Files
pcas/src/libCom/timer/osiTimer.cpp
2001-02-16 03:13:27 +00:00

726 lines
16 KiB
C++

/*
* $Id$
*
* Author Jeffrey O. Hill
* johill@lanl.gov
* 505 665 1831
*
* Experimental Physics and Industrial Control System (EPICS)
*
* Copyright 1991, the Regents of the University of California,
* and the University of Chicago Board of Governors.
*
* This software was produced under U.S. Government contracts:
* (W-7405-ENG-36) at the Los Alamos National Laboratory,
* and (W-31-109-ENG-38) at Argonne National Laboratory.
*
* Initial development by:
* The Controls and Automation Group (AT-8)
* Ground Test Accelerator
* Accelerator Technology Division
* Los Alamos National Laboratory
*
* Co-developed with
* The Controls and Computing Group
* Accelerator Systems Division
* Advanced Photon Source
* Argonne National Laboratory
*
*/
#ifndef assert // allow use of epicsAssert.h
#include <assert.h>
#endif
#include <stdio.h>
#include <float.h>
#define epicsExportSharedSymbols
#include "osiTimer.h"
#include "locationException.h"
#include "errlog.h"
class osiTimerThread : public epicsThreadRunable {
public:
osiTimerThread (osiTimerQueue &, unsigned priority);
virtual ~osiTimerThread();
private:
friend class osiTimer;
friend class osiTimerQueue;
epicsThread thread;
osiTimerQueue &queue;
virtual void run();
};
//
// default global timer queue
//
osiTimerQueue osiDefaultTimerQueue ( osiTimerQueue::mtsNoManagerThread );
//
// osiTimer::osiTimer ()
//
// create an active timer that will expire in delay seconds
//
osiTimer::osiTimer (double delay, osiTimerQueue & queueIn) :
queue (queueIn)
{
this->arm (delay);
}
//
// osiTimer::osiTimer ()
//
// create an active timer that will expire in delay seconds
//
osiTimer::osiTimer (double delay) :
queue (osiDefaultTimerQueue)
{
this->arm (delay);
}
//
// osiTimer::osiTimer ()
//
// create an inactive timer
//
osiTimer::osiTimer (osiTimerQueue & queueIn) :
curState (osiTimer::stateIdle), queue (queueIn)
{
this->queue.mutex.lock ();
this->queue.timerLists[stateIdle].add (*this);
this->queue.mutex.unlock ();
}
//
// osiTimer::osiTimer ()
//
// create an inactive timer
//
osiTimer::osiTimer () :
curState (osiTimer::stateIdle), queue (osiDefaultTimerQueue)
{
this->queue.mutex.lock ();
this->queue.timerLists[stateIdle].add (*this);
this->queue.mutex.unlock ();
}
//
// osiTimer::~osiTimer()
//
osiTimer::~osiTimer()
{
if ( this->curState == stateLimbo ) {
return; // queue was destroyed
}
this->queue.mutex.lock ();
//
// signal the timer queue if this
// occurring during the expire call
// back
//
if (this == this->queue.pExpireTmr) {
this->queue.pExpireTmr = 0;
}
this->queue.timerLists[this->curState].remove(*this);
this->curState = stateLimbo;
this->queue.mutex.unlock ();
}
//
// osiTimer::cancel ()
//
void osiTimer::cancel ()
{
if ( this->curState == stateLimbo ) {
return; // queue was destroyed
}
this->queue.mutex.lock ();
//
// signal the timer queue if this
// occurring during the expire call
// back
//
if (this == this->queue.pExpireTmr) {
this->queue.pExpireTmr = 0;
}
this->queue.timerLists[this->curState].remove (*this);
this->curState = stateIdle;
this->queue.timerLists[stateIdle].add (*this);
this->queue.mutex.unlock ();
this->destroy ();
}
//
// osiTimer::reschedule()
//
// pull this timer out of the queue and reinstall
// it with a new experation time
//
void osiTimer::reschedule ()
{
this->reschedule ( this->delay () );
}
//
// osiTimer::reschedule()
//
// pull this timer out of the queue ans reinstall
// it with a new experation time
//
void osiTimer::reschedule (double newDelay)
{
if ( this->curState == stateLimbo ) {
return; // queue was destroyed
}
this->queue.mutex.lock ();
