ACE_Thread_Timer_Queue_Adapter< TQ > Class Template Reference

Adapts an ACE timer queue using a separate thread for dispatching. More...

#include <Timer_Queue_Adapters.h>

Inheritance diagram for ACE_Thread_Timer_Queue_Adapter< TQ >:

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Collaboration diagram for ACE_Thread_Timer_Queue_Adapter< TQ >:

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List of all members.

Public Types

typedef TQ TIMER_QUEUE
 Trait for the underlying queue type.

Public Member Functions

 ACE_Thread_Timer_Queue_Adapter (ACE_Thread_Manager *=ACE_Thread_Manager::instance(), TQ *timer_queue=0)
virtual ~ACE_Thread_Timer_Queue_Adapter (void)
 Destructor.
long schedule (ACE_Event_Handler *handler, const void *act, const ACE_Time_Value &future_time, const ACE_Time_Value &interval=ACE_Time_Value::zero)
int cancel (long timer_id, const void **act=0)
virtual int svc (void)
 Runs the dispatching thread.
virtual void deactivate (void)
 Inform the dispatching thread that it should terminate.
ACE_SYNCH_RECURSIVE_MUTEX & mutex (void)
 Access the locking mechanism, useful for iteration.
int timer_queue (TQ *tq)
 Set a user-specified timer queue.
TQ * timer_queue (void) const
 Return the current <TQ>.
ACE_thread_t thr_id (void) const
 Return the thread id of our active object.
virtual int activate (long flags=THR_NEW_LWP|THR_JOINABLE, int n_threads=1, int force_active=0, long priority=ACE_DEFAULT_THREAD_PRIORITY, int grp_id=-1, ACE_Task_Base *task=0, ACE_hthread_t thread_handles[]=0, void *stack[]=0, size_t stack_size[]=0, ACE_thread_t thread_ids[]=0, const char *thr_name[]=0)

Private Attributes

TQ * timer_queue_
 The underlying Timer_Queue.
bool delete_timer_queue_
ACE_SYNCH_RECURSIVE_MUTEX mutex_
ACE_SYNCH_RECURSIVE_CONDITION condition_
bool active_
ACE_thread_t thr_id_
 Thread id of our active object task.

Detailed Description

template<class TQ>
class ACE_Thread_Timer_Queue_Adapter< TQ >

Adapts an ACE timer queue using a separate thread for dispatching.

This implementation uses a separate thread to dispatch the timers. The base queue need not be thread safe; this class takes all the necessary locks.

Note:
This is a case where template parameters will be useful, but (IMHO) the effort and portability problems discourage their use.

Definition at line 123 of file Timer_Queue_Adapters.h.

Member Typedef Documentation

template<class TQ>
typedef TQ ACE_Thread_Timer_Queue_Adapter< TQ >::TIMER_QUEUE

Trait for the underlying queue type.

Definition at line 127 of file Timer_Queue_Adapters.h.

Constructor & Destructor Documentation

template<class TQ>
ACE_Thread_Timer_Queue_Adapter< TQ >::ACE_Thread_Timer_Queue_Adapter ( ACE_Thread_Manager *  = ACE_Thread_Manager::instance(),
TQ *  timer_queue = 0 
)

Creates the timer queue. Activation of the task is the user's responsibility. Optionally a pointer to a timer queue can be passed, when no pointer is passed, a TQ is dynamically created

Definition at line 158 of file Timer_Queue_Adapters.cpp.

References ACE_NEW, ACE_Thread_Timer_Queue_Adapter< TQ >::delete_timer_queue_, and ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00160   : ACE_Task_Base (tm),
00161     timer_queue_(timer_queue),
00162     delete_timer_queue_(false),
00163     condition_ (mutex_),
00164     active_ (true), // Assume that we start in active mode.
00165     thr_id_ (ACE_OS::NULL_thread)
00166 {
00167   if (timer_queue_ == 0)
00168     {
00169       ACE_NEW (this->timer_queue_,
00170                TQ);
00171       this->delete_timer_queue_ = true;
00172     }
00173 }

template<class TQ>
ACE_Thread_Timer_Queue_Adapter< TQ >::~ACE_Thread_Timer_Queue_Adapter ( void   )  [virtual]

Destructor.

