scummvm/common/timer.cpp

141 lines
3.7 KiB
C++

/* ScummVM - Scumm Interpreter
* Copyright (C) 2002-2003 The ScummVM project
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*/
#ifndef __MORPHOS__
#include "stdafx.h"
#include "common/scummsys.h"
#include "common/timer.h"
static Timer *g_timer = NULL;
Timer::Timer(Engine * engine) :
_engine(engine),
_mutex(0),
_timerHandler(0),
_lastTime(0) {
_mutex = _engine->_system->create_mutex();
g_timer = this;
for (int i = 0; i < MAX_TIMERS; i++) {
_timerSlots[i].procedure = NULL;
_timerSlots[i].interval = 0;
_timerSlots[i].counter = 0;
}
_thisTime = _engine->_system->get_msecs();
// Set the timer last, after everything has been initialised
_engine->_system->set_timer(10, &timer_handler);
}
Timer::~Timer() {
_engine->_system->set_timer(0, NULL);
_engine->_system->lock_mutex(_mutex);
for (int i = 0; i < MAX_TIMERS; i++) {
_timerSlots[i].procedure = NULL;
_timerSlots[i].interval = 0;
_timerSlots[i].counter = 0;
}
_engine->_system->unlock_mutex(_mutex);
// FIXME: There is still a potential race condition here, depending on how
// the system backend implements set_timer: If timers are done using
// threads, and if set_timer does *not* gurantee that after it terminates
// that timer thread is not run anymore, we are fine. However, if the timer
// is still running in parallel to this destructor, then it might be that
// it is still waiting for the _mutex. So, again depending on the backend,
// we might end up unlocking the mutex then immediately deleting it, while
// the timer thread is about to lock it.
_engine->_system->delete_mutex(_mutex);
}
int Timer::timer_handler(int t) {
if (g_timer)
return g_timer->handler(t);
return 0;
}
int Timer::handler(int t) {
uint32 interval, l;
_engine->_system->lock_mutex(_mutex);
_lastTime = _thisTime;
_thisTime = _engine->_system->get_msecs();
interval = 1000 * (_thisTime - _lastTime);
for (l = 0; l < MAX_TIMERS; l++) {
if ((_timerSlots[l].procedure) && (_timerSlots[l].interval > 0)) {
_timerSlots[l].counter -= interval;
if (_timerSlots[l].counter <= 0) {
_timerSlots[l].counter += _timerSlots[l].interval;
_timerSlots[l].procedure (_engine);
}
}
}
_engine->_system->unlock_mutex(_mutex);
return t;
}
bool Timer::installProcedure (TimerProc procedure, int32 interval) {
int32 l;
bool found = false;
_engine->_system->lock_mutex(_mutex);
for (l = 0; l < MAX_TIMERS; l++) {
if (!_timerSlots[l].procedure) {
_timerSlots[l].procedure = procedure;
_timerSlots[l].interval = interval;
_timerSlots[l].counter = interval;
found = true;
break;
}
}
_engine->_system->unlock_mutex(_mutex);
if (!found)
warning("Couldn't find free timer slot!");
return found;
}
void Timer::releaseProcedure (TimerProc procedure) {
int32 l;
_engine->_system->lock_mutex(_mutex);
for (l = 0; l < MAX_TIMERS; l++) {
if (_timerSlots[l].procedure == procedure) {
_timerSlots[l].procedure = 0;
_timerSlots[l].interval = 0;
_timerSlots[l].counter = 0;
}
}
_engine->_system->unlock_mutex(_mutex);
}
#endif