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Commit ede6c3b8 authored by Eric Laurent's avatar Eric Laurent
Browse files

audioflinger: fix lost offload thread resume event 

It was possible that a resume request signaled by addTrack_l()
while waiting for an async write callback is lost. This is because
mSignalPending was not set and waitingAsyncCallback_l() would pause the
thread loop before executing prepareTracks_l().

The fix consists in using signal_l() method to wake the thread
loop o that mSignalPending is set.

Also make sure that sleepTime is reset to 0 when resuming to make sure
that we write any remaining bytes to the HAL.

Bug: 10810347.

Change-Id: If9a3b22cc3b9e6eb384a56c48c40e6258d0896ad
parent 5baf2af5

services/audioflinger/Threads.cpp

+32 −27
Original line number Diff line number Diff line
@@ -960,6 +960,7 @@ AudioFlinger::PlaybackThread::PlaybackThread(const sp<AudioFlinger>& audioFlinge 
        mUseAsyncWrite(false),

        mWriteAckSequence(0),

        mDrainSequence(0),

        mSignalPending(false),

        mScreenState(AudioFlinger::mScreenState),

        // index 0 is reserved for normal mixer's submix

        mFastTrackAvailMask(((1 << FastMixerState::kMaxFastTracks) - 1) & ~1),
@@ -1348,14 +1349,14 @@ void AudioFlinger::PlaybackThread::setStreamVolume(audio_stream_type_t stream, f 
{

    Mutex::Autolock _l(mLock);

    mStreamTypes[stream].volume = value;

    signal_l();

    broadcast_l();

}



void AudioFlinger::PlaybackThread::setStreamMute(audio_stream_type_t stream, bool muted)

{

    Mutex::Autolock _l(mLock);

    mStreamTypes[stream].mute = muted;

    signal_l();

    broadcast_l();

}



float AudioFlinger::PlaybackThread::streamVolume(audio_stream_type_t stream) const
@@ -1413,8 +1414,8 @@ status_t AudioFlinger::PlaybackThread::addTrack_l(const sp<Track>& track) 
        status = NO_ERROR;

    }



    ALOGV("mWaitWorkCV.broadcast");

    mWaitWorkCV.broadcast();

    ALOGV("signal playback thread");

    broadcast_l();



    return status;

}
@@ -1455,14 +1456,14 @@ void AudioFlinger::PlaybackThread::removeTrack_l(const sp<Track>& track) 
    }

}



void AudioFlinger::PlaybackThread::signal_l()

void AudioFlinger::PlaybackThread::broadcast_l()

{

    // Thread could be blocked waiting for async

    // so signal it to handle state changes immediately

    // If threadLoop is currently unlocked a signal of mWaitWorkCV will

    // be lost so we also flag to prevent it blocking on mWaitWorkCV

    mSignalPending = true;

    mWaitWorkCV.signal();

    mWaitWorkCV.broadcast();

}



String8 AudioFlinger::PlaybackThread::getParameters(const String8& keys)
@@ -2143,7 +2144,6 @@ bool AudioFlinger::PlaybackThread::threadLoop() 
            }



            saveOutputTracks();



            if (mSignalPending) {

                // A signal was raised while we were unlocked

                mSignalPending = false;
@@ -2158,10 +2158,10 @@ bool AudioFlinger::PlaybackThread::threadLoop() 
                acquireWakeLock_l();

                standbyTime = systemTime() + standbyDelay;

                sleepTime = 0;

                if (exitPending()) {

                    break;



                continue;

            }

            } else if ((!mActiveTracks.size() && systemTime() > standbyTime) ||

            if ((!mActiveTracks.size() && systemTime() > standbyTime) ||

                                   isSuspended()) {

                // put audio hardware into standby after short delay

                if (shouldStandby_l()) {
@@ -2203,7 +2203,6 @@ bool AudioFlinger::PlaybackThread::threadLoop() 
                    continue;

