MediaSyncEvent: Fix thread safety (93bb5735) · Commits · e / os / android_frameworks_av

services/audioflinger/AudioFlinger.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,7 @@

		#include <timing/MonotonicFrameCounter.h>
		#include <timing/SyncEvent.h>
		#include <timing/SynchronizedRecordState.h>

		#include "FastCapture.h"
		#include "FastMixer.h"

services/audioflinger/RecordTracks.h

+2 −4

Original line number	Diff line number	Diff line
		@@ -109,10 +109,8 @@ private:
		// be dropped and therefore not read by the application.
		sp<audioflinger::SyncEvent> mSyncStartEvent;

		// number of captured frames to drop after the start sync event has been received.
		// when < 0, maximum frames to drop before starting capture even if sync event is
		// not received
		ssize_t mFramesToDrop;
		audioflinger::SynchronizedRecordState
		mSynchronizedRecordState{mSampleRate}; // sampleRate defined in base

		// used by resampler to find source frames
		ResamplerBufferProvider *mResamplerBufferProvider;

services/audioflinger/Threads.cpp

+9 −36

Original line number	Diff line number	Diff line
		@@ -8222,7 +8222,11 @@ reacquire_wakelock:
		overrun = OVERRUN_FALSE;
		}

		if (activeTrack->mFramesToDrop == 0) {
		// MediaSyncEvent handling: Synchronize AudioRecord to AudioTrack completion.
		const ssize_t framesToDrop =
		activeTrack->mSynchronizedRecordState.updateRecordFrames(framesOut);
		if (framesToDrop == 0) {
		// no sync event, process normally, otherwise ignore.
		if (framesOut > 0) {
		activeTrack->mSink.frameCount = framesOut;
		// Sanitize before releasing if the track has no access to the source data
		@@ -8232,28 +8236,7 @@ reacquire_wakelock:
		}
		activeTrack->releaseBuffer(&activeTrack->mSink);
		}
		} else {
		// FIXME could do a partial drop of framesOut
		if (activeTrack->mFramesToDrop > 0) {
		activeTrack->mFramesToDrop -= (ssize_t)framesOut;
		if (activeTrack->mFramesToDrop <= 0) {
		activeTrack->clearSyncStartEvent();
		}
		} else {
		activeTrack->mFramesToDrop += framesOut;
		if (activeTrack->mFramesToDrop >= 0 \|\| activeTrack->mSyncStartEvent == 0 \|\|
		activeTrack->mSyncStartEvent->isCancelled()) {
		ALOGW("Synced record %s, session %d, trigger session %d",
		(activeTrack->mFramesToDrop >= 0) ? "timed out" : "cancelled",
		activeTrack->sessionId(),
		(activeTrack->mSyncStartEvent != 0) ?
		activeTrack->mSyncStartEvent->triggerSession() :
		AUDIO_SESSION_NONE);
		activeTrack->clearSyncStartEvent();
		}
		}
		}

		if (framesOut == 0) {
		break;
		}
		@@ -8586,20 +8569,10 @@ status_t AudioFlinger::RecordThread::start(RecordThread::RecordTrack* recordTrac
		if (event == AudioSystem::SYNC_EVENT_NONE) {
		recordTrack->clearSyncStartEvent();
		} else if (event != AudioSystem::SYNC_EVENT_SAME) {
		recordTrack->mSyncStartEvent = mAudioFlinger->createSyncEvent(event,
		triggerSession,
		recordTrack->sessionId(),
		syncStartEventCallback,
		recordTrack);
		// Sync event can be cancelled by the trigger session if the track is not in a
		// compatible state in which case we start record immediately
		if (recordTrack->mSyncStartEvent->isCancelled()) {
		recordTrack->clearSyncStartEvent();
		} else {
		// do not wait for the event for more than AudioSystem::kSyncRecordStartTimeOutMs
		recordTrack->mFramesToDrop = -(ssize_t)
		((AudioSystem::kSyncRecordStartTimeOutMs * recordTrack->mSampleRate) / 1000);
		}
		recordTrack->mSynchronizedRecordState.startRecording(
		mAudioFlinger->createSyncEvent(
		event, triggerSession,
		recordTrack->sessionId(), syncStartEventCallback, recordTrack));
		}

		{

services/audioflinger/Tracks.cpp

+13 −15

Original line number	Diff line number	Diff line
		@@ -1615,6 +1615,7 @@ void AudioFlinger::PlaybackThread::Track::triggerEvents(AudioSystem::sync_event_
		{
		for (auto it = mSyncEvents.begin(); it != mSyncEvents.end();) {
		if ((*it)->type() == type) {
		ALOGV("%s: triggering SyncEvent type %d", __func__, type);
		(*it)->trigger();
		it = mSyncEvents.erase(it);
		} else {
		@@ -1865,6 +1866,8 @@ void AudioFlinger::PlaybackThread::Track::updateTrackFrameInfo(
		}
		}

