OpenDDS::DCPS::SporadicEvent Class Reference

#include <SporadicEvent.h>

Inheritance diagram for OpenDDS::DCPS::SporadicEvent:

Collaboration diagram for OpenDDS::DCPS::SporadicEvent:

Public Member Functions
	SporadicEvent (EventDispatcher_rch dispatcher, EventBase_rch event)
void	schedule (const TimeDuration &duration)
void	cancel ()
void	handle_event ()
void	handle_cancel ()
Public Member Functions inherited from OpenDDS::DCPS::EventBase
virtual	~EventBase ()
virtual void	handle_error ()
	Only called when an exception is caught during handle_event. More...
void	operator() ()
Public Member Functions inherited from OpenDDS::DCPS::RcObject
virtual	~RcObject ()
virtual void	_add_ref ()
virtual void	_remove_ref ()
long	ref_count () const
WeakObject *	_get_weak_object () const

Private Member Functions
void	handle_event_scheduling ()

Private Attributes
ACE_Thread_Mutex	mutex_
ACE_Thread_Mutex	event_mutex_
WeakRcHandle< EventDispatcher >	dispatcher_
RcHandle< EventBase >	event_
MonotonicTimePoint	expiration_
long	timer_id_

Additional Inherited Members
Protected Member Functions inherited from OpenDDS::DCPS::RcObject
	RcObject ()

Detailed Description

SporadicEvent is an event which can be scheduled multiple times but will only dispatch once

SporadicEvent allows repeated calls to schedule (when the application is unsure if the event has already been scheduled), but cumulative calls to schedule will only result in a single dispatch. After the base event dispatches, additional calls to schedule will result in another dispatch. Additional calls to schedule may, however, shorten the scheduled time until the base event dispatches. The SporadicEvent takes both an EventDispatcher and a base event (c.f. EventBase) and handles the logic of scheduling, rescheduling, and canceling the base event with the EventDispatcher.

Definition at line 30 of file SporadicEvent.h.

Constructor & Destructor Documentation

SporadicEvent()

OpenDDS::DCPS::SporadicEvent::SporadicEvent	(	EventDispatcher_rch	dispatcher,
		EventBase_rch	event
	)

Creates a SporadicEvent to handle scheduling a base event with an EventDispatcher

Parameters

dispatcher	the EventDispatcher to use for scheduling
event	the base event (c.f EventBase) to schedule for dispatch

Definition at line 17 of file SporadicEvent.cpp.

 : dispatcher_(dispatcher)
 , event_(event)
 , timer_id_(0)
{
}

Member Function Documentation

cancel()

void OpenDDS::DCPS::SporadicEvent::cancel

(

void

)

Cancel the SporadicEvent, canceling the scheduled base event if scheduled.

Definition at line 54 of file SporadicEvent.cpp.

References OpenDDS::DCPS::EventDispatcher::cancel(), dispatcher_, mutex_, and timer_id_.

{
  ACE_Guard<ACE_Thread_Mutex> guard(mutex_);
  if (timer_id_ > 0) {
    EventDispatcher_rch dispatcher = dispatcher_.lock();
    if (dispatcher) {
      if (dispatcher->cancel(timer_id_)) {
        timer_id_ = 0;
      }
    }
  }
}

handle_cancel()

void OpenDDS::DCPS::SporadicEvent::handle_cancel ( )

virtual

For use by EventDispatcher

Reimplemented from OpenDDS::DCPS::EventBase.

Definition at line 84 of file SporadicEvent.cpp.

References event_, event_mutex_, OPENDDS_END_VERSIONED_NAMESPACE_DECL, and ACE_Guard< ACE_LOCK >::release().

{
  ACE_Guard<ACE_Thread_Mutex> guard(event_mutex_);
  if (event_) {
    RcHandle<EventBase> event_copy(event_);
    guard.release();
    event_copy->handle_cancel();
  }
}

handle_event()

void OpenDDS::DCPS::SporadicEvent::handle_event ( )

virtual

For use by EventDispatcher

Implements OpenDDS::DCPS::EventBase.

Definition at line 73 of file SporadicEvent.cpp.

References event_, event_mutex_, handle_event_scheduling(), and ACE_Guard< ACE_LOCK >::release().

{
  handle_event_scheduling();
  ACE_Guard<ACE_Thread_Mutex> guard(event_mutex_);
  if (event_) {
    RcHandle<EventBase> event_copy(event_);
    guard.release();
    event_copy->handle_event();
  }
}

handle_event_scheduling()

void OpenDDS::DCPS::SporadicEvent::handle_event_scheduling ( )

private

Definition at line 67 of file SporadicEvent.cpp.

References mutex_, and timer_id_.

Referenced by handle_event().

{
  ACE_Guard<ACE_Thread_Mutex> guard(mutex_);
  timer_id_ = 0;
}

schedule()

void OpenDDS::DCPS::SporadicEvent::schedule

(

const TimeDuration &

duration

)

Schedule the SporadicEvent to dispatch the base event after the specified duration. If the SporadicEvent is already scheduled, the duration is compared with the existing scheduled time and the shorter (sooner) of the two durations is used.

Parameters

duration

the time period used to schedule / reschedule the base event

Definition at line 24 of file SporadicEvent.cpp.

References OpenDDS::DCPS::EventDispatcher::cancel(), dispatcher_, expiration_, mutex_, OpenDDS::DCPS::TimePoint_T< MonotonicClock >::now(), OpenDDS::DCPS::rchandle_from(), OpenDDS::DCPS::EventDispatcher::schedule(), and timer_id_.

{
  const MonotonicTimePoint now = MonotonicTimePoint::now();
  ACE_Guard<ACE_Thread_Mutex> guard(mutex_);
  if (timer_id_ < 1) {
    EventDispatcher_rch dispatcher = dispatcher_.lock();
    if (dispatcher) {
      const MonotonicTimePoint expiration = now + duration;
      long id = dispatcher->schedule(rchandle_from(this), expiration);
      if (id > 0) {
        expiration_ = expiration;
        timer_id_ = id;
      }
    }
  } else if (now + duration < expiration_) {
    EventDispatcher_rch dispatcher = dispatcher_.lock();
    if (dispatcher) {
      if (dispatcher->cancel(timer_id_)) {
        timer_id_ = 0;
        const MonotonicTimePoint expiration = now + duration;
        long id = dispatcher->schedule(rchandle_from(this), expiration);
        if (id > 0) {
          expiration_ = expiration;
          timer_id_ = id;
        }
      }
    }
  }
}

Member Data Documentation

dispatcher_

WeakRcHandle<EventDispatcher> OpenDDS::DCPS::SporadicEvent::dispatcher_

private

Definition at line 70 of file SporadicEvent.h.

Referenced by cancel(), and schedule().

event_

RcHandle<EventBase> OpenDDS::DCPS::SporadicEvent::event_

private

Definition at line 71 of file SporadicEvent.h.

Referenced by handle_cancel(), and handle_event().

event_mutex_

ACE_Thread_Mutex OpenDDS::DCPS::SporadicEvent::event_mutex_

mutableprivate

Definition at line 69 of file SporadicEvent.h.

Referenced by handle_cancel(), and handle_event().

expiration_

MonotonicTimePoint OpenDDS::DCPS::SporadicEvent::expiration_

private

Definition at line 72 of file SporadicEvent.h.

Referenced by schedule().

mutex_

ACE_Thread_Mutex OpenDDS::DCPS::SporadicEvent::mutex_

mutableprivate

Definition at line 68 of file SporadicEvent.h.

Referenced by cancel(), handle_event_scheduling(), and schedule().

timer_id_

long OpenDDS::DCPS::SporadicEvent::timer_id_

private

Definition at line 73 of file SporadicEvent.h.

Referenced by cancel(), handle_event_scheduling(), and schedule().

---

The documentation for this class was generated from the following files:

• SporadicEvent.h
• SporadicEvent.cpp