quartz: Fix deadlock with transform filter, try 2

[Maarten Lankhorst]

Hi Michael,

2008/7/8 Michael Karcher <wine at mkarcher.dialup.fu-berlin.de>:
> Am Montag, den 07.07.2008, 18:22 -0700 schrieb Maarten Lankhorst:
>> Reworks the code so that the lock is taking in the called procedures now.
>
>> +    InputPin *pin = (InputPin *)pTransformFilter->ppPins[0];
>> +
>> +    EnterCriticalSection(&pTransformFilter->csFilter);
>> +    if (pTransformFilter->state == State_Stopped)
>> +    {
>> +        LeaveCriticalSection(&pTransformFilter->csFilter);
>> +        return VFW_E_WRONG_STATE;
>> +    }
>
> I have to admit that I don't know anything about quartz. Are you sure
> you may access pTransformFilter->ppPins[0] before taking the lock?
It's safe, pins are allocated during construction, and the pointers
themselves are not modified since. Doing operations on the pin
requires the lock though.

Cheers,
Maarten.