mirror of
https://github.com/ptitSeb/Serious-Engine
synced 2024-11-25 19:55:54 +01:00
323 lines
8.2 KiB
C++
323 lines
8.2 KiB
C++
/* Copyright (c) 2002-2012 Croteam Ltd.
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of version 2 of the GNU General Public License as published by
|
|
the Free Software Foundation
|
|
|
|
|
|
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.,
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
|
|
|
|
#ifdef PLATFORM_WIN32
|
|
|
|
#include "Engine/StdH.h"
|
|
|
|
#include <Engine/Base/Synchronization.h>
|
|
|
|
|
|
/*
|
|
This is implementation of OPTEX (optimized mutex),
|
|
originally from MSDN Periodicals 1996, by Jeffrey Richter.
|
|
|
|
It is updated for clearer comments, shielded with tons of asserts,
|
|
and modified to support TryToEnter() function. The original version
|
|
had timeout parameter, bu it didn't work.
|
|
|
|
NOTES:
|
|
- TryToEnter() was not tested with more than one thread, and perhaps
|
|
there might be some problems with the final decrementing and eventual event resetting
|
|
when lock fails. Dunno.
|
|
|
|
- take care to center the lock tests around 0 (-1 means not locked). that is
|
|
neccessary because win95 returns only <0, ==0 and >0 results from interlocked
|
|
functions, so testing against any other number than 0 doesn't work.
|
|
*/
|
|
|
|
// The opaque OPTEX data structure
|
|
typedef struct {
|
|
LONG lLockCount; // note: must center all tests around 0 for win95 compatibility!
|
|
DWORD dwThreadId;
|
|
LONG lRecurseCount;
|
|
HANDLE hEvent;
|
|
} OPTEX, *POPTEX;
|
|
|
|
_declspec(thread) INDEX _iLastLockedMutex = 0;
|
|
|
|
BOOL OPTEX_Initialize (POPTEX poptex) {
|
|
|
|
poptex->lLockCount = -1; // No threads have enterred the OPTEX
|
|
poptex->dwThreadId = 0; // The OPTEX is unowned
|
|
poptex->lRecurseCount = 0; // The OPTEX is unowned
|
|
poptex->hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
|
|
return(poptex->hEvent != NULL); // TRUE if the event is created
|
|
}
|
|
|
|
VOID OPTEX_Delete (POPTEX poptex) {
|
|
|
|
// No in-use check
|
|
CloseHandle(poptex->hEvent); // Close the event
|
|
}
|
|
|
|
INDEX OPTEX_Enter (POPTEX poptex)
|
|
{
|
|
|
|
DWORD dwThreadId = GetCurrentThreadId(); // The calling thread's ID
|
|
|
|
// increment lock counter
|
|
INDEX ctLocked = InterlockedIncrement(&poptex->lLockCount);
|
|
ASSERT(poptex->lLockCount>=0);
|
|
|
|
// if this is first thread that entered
|
|
if (ctLocked == 0) {
|
|
|
|
// mark that we own it, exactly once
|
|
ASSERT(poptex->dwThreadId==0);
|
|
ASSERT(poptex->lRecurseCount==0);
|
|
poptex->dwThreadId = dwThreadId;
|
|
poptex->lRecurseCount = 1;
|
|
|
|
// if already owned
|
|
} else {
|
|
|
|
// if owned by this thread
|
|
if (poptex->dwThreadId == dwThreadId) {
|
|
// just mark that we own it once more
|
|
poptex->lRecurseCount++;
|
|
ASSERT(poptex->lRecurseCount>1);
|