                }

            }



            // mMixerStatusIgnoringFastTracks is also updated internally

            mMixerStatus = prepareTracks_l(&tracksToRemove);
@@ -3855,13 +3854,14 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::OffloadThread::prepareTr 
    Vector< sp<Track> > *tracksToRemove

)

{

    ALOGV("OffloadThread::prepareTracks_l");

    size_t count = mActiveTracks.size();



    mixer_state mixerStatus = MIXER_IDLE;

    bool doHwPause = false;

    bool doHwResume = false;



    ALOGV("OffloadThread::prepareTracks_l active tracks %d", count);



    // find out which tracks need to be processed

    for (size_t i = 0; i < count; i++) {

        sp<Track> t = mActiveTracks[i].promote();
@@ -3915,23 +3915,27 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::OffloadThread::prepareTr 
                // make sure processVolume_l() will apply new volume even if 0

                mLeftVolFloat = mRightVolFloat = -1.0;

                if (track->mState == TrackBase::RESUMING) {

                    track->mState = TrackBase::ACTIVE;

                    if (last) {

                        if (mPausedBytesRemaining) {

                            // Need to continue write that was interrupted

                            mCurrentWriteLength = mPausedWriteLength;

                            mBytesRemaining = mPausedBytesRemaining;

                            mPausedBytesRemaining = 0;

                        }

                    track->mState = TrackBase::ACTIVE;

                }

            }



            if (last) {

                        if (mHwPaused) {

                            doHwResume = true;

                            mHwPaused = false;

                            // threadLoop_mix() will handle the case that we need to

                            // resume an interrupted write

                        }

                        // enable write to audio HAL

                        sleepTime = 0;

                    }

                }

            }



            if (last) {

                // reset retry count

                track->mRetryCount = kMaxTrackRetriesOffload;

                mActiveTrack = t;
@@ -3948,9 +3952,9 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::OffloadThread::prepareTr 
                    // has been written

                    ALOGV("OffloadThread: underrun and STOPPING_1 -> draining, STOPPING_2");

                    track->mState = TrackBase::STOPPING_2; // so presentation completes after drain

                    if (last) {

                        sleepTime = 0;

                        standbyTime = systemTime() + standbyDelay;

                    if (last) {

                        mixerStatus = MIXER_DRAIN_TRACK;

                        mDrainSequence += 2;

                        if (mHwPaused) {
@@ -4337,6 +4341,7 @@ bool AudioFlinger::RecordThread::threadLoop() 
                    mStandby = false;

                }

            }



            lockEffectChains_l(effectChains);

        }

services/audioflinger/Threads.h

+3 −1
Original line number Diff line number Diff line
@@ -526,7 +526,7 @@ private: 
    status_t    addTrack_l(const sp<Track>& track);

    bool        destroyTrack_l(const sp<Track>& track);

    void        removeTrack_l(const sp<Track>& track);

    void        signal_l();

    void        broadcast_l();



    void        readOutputParameters();
@@ -590,6 +590,8 @@ private: 
    // Bit 0 is reset by the async callback thread calling resetDraining(). Out of sequence

    // callbacks are ignored.

    uint32_t                        mDrainSequence;

    // A condition that must be evaluated by prepareTrack_l() has changed and we must not wait

    // for async write callback in the thread loop before evaluating it

    bool                            mSignalPending;

    sp<AsyncCallbackThread>         mCallbackThread;

services/audioflinger/Tracks.cpp

+2 −2
Original line number Diff line number Diff line
@@ -651,7 +651,7 @@ void AudioFlinger::PlaybackThread::Track::pause() 
        case RESUMING:

            mState = PAUSING;

            ALOGV("ACTIVE/RESUMING => PAUSING (%d) on thread %p", mName, thread.get());

            playbackThread->signal_l();

            playbackThread->broadcast_l();

            break;



        default:
@@ -711,7 +711,7 @@ void AudioFlinger::PlaybackThread::Track::flush() 
        // before mixer thread can run. This is important when offloading

        // because the hardware buffer could hold a large amount of audio

        playbackThread->flushOutput_l();

        playbackThread->signal_l();

        playbackThread->broadcast_l();

    }

}