AudioFlinger: Prevent offload underrun during active playback (cc43d161) · Commits · e / os / android_frameworks_av

services/audioflinger/Threads.cpp

+27 −7

Original line number	Diff line number	Diff line
		@@ -5184,7 +5184,8 @@ void AudioFlinger::AsyncCallbackThread::resetDraining()
		AudioFlinger::OffloadThread::OffloadThread(const sp<AudioFlinger>& audioFlinger,
		AudioStreamOut* output, audio_io_handle_t id, uint32_t device, bool systemReady)
		: DirectOutputThread(audioFlinger, output, id, device, OFFLOAD, systemReady),
		mPausedWriteLength(0), mPausedBytesRemaining(0), mKeepWakeLock(true)
		mPausedWriteLength(0), mPausedBytesRemaining(0), mKeepWakeLock(true),
		mOffloadUnderrunPosition(~0LL)
		{
		//FIXME: mStandby should be set to true by ThreadBase constructor
		mStandby = true;
		@@ -5390,12 +5391,30 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::OffloadThread::prepareTr
		// No buffers for this track. Give it a few chances to
		// fill a buffer, then remove it from active list.
		if (--(track->mRetryCount) <= 0) {
		bool running = false;
		if (mOutput->stream->get_presentation_position != nullptr) {
		uint64_t position = 0;
		struct timespec unused;
		// The running check restarts the retry counter at least once.
		int ret = mOutput->stream->get_presentation_position(
		mOutput->stream, &position, &unused);
		if (ret == NO_ERROR && position != mOffloadUnderrunPosition) {
		running = true;
		mOffloadUnderrunPosition = position;
		}
		ALOGVV("underrun counter, running(%d): %lld vs %lld", running,
		(long long)position, (long long)mOffloadUnderrunPosition);
		}
		if (running) { // still running, give us more time.
		track->mRetryCount = kMaxTrackRetriesOffload;
		} else {
		ALOGV("OffloadThread: BUFFER TIMEOUT: remove(%d) from active list",
		track->name());
		tracksToRemove->add(track);
		// indicate to client process that the track was disabled because of underrun;
		// it will then automatically call start() when data is available
		track->disable();
		}
		} else if (last){
		mixerStatus = MIXER_TRACKS_ENABLED;
		}
		@@ -5452,6 +5471,7 @@ void AudioFlinger::OffloadThread::flushHw_l()
		mPausedBytesRemaining = 0;
		// reset bytes written count to reflect that DSP buffers are empty after flush.
		mBytesWritten = 0;
		mOffloadUnderrunPosition = ~0LL;

		if (mUseAsyncWrite) {
		// discard any pending drain or write ack by incrementing sequence

services/audioflinger/Threads.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -1009,6 +1009,10 @@ private:
		size_t mPausedWriteLength; // length in bytes of write interrupted by pause
		size_t mPausedBytesRemaining; // bytes still waiting in mixbuffer after resume
		bool mKeepWakeLock; // keep wake lock while waiting for write callback
		uint64_t mOffloadUnderrunPosition; // Current frame position for offloaded playback
		// used and valid only during underrun. ~0 if
		// no underrun has occurred during playback and
		// is not reset on standby.
		};

		class AsyncCallbackThread : public Thread {