Merge "AudioFlinger: Use atomic pointer for AudioFlinger singleton." (b3bd0a07) · Commits · e / os / android_frameworks_av

services/audioflinger/AudioFlinger.cpp

+4 −9

Original line number	Diff line number	Diff line
		@@ -128,9 +128,6 @@ uint32_t AudioFlinger::mScreenState;
		// we define a minimum time during which a global effect is considered enabled.
		static const nsecs_t kMinGlobalEffectEnabletimeNs = seconds(7200);

		Mutex gLock;
		wp<AudioFlinger> gAudioFlinger;

		// Keep a strong reference to media.log service around forever.
		// The service is within our parent process so it can never die in a way that we could observe.
		// These two variables are const after initialization.
		@@ -268,7 +265,7 @@ void AudioFlinger::onFirstRef()

		mMode = AUDIO_MODE_NORMAL;

		gAudioFlinger = this;
		gAudioFlinger = this; // we are already refcounted, store into atomic pointer.

		mDevicesFactoryHalCallback = new DevicesFactoryHalCallbackImpl;
		mDevicesFactoryHal->setCallbackOnce(mDevicesFactoryHalCallback);
		@@ -325,11 +322,9 @@ status_t MmapStreamInterface::openMmapStream(MmapStreamInterface::stream_directi
		sp<MmapStreamInterface>& interface,
		audio_port_handle_t *handle)
		{
		sp<AudioFlinger> af;
		{
		Mutex::Autolock _l(gLock);
		af = gAudioFlinger.promote();
		}
		// TODO: Use ServiceManager to get IAudioFlinger instead of by atomic pointer.
		// This allows moving oboeservice (AAudio) to a separate process in the future.
		sp<AudioFlinger> af = AudioFlinger::gAudioFlinger.load(); // either nullptr or singleton AF.
		status_t ret = NO_INIT;
		if (af != 0) {
		ret = af->openMmapStream(

services/audioflinger/AudioFlinger.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -306,6 +306,24 @@ private:
		Mutex mUnregisteredWritersLock;

		public:
		// Life cycle of gAudioFlinger and AudioFlinger:
		//
		// AudioFlinger is created once and survives until audioserver crashes
		// irrespective of sp<> and wp<> as it is refcounted by ServiceManager and we
		// don't issue a ServiceManager::tryUnregisterService().
		//
		// gAudioFlinger is an atomic pointer set on AudioFlinger::onFirstRef().
		// After this is set, it is safe to obtain a wp<> or sp<> from it as the
		// underlying object does not go away.
		//
		// Note: For most inner classes, it is acceptable to hold a reference to the outer
		// AudioFlinger instance as creation requires AudioFlinger to exist in the first place.
		//
		// An atomic here ensures underlying writes have completed before setting
		// the pointer. Access by memory_order_seq_cst.
		//

		static inline std::atomic<AudioFlinger *> gAudioFlinger = nullptr;

		class SyncEvent;

services/audioflinger/Effects.cpp

+3 −13

Original line number	Diff line number	Diff line
		@@ -2785,11 +2785,7 @@ status_t AudioFlinger::EffectChain::EffectCallback::createEffectHal(
		const effect_uuid_t *pEffectUuid, int32_t sessionId, int32_t deviceId,
		sp<EffectHalInterface> *effect) {
		status_t status = NO_INIT;
		sp<AudioFlinger> af = mAudioFlinger.promote();
		if (af == nullptr) {
		return status;
		}
		sp<EffectsFactoryHalInterface> effectsFactory = af->getEffectsFactory();
		sp<EffectsFactoryHalInterface> effectsFactory = mAudioFlinger.getEffectsFactory();
		if (effectsFactory != 0) {
		status = effectsFactory->createEffect(pEffectUuid, sessionId, io(), deviceId, effect);
		}
		@@ -2798,19 +2794,13 @@ status_t AudioFlinger::EffectChain::EffectCallback::createEffectHal(

		bool AudioFlinger::EffectChain::EffectCallback::updateOrphanEffectChains(
		const sp<AudioFlinger::EffectBase>& effect) {
		sp<AudioFlinger> af = mAudioFlinger.promote();
		if (af == nullptr) {
		return false;
		}
		// in EffectChain context, an EffectBase is always from an EffectModule so static cast is safe
		return af->updateOrphanEffectChains(effect->asEffectModule());
		return mAudioFlinger.updateOrphanEffectChains(effect->asEffectModule());
		}

		status_t AudioFlinger::EffectChain::EffectCallback::allocateHalBuffer(
		size_t size, sp<EffectBufferHalInterface>* buffer) {
		sp<AudioFlinger> af = mAudioFlinger.promote();
		LOG_ALWAYS_FATAL_IF(af == nullptr, "allocateHalBuffer() could not retrieved audio flinger");
		return af->mEffectsFactoryHal->allocateBuffer(size, buffer);
		return mAudioFlinger.mEffectsFactoryHal->allocateBuffer(size, buffer);
		}

		status_t AudioFlinger::EffectChain::EffectCallback::addEffectToHal(

services/audioflinger/Effects.h

+4 −5

Original line number	Diff line number	Diff line
		@@ -524,8 +524,9 @@ private:
		// during construction (but may keep a reference for later promotion).
		EffectCallback(const wp<EffectChain>& owner,
		const wp<ThreadBase>& thread)
		: mChain(owner) {
		setThread(thread);
		: mChain(owner)
		, mThread(thread)
		, mAudioFlinger(*gAudioFlinger) {
		}

		status_t createEffectHal(const effect_uuid_t *pEffectUuid,
		@@ -566,14 +567,12 @@ private:

		void setThread(const wp<ThreadBase>& thread) {
		mThread = thread;
		sp<ThreadBase> p = thread.promote();
		mAudioFlinger = p ? p->mAudioFlinger : nullptr;
		}

		private:
		const wp<EffectChain> mChain;
		mediautils::atomic_wp<ThreadBase> mThread;
		wp<AudioFlinger> mAudioFlinger; // this could be const with some rearrangement.
		AudioFlinger &mAudioFlinger; // implementation detail: outer instance always exists.
		};

		friend class AudioFlinger; // for mThread, mEffects