Does the debug device support `ANARI_KHR_DEVICE_SYNCHRONIZATION`?

[stukowski]

It looks like the implementation of DebugDevice::newObjectHandle is not thread-safe. So I was wondering: Does the debug layer fully support the ANARI_KHR_DEVICE_SYNCHRONIZATION extension (given the wrapped device does support it)?

I am asking because I am observing occasional segfaults in multi-threaded application code that constructs ANARI scene objects.

[jeffamstutz]

It currently isn't thread safe, but really should be. The visgl device takes an approach that would work generically by putting all ANARI calls on a background thread, but that would need to be ported to the debug device. It's actually possible for that to be a generic layer, making it usable in more contexts. This is a good request to prioritize -- we will see where this can be worked on, but no time estimate just yet.

[stukowski]

Thanks. This is not urgent. I can continue without the debug layer for some time.

I had hoped that it would be sufficient to simply guard the DebugDevice::objects and DebugDevice::objectMap fields against concurrent accesses using an internal mutex. But maybe that would cost too much performance or the situation is more complicated than I think. I have not delved any deeper into the inner workings of the debug layer.