Summary:
This patch unifies the behavior of BlockingMutex on linux and mac,
resolving problems that can arise when BlockingMutex is used in
code shared by the two platforms but has different behavior depending
on the platform.
No longer requires that the calling thread own the mutex for
CheckLocked calls to pass.
Reviewers: dvyukov, kubamracek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29728
llvm-svn: 294614
2f1f1616ae