// -*- C++ -*- //==================================================================== /** * @file Service_Config.h * * $Id$ * * @author Douglas C. Schmidt */ //==================================================================== #ifndef ACE_SERVICE_CONFIG_H #define ACE_SERVICE_CONFIG_H #include /**/ "ace/pre.h" #include "ace/config-all.h" #include "ace/Default_Constants.h" #include "ace/Service_Gestalt.h" #if !defined (ACE_LACKS_PRAGMA_ONCE) # pragma once #endif /* ACE_LACKS_PRAGMA_ONCE */ #include "ace/SString.h" #include "ace/OS_NS_signal.h" ACE_BEGIN_VERSIONED_NAMESPACE_DECL // Forward decl. class ACE_Service_Object; class ACE_Service_Type; class ACE_Service_Type_Impl; class ACE_Service_Repository; class ACE_Sig_Adapter; class ACE_Allocator; class ACE_Reactor; class ACE_Thread_Manager; class ACE_DLL; #if (ACE_USES_CLASSIC_SVC_CONF == 1) #define ACE_DYNAMIC_SERVICE_DIRECTIVE(ident, libpathname, objectclass, parameters) \ ACE_LIB_TEXT ("dynamic ") \ ACE_LIB_TEXT (ident) \ ACE_LIB_TEXT (" Service_Object * ") \ ACE_LIB_TEXT (libpathname) \ ACE_LIB_TEXT (":") \ ACE_LIB_TEXT (objectclass) \ ACE_LIB_TEXT ("() \"") \ ACE_LIB_TEXT (parameters) \ ACE_LIB_TEXT ("\"") #define ACE_REMOVE_SERVICE_DIRECTIVE(ident) \ ACE_LIB_TEXT ("remove ") \ ACE_LIB_TEXT (ident) class ACE_Svc_Conf_Param; #else #define ACE_DYNAMIC_SERVICE_DIRECTIVE(ident, libpathname, objectclass, parameters) \ ACE_LIB_TEXT ("") \ ACE_LIB_TEXT ("") #define ACE_REMOVE_SERVICE_DIRECTIVE(ident) \ ACE_LIB_TEXT ("") class ACE_XML_Svc_Conf; #endif /* ACE_USES_CLASSIC_SVC_CONF == 1 */ ACE_END_VERSIONED_NAMESPACE_DECL extern "C" { typedef ACE_Service_Object *(*ACE_SERVICE_ALLOCATOR) (ACE_Service_Object_Exterminator *); } ACE_BEGIN_VERSIONED_NAMESPACE_DECL /** * @class ACE_Static_Svc_Descriptor * * @brief Holds the information necessary to describe a statically linked * Svc. */ class ACE_Static_Svc_Descriptor { public: /// Name of the service. const ACE_TCHAR *name_; /// Type of service. int type_; /// Factory function that allocates the service. ACE_SERVICE_ALLOCATOR alloc_; /// Bitmask flags indicating how the framework should delete memory. u_int flags_; /// Flag indicating whether the service starts out active. int active_; /// Dump the state of an object. void dump (void) const; /// Declare the dynamic allocation hooks. ACE_ALLOC_HOOK_DECLARE; public: /// Compare two service descriptors for equality. bool operator== (ACE_Static_Svc_Descriptor &) const; /// Compare two service descriptors for inequality. bool operator!= (ACE_Static_Svc_Descriptor &) const; }; #define ACE_Component_Config ACE_Service_Config /** * @class ACE_Service_Config * * @brief Supplies common server operations for dynamic and static * configuration of services. * * The ACE_Service_Config uses the Monostate pattern. Therefore, * you can only have one of these instantiated per-process. It * represents the process-wide collection of services, which is * typicaly shared among all other configurable entities. The only * ACE_Service_Config instance is registered with and owned by the * ACE_Object_Manager. * * By contrast, the ACE_Service_Gestalt represents the collection * of services, pertaining to a configurable entity. Typicaly, a * "configurable entity" is an instance, which owns an instance of * ACE_Service_Gestalt in order to ensure full controll over the * services it needs. * * Another facet of ACE_Service_Config is that for a given thread, * it provides access to its current, process-global * ACE_Service_Gestalt instance through its curent() method. * * @note The signal_handler_ static member is allocated by the * ACE_Object_Manager. The ACE_Service_Config constructor * uses signal_handler_. Therefore, if the program has any * static ACE_Service_Config objects, there might be * initialization order problems. They can be minimized, but * not eliminated, by _not_ #defining * ACE_HAS_NONSTATIC_OBJECT_MANAGER. */ class ACE_Export ACE_Service_Config: public ACE_Service_Gestalt { public: // = Initialization and termination methods. /** * Initialize the Service Repository. Note that initialising @a * signum to a negative number will prevent a signal handler being * registered when