Quote:
Originally Posted by MysteryX
I'm porting AvsFilterNet to work with AviSynth+ and Visual Studio 2015. The project was never finished; the hard work was done but a few things were missing or done wrong.
Ultim, I was wondering what are the MT issues you're talking about. Now I'm seeing weird things (testing with the latest AVS build).
When running in MT mode 3, the calls are coming from many different threads. When running in MT mode 2, I would expect the GetFrame calls to come from the same threads as the calls to the constructors, but that's not the case. C++ will either "work" or give undefined behaviors, but C# is a lot more thread-aware and won't let it slip by when working with non-thread-safe objects. I'm surprised that C++ code works anyway. I tested MT mode 3 in pure C++ code too and the calls were indeed coming from many different threads.
Also, if the CreateFilter function returns a "FlipVertical" which is MT mode 1, then the plugin also runs in MT mode 1.
Now that I'm testing with AviSynthShader, I'm also seeing something else weird. If I run even without MT mode, my class gets instantiated 6 times? Not sure who is responsible for this.
Better wait until you bring out your next version for testing.
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That you get the calls from different threads in MT mode 3 is normal. 3 only guarantees that the calls are never made at the same time, but none of the MT modes limits the calls to the same thread.
The main MT issue that I'm talking about is exactly the problem you described with FlipVertical. Of course it does not only affect FlipVertical, but any filter whose constructor returns another filter than itself which is of lesser protection. This is the infamous issue #37 in the bugtracker. When this gets solved, it will also allow plugin developers to specify MT modes again without relying on the non-final IScriptEnv2. I am also trying to improve the efficiency of MT mode 3, planning improvements to the threadpool(s), and add automated diagnostics. More details when each of these gets done.