Use a single GPU for proof generation

[mikhailUshakoff]

No description provided.

[Hyodar]

Looks okay to me, but I don't have much context on this!
Left some comments on possible refactorings and some remaining TODO comments.

[Hyodar]

What is this TODO about?

[Hyodar]

Maybe better to do this instead? Not an issue here but usually bad to unnecessarily nest mutex locks.

Suggested change

	{
	let mut gpus = gpus.lock().await;
	gpus.push_back(proof_request.gpu_number.unwrap());
	let mut tasks = tasks.lock().await;
	tasks.remove(&key);
	}
	{
	let mut gpus = gpus.lock().await;
	gpus.push_back(proof_request.gpu_number.unwrap());
	}
	{
	let mut tasks = tasks.lock().await;
	tasks.remove(&key);
	}

[Hyodar]

Fix what?

[Hyodar]

Maybe this? It uses a closure so no need for an explicit drop too. Not a Rust expert though, so must be taken with caution!

Suggested change

	// Set gpu number for task
	if proof_request.gpu_number.is_some() { panic!("GPU number is already set"); }
	let mut available_gpus = self.available_gpus.lock().await;
	if let Some(gpu_number) = available_gpus.pop_front() {
	proof_request.set_gpu_number(Some(gpu_number));
	} else {
	panic!("No available GPU");
	}
	drop(available_gpus);
	proof_request.set_gpu_number(Some({
	proof_request.gpu_number
	.as_ref()
	.inspect(|_| panic!("GPU number is already set"));
	self.available_gpus
	.lock()
	.await
	.pop_front()
	.ok_or_else(|| panic!("No available GPU"))
	}));

[Hyodar]

What is None?