeq_ptr id_seq = 0; - CosTrading::OfferIdIterator_var offer_id_iter_var (offer_id_iter); - - do - { - any_left = - offer_id_iter->next_n (length, - CosTrading::OfferIdSeq_out (id_seq), - TAO_TRY_ENV); - TAO_CHECK_ENV; - - CORBA::ULong offers = id_seq->length (); - for (CORBA::ULong i = 0; i < offers; i++) - { - register_if->withdraw (id_seq[i], TAO_TRY_ENV); - TAO_CHECK_ENV; - } - - delete id_seq; - } - while (any_left); - - offer_id_iter->destroy (TAO_TRY_ENV); - TAO_CHECK_ENV; - } -} -TAO_CATCHANY -{ - // Handle Errors. -} -TAO_ENDTRY;</pre> - </td> - </tr> -</table> - -<p>Here's an example a trader linking itself to another trader (<tt>this->trader_</tt> -is a colocated trader --- see the next section for more information): </p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>TAO_TRY - { - CosTrading::Link_var link_if = lookup_if->link_if (TAO_TRY_ENV); - TAO_CHECK_ENV; - - TAO_Trading_Components_Impl& trd_comp = - this->trader_->trading_components (); - CosTrading::Lookup_ptr our_lookup = trd_comp.lookup_if (); - CosTrading::Link_ptr our_link = trd_comp.link_if (); - - link_if->add_link (this->name_.in (), - our_lookup, - CosTrading::always, - CosTrading::always, - TAO_TRY_ENV); - TAO_CHECK_ENV; - - our_link->add_link ("Bootstrap_Trader", - lookup_if.in (), - CosTrading::always, - CosTrading::always, - TAO_TRY_ENV); - } -TAO_CATCHANY -{ - // Handle Errors. -} -TAO_ENDTRY;</pre> - </td> - </tr> -</table> - -<hr> - -<h1><a name="TheServerRole">The Server Role</a></h1> - -<p>The TAO Trading Service comes with an out-of-the-box executable suitable for common -use. However, it can also easily be colocated with any other TAO server to add Trading -Service functionality to that server.</p> - -<h2><a name="TheTAOTradingServiceApplication">The TAO Trading Service Application</a></h2> - -<p>This out-of-the-box server takes a number of command line arguments:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="26%"><tt>-TSthreadsafe</tt></td> - <td width="74%">The Trader will use reader/writer locks to protect the offer database and - link collection, and normal thread mutexes for the rest of the shared state --- global - policies, support attributes, and interface accessors. (default is not thread safe; Null - Mutexes are used)</td> - </tr> - <tr> - <td width="26%"><tt>-TSconformance</tt></td> - <td width="74%">Determines which conformance category the Trading Service will meet:<br> - <table border="0" width="100%" cellpadding="3"> - <tr> - <td width="18%"><ul> - <li><em>query</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Instantiates the <tt>Lookup</tt> interface only</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>simple</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Instantiates the <tt>Lookup</tt> and <tt>Register</tt> - interfaces</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>standalone</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Instantiates the <tt>Lookup</tt>, <tt>Register</tt>, - and <tt>Admin</tt> interfaces</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>linked</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Instantiates the <tt>Lookup</tt>, <tt>Register</tt>, - <tt>Admin</tt>, and <tt>Link</tt> interfaces (default)</td> - </tr> - </table> - </td> - </tr> - <tr> - <td width="26%"><tt>-TSsupports_dynamic_properties</tt></td> - <td width="74%"><table border="0" width="100%" cellpadding="3"> - <tr> - <td width="18%"><ul> - <li><em>true</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Will consider offers with dynamic properties in - queries unless explicitly disabled by a policy passed to the query method. (default)</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>false</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Will not consider offers with dynamic properties - in queries, unless explicitly enabled by a policy passed to the query method.</td> - </tr> - </table> - </td> - </tr> - <tr> - <td width="26%"><tt>-TSsupports_modifiable_properties</tt></td> - <td width="74%"><table border="0" width="100%" cellpadding="3"> - <tr> - <td width="18%"><ul> - <li><em>true</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Will consider offers with not explicitly - modifable properties in queries unless explicitly disabled by a policy passed to the query - method. Enables the <tt>modify</tt> method on the <tt>Register</tt> interface. (default)</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>false</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">Will not consider dynamic properties in queries, - unless explicitly overridden by a query policy. Diables <tt>modify</tt> method on the <tt>Register</tt> - interface.