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Diffstat (limited to 'ACE/ace/Object_Manager.h')
| -rw-r--r-- | ACE/ace/Object_Manager.h | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/ACE/ace/Object_Manager.h b/ACE/ace/Object_Manager.h new file mode 100644 index 00000000000..70477591e56 --- /dev/null +++ b/ACE/ace/Object_Manager.h @@ -0,0 +1,460 @@ +/* -*- C++ -*- */ + +//============================================================================= +/** + * @file Object_Manager.h + * + * $Id$ + * + * @author David L. Levine <levine@cs.wustl.edu> + * @author Matthias Kerkhoff + * @author Per Andersson + */ +//============================================================================= + +#ifndef ACE_OBJECT_MANAGER_H +#define ACE_OBJECT_MANAGER_H +#include /**/ "ace/pre.h" + +#include "ace/ACE_export.h" +#include "ace/Object_Manager_Base.h" +#include "ace/Global_Macros.h" + +#if !defined (ACE_LACKS_PRAGMA_ONCE) +# pragma once +#endif /* ACE_LACKS_PRAGMA_ONCE */ + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + +// Forward declarations. +class ACE_Object_Manager_Preallocations; +class ACE_Sig_Adapter; +class ACE_Sig_Set; + +ACE_END_VERSIONED_NAMESPACE_DECL + +#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + + class ACE_Mutex; + class ACE_Null_Mutex; + class ACE_Thread_Mutex; + class ACE_Recursive_Thread_Mutex; + class ACE_RW_Thread_Mutex; + +ACE_END_VERSIONED_NAMESPACE_DECL + +# include "ace/Recursive_Thread_Mutex.h" +#endif /* ACE_MT_SAFE */ + +ACE_BEGIN_VERSIONED_NAMESPACE_DECL + +// only used by ACE_OS_Object_Manager::ctor +# if defined (ACE_WIN32) +// Default WIN32 structured exception handler. +int ACE_SEH_Default_Exception_Selector (void *); +int ACE_SEH_Default_Exception_Handler (void *); +# endif /* ACE_WIN32 */ + +class ACE_Cleanup_Info_Node; +template <class T> class ACE_Cleanup_Adapter; + +// Configuration parameters. +#if !defined (ACE_MAX_MANAGED_OBJECTS) +# define ACE_MAX_MANAGED_OBJECTS 128 +#endif /* ! ACE_MAX_MANAGED_OBJECTS */ + +#if !defined (ACE_APPLICATION_PREALLOCATED_OBJECT_DECLARATIONS) +# define ACE_APPLICATION_PREALLOCATED_OBJECT_DECLARATIONS +#endif /* ! ACE_APPLICATION_PREALLOCATED_OBJECT_DECLARATIONS */ + +#if !defined (ACE_APPLICATION_PREALLOCATED_ARRAY_DECLARATIONS) +# define ACE_APPLICATION_PREALLOCATED_ARRAY_DECLARATIONS +#endif /* ! ACE_APPLICATION_PREALLOCATED_ARRAY_DECLARATIONS */ + +/** + * @class ACE_Object_Manager + * + * @brief Manager for ACE library services and singleton cleanup. + * + * The <ACE_Object_Manager> manages cleanup of objects, typically + * singletons, at program termination. In addition to managing + * the cleanup of the ACE library, it provides an interface for + * application to register objects to be cleaned up. + * This class also shuts down ACE library services, so that they + * can reclaim their storage, at program termination. It works + * by creating a static instance whose destructor gets called + * along with those of all other static objects. Hooks are + * provided for application code to register objects and arrays + * for cleanup, e.g., destruction. The order of such cleanup + * calls is in the reverse order of registration, i.e., that + * last object/array to register gets cleaned up first. + * The <ACE_Object_Manager> API includes <ACE_Managed_Object>. That + * class is contained in a separate file because it is a + * template class, and some compilers require that template and + * non-template class definitions appear in separate files. + * Please see ace/Managed_Object.h for a description of that + * part of the API. In summary, <ACE_Managed_Object> provides two + * adapters, the <ACE_Cleanup_Adapter> and <ACE_Managed_Object> + * template classes for adapting objects of any type to be + * easily managed by the <ACE_Object_Manager>. There are several + * mechanisms for adapting objects and arrays for cleanup at + * program termination, in roughly increasing order of ease-of-use: + * 1) Derive the object's class from <ACE_Cleanup>. + * 2) Allow the <ACE_Object_Manager> to both dynamically allocate + * and deallocate the object. + * 3) Provide an <ACE_CLEANUP_FUNC> cleanup hook for the object or + * array. + * 4) Allow the <ACE_Object_Manager> to both preallocate the object + * or array, either statically in global data or dynamically on + * the heap, when its singleton instance is construction. + * + * There are also several mechanisms for registering objects and + * arrays for cleanup. In decreasing order of flexibility and + * complexity (with the exception of the last mechanism): + * + * 1) ACE_Object_Manager::at_exit (void *object, + * ACE_CLEANUP_FUNC cleanup_hook, + * void *param); + * can be used to register any object or array for any + * cleanup activity at program termination. + * 2) ACE_Object_Manager::at_exit (ACE_Cleanup *object, + * void *param = 0); + * can be used to register an <ACE_Cleanup> object + * for any cleanup activity at program termination. + * The final mechanism is not general purpose, but can only + * be used to allocate objects and arrays at program startup: + * 3) ACE_Managed_Object::get_preallocated_object + * (ACE_Object_Manager::Preallocated_Object id); + * and + * ACE_Managed_Object::get_preallocated_array + * (ACE_Object_Manager::Preallocated_Array id); + * can only be used to allocate objects at program startup, + * either in global data or on the heap (selected at compile + * time). These are intended to replace static locks, etc. + * Instead of creating a static <ACE_Object_Manager> instance, one + * can alternatively be created on the stack of the main program + * thread. It is created just after entry to ::main (int, char + * *[]), and before any existing code in that function is + * executed. To enable this alternative, add #define + * ACE_HAS_NONSTATIC_OBJECT_MANAGER before including the platform + * specific config-* file in ace/config.h prior to + * building the ACE library and your applications. This #define + * is enabled in some config files that are supplied with ACE. + * + * To ensure a static object manager is used, #undef + * ACE_HAS_NONSTATIC_OBJECT_MANAGER *after* including the platform + * specific config-* file. + * Note that the ACE_Object_Manager _must_ be created before + * any threads are spawned by the program. + * If ACE_HAS_NONSTATIC_OBJECT_MANAGER is not #defined, the ACE + * library creates a static, singleton <ACE_Object_Manager> instance. + * The instance is placed in global program data, and constructed + * via a static object constructor. If ACE_HAS_NONSTATIC_OBJECT_MANAGER + * is #defined, the <ACE_Object_Manager> instance is created on the stack + * of the main program thread, as noted above. + * + * With ACE_HAS_NONSTATIC_OBJECT_MANAGER enabled, the ACE + * library has no static objects that require destruction. + * However, there are two drawbacks to using it: + * 1) main (int, char *[]) must be declared with arguments, even + * if they're not used. All of ACE is converted to this, so + * just applications have to be concerned with it. + * 2) If there any static objects that depend on those that are + * cleaned up by the Object_Manager, they'll get cleaned up too + * late. The ACE tests do not violate this requirement. + * However, applications may have trouble with it. + * NOTE on the use of <::exit> -- <::exit> does not destroy + * automatic objects. Therefore, if + * ACE_HAS_NONSTATIC_OBJECT_MANAGER is enabled, the + * <ACE_Object_Manager> instance will *not* be destroyed if + * <::exit> is called! However, <ACE_OS::exit> will properly + * destroy the ACE_Object_Manager. It is highly recommended + * that <ACE_OS::exit> be used instead of <::exit>. + * + * However, <::exit> and <ACE_OS::exit> are tricky to use + * properly, especially in multithread programs. It is much + * safer to throw an exception (or simulate that effect) that + * will be caught by <main> instead of calling exit. Then, + * <main> can perform any necessary application-specific cleanup + * and return the status value. In addition, it's usually best + * to avoid calling <::exit> and <ACE_OS::exit> from threads + * other than the main thread. Thanks to Jeff Greif + * <jmg@trivida.com> for pointing out that <::exit> doesn't + * destroy automatic objects, and for developing the + * recommendations in this paragraph. + * + * Instead of creating a static <ACE_Object_Manager>, or letting + * ACE create it on the stack of <main> for you, another + * alternative is to #define + * ACE_DOESNT_INSTANTIATE_NONSTATIC_OBJECT_MANAGER. With that + * #define, the application must create the ACE_Object_Manager. + * The recommended way is to call <ACE::init> at the start of + * the program, and call <ACE::fini> at the end. Alternatively, + * the application could explicity construct an + * <ACE_Object_Manager>. + */ +class ACE_Export ACE_Object_Manager : public ACE_Object_Manager_Base +{ + +public: + /** + * Explicitly initialize (construct the singleton instance of) the + * ACE_Object_Manager. Returns 0 on success, -1 on failure, and 1 + * if it had