//
// signal the timer queue if this
// occurring during the expire call
// back
//
if ( this == this->queue.pExpireTmr ) {
this->queue.pExpireTmr = 0;
}
this->queue.timerLists[this->curState].remove (*this);
this->curState = stateLimbo;
this->arm (newDelay);
this->queue.mutex.unlock ();
}
//
// Start the timer with delay this->delay() if inactive
//
epicsShareFunc void osiTimer::activate ()
{
this->activate ( this->delay () );
}
//
// Start the timer with delay newDelay if inactive
//
epicsShareFunc void osiTimer::activate ( double newDelay )
{
if ( this->curState == stateLimbo ) {
return; // queue was destroyed
}
this->queue.mutex.lock ();
if ( this->curState == stateIdle ) {
//
// signal the timer queue if this
// occurring during the expire call
// back
//
if ( this == this->queue.pExpireTmr ) {
this->queue.pExpireTmr = 0;
}
this->queue.timerLists[this->curState].remove (*this);
this->curState = stateLimbo;
this->arm (newDelay);
}
this->queue.mutex.unlock ();
}
//
// osiTimer::arm ()
//
void osiTimer::arm (double initialDelay)
{
bool first;
# ifdef DEBUG
unsigned preemptCount=0u;
# endif
this->queue.mutex.lock ();
//
// create manager thread on demand so we dont have threads hanging
// around that are not used
//
if ( ! this->queue.terminateFlag && this->queue.pMgrThread == NULL ) {
this->queue.pMgrThread = new osiTimerThread (this->queue, this->queue.mgrThreadPriority);
if ( this->queue.pMgrThread == NULL ) {
this->queue.mutex.unlock ();
throwWithLocation ( noMemory () );
}
}
//
// calculate absolute expiration time
//
this->exp = epicsTime::getCurrent () + initialDelay;
//
// insert into the pending queue
//
// Finds proper time sorted location using
// a linear search.
//
// **** this should use a binary tree ????
//
tsDLIterBD<osiTimer> iter = this->queue.timerLists[statePending].lastIter ();
while (1) {
if ( ! iter.valid () ) {
//
// add to the beginning of the list
//
this->queue.timerLists[statePending].push (*this);
first = true;
break;
}
if ( iter->exp <= this->exp ) {
//
// add after the item found that expires earlier
//
this->queue.timerLists[statePending].insertAfter (*this, *iter);
first = false;
break;
}
# ifdef DEBUG
preemptCount++;
# endif
--iter;
}
this->curState = osiTimer::statePending;
# ifdef DEBUG
this->show (10u);
# endif
# ifdef DEBUG
//
// name virtual function isnt always useful here because this is
// often called inside the constructor (unless we are
// rearming the same timer)
//
printf ("Arm of \"%s\" with delay %f at %lx preempting %u\n",
this->name(), initialDelay, (unsigned long)this, preemptCount);
# endif
this->queue.mutex.unlock ();
if (first) {
this->queue.rescheduleEvent.signal ();
}
}
//
// osiTimer::again()
//
bool osiTimer::again () const
{
//
// default is to run the timer only once
//
return false;
}
//
// osiTimer::destroy()
//
void osiTimer::destroy ()
{
delete this;
}
//
// osiTimer::delay()
//
double osiTimer::delay () const
{
throwWithLocation ( noDelaySpecified () );
return DBL_MAX; // never here
}
//
// osiTimer::show()
//
void osiTimer::show (unsigned level) const
{
epicsTime cur = epicsTime::getCurrent ();
printf ("osiTimer at %p for \"%s\" with again = %d\n",
static_cast <const void *> (this), this->name(), this->again());
if (level>=1u) {
double delay = this->exp - cur;
printf ("\tdelay to expire = %f, state = %d\n",
delay, this->curState);
}
}
//
// osiTimer::name()
// virtual base default
//
const char *osiTimer::name() const
{
return "osiTimer";
}
//
// osiTimer::timeRemaining()
//
// return the number of seconds remaining before
// this timer will expire
//
double osiTimer::timeRemaining () const
{
double delay;
