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// -*- C++ -*-
// $Id$
// ============================================================================
//
// = LIBRARY
// ace
//
// = FILENAME
// Timer_Queue_Adapters.h
//
// = AUTHOR
// Douglas C. Schmidt and Carlos O'Ryan
//
// ============================================================================
#ifndef ACE_TIMER_QUEUE_ADAPTERS_H
# define ACE_TIMER_QUEUE_ADAPTERS_H
# include "ace/pre.h"
# include "ace/Task.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
# include "ace/Signal.h"
template <class TQ>
class ACE_Export ACE_Async_Timer_Queue_Adapter : public ACE_Event_Handler
{
// = TITLE
// Adapts a <TQ> to be run asynchronously.
//
// = DESCRIPTION
// This implementation uses the <ualarm> call, which generates
// the SIGARLM signal that is caught by this class.
public:
typedef TQ TIMER_QUEUE;
ACE_Async_Timer_Queue_Adapter (ACE_Sig_Set *mask = 0);
// Register the SIGALRM handler. If <mask> == 0 then block all
// signals when <SIGALRM> is run. Otherwise, just block the signals
// indicated in <mask>.
long schedule (ACE_Event_Handler *type,
const void *act,
const ACE_Time_Value &delay,
const ACE_Time_Value &interval = ACE_Time_Value::zero);
// Schedule the timer according to the semantics of the
// <ACE_Timer_List>. However, this timer gets dispatched via a
// signal, rather than by a user calling <expire>.
int cancel (long timer_id, const void **act = 0);
// Cancel the <timer_id> and pass back the <act> if an address is
// passed in.
int expire (void);
// Dispatch all timers whose values are <= <cur_time>. Returns the
// number of timers canceled.
TQ &timer_queue (void);
// Access the underlying <TIMER_QUEUE>.
private:
virtual int schedule_ualarm (void);
// Perform the logic to compute the new ualarm(2) setting.
virtual int handle_signal (int signum, siginfo_t *, ucontext_t *);
// Called back by <SIGALRM> handler.
ACE_Sig_Handler sig_handler_;
// Handler for the <SIGALRM> signal, so that we can access our state
// without requiring any global variables.
TQ timer_queue_;
// Implementation of the timer queue (e.g., <ACE_Timer_List>,
// <ACE_Timer_Heap>, etc.).
ACE_Sig_Set mask_;
// Mask of signals to be blocked when we're servicing <SIGALRM>.
};
template <class TQ>
class ACE_Export ACE_Thread_Timer_Queue_Adapter : public ACE_Task_Base
{
// = TITLE
// Adapts a Timer_Queue using a separate thread for dispatching.
//
// = DESCRIPTION
// This implementation of a Timer_Queue 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 were template parameters will be useful, but
// (IMHO) the effort and portability problems discourage their
// use.
public:
typedef TQ TIMER_QUEUE;
// Trait for the underlying queue type.
# if defined (ACE_HAS_DEFERRED_TIMER_COMMANDS)
enum COMMAND_ENQUEUE_POSITION {HEAD, TAIL};
// Typedef for the position at which to enqueue a deferred execution command.
# endif /* ACE_HAS_DEFERRED_TIMER_COMMANDS */
ACE_Thread_Timer_Queue_Adapter (ACE_Thread_Manager * = ACE_Thread_Manager::instance ());
// Creates the timer queue. Activation of the task is the user's
// responsibility.
long schedule (ACE_Event_Handler* handler,
const void *act,
const ACE_Time_Value &delay,
const ACE_Time_Value &interval = ACE_Time_Value::zero);
// Schedule the timer according to the semantics of the <TQ>; wakes
// up the dispatching thread.
int cancel (long timer_id, const void **act = 0);
// Cancel the <timer_id> add return the <act> parameter if an
// address is passed in. Also wakes up the dispatching thread.
virtual int svc (void);
// Runs the dispatching thread.
virtual void deactivate (void);
// Inform the dispatching thread that it should terminate.
ACE_SYNCH_MUTEX &mutex (void);
// Access the locking mechanism, useful for iteration.
TQ &timer_queue (void);
// Access the implementation queue, useful for iteration.
ACE_thread_t thr_id (void);
// 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_names[] = 0);
// 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...
# if defined (ACE_HAS_DEFERRED_TIMER_COMMANDS)
int enqueue_command (ACE_Command_Base *command_,
COMMAND_ENQUEUE_POSITION pos = TAIL);
// Enqueues a command object for execution just before waiting on the next
// timer event. This allows deferred execution of commands that cannot
// be performed in the timer event handler context, such as registering
// or cancelling timers on platforms where the timer queue mutex is not
// recursive.
# endif /* ACE_HAS_DEFERRED_TIMER_COMMANDS */
private:
# if defined (ACE_HAS_DEFERRED_TIMER_COMMANDS)
int dispatch_commands (void);
// Dispatches all command objects enqueued in the most
// recent event handler context.
ACE_Unbounded_Queue<ACE_Command_Base *> command_queue_;
// Queue of commands for deferred execution.
ACE_SYNCH_MUTEX command_mutex_;
// The mutual exclusion mechanism for the command queue.
# endif /* ACE_HAS_DEFERRED_TIMER_COMMANDS */
TQ timer_queue_;
// The underlying Timer_Queue.
ACE_SYNCH_CONDITION condition_;
// 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.
ACE_SYNCH_MUTEX mutex_;
// The mutual exclusion mechanism which is required to use the
// <condition_>.
int active_;
// When deactivate is called this variable turns to false and the
// dispatching thread is signalled, to terminate its main loop.
ACE_thread_t thr_id_;
// Thread id of our active object task.
};
# if defined (__ACE_INLINE__)
# include "ace/Timer_Queue_Adapters.i"
# endif /* __ACE_INLINE__ */
# if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
# include "ace/Timer_Queue_Adapters.cpp"
# endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
# if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
# pragma implementation ("Timer_Queue_Adapters.cpp")
# endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */
# include "ace/post.h"
#endif /* ACE_TIMER_QUEUE_ADAPTERS_H */
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