diff options
author | Mathieu Chartier <mathieuc@google.com> | 2014-04-10 10:56:55 -0700 |
---|---|---|
committer | Mathieu Chartier <mathieuc@google.com> | 2014-04-10 12:48:48 -0700 |
commit | b38d483b742eafc7833fac1ebb4fa1481cbac179 (patch) | |
tree | 05437041ee24b89481e9c3ef0be7589fa3e25e44 | |
parent | 22839a631bb3591a1c0037c388d51a4f18b5fb5e (diff) | |
download | art-b38d483b742eafc7833fac1ebb4fa1481cbac179.zip art-b38d483b742eafc7833fac1ebb4fa1481cbac179.tar.gz art-b38d483b742eafc7833fac1ebb4fa1481cbac179.tar.bz2 |
Fix race condition in TransitionCollector.
There was a race condition where if multiple threads were calling
TransitionCollector it could cause a crash due to an invalid
collector transition if another thread did the collector transition
before the SuspendAll.
Bug: 13929101
Change-Id: I8c162a83c1f53d0cbdefab62b0a5bcbb151d6c42
-rw-r--r-- | runtime/gc/heap.cc | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/runtime/gc/heap.cc b/runtime/gc/heap.cc index 91f249a..fcf9fe9 100644 --- a/runtime/gc/heap.cc +++ b/runtime/gc/heap.cc @@ -1408,6 +1408,13 @@ void Heap::TransitionCollector(CollectorType collector_type) { MutexLock mu(self, *gc_complete_lock_); // Ensure there is only one GC at a time. WaitForGcToCompleteLocked(self); + // If someone else beat us to it and changed the collector before we could, exit. + // This is safe to do before the suspend all since we set the collector_type_running_ before + // we exit the loop. If another thread attempts to do the heap transition before we exit, + // then it would get blocked on WaitForGcToCompleteLocked. + if (collector_type == collector_type_) { + return; + } // GC can be disabled if someone has a used GetPrimitiveArrayCritical but not yet released. if (!copying_transition || disable_moving_gc_count_ == 0) { // TODO: Not hard code in semi-space collector? |