this->queue.mutex.lock ();
switch (this->curState) {
case statePending:
delay = this->exp - epicsTime::getCurrent();
if ( delay < 0.0 ) {
delay = 0.0;
}
break;
case stateIdle:
delay = DBL_MAX;
break;
case stateExpired:
delay = 0.0;
break;
case stateLimbo:
errlogPrintf ("time remaning fetched on a osiTimer with no queue?\n");
delay = DBL_MAX; // queue was destroyed
break;
default:
errlogPrintf ("saw osiTimer in undefined state\n");
delay = DBL_MAX;
break;
}
this->queue.mutex.unlock ();
return delay;
}
//
// osiTimerQueue::osiTimerQueue ()
//
epicsShareFunc osiTimerQueue::osiTimerQueue ( managerThreadSelect mts,
unsigned managerThreadPriority ) :
pExpireTmr (0), pMgrThread (0), mgrThreadPriority (managerThreadPriority),
inProcess (false), exitFlag (false)
{
this->terminateFlag = ( mts != mtsCreateManagerThread );
}
//
// osiTimerQueue::~osiTimerQueue()
//
osiTimerQueue::~osiTimerQueue()
{
osiTimer *pTmr;
this->terminateManagerThread ();
this->mutex.lock ();
//
// destroy any unexpired timers
//
while ( ( pTmr = this->timerLists[osiTimer::statePending].get () ) ) {
pTmr->curState = osiTimer::stateLimbo;
pTmr->destroy ();
}
//
// destroy any expired timers
//
while ( (pTmr = this->timerLists[osiTimer::stateExpired].get()) ) {
pTmr->curState = osiTimer::stateLimbo;
pTmr->destroy ();
}
}
//
// osiTimerQueue::terminateManagerThread ()
//
void osiTimerQueue::terminateManagerThread ()
{
// stop current thread if started and
// prevent launching of thread in the future
this->terminateFlag = true;
if ( this->pMgrThread ) {
this->rescheduleEvent.signal ();
while ( ! this->exitFlag && ! this->pMgrThread->thread.isSuspended () ) {
this->exitEvent.wait ( 1.0 );
}
this->mutex.lock ();
if ( this->pMgrThread ) {
delete this->pMgrThread;
this->pMgrThread = 0;
}
this->mutex.unlock ();
// in case other threads are waiting here also
this->exitEvent.signal ();
}
}
//
// osiTimerThread::osiTimerThread ()
//
osiTimerThread::osiTimerThread (osiTimerQueue &queueIn, unsigned priority) :
thread( *this, "osiTimerQueue",
epicsThreadGetStackSize (epicsThreadStackMedium), priority) ,
queue (queueIn)
{
this->thread.start ();
}
osiTimerThread::~osiTimerThread() {};
//
// osiTimerThread::run ()
//
void osiTimerThread::run ()
{
queue.exitFlag = false;
while ( ! queue.terminateFlag ) {
queue.privateProcess ();
double delay = queue.delayToFirstExpire ();
queue.rescheduleEvent.wait ( delay );
}
queue.exitFlag = true;
queue.exitEvent.signal (); // no access to queue after exitEvent signal
}
//
// osiTimerQueue::delayToFirstExpire ()
//
double osiTimerQueue::delayToFirstExpire () const
{
osiTimer *pTmr;
double delay;
this->mutex.lock ();
pTmr = this->timerLists[osiTimer::statePending].first ();
if (pTmr) {
delay = pTmr->timeRemaining ();
# ifdef DEBUG
printf ("delay for %f sec for %s\n", delay, pTmr->name () );
# endif
}
else {
//
// no timer in the queue - return a long delay - 30 min
//
delay = 30u * epicsTime::secPerMin;
}
this->mutex.unlock ();
return delay; // seconds
}
//
// osiTimerQueue::process()
//
void osiTimerQueue::process ()
{
if ( this->terminateFlag ) {
this->privateProcess ();
}
}
void osiTimerQueue::privateProcess ()
{
epicsTime cur ( epicsTime::getCurrent () );
osiTimer *pTmr;
this->mutex.lock ();
// no recursion
if (this->inProcess) {
this->mutex.unlock ();
return;
}
this->inProcess = true;
tsDLIterBD <osiTimer> iter = this->timerLists[osiTimer::statePending].firstIter ();
while ( iter.valid () ) {
if ( iter->exp > cur ) {
break;
}
tsDLIterBD <osiTimer> tmp = iter;
++tmp;
this->timerLists[osiTimer::statePending].remove(*iter);
iter->curState = osiTimer::stateExpired;
this->timerLists[osiTimer::stateExpired].add(*iter);
