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don't increment the lock count twice in RtlTryEnterCriticalSection() and added some more comments
svn path=/trunk/; revision=13642
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@ -305,27 +305,33 @@ STDCALL
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RtlLeaveCriticalSection(
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PRTL_CRITICAL_SECTION CriticalSection)
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{
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#ifndef NDEBUG
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HANDLE Thread = (HANDLE)NtCurrentTeb()->Cid.UniqueThread;
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/* In win this case isn't checked. However it's a valid check so it should only
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be performed in debug builds! */
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if (Thread != CriticalSection->OwningThread)
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{
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DPRINT1("Releasing critical section not owned!\n");
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/* FIXME: raise exception */
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return STATUS_INVALID_PARAMETER;
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}
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#endif
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/* Decrease the Recursion Count */
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/* Decrease the Recursion Count. No need to do this atomically because only
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the thread who holds the lock can call this function (unless the program
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is totally screwed... */
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if (--CriticalSection->RecursionCount) {
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/* Someone still owns us, but we are free */
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/* Someone still owns us, but we are free. This needs to be done atomically. */
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InterlockedDecrement(&CriticalSection->LockCount);
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} else {
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/* Nobody owns us anymore */
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/* Nobody owns us anymore. No need to do this atomically. See comment
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above. */
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CriticalSection->OwningThread = 0;
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/* Was someone wanting us? */
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/* Was someone wanting us? This needs to be done atomically. */
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if (InterlockedDecrement(&CriticalSection->LockCount) >= 0) {
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/* Let him have us */
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@ -360,19 +366,19 @@ RtlTryEnterCriticalSection(
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PRTL_CRITICAL_SECTION CriticalSection)
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{
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/* Try to take control */
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if (InterlockedCompareExchange(&CriticalSection->LockCount,
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0,
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-1) == -1) {
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if (InterlockedCompareExchange(&CriticalSection->LockCount, 0, -1) == -1) {
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/* It's ours */
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/* It's ours. Changing this information does not have to be serialized
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because we just obtained the lock. */
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CriticalSection->OwningThread = NtCurrentTeb()->Cid.UniqueThread;
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CriticalSection->RecursionCount = 1;
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return TRUE;
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} else if (CriticalSection->OwningThread == NtCurrentTeb()->Cid.UniqueThread) {
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/* It's already ours */
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InterlockedIncrement(&CriticalSection->LockCount);
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/* It's already ours, just increment the recursion counter. This doesn't
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have to be serialized because only the thread who already holds the
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lock can do this. */
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CriticalSection->RecursionCount++;
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return TRUE;
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}
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