pytorch

fd0f9811 - add timeout for RPC futures, and ability to set timeout when initializing rpc (#28392)

add timeout for RPC futures, and ability to set timeout when initializing rpc (#28392) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/28392 Per #25531, we want to clean up futures when we detect that there are failures/timeouts. As a first step, this diff adds timers to the future object, provides functionality to check if a future is timed out, and allows specification of the timeout when initializing rpc. A future diff will check for these timeouts and mark the future completed with an exception indicating that it has timed out. ghstack-source-id: 93192622 Test Plan: Added unit tests. Differential Revision: D18025163 fbshipit-source-id: 195fb50c736caf5c7b2bada9a5f6116bb106ed33