Multithreaded shader compilation

[daniilvinn]

Hello everyone! I am switching from shaderc to Slang and want to know if it is possible to make a multithreaded compilation of multiple independent .slang files (though they may share some other .slang file, say Common.slang) using a single global session?

On my machine, it takes from 0.18s to 0.5s to init a global session, and as I understand, the creation of a global session basically means loading a Slang.dll and other dynamic libraries.

Since global session init takes quite a lot of time, I wouldn't want to create a global session per shader, nor would I want to create a global session per thread (if it's even possible).

If I can safely reuse a single global session for concurrent shader compilation on multiple threads, do I need to create a local session per shader?

[csyonghe]

At the moment we don't support calling global session functions concurrently, so you will still need to create one global session per thread, or use a pool of global sessions and ensure only one thread is using a global session at a time.

We would like to improve this situation by allowing sharing a single global session, and allow working on different ISessions concurrently as the next step. However we don't have a timeline for this improvement.

However, if anyone feel like contributing a patch to make the API more multi-threading friendly, we are happy to share more technical details and work together with you to make it happen sooner.

[obfuscate]

We would like to improve this situation by allowing sharing a single global session, and allow working on different ISessions concurrently as the next step. However we don't have a timeline for this improvement.

So, does it mean that using Slang::ComPtr<slang::ISession> session; per thread don't save the situation?

[daniilvinn]

Seems like that. Only a global session per thread.

[obfuscate]

Sounds badly. Thanks for the answer!