Resolved Are jobs run using IJobExtensions.Run() burst-compiled?

as the topic says

Most of the documentation only mentions that this can be used for debugging purposes but I need the burst compilation on this one job and it also needs to run synchronously on the main thread.

Will it be burst-compiled if I run it using Run() instead of Schedule()?

 

I'd also like to know if running a job this way has an overhead compared to just calling the function.

I'm heavily relying on the manual SIMD-ification using Unity.Mathematics library and so using Burst Compiler is a must, and does give a significant improvement, but I don't know what the overhead of running it on the main thread is.

 

Don't know - don't care. But you can easily test it by placing...

Code (CSharp):

1. if (Unity.Burst.CompilerServices.Constant.IsConstantExpression(1))
2. {
3.     throw new Exception("This was a P/Invoke of a Burst compiled job");
4. }

... in your job struct's

Execute()

, with the

[BurstCompile(CompileSynchronously = true)]

attribute on the IJob struct.

 

did the test

works, Run() compiles the job with burst

 

A more complete, less flippant, answer:

- As you've seen, yes, Run uses the burst compiled version if the job has the burst attribute, burst compilation is enabled, and if the compilation has finished (CompileSynchronously will naturally delay execution to compile on first use)

- Yes there is an overhead compared to calling a regular method. There is (iirc) always a slight cost to transitioning between managed and unmanaged code, but as long as your burst code is doing something substantial, the cost is almost always worth it. I also recall Run having more of an overhead than burst function pointers, but (at the time of writing) the argument restrictions on those can be frustrating enough that Run on a job can still feel preferable.