already been called. + */ + virtual int init (void); + + /** + * Explicitly destroy the singleton instance of the + * ACE_Object_Manager. Returns 0 on success, -1 on failure, and 1 + * if it had already been called. + */ + virtual int fini (void); + + /** + * Returns 1 before the ACE_Object_Manager has been constructed. + * This flag can be used to determine if the program is constructing + * static objects. If no static object spawns any threads, the + * program will be single-threaded when this flag returns 1. (Note + * that the program still might construct some static objects when + * this flag returns 0, if ACE_HAS_NONSTATIC_OBJECT_MANAGER is not + * defined.) + */ + static int starting_up (void); + + /** + * Returns 1 after the ACE_Object_Manager has been destroyed. This + * flag can be used to determine if the program is in the midst of + * destroying static objects. (Note that the program might destroy + * some static objects before this flag can return 1, if + * ACE_HAS_NONSTATIC_OBJECT_MANAGER is not defined.) + */ + static int shutting_down (void); + + /** + * Register an ACE_Cleanup object for cleanup at process + * termination. The object is deleted via the + * <ace_cleanup_destroyer>. If you need more flexiblity, see the + * <other at_exit> method below. For OS's that do not have + * processes, cleanup takes place at the end of <main>. Returns 0 + * on success. On failure, returns -1 and sets errno to: EAGAIN if + * shutting down, ENOMEM if insufficient virtual memory, or EEXIST + * if the object (or array) had already been registered. + */ + static int at_exit (ACE_Cleanup *object, void *param = 0); + + /** + * Register an object (or array) for cleanup at process termination. + * "cleanup_hook" points to a (global, or static member) function + * that is called for the object or array when it to be destroyed. + * It may perform any necessary cleanup specific for that object or + * its class. "param" is passed as the second parameter to the + * "cleanup_hook" function; the first parameter is the object (or + * array) to be destroyed. "cleanup_hook", for example, may delete + * the object (or array). For OS's that do not have processes, this + * function is the same as <at_thread_exit>. Returns 0 on success. + * On failure, returns -1 and sets errno to: EAGAIN if shutting + * down, ENOMEM if insufficient virtual memory, or EEXIST if the + * object (or array) had already been registered. + */ + static int at_exit (void *object, + ACE_CLEANUP_FUNC cleanup_hook, + void *param); + +#if 0 /* not implemented yet */ + /// Similar to <at_exit>, except that the cleanup_hook is called + /// when the current thread exits instead of when the program terminates. + static int at_thread_exit (void *object, + ACE_CLEANUP_FUNC cleanup_hook, + void *param); +#endif /* 0 */ + + /// Unique identifiers for preallocated objects. Please see + /// ace/Managed_Object.h for information on accessing preallocated + /// objects. + enum Preallocated_Object + { + ACE_FILECACHE_LOCK, +#if defined (ACE_HAS_THREADS) + ACE_STATIC_OBJECT_LOCK, +#endif /* ACE_HAS_THREADS */ +#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) + ACE_MT_CORBA_HANDLER_LOCK, + ACE_DUMP_LOCK, + ACE_SIG_HANDLER_LOCK, + ACE_SINGLETON_NULL_LOCK, + ACE_SINGLETON_RECURSIVE_THREAD_LOCK, + ACE_THREAD_EXIT_LOCK, +#if !defined (ACE_LACKS_ACE_TOKEN) + ACE_TOKEN_MANAGER_CREATION_LOCK, + ACE_TOKEN_INVARIANTS_CREATION_LOCK, +#endif /* ! ACE_LACKS_ACE_TOKEN */ + ACE_PROACTOR_EVENT_LOOP_LOCK, +#endif /* ACE_MT_SAFE */ + + // Hook for preallocated objects provided by application. + ACE_APPLICATION_PREALLOCATED_OBJECT_DECLARATIONS + + ACE_PREALLOCATED_OBJECTS // This enum value must be last! + }; + + /// Unique identifiers for preallocated arrays. Please see + /// ace/Managed_Object.h for information on accessing preallocated + /// arrays. + enum Preallocated_Array + { + /// There currently are no preallocated arrays in the ACE + /// library. If the application doesn't have any, make sure + /// the the preallocated_array size is at least one by declaring + /// this dummy . . . + ACE_EMPTY_PREALLOCATED_ARRAY, + + /// Hook for preallocated arrays provided by application. + ACE_APPLICATION_PREALLOCATED_ARRAY_DECLARATIONS + + ACE_PREALLOCATED_ARRAYS // This enum value must be last! + }; + + /** + * @deprecated Accesses a default signal set used, for example, + * in ACE_Sig_Guard methods. + * Deprecated: use ACE_Object_Manager::default_mask () instead. + */ + static ACE_Sig_Set &default_mask (void); + +private: + /// For at_exit support. + ACE_OS_Exit_Info exit_info_; + +#if !defined (ACE_LACKS_ACE_SVCCONF) + /// Preallocated objects collection. + ACE_Object_Manager_Preallocations *preallocations_; + + /// ACE_Service_Config signal handler. + ACE_Sig_Adapter *ace_service_config_sig_handler_; +#endif /* ! ACE_LACKS_ACE_SVCCONF */ + + /// Register an object or array for deletion at program termination. + /// See description of static version above for return values. + int at_exit_i (void *object, ACE_CLEANUP_FUNC cleanup_hook, void *param); + +#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) +public: + // = The <get_singleton_lock> accessors are for internal + // use by ACE_Singleton _only_. + + /** + * Accesses an ACE_Null_Mutex to be used for construction of + * <ACE_Singletons>. Returns 0, and the lock in the argument, on + * success; returns -1 on failure. + */ + static int get_singleton_lock (ACE_Null_Mutex *&); + + /** + * Accesses a non-recursive ACE_Thread_Mutex to be used for + * construction of <ACE_Singletons>. Returns 0, and the lock in the + * argument, on success; returns -1 on failure. + */ + static int get_singleton_lock (ACE_Thread_Mutex *&); + + /** + * Accesses a non-recursive <ACE_Mutex> to be used for construction + * of <ACE_Singletons>. Returns 0, and the lock in the argument, on + * success; returns -1 on failure. + */ + static int get_singleton_lock (ACE_Mutex *&); + + /** + * Accesses a recursive ACE_Recursive_Thread_Mutex to be used for + * construction of <ACE_Singletons>. Returns 0, and the lock in the + * argument, on success; returns -1 on failure. + */ + static int get_singleton_lock (ACE_Recursive_Thread_Mutex *&); + + /** + * Accesses a readers/writer <ACE_RW_Thread_Mutex> to be used for + * construction of <ACE_Singletons>. Returns 0, and the lock in the + * argument, on success; returns -1 on failure. + */ + static int get_singleton_lock (ACE_RW_Thread_Mutex *&); +#endif /* ACE_MT_SAFE */ + +public: + // For internal use only by ACE_Managed_Objects. + + /** + * Accessor to singleton instance. Because static member functions + * are provided in the interface, this should not be public. However, + * it is public so that ACE_Managed_Object<TYPE> can access it. + */ + static ACE_Object_Manager *instance (void); + + /// Table of preallocated objects. + static void *preallocated_object[ACE_PREALLOCATED_OBJECTS]; + + /// Table of preallocated arrays. + static void *preallocated_array[ACE_PREALLOCATED_ARRAYS]; + +public: + // Application code should not use these explicitly, so they're + // hidden here. They're public so that the ACE_Object_Manager can + // be constructed/destructed in <main> with + // ACE_HAS_NONSTATIC_OBJECT_MANAGER. + ACE_Object_Manager (void); + ~ACE_Object_Manager (void); + +private: + /// Singleton pointer. + static ACE_Object_Manager *instance_; + +#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) + /// Lock that is used to guard internal structures. + ACE_Recursive_Thread_Mutex *internal_lock_; + + /// Null lock for guarding singleton creation. + ACE_Cleanup_Adapter<ACE_Null_Mutex> *singleton_null_lock_; + + /// Lock for guarding singleton creation, when Object_Manager + /// hasn't been started up, or has already been shut down. + ACE_Cleanup_Adapter<ACE_Recursive_Thread_Mutex> *singleton_recursive_lock_; +#endif /* ACE_MT_SAFE */ + +#if defined (ACE_HAS_TSS_EMULATION) + // Main thread's thread-specific storage array. + void *ts_storage_[ACE_TSS_Emulation::ACE_TSS_THREAD_KEYS_MAX]; +#endif /* ACE_HAS_TSS_EMULATION */ + +#if !defined (ACE_HAS_NONSTATIC_OBJECT_MANAGER) + friend class ACE_Object_Manager_Manager; +#endif /* ACE_HAS_NONSTATIC_OBJECT_MANAGER */ + + // Disallow copying by not implementing the following . . . + ACE_Object_Manager (const ACE_Object_Manager &); + ACE_Object_Manager &operator= (const ACE_Object_Manager &); +}; + +ACE_END_VERSIONED_NAMESPACE_DECL + +#include "ace/Static_Object_Lock.h" + +#if defined (__ACE_INLINE__) +#include "ace/Object_Manager.inl" +#endif /* __ACE_INLINE__ */ + +#include "ace/Managed_Object.h" + +#if !defined (ACE_LACKS_ACE_SVCCONF) +// We can't use the ACE_SVC_FACTORY_DECLARE macro here because this +// needs to be in the ACE_Export context rather than the +// ACE_Svc_Export context. +ACE_BEGIN_VERSIONED_NAMESPACE_DECL +class ACE_Service_Object; +ACE_END_VERSIONED_NAMESPACE_DECL +ACE_FACTORY_DECLARE (ACE, ACE_Service_Manager) +#endif /* ! ACE_LACKS_ACE_SVCCONF */ + + +#include /**/ "ace/post.h" +#endif /* ACE_OBJECT_MANAGER_H */ |