Merge "Throttle MixerThread data pull to no more than twice expected rate" into mnc-dev (9cf332ca) · Commits · e / os / android_frameworks_av

services/audioflinger/Threads.cpp

+35 −3

Original line number	Diff line number	Diff line
		@@ -2191,6 +2191,10 @@ void AudioFlinger::PlaybackThread::readOutputParameters_l()
		ALOGI("HAL output buffer size %u frames, normal sink buffer size %u frames", mFrameCount,
		mNormalFrameCount);

		// Check if we want to throttle the processing to no more than 2x normal rate
		mThreadThrottle = property_get_bool("af.thread.throttle", true /* default_value */);
		mHalfBufferMs = mNormalFrameCount * 1000 / (2 * mSampleRate);

		// mSinkBuffer is the sink buffer. Size is always multiple-of-16 frames.
		// Originally this was int16_t[] array, need to remove legacy implications.
		free(mSinkBuffer);
		@@ -2908,8 +2912,9 @@ bool AudioFlinger::PlaybackThread::threadLoop()
		if (!waitingAsyncCallback()) {
		// mSleepTimeUs == 0 means we must write to audio hardware
		if (mSleepTimeUs == 0) {
		ssize_t ret = 0;
		if (mBytesRemaining) {
		ssize_t ret = threadLoop_write();
		ret = threadLoop_write();
		if (ret < 0) {
		mBytesRemaining = 0;
		} else {
		@@ -2920,11 +2925,11 @@ bool AudioFlinger::PlaybackThread::threadLoop()
		(mMixerStatus == MIXER_DRAIN_ALL)) {
		threadLoop_drain();
		}
		if (mType == MIXER) {
		if (mType == MIXER && !mStandby) {
		// write blocked detection
		nsecs_t now = systemTime();
		nsecs_t delta = now - mLastWriteTime;
		if (!mStandby && delta > maxPeriod) {
		if (delta > maxPeriod) {
		mNumDelayedWrites++;
		if ((now - lastWarning) > kWarningThrottleNs) {
		ATRACE_NAME("underrun");
		@@ -2933,6 +2938,31 @@ bool AudioFlinger::PlaybackThread::threadLoop()
		lastWarning = now;
		}
		}

		if (mThreadThrottle
		&& mMixerStatus == MIXER_TRACKS_READY // we are mixing (active tracks)
		&& ret > 0) { // we wrote something
		// Limit MixerThread data processing to no more than twice the
		// expected processing rate.
		//
		// This helps prevent underruns with NuPlayer and other applications
		// which may set up buffers that are close to the minimum size, or use
		// deep buffers, and rely on a double-buffering sleep strategy to fill.
		//
		// The throttle smooths out sudden large data drains from the device,
		// e.g. when it comes out of standby, which often causes problems with
		// (1) mixer threads without a fast mixer (which has its own warm-up)
		// (2) minimum buffer sized tracks (even if the track is full,
		// the app won't fill fast enough to handle the sudden draw).

		const int32_t deltaMs = delta / 1000000;
		const int32_t throttleMs = mHalfBufferMs - deltaMs;
		if ((signed)mHalfBufferMs >= throttleMs && throttleMs > 0) {
		usleep(throttleMs * 1000);
		ALOGD("mixer(%p) throttle: ret(%zd) deltaMs(%d) requires sleep %d ms",
		this, ret, deltaMs, throttleMs);
		}
		}
		}

		} else {
		@@ -4023,6 +4053,8 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::MixerThread::prepareTrac
		}
		} else {
		if (framesReady < desiredFrames && !track->isStopped() && !track->isPaused()) {
		ALOGV("track(%p) underrun, framesReady(%zu) < framesDesired(%zd)",
		track, framesReady, desiredFrames);
		track->mAudioTrackServerProxy->tallyUnderrunFrames(desiredFrames);
		}
		// clear effect chain input buffer if an active track underruns to avoid sending

services/audioflinger/Threads.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -613,6 +613,9 @@ protected:
		// updated by readOutputParameters_l()
		size_t mNormalFrameCount; // normal mixer and effects

		bool mThreadThrottle; // throttle the thread processing
		uint32_t mHalfBufferMs; // half the buffer size in milliseconds

		void* mSinkBuffer; // frame size aligned sink buffer

		// TODO: