epics::pvData::Timer Class Reference

Support for delayed or periodic callback execution. More...

#include "timer.h"

Inheritance diagram for epics::pvData::Timer:

Collaboration diagram for epics::pvData::Timer:

Public Member Functions
	POINTER_DEFINITIONS (Timer)
	Timer (std::string threadName, ThreadPriority priority)
virtual	~Timer ()
void	close ()
	Prevent new callbacks from being scheduled, and cancel pending callbacks. More...
void	scheduleAfterDelay (TimerCallbackPtr const &timerCallback, double delay)
void	schedulePeriodic (TimerCallbackPtr const &timerCallback, double delay, double period)
bool	cancel (TimerCallbackPtr const &timerCallback)
bool	isScheduled (TimerCallbackPtr const &timerCallback) const
void	dump (std::ostream &o) const

Detailed Description

Support for delayed or periodic callback execution.

Definition at line 71 of file timer.h.

Constructor & Destructor Documentation

epics::pvData::Timer::Timer	(	std::string	threadName,
		ThreadPriority	priority
	)

Create a new timer queue

Parameters

threadName	name for the timer thread.
priority	thread priority

Definition at line 30 of file timer.cpp.

    :waitForWork(false)
    ,waiting(false)
    ,alive(true)
    ,thread(threadName,priority,this)
{}

epics::pvData::Timer::~Timer ( )

virtual

Definition at line 137 of file timer.cpp.

              {
    close();
}

Member Function Documentation

bool epics::pvData::Timer::cancel

(

TimerCallbackPtr const &

timerCallback

)

cancel a callback.

Parameters

timerCallback

the timerCallback to cancel.

Returns

true if the timer was queued, and now is cancelled

Definition at line 60 of file timer.cpp.

{
    Lock xx(mutex);
    if(!timerCallback->onList) return false;
    if(!alive) {
        timerCallback->onList = false;
        return true;
    }
    for(queue_t::iterator it(queue.begin()), end(queue.end()); it != end; ++it)
    {
        TimerCallbackPtr& cur = *it;
        if(cur.get() == timerCallback.get()) {
            cur->onList = false;
            queue.erase(it); // invalidates cur and it
            return true;
        }
    }
    throw std::logic_error("Timer::cancel() onList==true, but not found");
}

void epics::pvData::Timer::close

(

)

Prevent new callbacks from being scheduled, and cancel pending callbacks.

Definition at line 141 of file timer.cpp.

                  {
    {
         Lock xx(mutex);
         if(!alive)
             return; // already closed
         alive = false;
    }
    waitForWork.signal();
    thread.exitWait();

    queue_t temp;
    temp.swap(queue);

    for(;!temp.empty(); temp.pop_front()) {
        TimerCallbackPtr& head = temp.front();
        head->onList = false;
        head->timerStopped();
    }
}

void epics::pvData::Timer::dump

(

std::ostream &

o

)

const

show the elements in the timer queue.

Parameters

o	The output stream for the output

Definition at line 197 of file timer.cpp.

{
    Lock xx(mutex);
    if(!alive) return;
    epicsTime now(epicsTime::getCurrent());

    for(queue_t::const_iterator it(queue.begin()), end(queue.end()); it!=end; ++it) {
        const TimerCallbackPtr& nodeToCall = *it;
        o << "timeToRun " << (nodeToCall->timeToRun - now)
          << " period " << nodeToCall->period << "\n";
    }
}

bool epics::pvData::Timer::isScheduled

(

TimerCallbackPtr const &

timerCallback

)

const

Is the callback scheduled to be called?

Parameters

timerCallback

the timerCallback.

Returns

(false,true) if (not, is) scheduled.

Definition at line 80 of file timer.cpp.

{
    Lock xx(mutex);
    return timerCallback->onList;
}

epics::pvData::Timer::POINTER_DEFINITIONS

(

Timer

)

void epics::pvData::Timer::scheduleAfterDelay	(	TimerCallbackPtr const &	timerCallback,
		double	delay
	)

schedule a callback after a delay.

Parameters

timerCallback	the timerCallback instance.
delay	number of seconds before calling callback.

Definition at line 161 of file timer.cpp.

{
    schedulePeriodic(timerCallback,delay,0.0);
}

void epics::pvData::Timer::schedulePeriodic	(	TimerCallbackPtr const &	timerCallback,
		double	delay,
		double	period
	)

schedule a periodic callback.`

Parameters

timerCallback	the timerCallback instance.
delay	number of seconds before first callback.
period	time in seconds between each callback.

Definition at line 168 of file timer.cpp.

{
    epicsTime now(epicsTime::getCurrent());

    bool wakeup;
    {
        Lock xx(mutex);
        if(timerCallback->onList) {
            throw std::logic_error(string("already queued"));
        }

        if(!alive) {
            xx.unlock();
            timerCallback->timerStopped();
            return;
        }

        timerCallback->timeToRun = now + delay;
        timerCallback->period = period;

        addElement(timerCallback);
        wakeup = waiting && queue.front()==timerCallback;
    }
    if(wakeup) waitForWork.signal();
}

---

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

• modules/pvData/src/misc/pv/timer.h
• modules/pvData/src/misc/timer.cpp