Definition at line 176 of file Timer_Queue_Adapters.cpp.

References ACE_Thread_Timer_Queue_Adapter< TQ >::delete_timer_queue_, and ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00177 {
00178   if (this->delete_timer_queue_)
00179     {
00180       delete this->timer_queue_;
00181       this->timer_queue_ = 0;
00182       this->delete_timer_queue_ = false;
00183     }
00184 }

Member Function Documentation

template<class TQ>
int ACE_Thread_Timer_Queue_Adapter< TQ >::activate ( long  flags = THR_NEW_LWP|THR_JOINABLE,
int  n_threads = 1,
int  force_active = 0,
long  priority = ACE_DEFAULT_THREAD_PRIORITY,
int  grp_id = -1,
ACE_Task_Base *  task = 0,
ACE_hthread_t  thread_handles[] = 0,
void *  stack[] = 0,
size_t  stack_size[] = 0,
ACE_thread_t  thread_ids[] = 0,
const char *  thr_name[] = 0 
) [virtual]

We override the default activate() method so that we can ensure that only a single thread is ever spawned. Otherwise, too many weird things can happen...

Reimplemented from ACE_Task_Base.

Definition at line 294 of file Timer_Queue_Adapters.cpp.

References ACE_Task_Base::activate(), and ACE_Thread_Timer_Queue_Adapter< TQ >::active_.

00305 {
00306   // Make sure to set this flag in case we were deactivated earlier.
00307   this->active_ = true;
00308 
00309   // Make sure that we only allow a single thread to be spawned for
00310   // our adapter.  Otherwise, too many weird things can happen.
00311   return ACE_Task_Base::activate (flags, 1, 0, priority, grp_id, task, 0,
00312                                   stack, stack_size, thread_ids, thr_name);
00313 }

template<class TQ>
int ACE_Thread_Timer_Queue_Adapter< TQ >::cancel ( long  timer_id,
const void **  act = 0 
)

Cancel the timer_id and return the act parameter if an address is passed in. Also wakes up the dispatching thread.

Definition at line 207 of file Timer_Queue_Adapters.cpp.

References ACE_GUARD_RETURN, ACE_SYNCH_RECURSIVE_MUTEX, ACE_Thread_Timer_Queue_Adapter< TQ >::condition_, and ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00209 {
00210   ACE_GUARD_RETURN (ACE_SYNCH_RECURSIVE_MUTEX, guard, this->mutex_, -1);
00211 
00212   int result = this->timer_queue_->cancel (timer_id, act);
00213   condition_.signal ();
00214   return result;
00215 }

template<class TQ>
void ACE_Thread_Timer_Queue_Adapter< TQ >::deactivate ( void   )  [virtual]

Inform the dispatching thread that it should terminate.

Definition at line 218 of file Timer_Queue_Adapters.cpp.

References ACE_GUARD, ACE_SYNCH_RECURSIVE_MUTEX, ACE_Thread_Timer_Queue_Adapter< TQ >::active_, and ACE_Thread_Timer_Queue_Adapter< TQ >::condition_.

00219 {
00220   ACE_GUARD (ACE_SYNCH_RECURSIVE_MUTEX, guard, this->mutex_);
00221 
00222   this->active_ = false;
00223   this->condition_.signal ();
00224 }

template<class TQ>
ACE_SYNCH_RECURSIVE_MUTEX & ACE_Thread_Timer_Queue_Adapter< TQ >::mutex ( void   ) 

Access the locking mechanism, useful for iteration.

Definition at line 187 of file Timer_Queue_Adapters.cpp.

References ACE_Thread_Timer_Queue_Adapter< TQ >::mutex_.

00188 {
00189   return this->mutex_;
00190 }

template<class TQ>
long ACE_Thread_Timer_Queue_Adapter< TQ >::schedule ( ACE_Event_Handler *  handler,
const void *  act,
const ACE_Time_Value &  future_time,
const ACE_Time_Value &  interval = ACE_Time_Value::zero 
)

Schedule the timer according to the semantics of the <TQ>; wakes up the dispatching thread.