|
|
|
// if owned by some other thread
|
|
} else {
|
|
|
|
// wait for the owning thread to release the OPTEX
|
|
DWORD dwRet = WaitForSingleObject(poptex->hEvent, INFINITE);
|
|
ASSERT(dwRet == WAIT_OBJECT_0);
|
|
|
|
// mark that we own it, exactly once
|
|
ASSERT(poptex->dwThreadId==0);
|
|
ASSERT(poptex->lRecurseCount==0);
|
|
poptex->dwThreadId = dwThreadId;
|
|
poptex->lRecurseCount = 1;
|
|
}
|
|
}
|
|
ASSERT(poptex->lRecurseCount>=1);
|
|
ASSERT(poptex->lLockCount>=0);
|
|
return poptex->lRecurseCount;
|
|
}
|
|
|
|
INDEX OPTEX_TryToEnter (POPTEX poptex)
|
|
{
|
|
ASSERT(poptex->lLockCount>=-1);
|
|
DWORD dwThreadId = GetCurrentThreadId(); // The calling thread's ID
|
|
|
|
// increment lock counter
|
|
INDEX ctLocked = InterlockedIncrement(&poptex->lLockCount);
|
|
ASSERT(poptex->lLockCount>=0);
|
|
|
|
// if this is first thread that entered
|
|
if (ctLocked == 0) {
|
|
|
|
// mark that we own it, exactly once
|
|
ASSERT(poptex->dwThreadId==0);
|
|
ASSERT(poptex->lRecurseCount==0);
|
|
poptex->dwThreadId = dwThreadId;
|
|
poptex->lRecurseCount = 1;
|
|
// lock succeeded
|
|
return poptex->lRecurseCount;
|
|
|
|
// if already owned
|
|
} else {
|
|
|
|
// if owned by this thread
|
|
if (poptex->dwThreadId == dwThreadId) {
|
|
|
|
// just mark that we own it once more
|
|
poptex->lRecurseCount++;
|
|
ASSERT(poptex->lRecurseCount>=1);
|
|
|
|
// lock succeeded
|
|
return poptex->lRecurseCount;
|
|
|
|
// if owned by some other thread
|
|
} else {
|
|
|
|
// give up taking it
|
|
INDEX ctLocked = InterlockedDecrement(&poptex->lLockCount);
|
|
ASSERT(poptex->lLockCount>=-1);
|
|
|
|
// if unlocked in the mean time
|
|
if (ctLocked<0) {
|
|
// NOTE: this has not been tested!
|
|
// ignore sent the signal
|
|
ResetEvent(poptex->hEvent);
|
|
}
|
|
|
|
// lock failed
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
INDEX OPTEX_Leave (POPTEX poptex)
|
|
{
|
|
|
|
ASSERT(poptex->dwThreadId==GetCurrentThreadId());
|
|
|
|
// we own in one time less
|
|
poptex->lRecurseCount--;
|
|
ASSERT(poptex->lRecurseCount>=0);
|
|
INDEX ctResult = poptex->lRecurseCount;
|
|
|
|
// if more multiple locks from this thread
|
|
if (poptex->lRecurseCount > 0) {
|
|
|
|
// just decrement the lock count
|
|
InterlockedDecrement(&poptex->lLockCount);
|
|
ASSERT(poptex->lLockCount>=-1);
|
|
|
|
// if no more multiple locks from this thread
|
|
} else {
|
|
|
|
// mark that this thread doesn't own it
|
|
poptex->dwThreadId = 0;
|
|
// decrement the lock count
|
|
INDEX ctLocked = InterlockedDecrement(&poptex->lLockCount);
|
|
ASSERT(poptex->lLockCount>=-1);
|
|
// if some threads are waiting for it
|
|
if ( ctLocked >= 0) {
|
|
// wake one of them
|
|
SetEvent(poptex->hEvent);
|
|
}
|
|
}
|
|
|
|
ASSERT(poptex->lRecurseCount>=0);
|
|
ASSERT(poptex->lLockCount>=-1);
|
|
return ctResult;
|
|
}
|
|
|
|
// these are just wrapper classes for locking/unlocking
