scummvm/common/coroutines.cpp
2021-12-26 18:48:43 +01:00

732 lines
18 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/coroutines.h"
#include "common/algorithm.h"
#include "common/debug.h"
#include "common/hashmap.h"
#include "common/hash-str.h"
#include "common/system.h"
#include "common/textconsole.h"
namespace Common {
/** Helper null context instance */
CoroContext nullContext = nullptr;
DECLARE_SINGLETON(CoroutineScheduler);
#ifdef COROUTINE_DEBUG
namespace {
/** Count of active coroutines */
static int s_coroCount = 0;
typedef Common::HashMap<Common::String, int> CoroHashMap;
static CoroHashMap *s_coroFuncs = 0;
/**
* Change the current coroutine status
*/
static void changeCoroStats(const char *func, int change) {
if (!s_coroFuncs)
s_coroFuncs = new CoroHashMap();
(*s_coroFuncs)[func] += change;
}
/**
* Display the details of active coroutines
*/
static void displayCoroStats() {
debug("%d active coros", s_coroCount);
// Loop over s_coroFuncs and print info about active coros
if (!s_coroFuncs)
return;
for (CoroHashMap::const_iterator it = s_coroFuncs->begin();
it != s_coroFuncs->end(); ++it) {
if (it->_value != 0)
debug(" %3d x %s", it->_value, it->_key.c_str());
}
}
} // End of anonymous namespace
#endif
CoroBaseContext::CoroBaseContext(const char *func)
: _line(0), _sleep(0), _subctx(nullptr) {
#ifdef COROUTINE_DEBUG
_funcName = func;
changeCoroStats(_funcName, +1);
s_coroCount++;
#endif
}
CoroBaseContext::~CoroBaseContext() {
#ifdef COROUTINE_DEBUG
s_coroCount--;
changeCoroStats(_funcName, -1);
debug("Deleting coro in %s at %p (subctx %p)",
_funcName, (void *)this, (void *)_subctx);
displayCoroStats();
#endif
delete _subctx;
}
//--------------------- Scheduler Class ------------------------
CoroutineScheduler::CoroutineScheduler() {
processList = nullptr;
pFreeProcesses = nullptr;
pCurrent = nullptr;
#ifdef DEBUG
// diagnostic process counters
numProcs = 0;
maxProcs = 0;
#endif
pRCfunction = nullptr;
pidCounter = 0;
active = new PROCESS;
active->pPrevious = nullptr;
active->pNext = nullptr;
reset();
}
CoroutineScheduler::~CoroutineScheduler() {
// Kill all running processes (i.e. free memory allocated for their state).
PROCESS *pProc = active->pNext;
while (pProc != nullptr) {
delete pProc->state;
pProc->state = nullptr;
pProc = pProc->pNext;
}
free(processList);
processList = nullptr;
delete active;
active = nullptr;
// Clear the event list
Common::List<EVENT *>::iterator i;
for (i = _events.begin(); i != _events.end(); ++i)
delete *i;
}
void CoroutineScheduler::reset() {
#ifdef DEBUG
// clear number of process in use
numProcs = 0;
#endif
if (processList == nullptr) {
// first time - allocate memory for process list
processList = (PROCESS *)calloc(CORO_MAX_PROCESSES, sizeof(PROCESS));
// make sure memory allocated
if (processList == nullptr) {
error("Cannot allocate memory for process data");
}
// fill with garbage
memset(processList, 'S', CORO_MAX_PROCESSES * sizeof(PROCESS));
}
// Kill all running processes (i.e. free memory allocated for their state).
