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diff --git a/CIAO/docs/RT-Extension.html b/CIAO/docs/RT-Extension.html new file mode 100644 index 00000000000..3414a30b78e --- /dev/null +++ b/CIAO/docs/RT-Extension.html @@ -0,0 +1,132 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> +<!-- $Id$ --> +<html> <head> +<title>Using the Real-time Extension in CIAO</title> +</head> + +<body> +<h1>Using the Real-time Extension in CIAO</h1> + +<!-- ============================================================ --> +<h3>Abstract</H3> + +The real-time extension support in CIAO enables application developers +to deploy real-time applications by specifying real-time +configurations as XML descriptors without modifying the component +implementation. In fact, embedding the real-time configuration +policies in component implementations decrease the reusability of the +software components. + +Different types of real-time policy can be applied at different +stage of the component development lifecycle, e.g., +<ul> + <li>Component implementation + <li>Component packaging + <li>Application composition + <li>Target platform configuration + <li>Deployment configuration +</ul> + +Real-time policies can also be applied to various scope in an +applications, e.g., many real-time policies can be associate with some +or all of the following ORB mechanisms: +<ul> + <li>ORBs + <li>POAs + <li>Threads + <li>Object references +</ul> + +<!-- ============================================================ --> +<h3>CIAO's Real-time Extension</h3> + +CIAO extends CCM's assembly descriptor to support the specifications +of real-time policies. This mechanism allows you to allocate +resources that are global to a RTComponentServer and to define real-time +policies required by a component installation. Currently, CIAO +support configuration of certain real-time policies at the POA level, +i.e., in CCM's terminology, the container level. These policies +include: + +<ol> + <li>Priority Model Policy + <li>Threadpool Policy + <li>Banded Connection Policy +</ol> + +The kind of resources that are global to a RT component server that CIAO +real-time extension specifies include: + +<ol> + <li>Threadpool + <li>Threadpool with lanes + <li>Connection bands +</ol> + +<!-- ============================================================ --> +<h3>Using the CIAO Real-time Extension</h3> + +Application developers can define the aforementioned Real-Time +extension Descriptor (.rtd file) that CIAO defines to allocate +resources and specify real-time policies. The Document Type +Definition (DTD) for the real-time extension description is defined in +this <a href="XML/ciao_rt_cad_ext.dtd">file</a>. Each .RTD file +specifies the required resources and the policy definitions within a +RTComponentServer. + +A RTComponentServer can be associated to a .RTD file. This is done by +using the "extension" element with "class" attributed set to +"RT-CAD-EXT", within a processcollocation or hostcollocation element. +Here is an example: +<code><pre> + + <processcollocation> + . + . + . + <extension class="RT-CAD-EXT" origin="CIAO">somefile.rtd</extension> + . + </processcollocation> +</pre></code> + +Each .RTD file contains the two major subelements: +<ul> + <li><rtresources>: defines all the RT resources the assciating + RTComponentServer should provide. + <li><rtpolicysets>: defines named collections of policies + (<rtpolicyset>) that apply to component installations in + the RTComponentServer. +</ul> + +The <rtpolicyset>'s defined in the .RTD file can be associated +to a component installation, i.e., a component placement within the +RTComponentServer to which the .RTD file is associated. For example, + +<code><pre> + <homeplacement> + . + . + , + <extension class="RT-POLICY-SET" + origin="CIAO">A_POLICY_NAME</extension> + . + </homeplacement> +</pre></code> + +<h3>Future Addition</h3> + +As mentioned earlier, RT policies can be applied at various stages of +component-based deployment lifecycle and at different scope. For +example, applying RTpolicies at the ORB level, or at the object +reference level of a component receptacle. These extensions involve +at least, extending the "appropriate" XML descriptor definition and +extending the CIAO runtime, including core and/or the CIDL generated +code to configure the policies. How other RT-related policies can be +added will be reviewed in my thesis available shortly. + +<hr> +<address>Nanbor Wang</address> +<!-- hhmts start --> +Last modified: Sun Nov 30 19:23:25 Mountain Standard Time 2003 +<!-- hhmts end --> +</body> </html> |