|
|
|
|
CTCriticalSection::CTCriticalSection(void)
|
|
{
|
|
// index must be set before using the mutex
|
|
cs_iIndex = -2;
|
|
cs_pvObject = new OPTEX;
|
|
OPTEX_Initialize((OPTEX*)cs_pvObject);
|
|
}
|
|
CTCriticalSection::~CTCriticalSection(void)
|
|
{
|
|
OPTEX_Delete((OPTEX*)cs_pvObject);
|
|
delete (OPTEX*)cs_pvObject;
|
|
}
|
|
INDEX CTCriticalSection::Lock(void)
|
|
{
|
|
return OPTEX_Enter((OPTEX*)cs_pvObject);
|
|
}
|
|
INDEX CTCriticalSection::TryToLock(void)
|
|
{
|
|
return OPTEX_TryToEnter((OPTEX*)cs_pvObject);
|
|
}
|
|
INDEX CTCriticalSection::Unlock(void)
|
|
{
|
|
return OPTEX_Leave((OPTEX*)cs_pvObject);
|
|
}
|
|
|
|
CTSingleLock::CTSingleLock(CTCriticalSection *pcs, BOOL bLock) : sl_cs(*pcs)
|
|
{
|
|
// initially not locked
|
|
sl_bLocked = FALSE;
|
|
sl_iLastLockedIndex = -2;
|
|
// critical section must have index assigned
|
|
ASSERT(sl_cs.cs_iIndex>=1||sl_cs.cs_iIndex==-1);
|
|
// if should lock immediately
|
|
if (bLock) {
|
|
Lock();
|
|
}
|
|
}
|
|
CTSingleLock::~CTSingleLock(void)
|
|
{
|
|
// if locked
|
|
if (sl_bLocked) {
|
|
// unlock
|
|
Unlock();
|
|
}
|
|
}
|
|
void CTSingleLock::Lock(void)
|
|
{
|
|
// must not be locked
|
|
ASSERT(!sl_bLocked);
|
|
ASSERT(sl_iLastLockedIndex==-2);
|
|
|
|
// if not locked
|
|
if (!sl_bLocked) {
|
|
// lock
|
|
INDEX ctLocks = sl_cs.Lock();
|
|
// if this mutex was not locked already
|
|
if (ctLocks==1) {
|
|
// check that locking in given order
|
|
if (sl_cs.cs_iIndex!=-1) {
|
|
ASSERT(_iLastLockedMutex<sl_cs.cs_iIndex);
|
|
sl_iLastLockedIndex = _iLastLockedMutex;
|
|
_iLastLockedMutex = sl_cs.cs_iIndex;
|
|
}
|
|
}
|
|
}
|
|
sl_bLocked = TRUE;
|
|
}
|
|
|
|
BOOL CTSingleLock::TryToLock(void)
|
|
{
|
|
// must not be locked
|
|
ASSERT(!sl_bLocked);
|
|
// if not locked
|
|
if (!sl_bLocked) {
|
|
// if can lock
|
|
INDEX ctLocks = sl_cs.TryToLock();
|
|
if (ctLocks>=1) {
|
|
sl_bLocked = TRUE;
|
|
|
|
// if this mutex was not locked already
|
|
if (ctLocks==1) {
|
|
// check that locking in given order
|
|
if (sl_cs.cs_iIndex!=-1) {
|
|
ASSERT(_iLastLockedMutex<sl_cs.cs_iIndex);
|
|
sl_iLastLockedIndex = _iLastLockedMutex;
|
|
_iLastLockedMutex = sl_cs.cs_iIndex;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return sl_bLocked;
|
|
}
|
|
BOOL CTSingleLock::IsLocked(void)
|
|
{
|
|
return sl_bLocked;
|
|
}
|
|
|
|
void CTSingleLock::Unlock(void)
|
|
{
|
|
// must be locked
|
|
ASSERT(sl_bLocked);
|
|
// if locked
|
|
if (sl_bLocked) {
|
|
// unlock
|
|
INDEX ctLocks = sl_cs.Unlock();
|
|
// if unlocked completely
|
|
if (ctLocks==0) {
|
|
// check that unlocking in exact reverse order
|
|
if (sl_cs.cs_iIndex!=-1) {
|
|
ASSERT(_iLastLockedMutex==sl_cs.cs_iIndex);
|
|
_iLastLockedMutex = sl_iLastLockedIndex;
|
|
sl_iLastLockedIndex = -2;
|
|
}
|
|
}
|
|
}
|
|
sl_bLocked = FALSE;
|
|
}
|
|
|
|
#endif //PLATFORM_WIN32
|