</td> - </tr> - </table> - </td> - </tr> - <tr> - <td width="26%"><tt>-TSdef_search_card</tt></td> - <td width="74%">Search cardinality if none is specified as a query policy. (default is - 200)</td> - </tr> - <tr> - <td width="26%"><tt>-TSmax_search_card</tt></td> - <td width="74%">Upper limit on the search cardinality for a query. (default is 500)</td> - </tr> - <tr> - <td width="26%"><tt>-TSdef_match_card</tt></td> - <td width="74%">Match cardinality if none is specified as a query policy. (default is 200)</td> - </tr> - <tr> - <td width="26%"><tt>-TSmax_match_card</tt></td> - <td width="74%">Upper limit on the match cardinality for a query. (default is 500)</td> - </tr> - <tr> - <td width="26%"><tt>-TSdef_return_card</tt></td> - <td width="74%">Return cardinality if none is specified as a query policy. (default is - 200)</td> - </tr> - <tr> - <td width="26%"><tt>-TSmax_return_card</tt></td> - <td width="74%">Upper limit on the return cardinality for a query. (default is 500)</td> - </tr> - <tr> - <td width="26%"><tt>-TSdef_hop_count</tt></td> - <td width="74%">The depths a federated query may go if no query policy is specified. - (default 5)</td> - </tr> - <tr> - <td width="26%"><tt>-TSmax_hop_count</tt></td> - <td width="74%">The maximum number of links a federated query can travel after it passes - through this trader. (default is 10) </td> - </tr> - <tr> - <td width="26%"><tt>-TSdef_follow_policy</tt></td> - <td width="74%"><table border="0" width="100%" cellpadding="3"> - <tr> - <td width="18%"><ul> - <li><em>always</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader will always pass a query onto the - next available linked trader.</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>if_no_local</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader will pass a query onto the next - trader only if the local search produced no results. (default)</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>local_only</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader will never pass on a query.</td> - </tr> - </table> - </td> - </tr> - <tr> - <td width="26%"><tt>-TSmax_follow_policy</tt></td> - <td width="74%"><table border="0" width="100%" cellpadding="3"> - <tr> - <td width="18%"><ul> - <li><em>always</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader doesn't limit the importer to the - local offer space. (default)</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>if_no_local</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader refuses to pass on queries of the - local search matched offers.</td> - </tr> - <tr> - <td width="18%"><ul> - <li><em>local_only</em></li> - </ul> - </td> - <td width="82%" valign="top" align="left">The trader will never allow federated queries.</td> - </tr> - </table> - </td> - </tr> - <tr> - <td width="26%"><tt>-ORBtradingserviceport</tt></td> - <td width="74%">Port on which to listen for multicast bootstrap requests.</td> - </tr> - <tr> - <td width="26%"><tt>-ORBtradingserviceport</tt></td> - <td width="74%">Port on which to listen for multicast bootstrap requests.</td> - </tr> - <tr> - <td width="26%"><tt>-TSdumpior</tt></td> - <td width="74%">Dumps the trader's IOR to a file (default is stdout).</td> - </tr> -</table> - -<p>By default the trader will listen for multicast <tt>resolve_initial_references</tt> -requests, and respond with the IOR of its <tt>Lookup</tt> inteface. For the purposes of -testing federated queries, when passed the <tt>-TSfederate</tt> method, instead of -becoming a bootstrappable server, the <tt>Trading_Service</tt> application will bootstrap -itself to a multicast trader, link itself to that trader and every other trader accessible -through that trader. This protocol will have all traders on the multicast network form a -complete graph. </p> - -<h2><a name="ColocatingtheTradingServiceinaTAOApplication">Colocating the Trading Service -in a TAO Application</a></h2> - -<p>Colocating the Trading Service in a TAO application amounts to constructing a <tt>TAO_TRADER</tt> -object using the <tt>TAO_Trader_Factory::construct_trader</tt> call. The <tt>argc</tt> and -<tt>argv</tt> parameters to <tt>construct_trader</tt> contain the configuration parameters -described in the previous section. The trader is also configurable programatically through -its attribute classes. The follow code exerpt demonstrates this. </p> - -<p>In addition the application will need to create a service type repository -implementation --- TAO's being the <tt>TAO_Service_Type_Repository</tt> --- and configure -the trader with it. The service type repository is separate from the trader in this way to -allow, for example, multiple traders to share the same service type repository. The -following code exerpt also demontrates configuring the repository:</p> - -<table border="1" width="100%" cellpadding="3"> - <tr> - <td width="100%"><pre>TAO_TRADER* trader = TAO_Trader_Factory::create_trader (argc, argv); -TAO_Support_Attributes_Impl& sup_attr = trader->support_attributes (); -TAO_Import_Attributes_Impl& imp_attr = trader->trading_components (); - -// Configure the trader with a service type repository. -CORBA::Environment _env; -TAO_Service_Type_Repository type_repos* type_repos = 0; -ACE_NEW (type_repos, TAO_Service_Type_Repository); -sup_attr.type_repos (type_repos->_this (_env)); -TAO_CHECK_ENV_RETURN (_env, -1);</pre> - <pre>// Configure other policies, overriding the command line arguments. -imp_attr.search_card (20); -sup_attr.supports_dynamic_properties (CORBA::B_FALSE);</pre> - </td> - </tr> -</table> - -<p>The trader interfaces register themselves with the default POA during the Trading -Service's construction. All that remains is to activate the POA and enter the ORB event -loop. </p> - -<hr> - -<h1><a name="RunningtheTradingServiceTests">Running the Trading Service Tests</a></h1> - -<p>There are two executables that test the Trading Service funtionality --- one to test -the exporter role, and the other, the importer role. To run the tests simply launch the <tt>Trading_Service</tt> -application, then run the <tt>export_test</tt> executable found in the <tt>orbsvcs/tests/Trading</tt> -directory. When the <tt>export_test</tt> ceases to output data and enters the event loop, -run the <tt>import_test</tt> found in the same directory. </p> - -<p>Also of importance: the <tt>-TSdumpior filename </tt> argument to the trader dumps -its IOR to the file. You can then paste the contents on the command line to -the tests with <tt>-ORBtradingserviceior IOR</tt>, or into the environment variable -<tt>TradingServiceIOR</tt>.</p> - -<p>The expected output of the tests can be found in the README file in the -tests directory.</p> - -<p>To test federated queries, run at least three copies of the <tt>Trading_Service</tt> -application, each using the <tt>-TSfederate</tt> flag. The traders will form a complete -graph, with each link follow policy set to <tt>CosTrading::always</tt>. When run with the <tt>-f</tt> -flag, the <tt>export_test</tt> will add the service types and export offers to each of the -traders in the federation. When run with the <tt>-f</tt> flag, the <tt>import_test </tt>will -perform a directed query to a trader two links distant from the trader boostrapped to, in -addition to performing federated queries. </p> - -<p>By default the tests dump the contents of service types and offers to the screen so the -tester can validate the results. To run the tests in quiet mode, where the results of the -describe and query methods are concealed, use the <tt>-q</tt> flag.</p> - -<hr> - -<h1><a name="KnownBugsandWorkarounds">Known Bugs and Workarounds</a></h1> - - <p>At this point there are no known problems with TAO that affect the - Trading service.</p> - -<hr> - -<h1><a name="FutureWork">Future Work</a></h1> - -<ul> - <li><strong>Persistence</strong> --- Have the Trading Service offer database and service - type repository survive the lifetime of a single Trading Service process. This would be - accomplished by either taking advantage of the ability to serialize IDL types --- using - CDR streams --- or through memory-mapped files, <em>a la </em>the ACE Naming Service.</li> -</ul> - -<ul> - <li><strong>The <tt>Proxy</tt> Interface </strong>--- Should we ever feel so motivated, we - might implement the <tt>Proxy</tt> interface. </li> -</ul> - -<hr> - -<address> - <a href="mailto:sbw1@cs.wustl.edu">Seth Benjamin Widoff</a> -</address> -<!-- Created: Mon Jun 29 12:26:36 CDT 1998 --> -<!-- hhmts start --> -</body> -</html> |