tree e4bdff5a4697cf77d550a3c4ecbbddbb1af1a916
parent 197f1ef6f4f2411d011d7e8f696775c3fbcffd86
author Ivan Maidanski <i.maidanski@samsung.com> 1526295048 +0300
committer Mathieu Chartier <mathieuc@google.com> 1528225454 +0000

Fix deadlock between ConcurrentCopying and thread holding dex_lock exclusively

Similar to the issue addressed by
https://android-review.googlesource.com/628465, we observe a deadlock
between

- a thread executing ConcurrentCopying::RevokeThreadLocalMarkStacks
  which has disabled weak references access and waiting for check_point
  barrier;
- a thread which had acquired the mutator lock exclusively and was blocking
  on a condition variable regarding weak references access; and
- a thread which cannot execute the checkpoint until it acquires the
  dex_lock.

This change prevents garbage collection from occurring when dex_lock is held
exclusively.

Bug: 109720594
Test: m test-art-host
Change-Id: I7a7e8e20aada4a9fad344b2f2f45a233639cda14