PROCESS *pProc = active->pNext;
while (pProc != nullptr) {
delete pProc->state;
pProc->state = nullptr;
Common::fill(&pProc->pidWaiting[0], &pProc->pidWaiting[CORO_MAX_PID_WAITING], 0);
pProc = pProc->pNext;
}
// no active processes
pCurrent = active->pNext = nullptr;
// place first process on free list
pFreeProcesses = processList;
// link all other processes after first
for (int i = 1; i <= CORO_NUM_PROCESS; i++) {
processList[i - 1].pNext = (i == CORO_NUM_PROCESS) ? nullptr : processList + i;
processList[i - 1].pPrevious = (i == 1) ? active : processList + (i - 2);
}
}
#ifdef DEBUG
void CoroutineScheduler::printStats() {
debug("%i process of %i used", maxProcs, CORO_NUM_PROCESS);
}
#endif
#ifdef DEBUG
void CoroutineScheduler::checkStack() {
Common::List<PROCESS *> pList;
// Check both the active and free process lists
for (int i = 0; i < 2; ++i) {
PROCESS *p = (i == 0) ? active : pFreeProcesses;
if (p != NULL) {
// Make sure the linkages are correct
while (p->pNext != NULL) {
assert(p->pNext->pPrevious == p);
pList.push_back(p);
p = p->pNext;
}
pList.push_back(p);
}
}
// Make sure all processes are accounted for
for (int idx = 0; idx < CORO_NUM_PROCESS; idx++) {
bool found = false;
for (Common::List<PROCESS *>::iterator i = pList.begin(); i != pList.end(); ++i) {
PROCESS *pTemp = *i;
if (*i == &processList[idx]) {
found = true;
break;
}
}
assert(found);
}
}
#endif
void CoroutineScheduler::schedule() {
// start dispatching active process list
PROCESS *pNext;
PROCESS *pProc = active->pNext;
while (pProc != nullptr) {
pNext = pProc->pNext;
if (--pProc->sleepTime <= 0) {
// process is ready for dispatch, activate it
pCurrent = pProc;
pProc->coroAddr(pProc->state, pProc->param);
if (!pProc->state || pProc->state->_sleep <= 0) {
// Coroutine finished
pCurrent = pCurrent->pPrevious;
killProcess(pProc);
} else {
pProc->sleepTime = pProc->state->_sleep;
}
// pCurrent may have been changed
pNext = pCurrent->pNext;
pCurrent = nullptr;
}
pProc = pNext;
}
// Disable any events that were pulsed
Common::List<EVENT *>::iterator i;
for (i = _events.begin(); i != _events.end(); ++i) {
EVENT *evt = *i;
if (evt->pulsing) {
evt->pulsing = evt->signalled = false;
}
}
}
void CoroutineScheduler::rescheduleAll() {
assert(pCurrent);
// Unlink current process
pCurrent->pPrevious->pNext = pCurrent->pNext;
if (pCurrent->pNext)
pCurrent->pNext->pPrevious = pCurrent->pPrevious;
// Add process to the start of the active list
pCurrent->pNext = active->pNext;
active->pNext->pPrevious = pCurrent;
active->pNext = pCurrent;
pCurrent->pPrevious = active;
}
void CoroutineScheduler::reschedule(PPROCESS pReSchedProc) {
// If not currently processing the schedule list, then no action is needed
if (!pCurrent)
return;
if (!pReSchedProc)
pReSchedProc = pCurrent;
PPROCESS pEnd;
// Find the last process in the list.
// But if the target process is down the list from here, do nothing
for (pEnd = pCurrent; pEnd->pNext != nullptr; pEnd = pEnd->pNext) {
if (pEnd->pNext == pReSchedProc)
return;
}
assert(pEnd->pNext == nullptr);
// Could be in the middle of a KillProc()!
// Dying process was last and this process was penultimate
if (pReSchedProc->pNext == nullptr)
return;
// If we're moving the current process, move it back by one, so that the next
// schedule() iteration moves to the now next one
if (pCurrent == pReSchedProc)
pCurrent = pCurrent->pPrevious;
// Unlink the process, and add it at the end
pReSchedProc->pPrevious->pNext = pReSchedProc->pNext;
pReSchedProc->pNext->pPrevious = pReSchedProc->pPrevious;
pEnd->pNext = pReSchedProc;
pReSchedProc->pPrevious = pEnd;
pReSchedProc->pNext = nullptr;
}
void CoroutineScheduler::giveWay(PPROCESS pReSchedProc) {
// If not currently processing the schedule list, then no action is needed
if (!pCurrent)
return;
if (!pReSchedProc)
pReSchedProc = pCurrent;
// If the process is already at the end of the queue, nothing has to be done
if (!pReSchedProc->pNext)
return;
PPROCESS pEnd;
// Find the last process in the list.