the repository is opened. */ ACE_Service_Config (int ignore_static_svcs = 1, size_t size = ACE_Service_Gestalt::MAX_SERVICES, int signum = SIGHUP); /** * Performs an open without parsing command-line arguments. The * @a logger_key indicates where to write the logging output, which * is typically either a STREAM pipe or a socket address. */ ACE_Service_Config (const ACE_TCHAR program_name[], const ACE_TCHAR *logger_key = ACE_DEFAULT_LOGGER_KEY); /// Perform user-specified close activities and remove dynamic /// memory. virtual ~ACE_Service_Config (void); protected: /** * Performs an open without parsing command-line arguments. * Implements whats different in the opening sequence * for this class, as opposed to the base class. * * The @a logger_key indicates where to write the logging output, which * is typically either a STREAM pipe or a socket address. If * @a ignore_default_svc_conf_file is non-0 then the "svc.conf" file * will be ignored. If @a ignore_debug_flag is non-0 then the * application is responsible for setting the * @c ACE_Log_Msg::priority_mask() appropriately. Returns number of * errors that occurred on failure and 0 otherwise. */ virtual int open_i (const ACE_TCHAR program_name[], const ACE_TCHAR *logger_key, bool ignore_static_svcs, bool ignore_default_svc_conf_file, bool ignore_debug_flag); /** * Implements whats different in the command line parameter processing * for this class, as opposed to the base class. */ virtual int parse_args_i (int argc, ACE_TCHAR *argv[]); /// = Static interfaces private: /// A private, non-locking mutator to set the "current" (TSS) gestalt instance. /// Make sure to call with the proper locks held! static ACE_Service_Gestalt* current_i (ACE_Service_Gestalt *newcurrent); /// A Wrapper for the TSS-stored pointer. struct TSS_Resources { TSS_Resources (void) : ptr_ (0) {}; ACE_Service_Gestalt *ptr_; }; /// A type for the TSS-stored resources. The typedef helps to /// abstract from the particularities of single-threaded vs /// multi-threaded environments. typedef ACE_TSS_TYPE (ACE_Service_Config::TSS_Resources) TSS_Service_Gestalt_Ptr; /// Provides access to the static ptr, containing the TSS /// accessor. Ensures the desired order of initialization, even when /// other static initializers need the value. static TSS_Service_Gestalt_Ptr * & impl_ (void); protected: /// Mutator to set the (TSS) global instance. Intended for use by helper /// classes, like ACE_Service_Config_Guard which when instantiated on the /// stack, can temporarily change which gestalt instance is viewed as /// global from the point of view of the static initializers in DLLs. static ACE_Service_Gestalt* current (ACE_Service_Gestalt*); public: /// If not yet initialized, creates a process-wide instance /// global instance, which is registered with the ACE_Object_Manager, /// via ACE_Singleton. Note that this is allways the same instance, /// in contrast with current (), which may be different instance at /// different times, dependent on the context. static ACE_Service_Gestalt* global (void); /// Accessor for the "current" service repository through a pointer /// held in TSS. static ACE_Service_Gestalt* current (void); /// This is what the static service initializators are hard-wired /// to use, so in order to keep interface changes to a minimum this /// method merely forwards to current(). Thus it is possible to /// temporarily replace what those initializers think is the global /// service repository, for instance when dynamically loading a /// service from a DLL, which in turn, contains its own static services. static ACE_Service_Gestalt* instance (void); /** * Performs an open without parsing command-line arguments. The * @a logger_key indicates where to write the logging output, which * is typically either a STREAM pipe or a socket address. If * @a ignore_static_svcs is 1 then static services are not loaded, * otherwise, they are loaded. If @a ignore_default_svc_conf_file is * non-0 then the configuration file will be ignored. * Returns zero upon success, -1 if the file is not found or cannot * be opened (errno is set accordingly), otherwise returns the * number of errors encountered