guard dyndep with a lock (#26153)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26153
I am suspecting that our multithreaded test-system causes issue with dyndep, if two places try to concurrently InitOpsLibrary. So perhaps we just guard this by a lock. This is just a guess-fix, as it is impossible to repro.
Test Plan: sandcastle
Reviewed By: bddppq
Differential Revision: D17361310
fbshipit-source-id: 596634a2098b18881abbd26a5a727a5ba0d03b6e
