audiopolicy: Synchronize calls to Effects state
Synchronize calls that might access Effects state (alternate approach)
Bug: 26516500
Change-Id: Ie03de9c67232e0ac7f5db5cbfe87ec058acbfc8e
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 160f4f0..a91c560 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -553,6 +553,10 @@
mutable Mutex mLock; // prevents concurrent access to AudioPolicy manager functions changing
// device connection state or routing
+ mutable Mutex mEffectsLock; // serialize access to Effect state within APM.
+ // Note: lock acquisition order is always mLock > mEffectsLock:
+ // mLock protects AudioPolicyManager methods that can call into audio flinger
+ // and possibly back in to audio policy service and acquire mEffectsLock.
sp<AudioCommandThread> mAudioCommandThread; // audio commands thread
sp<AudioCommandThread> mTonePlaybackThread; // tone playback thread
sp<AudioCommandThread> mOutputCommandThread; // process stop and release output