loading the services in the * specified svc.conf configuration file. If @a ignore_debug_flag is * non-0 then the application is responsible for setting the * @c ACE_Log_Msg::priority_mask appropriately. */ static int open (const ACE_TCHAR program_name[], const ACE_TCHAR *logger_key = ACE_DEFAULT_LOGGER_KEY, int ignore_static_svcs = 1, int ignore_default_svc_conf_file = 0, int ignore_debug_flag = 0); /** * This is the primary entry point into the ACE_Service_Config (the * constructor just handles simple initializations). It parses * arguments passed in from @a argc and @a argv parameters. The * arguments that are valid in a call to this method include: * * - '-b' Option to indicate that we should be a daemon. Note that when * this option is used, the process will be daemonized before the * service configuration file(s) are read. During daemonization, * (on POSIX systems) the current directory will be changed to "/" * so the caller should either fully specify the file names, or * execute a @c chroot() to the appropriate directory. * @sa ACE::daemonize(). * - '-d' Turn on debugging mode * - '-f' Specifies a configuration file name other than the default * svc.conf. Can be specified multiple times to use multiple files. * - '-k' Specifies the rendezvous point to use for the ACE distributed * logger. * - '-y' Explicitly enables the use of static services. This flag * overrides the @a ignore_static_svcs parameter value. * - '-n' Explicitly disables the use of static services. This flag * overrides the @a ignore_static_svcs parameter value. * - '-p' Specifies a pathname which is used to store the process id. * - '-s' Specifies a signal number other than SIGHUP to trigger reprocessing * of the configuration file(s). Ignored for platforms that do not * have POSIX signals, such as Windows. * - '-S' Specifies a service directive string. Enclose the string in quotes * and escape any embedded quotes with a backslash. This option * specifies service directives without the need for a configuration * file. * * @param argc The number of commandline arguments. * @param argv The array with commandline arguments * @param logger_key Indicates where to write the logging output, * which is typically either a STREAM pipe or a * socket address. * @param ignore_static_svcs If 1 then static services are not loaded, * otherwise, they are loaded. * @param ignore_default_svc_conf_file If non-0 then the @c svc.conf * configuration file will be ignored. * @param ignore_debug_flag If non-0 then the application is responsible * for setting the @c ACE_Log_Msg::priority_mask * appropriately. * * @retval -1 The configuration file is not found or cannot * be opened (errno is set accordingly). * @retval 0 Success. * @retval >0 The number of errors encountered while processing * the service configuration file(s). */ static int open (int argc, ACE_TCHAR *argv[], const ACE_TCHAR *logger_key = ACE_DEFAULT_LOGGER_KEY, int ignore_static_svcs = 1, int ignore_default_svc_conf_file = 0, int ignore_debug_flag = 0); /// Tidy up and perform last rites when ACE_Service_Config is shut /// down. This method calls . Returns 0. static int close (void); /// Perform user-specified close hooks and possibly delete all of the /// configured services in the . static int fini_svcs (void); /** * Perform user-specified close hooks on all of the configured * services in the Service_Repository, then delete the * Service_Repository itself. Returns 0. */ static int close_svcs (void); /// True if reconfiguration occurred. static int reconfig_occurred (void); /// Indicate that reconfiguration occurred. static void reconfig_occurred (int); /// Perform the reconfiguration process. static void reconfigure (void); // = The following methods are static in order to enforce Singleton // semantics for the Reactor, Service_Repository, Thread_Manager, // and Acceptor/Connector Strategy factory. Other portions of the // system may need to access them at some point or another... // = This is not strictly needed, anymore since the service configurator // has been refactored to allow multiple service configuration // instances (called gestalts). The interfaces, however were retained in