for (pEnd = pCurrent; pEnd->pNext != nullptr; pEnd = pEnd->pNext)
;
assert(pEnd->pNext == nullptr);
// If we're moving the current process, move it back by one, so that the next
// schedule() iteration moves to the now next one
if (pCurrent == pReSchedProc)
pCurrent = pCurrent->pPrevious;
// Unlink the process, and add it at the end
pReSchedProc->pPrevious->pNext = pReSchedProc->pNext;
pReSchedProc->pNext->pPrevious = pReSchedProc->pPrevious;
pEnd->pNext = pReSchedProc;
pReSchedProc->pPrevious = pEnd;
pReSchedProc->pNext = nullptr;
}
void CoroutineScheduler::waitForSingleObject(CORO_PARAM, int pid, uint32 duration, bool *expired) {
if (!pCurrent)
error("Called CoroutineScheduler::waitForSingleObject from the main process");
CORO_BEGIN_CONTEXT;
uint32 endTime;
PROCESS *pProcess;
EVENT *pEvent;
CORO_END_CONTEXT(_ctx);
CORO_BEGIN_CODE(_ctx);
// Signal the process Id this process is now waiting for
pCurrent->pidWaiting[0] = pid;
_ctx->endTime = (duration == CORO_INFINITE) ? CORO_INFINITE : g_system->getMillis() + duration;
if (expired)
// Presume it will expire
*expired = true;
// Outer loop for doing checks until expiry
while (g_system->getMillis() <= _ctx->endTime) {
// Check to see if a process or event with the given Id exists
_ctx->pProcess = getProcess(pid);
_ctx->pEvent = !_ctx->pProcess ? getEvent(pid) : nullptr;
// If there's no active process or event, presume it's a process that's finished,
// so the waiting can immediately exit
if ((_ctx->pProcess == nullptr) && (_ctx->pEvent == nullptr)) {
if (expired)
*expired = false;
break;
}
// If a process was found, don't go into the if statement, and keep waiting.
// Likewise if it's an event that's not yet signalled
if ((_ctx->pEvent != nullptr) && _ctx->pEvent->signalled) {
// Unless the event is flagged for manual reset, reset it now
if (!_ctx->pEvent->manualReset)
_ctx->pEvent->signalled = false;
if (expired)
*expired = false;
break;
}
// Sleep until the next cycle
CORO_SLEEP(1);
}
// Signal waiting is done
Common::fill(&pCurrent->pidWaiting[0], &pCurrent->pidWaiting[CORO_MAX_PID_WAITING], 0);
CORO_END_CODE;
}
void CoroutineScheduler::waitForMultipleObjects(CORO_PARAM, int nCount, uint32 *pidList, bool bWaitAll,
uint32 duration, bool *expired) {
if (!pCurrent)
error("Called CoroutineScheduler::waitForMultipleObjects from the main process");
CORO_BEGIN_CONTEXT;
uint32 endTime;
bool signalled;
bool pidSignalled;
int i;
PROCESS *pProcess;
EVENT *pEvent;
CORO_END_CONTEXT(_ctx);
CORO_BEGIN_CODE(_ctx);
// Signal the waiting events
assert(nCount < CORO_MAX_PID_WAITING);
Common::copy(pidList, pidList + nCount, pCurrent->pidWaiting);
_ctx->endTime = (duration == CORO_INFINITE) ? CORO_INFINITE : g_system->getMillis() + duration;
if (expired)
// Presume that delay will expire
*expired = true;
// Outer loop for doing checks until expiry
while (g_system->getMillis() <= _ctx->endTime) {
_ctx->signalled = bWaitAll;
for (_ctx->i = 0; _ctx->i < nCount; ++_ctx->i) {
_ctx->pProcess = getProcess(pidList[_ctx->i]);
_ctx->pEvent = !_ctx->pProcess ? getEvent(pidList[_ctx->i]) : nullptr;
// Determine the signalled state
