Avoid deadlock between recognition events and SoundTriggerHwService.
If an event is generated from the HAL on a separate thread, it is
possible to enter a deadlocked state. This is due to the HAL typically
holding a lock when it starts the callback, which then needed to grab
the SoundTriggerHwService's main lock. However, if there was another
call coming down from somewhere else in the framework, it typically
tries to grab the service's main lock, then enter the HAL (which also
will likely try to grab a lock).
By removing the need to grab the mServiceLock on any of the paths that
respond to events generated by the HAL, this deadlock can be avoided.
Test: Manually on device.
Change-Id: Iac5f96ea67f618ce70e7f75300165f3588613947
diff --git a/services/soundtrigger/SoundTriggerHwService.h b/services/soundtrigger/SoundTriggerHwService.h
index 95efc4b..a955f40 100644
--- a/services/soundtrigger/SoundTriggerHwService.h
+++ b/services/soundtrigger/SoundTriggerHwService.h
@@ -214,11 +214,11 @@
};
static void recognitionCallback(struct sound_trigger_recognition_event *event, void *cookie);
- sp<IMemory> prepareRecognitionEvent_l(struct sound_trigger_recognition_event *event);
+ sp<IMemory> prepareRecognitionEvent(struct sound_trigger_recognition_event *event);
void sendRecognitionEvent(struct sound_trigger_recognition_event *event, Module *module);
static void soundModelCallback(struct sound_trigger_model_event *event, void *cookie);
- sp<IMemory> prepareSoundModelEvent_l(struct sound_trigger_model_event *event);
+ sp<IMemory> prepareSoundModelEvent(struct sound_trigger_model_event *event);
void sendSoundModelEvent(struct sound_trigger_model_event *event, Module *module);
sp<IMemory> prepareServiceStateEvent_l(sound_trigger_service_state_t state);
@@ -226,7 +226,7 @@
void sendServiceStateEvent_l(sound_trigger_service_state_t state,
ModuleClient *moduleClient);
- void sendCallbackEvent_l(const sp<CallbackEvent>& event);
+ void sendCallbackEvent(const sp<CallbackEvent>& event);
void onCallbackEvent(const sp<CallbackEvent>& event);
private:
@@ -238,6 +238,7 @@
DefaultKeyedVector< sound_trigger_module_handle_t, sp<Module> > mModules;
sp<CallbackThread> mCallbackThread;
sp<MemoryDealer> mMemoryDealer;
+ Mutex mMemoryDealerLock;
bool mCaptureState;
};