iter = tmp;
}
//
// I am careful to prevent problems if they access the
// above list while in an "expire()" call back
//
while ( ( pTmr = this->timerLists[osiTimer::stateExpired].get () ) ) {
pTmr->curState = osiTimer::stateIdle;
this->timerLists[osiTimer::stateIdle].add (*pTmr);
//
// Tag current tmr so that we
// can detect if it was deleted
// during the expire call back
//
this->pExpireTmr = pTmr;
//
// remove lock while calling their callback
//
this->mutex.unlock ();
#ifdef DEBUG
double diff = cur-pTmr->exp;
printf ("expired %lx for \"%s\" with error %f\n",
(unsigned long)pTmr, pTmr->name(), diff);
#endif
pTmr->expire();
this-> mutex.lock();
if ( this->pExpireTmr == pTmr ) {
if ( pTmr->again () ) {
this->timerLists[osiTimer::stateIdle].remove (*pTmr);
pTmr->arm (pTmr->delay());
}
else {
pTmr->destroy ();
}
}
else {
//
// no recursive calls to process allowed
//
assert (this->pExpireTmr == 0);
}
}
this->inProcess = false;
this->mutex.unlock();
}
//
// osiTimerQueue::show() const
//
void osiTimerQueue::show(unsigned level) const
{
this->mutex.lock();
printf("osiTimerQueue with %u items pending and %u items expired\n",
this->timerLists[osiTimer::statePending].count(),
this->timerLists[osiTimer::stateExpired].count());
tsDLIterConstBD <osiTimer> iter = this->timerLists[osiTimer::statePending].firstIter ();
while ( iter.valid () ) {
iter->show(level);
++iter;
}
this->mutex.unlock();
}
extern "C" epicsShareFunc osiTimerQueueId epicsShareAPI osiTimerQueueCreate ( unsigned managerThreadPriority )
{
return (osiTimerQueueId) new osiTimerQueue ( osiTimerQueue::mtsCreateManagerThread, managerThreadPriority );
}
class osiTimerForC : public osiTimer {
epicsShareFunc virtual void expire();
epicsShareFunc virtual void destroy();
epicsShareFunc virtual bool again() const;
epicsShareFunc virtual double delay() const;
epicsShareFunc virtual void show (unsigned level) const;
const osiTimerJumpTable &jt;
void * pPrivate;
public:
osiTimerForC (const osiTimerJumpTable &jtIn, osiTimerQueue &queue, void *pPrivateIn);
};
osiTimerForC::osiTimerForC (const osiTimerJumpTable &jtIn, osiTimerQueue &queue, void *pPrivateIn) :
osiTimer (queue), jt (jtIn), pPrivate (pPrivateIn) {}
void osiTimerForC::expire ()
{
(*this->jt.expire) (this->pPrivate);
}
void osiTimerForC::destroy ()
{
(*this->jt.destroy) (this->pPrivate);
}
bool osiTimerForC::again () const
{
return (*this->jt.again) (this->pPrivate) ? true : false ;
}
double osiTimerForC::delay () const
{
return (*this->jt.delay) (this->pPrivate);
}
void osiTimerForC::show (unsigned level) const
{
(*this->jt.show) (this->pPrivate, level);
}
extern "C" epicsShareFunc osiTimerId epicsShareAPI osiTimerCreate (const osiTimerJumpTable *pjtIn, osiTimerQueueId queueIdIn, void *pPrivateIn)
{
assert (pjtIn);
assert (queueIdIn);
return (osiTimerId) new osiTimerForC (*pjtIn, *static_cast<osiTimerQueue *>(queueIdIn), pPrivateIn);
}
extern "C" epicsShareFunc void epicsShareAPI osiTimerArm (osiTimerId tmrIdIn, double delay)
{
osiTimerForC *pTmr = static_cast<osiTimerForC *>(tmrIdIn);
assert (pTmr);
pTmr->reschedule (delay);
}
extern "C" epicsShareFunc void epicsShareAPI osiTimerCancel (osiTimerId tmrIdIn)
{
osiTimerForC *pTmr = static_cast<osiTimerForC *>(tmrIdIn);
assert (pTmr);
pTmr->cancel ();
}
extern "C" epicsShareFunc double epicsShareAPI osiTimerTimeRemaining (osiTimerId idIn)
{
osiTimerForC *pTmr = static_cast<osiTimerForC *> (idIn);
assert (pTmr);
return pTmr->timeRemaining ();
}
extern "C" epicsShareFunc epicsTimeStamp epicsShareAPI osiTimerExpirationDate (osiTimerId idIn)
{
osiTimerForC *pTmr = static_cast<osiTimerForC *> (idIn);
assert (pTmr);
return pTmr->expirationDate ();
}