Definition at line 194 of file Timer_Queue_Adapters.cpp.

References ACE_GUARD_RETURN, and ACE_SYNCH_RECURSIVE_MUTEX.

00198 {
00199   ACE_GUARD_RETURN (ACE_SYNCH_RECURSIVE_MUTEX, guard, this->mutex_, -1);
00200 
00201   long result = this->timer_queue_->schedule (handler, act, future_time, interval);
00202   this->condition_.signal ();
00203   return result;
00204 }

template<class TQ>
int ACE_Thread_Timer_Queue_Adapter< TQ >::svc ( void   )  [virtual]

Runs the dispatching thread.

Reimplemented from ACE_Task_Base.

Definition at line 227 of file Timer_Queue_Adapters.cpp.

References ACE_GUARD_RETURN, ACE_PTHREAD_CLEANUP_POP, ACE_PTHREAD_CLEANUP_PUSH, ACE_SYNCH_RECURSIVE_MUTEX, ACE_Thread_Timer_Queue_Adapter< TQ >::condition_, ACE_OS::gettimeofday(), ACE_Thread_Timer_Queue_Adapter< TQ >::mutex_, ACE_Thread::self(), ACE_Thread_Timer_Queue_Adapter< TQ >::thr_id_, and ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00228 {
00229   ACE_GUARD_RETURN (ACE_SYNCH_RECURSIVE_MUTEX, guard, this->mutex_, -1);
00230 
00231   this->thr_id_ = ACE_Thread::self ();
00232 
00233   // Thread cancellation point, if ACE supports it.
00234   //
00235   // Note: This call generates a warning under Solaris because the header
00236   //       file /usr/include/pthread.h redefines the routine argument. This
00237   //       is a bug in the Solaris header files and has nothing to do with
00238   //       ACE.
00239 # if !defined (ACE_LACKS_PTHREAD_CANCEL)
00240   ACE_PTHREAD_CLEANUP_PUSH (&this->condition_.mutex ().get_nesting_mutex ());
00241 # endif /* ACE_LACKS_PTHREAD_CANCEL */
00242 
00243   while (this->active_)
00244     {
00245 # if defined (ACE_HAS_DEFERRED_TIMER_COMMANDS)
00246       // Temporarily suspend ownership of the timer queue mutex in
00247       // order to dispatch deferred execution commands.  These
00248       // commands are to be treated as executing in a context
00249       // "external" to the timer queue adapter, and thus must compete
00250       // separately for this lock.
00251       mutex_.release ();
00252       this->dispatch_commands ();
00253 
00254       // Re-acquire ownership of the timer queue mutex in order to
00255       // restore the "internal" timer queue adapter context
00256       mutex_.acquire ();
00257 # endif /* ACE_HAS_DEFERRED_TIMER_COMMANDS */
00258 
00259       // If the queue is empty, sleep until there is a change on it.
00260       if (this->timer_queue_->is_empty ())
00261         this->condition_.wait ();
00262       else
00263         {
00264           // Compute the remaining time, being careful not to sleep
00265           // for "negative" amounts of time.
00266           ACE_Time_Value const tv_curr = this->timer_queue_->gettimeofday ();
00267           ACE_Time_Value const tv_earl = this->timer_queue_->earliest_time ();
00268 
00269           if (tv_earl > tv_curr)
00270             {
00271               // The earliest time on the Timer_Queue is in future, so
00272               // use ACE_OS::gettimeofday() to convert the tv to the
00273               // absolute time.
00274               ACE_Time_Value const tv = ACE_OS::gettimeofday () + (tv_earl - tv_curr);
00275               // ACE_DEBUG ((LM_DEBUG,  ACE_TEXT ("waiting until %u.%3.3u secs\n"),
00276               // tv.sec(), tv.msec()));
00277               this->condition_.wait (&tv);
00278             }
00279         }
00280 
00281       // Expire timers anyway, at worst this is a no-op.
00282       this->timer_queue_->expire ();
00283     }
00284 
00285    // Thread cancellation point, if ACE supports it.
00286 # if !defined (ACE_LACKS_PTHREAD_CANCEL)
00287   ACE_PTHREAD_CLEANUP_POP (0);
00288 # endif /* ACE_LACKS_PTHREAD_CANCEL */
00289 
00290   return 0;
00291 }

template<class TQ>
ACE_INLINE ACE_thread_t ACE_Thread_Timer_Queue_Adapter< TQ >::thr_id ( void   )  const

Return the thread id of our active object.

