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author | Eric Laurent <elaurent@google.com> | 2015-09-23 10:25:31 -0700 |
---|---|---|
committer | Christian Bejram <cbejram@google.com> | 2015-10-16 16:48:45 -0700 |
commit | 74ce88ff0f24a8c08fdab3a1140212183089c2b5 (patch) | |
tree | da2c975edfeada4f3d1e2d7ca37cad9ada599f4b | |
parent | 7b80648180feaad1e7edaecd078246f5002a8fb6 (diff) | |
download | frameworks_av-74ce88ff0f24a8c08fdab3a1140212183089c2b5.zip frameworks_av-74ce88ff0f24a8c08fdab3a1140212183089c2b5.tar.gz frameworks_av-74ce88ff0f24a8c08fdab3a1140212183089c2b5.tar.bz2 |
AudioPolicyService: fix race in AudioCommandThread
Fixe race condition in AudioCommandThread::threadLoop() where a
command can be inserted in first position in the queue after the sleep
time has been calculated causing a longer delay than expected.
Also fix a failure to hold a wake lock while commands are still in the queue.
Bug: 22707905.
Change-Id: I813626986677bf00106acb37ee20d3dd75d5cf33
-rw-r--r-- | services/audiopolicy/service/AudioPolicyService.cpp | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp index eefff3d..c77cc45 100644 --- a/services/audiopolicy/service/AudioPolicyService.cpp +++ b/services/audiopolicy/service/AudioPolicyService.cpp @@ -577,22 +577,28 @@ bool AudioPolicyService::AudioCommandThread::threadLoop() } } waitTime = INT64_MAX; + // release mLock before releasing strong reference on the service as + // AudioPolicyService destructor calls AudioCommandThread::exit() which + // acquires mLock. + mLock.unlock(); + svc.clear(); + mLock.lock(); } else { waitTime = mAudioCommands[0]->mTime - curTime; break; } } - // release mLock before releasing strong reference on the service as - // AudioPolicyService destructor calls AudioCommandThread::exit() which acquires mLock. - mLock.unlock(); - svc.clear(); - mLock.lock(); - if (!exitPending() && (mAudioCommands.isEmpty() || waitTime != INT64_MAX)) { - // release delayed commands wake lock + + // release delayed commands wake lock if the queue is empty + if (mAudioCommands.isEmpty()) { release_wake_lock(mName.string()); + } + + // At this stage we have either an empty command queue or the first command in the queue + // has a finite delay. So unless we are exiting it is safe to wait. + if (!exitPending()) { ALOGV("AudioCommandThread() going to sleep"); mWaitWorkCV.waitRelative(mLock, waitTime); - ALOGV("AudioCommandThread() waking up"); } } // release delayed commands wake lock before quitting @@ -1003,6 +1009,8 @@ void AudioPolicyService::AudioCommandThread::exit() requestExit(); mWaitWorkCV.signal(); } + // Note that we can call it from the thread loop if all other references have been released + // but it will safely return WOULD_BLOCK in this case requestExitAndWait(); } |