2008/6/23 Maarten Lankhorst <[EMAIL PROTECTED]>:
> @@ -286,19 +287,24 @@ static HRESULT WINAPI
> BaseMemAllocator_GetBuffer(IMemAllocator * iface, IMediaSa
>
> *pSample = NULL;
>
> - if (!This->bCommitted)
> - return VFW_E_NOT_COMMITTED;
> + EnterCriticalSection(This->pCritSect);
> + if (!This->bCommitted || This->bDecommitQueued)
> + hr = VFW_E_NOT_COMMITTED;
> + else
> + ++This->lWaiting;
> + LeaveCriticalSection(This->pCritSect);
> + if (FAILED(hr))
> + return hr;
>
> - This->lWaiting++;
> if (WaitForSingleObject(This->hSemWaiting, (dwFlags & AM_GBF_NOWAIT) ? 0
> : INFINITE) != WAIT_OBJECT_0)
> {
> - This->lWaiting--;
> + InterlockedDecrement(&This->lWaiting);
> return VFW_E_TIMEOUT;
> }
> - This->lWaiting--;
>
> EnterCriticalSection(This->pCritSect);
> {
> + --This->lWaiting;
> if (!This->bCommitted)
> hr = VFW_E_NOT_COMMITTED;
> else if (This->bDecommitQueued)
Just because you increment a variable inside a critical section, it
doesn't mean that it's safe against another thread using
InterlockedIncrement/Decrement on it. Either only change the variable
inside a critical section or only change it using interlocked
functions.
--
Rob Shearman
