Ensure torch.futures.wait_all exits early on error. (#53953)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53953
torch.futures.wait_all, would wait for all specified futures to
complete before it returned. As a result, if there was an error it would still
wait for a long time (ex: long running RPCs) before it returned an error to the
user.
This PR ensures `wait_all` returns and error as soon as any future runs into an
error and doesn't wait for all futures to complete.
I removed the logic _invoke_rpc_python_udf which raised an error in the unwrap
function, because ideally the error should be set on the Future and not be
raised to the user only when `wait()` is called. As an example, in the case of
`wait_all`, the user never calls `wait()` on the future that errored out but a
future down the chain and we should propagate these errors via `setError`
instead.
ghstack-source-id: 124721216
Test Plan:
1) Unit test added.
2) waitforbuildbot
Reviewed By: mrshenli
Differential Revision: D27032362
fbshipit-source-id: c719e2277c27ff3d45f1511d5dc6f1f71a03e3a8