_ctx->pidSignalled = (_ctx->pProcess) || !_ctx->pEvent ? false : _ctx->pEvent->signalled;
if (bWaitAll && !_ctx->pidSignalled)
_ctx->signalled = false;
else if (!bWaitAll && _ctx->pidSignalled)
_ctx->signalled = true;
}
// At this point, if the signalled variable is set, waiting is finished
if (_ctx->signalled) {
// Automatically reset any events not flagged for manual reset
for (_ctx->i = 0; _ctx->i < nCount; ++_ctx->i) {
_ctx->pEvent = getEvent(pidList[_ctx->i]);
if (!_ctx->pEvent->manualReset)
_ctx->pEvent->signalled = false;
}
if (expired)
*expired = false;
break;
}
// Sleep until the next cycle
CORO_SLEEP(1);
}
// Signal waiting is done
Common::fill(&pCurrent->pidWaiting[0], &pCurrent->pidWaiting[CORO_MAX_PID_WAITING], 0);
CORO_END_CODE;
}
void CoroutineScheduler::sleep(CORO_PARAM, uint32 duration) {
if (!pCurrent)
error("Called CoroutineScheduler::sleep from the main process");
CORO_BEGIN_CONTEXT;
uint32 endTime;
PROCESS *pProcess;
EVENT *pEvent;
CORO_END_CONTEXT(_ctx);
CORO_BEGIN_CODE(_ctx);
_ctx->endTime = g_system->getMillis() + duration;
// Outer loop for doing checks until expiry
while (g_system->getMillis() < _ctx->endTime) {
// Sleep until the next cycle
CORO_SLEEP(1);
}
CORO_END_CODE;
}
PROCESS *CoroutineScheduler::createProcess(uint32 pid, CORO_ADDR coroAddr, const void *pParam, int sizeParam) {
PROCESS *pProc;
// get a free process
pProc = pFreeProcesses;
// trap no free process
assert(pProc != nullptr); // Out of processes
#ifdef DEBUG
// one more process in use
if (++numProcs > maxProcs)
maxProcs = numProcs;
#endif
// get link to next free process
pFreeProcesses = pProc->pNext;
if (pFreeProcesses)
pFreeProcesses->pPrevious = nullptr;
if (pCurrent != nullptr) {
// place new process before the next active process
pProc->pNext = pCurrent->pNext;
if (pProc->pNext)
pProc->pNext->pPrevious = pProc;
// make this new process the next active process
pCurrent->pNext = pProc;
pProc->pPrevious = pCurrent;
} else { // no active processes, place process at head of list
pProc->pNext = active->pNext;
pProc->pPrevious = active;
if (pProc->pNext)
pProc->pNext->pPrevious = pProc;
active->pNext = pProc;
}
// set coroutine entry point
pProc->coroAddr = coroAddr;
// clear coroutine state
pProc->state = nullptr;
// wake process up as soon as possible
pProc->sleepTime = 1;
// set new process id
pProc->pid = pid;
// set new process specific info
if (sizeParam) {
assert(sizeParam > 0 && sizeParam <= CORO_PARAM_SIZE);
// set new process specific info
memcpy(pProc->param, pParam, sizeParam);
}
// return created process
return pProc;
}
uint32 CoroutineScheduler::createProcess(CORO_ADDR coroAddr, const void *pParam, int sizeParam) {
PROCESS *pProc = createProcess(++pidCounter, coroAddr, pParam, sizeParam);
return pProc->pid;
}
uint32 CoroutineScheduler::createProcess(CORO_ADDR coroAddr, const void *pParam) {
return createProcess(coroAddr, &pParam, sizeof(void *));
}
void CoroutineScheduler::killProcess(PROCESS *pKillProc) {
// make sure a valid process pointer
assert(pKillProc >= processList && pKillProc <= processList + CORO_NUM_PROCESS - 1);
// can not kill the current process using killProcess !
