pytorch

5b321a09 - [rpc] make handling of FORWARD_AUTOGRAD_REQ in request_callback_impl (#32476)

[rpc] make handling of FORWARD_AUTOGRAD_REQ in request_callback_impl (#32476) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/32476 This makes the handling of FORWARD_AUTOGRAD_REQ in request_callback nonblocking. Processing this message requires unwrapping the message with autograd information, processing the original message, and sending back the message with autograd information wrapped. This makes the processing the original message nonblocking by grabbing a future to it and marking the parent future as completed when this one completes. ghstack-source-id: 97221251 Test Plan: `test_rpc_spawn.py` and `test_dist_autograd_spawn.py` both pass. Differential Revision: D19509501 fbshipit-source-id: 84ad2f9c5305ed11ed9bb0144b1aaf5f8698cd2b