		ALOGV("%s: trackFramesReleased:%lld sinkFramesWritten:%lld setDrained: %d",
		__func__, (long long)trackFramesReleased, (long long)sinkFramesWritten, drained);
		mAudioTrackServerProxy->setDrained(drained);
		// Set correction for flushed frames that are not accounted for in released.
		local.mFlushed = mAudioTrackServerProxy->framesFlushed();
		@@ -2399,7 +2402,6 @@ AudioFlinger::RecordThread::RecordTrack::RecordTrack(
		type, portId,
		std::string(AMEDIAMETRICS_KEY_PREFIX_AUDIO_RECORD) + std::to_string(portId)),
		mOverflow(false),
		mFramesToDrop(0),
		mResamplerBufferProvider(NULL), // initialize in case of early constructor exit
		mRecordBufferConverter(NULL),
		mFlags(flags),
		@@ -2601,28 +2603,24 @@ void AudioFlinger::RecordThread::RecordTrack::appendDump(String8& result, bool a
		result.append("\n");
		}

		// This is invoked by SyncEvent callback.
		void AudioFlinger::RecordThread::RecordTrack::handleSyncStartEvent(
		const sp<audioflinger::SyncEvent>& event)
		{
		if (event == mSyncStartEvent) {
		ssize_t framesToDrop = 0;
		size_t framesToDrop = 0;
		sp<ThreadBase> threadBase = mThread.promote();
		if (threadBase != 0) {
		// TODO: use actual buffer filling status instead of 2 buffers when info is available
		// from audio HAL
		framesToDrop = threadBase->mFrameCount * 2;
		}
		mFramesToDrop = framesToDrop;
		}

		mSynchronizedRecordState.onPlaybackFinished(event, framesToDrop);
		}

		void AudioFlinger::RecordThread::RecordTrack::clearSyncStartEvent()
		{
		if (mSyncStartEvent != 0) {
		mSyncStartEvent->cancel();
		mSyncStartEvent.clear();
		}
		mFramesToDrop = 0;
		mSynchronizedRecordState.clear();
		}

		void AudioFlinger::RecordThread::RecordTrack::updateTrackFrameInfo(

services/audioflinger/timing/SynchronizedRecordState.h

0 → 100644

+112 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2023 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#pragma once

		#include "SyncEvent.h"

		#pragma push_macro("LOG_TAG")
		#undef LOG_TAG
		#define LOG_TAG "SynchronizedRecordState"

		namespace android::audioflinger {

		class SynchronizedRecordState {
		public:
		explicit SynchronizedRecordState(uint32_t sampleRate)
		: mSampleRate(sampleRate)
		{}

		void clear() {
		std::lock_guard lg(mLock);
		clear_l();
		}

		// Called by the RecordThread when recording is starting.
		void startRecording(const sp<SyncEvent>& event) {
		std::lock_guard lg(mLock);
		mSyncStartEvent = event;
		// Sync event can be cancelled by the trigger session if the track is not in a
		// compatible state in which case we start record immediately
		if (mSyncStartEvent->isCancelled()) {
		clear_l();
		} else {
		mFramesToDrop = -(ssize_t)
		((AudioSystem::kSyncRecordStartTimeOutMs * mSampleRate) / 1000);
		}
		}

		// Invoked by SyncEvent callback.
		void onPlaybackFinished(const sp<SyncEvent>& event, size_t framesToDrop = 1) {
		std::lock_guard lg(mLock);
		if (event == mSyncStartEvent) {
		mFramesToDrop = framesToDrop; // compute this
		ALOGV("%s: framesToDrop:%zd", __func__, mFramesToDrop);
		}
		}

		// Returns the current FramesToDrop counter
		//
		// if <0 waiting (drop the frames)
		// if >0 draining (drop the frames)
		// else if ==0 proceed to record.
		ssize_t updateRecordFrames(size_t frames) {
		std::lock_guard lg(mLock);
		if (mFramesToDrop > 0) {
		// we've been triggered, we count down for start delay
		ALOGV("%s: trigger countdown %zd by %zu frames", __func__, mFramesToDrop, frames);
		mFramesToDrop -= (ssize_t)frames;
		if (mFramesToDrop <= 0) clear_l();
		} else if (mFramesToDrop < 0) {
		// we're waiting to be triggered.
		// ALOGD("%s: timeout countup %zd with %zu frames", __func__, mFramesToDrop, frames);
		mFramesToDrop += (ssize_t)frames;
		if (mFramesToDrop >= 0 \|\| !mSyncStartEvent \|\| mSyncStartEvent->isCancelled()) {
		ALOGW("Synced record %s, trigger session %d",
		(mFramesToDrop >= 0) ? "timed out" : "cancelled",
		(mSyncStartEvent) ? mSyncStartEvent->triggerSession()
		: AUDIO_SESSION_NONE);
		clear_l();
		}
		}
		return mFramesToDrop;
		}

		private:
		const uint32_t mSampleRate;

		std::mutex mLock;
		// number of captured frames to drop after the start sync event has been received.
		// when < 0, maximum frames to drop before starting capture even if sync event is
		// not received
		ssize_t mFramesToDrop GUARDED_BY(mLock) = 0;

		// sync event triggering actual audio capture. Frames read before this event will
		// be dropped and therefore not read by the application.
		sp<SyncEvent> mSyncStartEvent GUARDED_BY(mLock);

		void clear_l() REQUIRES(mLock) {
		if (mSyncStartEvent) {
		mSyncStartEvent->cancel();
		mSyncStartEvent.clear();
		}
		mFramesToDrop = 0;
		}
		};

		} // namespace android::audioflinger

		#pragma pop_macro("LOG_TAG")