#include <ace/Object_Manager.h>
class ACE_Object_Manager {
public:
static int at_exit (ACE_Cleanup *object, void *param = 0);
static int at_exit ( void *object, ACE_CLEANUP_FUNC cleanup_hook, void *param );
static int at_thread_exit ( void *object, ACE_CLEANUP_FUNC cleanup_hook, void *param );
enum Preallocated_Object{ ACE_FILECACHE_LOCK, #if defined ( ACE_HAS_THREADS) ACE_STATIC_OBJECT_LOCK, #endif #if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) ACE_LOG_MSG_INSTANCE_LOCK, ACE_MT_CORBA_HANDLER_LOCK, ACE_DUMP_LOCK, ACE_OS_MONITOR_LOCK, ACE_SIG_HANDLER_LOCK, ACE_SINGLETON_NULL_LOCK, ACE_SINGLETON_RECURSIVE_THREAD_LOCK, ACE_THREAD_EXIT_LOCK, ACE_TOKEN_MANAGER_CREATION_LOCK, ACE_TOKEN_INVARIANTS_CREATION_LOCK, ACE_TSS_CLEANUP_LOCK, #endif ACE_APPLICATION_PREALLOCATED_OBJECT_DECLARATIONS ACE_PREALLOCATED_OBJECTS };
enum Preallocated_Array{ ACE_EMPTY_PREALLOCATED_ARRAY, ACE_APPLICATION_PREALLOCATED_ARRAY_DECLARATIONS ACE_PREALLOCATED_ARRAYS };static int starting_up ();
static int shutting_down ();
static ACE_Sig_Set &default_mask (void);
static int get_singleton_lock (ACE_Null_Mutex *&);
static int get_singleton_lock (ACE_Thread_Mutex *&);
static int get_singleton_lock (ACE_Mutex *&);
static int get_singleton_lock (ACE_Recursive_Thread_Mutex *&);
static int get_singleton_lock (ACE_RW_Thread_Mutex *&);
ACE_Recursive_Thread_Mutex *lock_;
static ACE_Object_Manager *instance (void);
static void *managed_object[ACE_MAX_MANAGED_OBJECTS];
static u_int next_managed_object;
static void *preallocated_object[ACE_PREALLOCATED_OBJECTS];
static void *preallocated_array[ACE_PREALLOCATED_ARRAYS];
ACE_Object_Manager (void);
~ACE_Object_Manager (void);
private:
ACE_Unbounded_Queue<ACE_Cleanup_Info> *registered_objects_;
int at_exit_i ( void *object, ACE_CLEANUP_FUNC cleanup_hook, void *param );
static ACE_Object_Manager *instance_;
static int starting_up_;
static int shutting_down_;
static ACE_Sig_Set *default_mask_p_;
void *ts_storage_[ACE_TSS_Emulation::ACE_TSS_THREAD_KEYS_MAX];
friend class ACE_Object_Manager_Destroyer;
ACE_Object_Manager (const ACE_Object_Manager &);
ACE_Object_Manager &operator= (const ACE_Object_Manager &);
};
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 to ace/config.h prior to
building the ACE library and your applications. This #define
is enabled in the VxWorks config files that are supplied with
ACE.
By default (except on VxWorks), 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. Optionally, the
ACE_Object_Manager
instance can be created on the stack of
the main program thread. This option is enabled by added
"#define ACE_HAS_NONSTATIC_OBJECT_MANAGER" to ace/config.h
before building libACE. This option is enabled by default on
VxWorks.
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.
static int at_exit (ACE_Cleanup *object, void *param = 0);
static int at_exit (
void *object,
ACE_CLEANUP_FUNC cleanup_hook,
void *param
);
static int at_thread_exit (
void *object,
ACE_CLEANUP_FUNC cleanup_hook,
void *param
);
static int starting_up ();
static int shutting_down ();
static ACE_Sig_Set &default_mask (void);
static int get_singleton_lock (ACE_Null_Mutex *&);
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. The argument is ignored -- it is
only used for overload resolution.
static int get_singleton_lock (ACE_Thread_Mutex *&);
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. The argument is
ignored -- it is only used for overload resolution.
static int get_singleton_lock (ACE_Mutex *&);
ACE_Mutex
to be used for construction
of ACE_Singletons
. Returns 0, and the lock in the argument, on
success; returns -1 on failure. The argument is ignored -- it is
only used for overload resolution.
static int get_singleton_lock (ACE_Recursive_Thread_Mutex *&);
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_RW_Thread_Mutex *&);
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.
ACE_Recursive_Thread_Mutex *lock_;
static ACE_Object_Manager *instance (void);
TYPE
can access it.
static void *managed_object[ACE_MAX_MANAGED_OBJECTS];
static u_int next_managed_object;
static void *preallocated_object[ACE_PREALLOCATED_OBJECTS];
static void *preallocated_array[ACE_PREALLOCATED_ARRAYS];
ACE_Object_Manager (void);
~ACE_Object_Manager (void);
ACE_Unbounded_Queue<ACE_Cleanup_Info> *registered_objects_;
int at_exit_i (
void *object,
ACE_CLEANUP_FUNC cleanup_hook,
void *param
);
static ACE_Object_Manager *instance_;
static int starting_up_;
static int shutting_down_;
static ACE_Sig_Set *default_mask_p_;
void *ts_storage_[ACE_TSS_Emulation::ACE_TSS_THREAD_KEYS_MAX];
friend class ACE_Object_Manager_Destroyer;
ACE_Object_Manager (const ACE_Object_Manager &);
ACE_Object_Manager &operator= (const ACE_Object_Manager &);