for // the sake of maintaining source-code compatibility. // = Accessors and mutators for process-wide Singletons. /// Returns a pointer to the list of statically linked services. /// /// @deprecated - Same as instance(), but still useful in legacy code, /// (notably, one that can not be easily modified) which uses the following /// idiom for registering static services: /// /// ACE_Service_Config::static_svcs ()->insert (...); static ACE_Service_Gestalt *static_svcs (void); /// Insert a static service descriptor for processing on open_i(). The /// corresponding ACE_STATIC_SVC_* macros were chaged to use this method /// instead of obtaining a ptr to a container. See the note on static_svcs(). /// Added to prevent exposing the internal storage representation of the /// services repository and provide a better way of debugging service /// loading and registration problems. static int insert (ACE_Static_Svc_Descriptor *svc); // = Utility methods. /// Dynamically link the shared object file and retrieve a pointer to /// the designated shared object in this file. static int initialize (const ACE_Service_Type *, const ACE_TCHAR *parameters); /// Initialize and activate a statically @a svc_name service. static int initialize (const ACE_TCHAR *svc_name, const ACE_TCHAR *parameters); /// Resume a @a svc_name that was previously suspended or has not yet /// been resumed (e.g., a static service). static int resume (const ACE_TCHAR svc_name[]); /** * Suspend @a svc_name. Note that this will not unlink the service * from the daemon if it was dynamically linked, it will mark it as * being suspended in the Service Repository and call the * member function on the appropriate ACE_Service_Object. A * service can be resumed later on by calling the member * function... */ static int suspend (const ACE_TCHAR svc_name[]); /// Totally remove @a svc_name from the daemon by removing it /// from the ACE_Reactor, and unlinking it if necessary. static int remove (const ACE_TCHAR svc_name[]); #if defined (ACE_HAS_WINCE) && defined (ACE_USES_WCHAR) // We must provide these function to bridge the Svc_Conf parser // with ACE. static int initialize (const ACE_Service_Type *, ACE_ANTI_TCHAR []); static int initialize (const char svc_name[], ACE_ANTI_TCHAR parameters[]); static int resume (const ACE_ANTI_TCHAR svc_name[]); static int suspend (const ACE_ANTI_TCHAR svc_name[]); static int remove (const ACE_ANTI_TCHAR svc_name[]); #endif /* ACE_HAS_WINCE */ /// Dump the state of an object. void dump (void) const; /// Set the signal_handler;for internal use by ACE_Object_Manager only. static ACE_INLINE void signal_handler (ACE_Sig_Adapter *); /// Declare the dynamic allocation hooks. ACE_ALLOC_HOOK_DECLARE; /// Process a file containing a list of service configuration /// directives. static int process_file (const ACE_TCHAR file[]); /// Process one service configuration @a directive, which is passed as /// a string. Returns the number of errors that occurred. static int process_directive (const ACE_TCHAR directive[]); /// Process one static service definition. /** * Load a new static service into the ACE_Service_Repository. * * @param ssd Service descriptor, see the document of * ACE_Static_Svc_Descriptor for more details. * * @param force_replace If set the new service descriptor replaces * any previous instance in the ACE_Service_Repository. * * @return Returns -1 if the service cannot be 'loaded'. */ static int process_directive (const ACE_Static_Svc_Descriptor &ssd, int force_replace = 0); /** * Process (or re-process) service configuration requests that are * provided in the svc.conf file(s). Returns the number of errors * that occurred. */ static int process_directives (void); /// Handles signals to trigger reconfigurations. static void handle_signal (int sig, siginfo_t *, ucontext_t *); /** * Handle the command-line options intended for the * ACE_Service_Config. Note that @c argv[0] is assumed to be the * program name. * The arguments that are valid in a call to this method are * - '-b' Option to indicate that we should be a daemon * - '-d' Turn on debugging mode * - '-f' Option to read in the list of svc.conf file names * - '-k' Option