assert(pCurrent != pKillProc);
#ifdef DEBUG
// one less process in use
--numProcs;
assert(numProcs >= 0);
#endif
// Free process' resources
if (pRCfunction != nullptr)
(pRCfunction)(pKillProc);
delete pKillProc->state;
pKillProc->state = nullptr;
// Take the process out of the active chain list
pKillProc->pPrevious->pNext = pKillProc->pNext;
if (pKillProc->pNext)
pKillProc->pNext->pPrevious = pKillProc->pPrevious;
// link first free process after pProc
pKillProc->pNext = pFreeProcesses;
if (pFreeProcesses)
pKillProc->pNext->pPrevious = pKillProc;
pKillProc->pPrevious = nullptr;
// make pKillProc the first free process
pFreeProcesses = pKillProc;
}
PROCESS *CoroutineScheduler::getCurrentProcess() {
return pCurrent;
}
int CoroutineScheduler::getCurrentPID() const {
PROCESS *pProc = pCurrent;
// make sure a valid process pointer
assert(pProc >= processList && pProc <= processList + CORO_NUM_PROCESS - 1);
// return processes PID
return pProc->pid;
}
int CoroutineScheduler::killMatchingProcess(uint32 pidKill, int pidMask) {
int numKilled = 0;
PROCESS *pProc, *pPrev; // process list pointers
for (pProc = active->pNext, pPrev = active; pProc != nullptr; pPrev = pProc, pProc = pProc->pNext) {
if ((pProc->pid & (uint32)pidMask) == pidKill) {
// found a matching process
// dont kill the current process
if (pProc != pCurrent) {
// kill this process
numKilled++;
// Free the process' resources
if (pRCfunction != nullptr)
(pRCfunction)(pProc);
delete pProc->state;
pProc->state = nullptr;
// make prev point to next to unlink pProc
pPrev->pNext = pProc->pNext;
if (pProc->pNext)
pPrev->pNext->pPrevious = pPrev;
// link first free process after pProc
pProc->pNext = pFreeProcesses;
pProc->pPrevious = nullptr;
pFreeProcesses->pPrevious = pProc;
// make pProc the first free process
pFreeProcesses = pProc;
// set to a process on the active list
pProc = pPrev;
}
}
}
#ifdef DEBUG
// adjust process in use
numProcs -= numKilled;
assert(numProcs >= 0);
#endif
// return number of processes killed
return numKilled;
}
void CoroutineScheduler::setResourceCallback(VFPTRPP pFunc) {
pRCfunction = pFunc;
}
PROCESS *CoroutineScheduler::getProcess(uint32 pid) {
PROCESS *pProc = active->pNext;
while ((pProc != nullptr) && (pProc->pid != pid))
pProc = pProc->pNext;
return pProc;
}
EVENT *CoroutineScheduler::getEvent(uint32 pid) {
Common::List<EVENT *>::iterator i;
for (i = _events.begin(); i != _events.end(); ++i) {
EVENT *evt = *i;
if (evt->pid == pid)
return evt;
}
return nullptr;
}
uint32 CoroutineScheduler::createEvent(bool bManualReset, bool bInitialState) {
EVENT *evt = new EVENT();
evt->pid = ++pidCounter;
evt->manualReset = bManualReset;
evt->signalled = bInitialState;
evt->pulsing = false;
_events.push_back(evt);
return evt->pid;
}
void CoroutineScheduler::closeEvent(uint32 pidEvent) {
EVENT *evt = getEvent(pidEvent);
if (evt) {
_events.remove(evt);
delete evt;
}
}
void CoroutineScheduler::setEvent(uint32 pidEvent) {
EVENT *evt = getEvent(pidEvent);
if (evt)
evt->signalled = true;
}
void CoroutineScheduler::resetEvent(uint32 pidEvent) {
EVENT *evt = getEvent(pidEvent);
if (evt)
evt->signalled = false;
}
void CoroutineScheduler::pulseEvent(uint32 pidEvent) {
EVENT *evt = getEvent(pidEvent);
if (!evt)
return;
// Set the event as signalled and pulsing
evt->signalled = true;
evt->pulsing = true;
// If there's an active process, and it's not the first in the queue, then reschedule all
// the other prcoesses in the queue to run again this frame
if (pCurrent && pCurrent != active->pNext)
rescheduleAll();
}
} // end of namespace Common