a3df65dea8
The issue was caused by OSL using TLS which is required to be freed before the Cycles session is freed. This is quite tricky to do in Cycles because different render session are sharing the same task scheduler, so when one session is being freed TLS might need to be active still. In order to solve this, we are now doing JIT optimization ahead of the time which ensures either TLS of JIT is freed before the render on multi-core system or freed on OSLRenderSession destroy on single-core system. This might increase synchronization time due to JIT of unused function, but that we can solve later with some smart idea,