Any known threading/GIL issues?

[PallHaraldsson]

Compared to e.g. PyCall, FYI: JuliaPy/PyCall.jl#882

[cjdoris]

Not as far as I know. Let me know if you have any specific issues.

[Moelf]

so do we drop GIL when using JuliaCall? One limitation from JuliaPy is that it doesn't drop GIL, so it's slow when trying to Julia via it as backend of some Python packge

[cjdoris]

Yeah calling into Julia from Julia doesn't unlock the GIL. This is because the Julia code could well call back into Python, which would require automatically relocking the GIL, which is all quite complicated and probably slow in general. If you can guarantee your Julia code doesn't call back into Python, you can release the GIL yourself. A future version of JuliaCall will allow something like some_julia_function.jl_call_nogil(x, y, z) to make this a bit easier.

[Moelf]

you can release the GIL yourself.

I don't think you can drop GIL from within normal Python

[cjdoris]

Sure but you can drop it in the Julia code that you're calling.

[Moelf]

how do I do that? "host" is Python, they're using calling Julia function for performance