Definition at line 24 of file Timer_Queue_Adapters.inl.

References ACE_Thread_Timer_Queue_Adapter< TQ >::thr_id_.

00025 {
00026   return this->thr_id_;
00027 }

template<class TQ>
ACE_BEGIN_VERSIONED_NAMESPACE_DECL ACE_INLINE TQ * ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue ( void   )  const

Return the current <TQ>.

Definition at line 8 of file Timer_Queue_Adapters.inl.

References ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00009 {
00010   return this->timer_queue_;
00011 }

template<class TQ>
ACE_INLINE int ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue ( TQ *  tq  ) 

Set a user-specified timer queue.

Definition at line 14 of file Timer_Queue_Adapters.inl.

References ACE_Thread_Timer_Queue_Adapter< TQ >::delete_timer_queue_, and ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_.

00015 {
00016   if (this->delete_timer_queue_)
00017     delete this->timer_queue_;
00018   this->timer_queue_ = tq;
00019   this->delete_timer_queue_ = false;
00020   return 0;
00021 }

Member Data Documentation

template<class TQ>
bool ACE_Thread_Timer_Queue_Adapter< TQ >::active_ [private]

When deactivate is called this variable turns to false and the dispatching thread is signalled, to terminate its main loop.

Definition at line 240 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::activate(), and ACE_Thread_Timer_Queue_Adapter< TQ >::deactivate().

template<class TQ>
ACE_SYNCH_RECURSIVE_CONDITION ACE_Thread_Timer_Queue_Adapter< TQ >::condition_ [private]

The dispatching thread sleeps on this condition while waiting to dispatch the next timer; it is used to wake it up if there is a change on the timer queue.

Definition at line 236 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::cancel(), ACE_Thread_Timer_Queue_Adapter< TQ >::deactivate(), and ACE_Thread_Timer_Queue_Adapter< TQ >::svc().

template<class TQ>
bool ACE_Thread_Timer_Queue_Adapter< TQ >::delete_timer_queue_ [private]

Keeps track of whether we should delete the timer queue (if we didn't create it, then we don't delete it).

Definition at line 225 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::ACE_Thread_Timer_Queue_Adapter(), ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue(), and ACE_Thread_Timer_Queue_Adapter< TQ >::~ACE_Thread_Timer_Queue_Adapter().

template<class TQ>
ACE_SYNCH_RECURSIVE_MUTEX ACE_Thread_Timer_Queue_Adapter< TQ >::mutex_ [private]

The mutual exclusion mechanism that is required to use the <condition_>.

Definition at line 229 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::mutex(), and ACE_Thread_Timer_Queue_Adapter< TQ >::svc().

template<class TQ>
ACE_thread_t ACE_Thread_Timer_Queue_Adapter< TQ >::thr_id_ [private]

Thread id of our active object task.

Definition at line 243 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::svc(), and ACE_Thread_Timer_Queue_Adapter< TQ >::thr_id().

template<class TQ>
TQ* ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue_ [private]

The underlying Timer_Queue.

Definition at line 221 of file Timer_Queue_Adapters.h.

Referenced by ACE_Thread_Timer_Queue_Adapter< TQ >::ACE_Thread_Timer_Queue_Adapter(), ACE_Thread_Timer_Queue_Adapter< TQ >::cancel(), ACE_Thread_Timer_Queue_Adapter< TQ >::svc(), ACE_Thread_Timer_Queue_Adapter< TQ >::timer_queue(), and ACE_Thread_Timer_Queue_Adapter< TQ >::~ACE_Thread_Timer_Queue_Adapter().

The documentation for this class was generated from the following files:
Generated on Tue Feb 2 17:35:46 2010 for ACE by  doxygen 1.4.7