to read a wide string where in the logger output can * be written * - '-y' Turn on the flag for a repository of statically * linked services * - '-n' Need not have a repository of statically linked services * - '-S' Option to read in the list of services on the command-line * Please observe the difference between options '-f' that looks * for a list of files and here a list of services. */ static int parse_args (int, ACE_TCHAR *argv[]); #if (ACE_USES_CLASSIC_SVC_CONF == 0) static ACE_Service_Type *create_service_type (const ACE_TCHAR *n, ACE_Service_Type_Impl *o, ACE_DLL &dll, int active); #endif /* ACE_USES_CLASSIC_SVC_CONF == 0 */ static ACE_Service_Type_Impl * create_service_type_impl (const ACE_TCHAR *name, int type, void *symbol, u_int flags, ACE_Service_Object_Exterminator gobbler); protected: /// Process service configuration requests that were provided on the /// command-line. Returns the number of errors that occurred. static int process_commandline_directives (void); #if (ACE_USES_CLASSIC_SVC_CONF == 1) /// This is the implementation function that process_directives() /// and process_directive() both call. Returns the number of errors /// that occurred. static int process_directives_i (ACE_Svc_Conf_Param *param); #else /// Helper function to dynamically link in the XML Service Configurator /// parser. static ACE_XML_Svc_Conf *get_xml_svc_conf (ACE_DLL &d); #endif /* ACE_USES_CLASSIC_SVC_CONF == 1 */ /// Become a daemon. static int start_daemon (void); /// Add the default statically-linked services to the /// ACE_Service_Repository. static int load_static_svcs (void); private: /// True if reconfiguration occurred. static sig_atomic_t reconfig_occurred_; // = Set by command-line options. /// Shall we become a daemon process? static int be_a_daemon_; /// Pathname of file to write process id. static ACE_TCHAR *pid_file_name_; /// Number of the signal used to trigger reconfiguration. static int signum_; /// Handles the reconfiguration signals. static ACE_Sig_Adapter *signal_handler_; /// Pointer to the Singleton (ACE_Cleanup) Gestalt instance. /// There is thread-specific global instance pointer, which is used to /// temporarily change which Gestalt instance is used for static service /// registrations. /// /// A specific use case is a thread, which loads a _dynamic_ service from /// a DLL. If the said DLL also contains additional _static_ services, /// those *must* be registered with the same configuration repository as /// the dynamic service. Otherwise, the DLL's static services would be /// registered with the global Gestalt and may outlive the DLL that /// contains their code and perhaps the memory in which they are in. /// This is a problem because if the DLL gets unloaded (as it will, if /// it was loaded in an instance of Gestalt), the DLL's memory will be /// deallocated, but the global service repository will still "think" /// it must finalize the (DLL's) static services - with disastrous /// consequences, occurring in the post-main code (at_exit()). /// This class needs the intimate access to be able to swap the /// current TSS pointer for the global Gestalt. friend class ACE_Service_Config_Guard; }; /** * @class ACE_Service_Config_Guard * * @brief A guard class, designed to be instantiated on the stack. * * Instantiating it with a specific configuration ensures any references to * ACE_Service_Config::instance(), even when occuring in static constructors, * will allways access the designated configuration instance. * This comes very handy when a dynamic service also registers any static * services of its own and their static factories. */ class ACE_Export ACE_Service_Config_Guard { public: ACE_Service_Config_Guard (ACE_Service_Gestalt * psg); ~ACE_Service_Config_Guard (void); private: // Private AND not implemented to disable copying ACE_Service_Config_Guard(const ACE_Service_Config_Guard&); ACE_Service_Config_Guard& operator= (const ACE_Service_Config_Guard&); private: ACE_Service_Gestalt* saved_; }; ACE_END_VERSIONED_NAMESPACE_DECL #if defined (__ACE_INLINE__) #include "ace/Service_Config.inl" #endif /* __ACE_INLINE__ */ #include /**/ "ace/post.h" #endif /* ACE_SERVICE_CONFIG_H */