Boolean VNonVirtualCriticalSection::Lock()
{
VTaskID currentTaskID = VTask::GetCurrentID();
do {
VTaskID owner = (VTaskID) VInterlocked::CompareExchange((sLONG*) &fOwner, (sLONG) NULL_TASK_ID, (sLONG) currentTaskID);
if (owner == NULL_TASK_ID)
{
assert(fUseCount == 0);
fUseCount = 1;
}
else if (fOwner == currentTaskID)
{
++fUseCount;
}
else
{
sLONG unlockCount = sUnlockCount;
VSyncEvent* event = VInterlocked::ExchangePtr( &fEvent);
if (event != NULL)
{
event->Retain();
if (VInterlocked::CompareExchangePtr((void **)&fEvent, NULL, event) != NULL)
{
event->Unlock();
event->Release();
VTask::YieldNow();
}
else
{
while (VInterlocked::CompareExchange(&sUnlockCount, sUnlockCount, sUnlockCount) != sUnlockCount)
VTask::YieldNow();
if (sUnlockCount == unlockCount)
event->Lock( 100);
else
VTask::YieldNow();
}
event->Release();
}
else
{
event = new VSyncEvent;
if (VInterlocked::CompareExchangePtr((void **)&fEvent, NULL, event) != NULL)
{
event->Unlock();
event->Release();
VTask::YieldNow();
}
}
}
} while(fOwner != currentTaskID);
return true;
}
Boolean VSmallCriticalSection::Unlock()
{
//assert((fOwner == (sWORD)VTask::GetCurrentID()) && (fUseCount > 0) && (fUseCount < 32000L));
assert(fUseCount > 0);
VSyncEvent* event = NULL;
VInterlocked::Increment(&sUnlockCount);
// Unlock or another successfull lock can only be called from same thead (so no contention can occur on fUseCount)
if (--fUseCount == 0)
{
// capture currently set event
event = VInterlocked::ExchangePtr(&fEvent);
VTaskID owner = VInterlocked::Exchange((sLONG*) &fOwner, (sLONG) 0);
//assert(owner == VTask::GetCurrentID());
if (event != NULL)
{
event->Unlock();
event->Release();
}
}
return true;
}
Boolean VSmallCriticalSection::Lock()
{
sWORD currentTaskID = (sWORD)VTask::GetCurrentID();
LongAsDoubleWord doubleWord;
doubleWord.first = (sWORD)currentTaskID;
doubleWord.second = 0;
do {
sLONG owner = VInterlocked::CompareExchange((sLONG*) &fOwner, (sLONG) 0, *((sLONG*) &doubleWord));
if (owner == 0)
{
assert(fUseCount == 0);
fUseCount = 1;
}
else if (fOwner == currentTaskID)
{
++fUseCount;
}
else
{
sLONG unlockCount = sUnlockCount;
VSyncEvent* event = VInterlocked::ExchangePtr(&fEvent);
if (event != NULL)
{
event->Retain();
if (VInterlocked::CompareExchangePtr((void**)&fEvent, NULL, event) != NULL)
{
event->Unlock();
VTask::YieldNow();
}
else
{
if (sUnlockCount == unlockCount)
event->Lock(100);
else
VTask::YieldNow();
}
event->Release();
}
else
{
event = new VSyncEvent;
if (VInterlocked::CompareExchangePtr((void**)&fEvent, NULL, event) != NULL)
{
event->Release();
VTask::YieldNow();
}
}
}
} while (fOwner != currentTaskID);
return true;
}
Boolean VNonVirtualCriticalSection::Unlock()
{
assert((fOwner == VTask::GetCurrentID()) && (fUseCount > 0) && (fUseCount < 32000L));
//assert(fUseCount > 0);
VSyncEvent* event = NULL;
VInterlocked::Increment(&sUnlockCount);
if (--fUseCount == 0)
{
event = VInterlocked::ExchangePtr(&fEvent);
VTaskID owner = VInterlocked::Exchange((sLONG*) &fOwner, (sLONG) NULL_TASK_ID);
//assert(owner == VTask::GetCurrentID());
if (event != NULL)
{
event->Unlock();
event->Release();
}
}
return true;
}