pytorch

493a233c - [torch/elastic] Revise the rendezvous handler registry logic. (#55466)

[torch/elastic] Revise the rendezvous handler registry logic. (#55466) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/55466 Improve the implementation and the unit test coverage of `RendezvousHandlerRegistry`. ### Note See the original diff (D27442325 (https://github.com/pytorch/pytorch/commit/df299dbd7d8241669aaac7ce07ed0c034f219b4f)) that had to be reverted due to an unexpected Python version incompatibility between the internal and external PyTorch CI tests. Test Plan: Run the existing and newly-introduced unit tests. Reviewed By: tierex Differential Revision: D27623215 fbshipit-source-id: 51538d0f154f64e04f685a95d40d805b478c93f9