Merge "Keep extra reference of shared memory for AudioTrack data callback." into udc-dev

        // obtainBuffer() is called with mutex unlocked, so keep extra references to these fields to

        // keep them from going away if another thread re-creates the track during obtainBuffer()

        sp<AudioTrackClientProxy> proxy;

        sp<IMemory> iMem;

        {   // start of lock scope

            AutoMutex lock(mLock);

            }

            // Keep the extra references

            mProxyObtainBufferRef = mProxy;

            proxy = mProxy;

            iMem = mCblkMemory;

            mCblkMemoryObtainBufferRef = mCblkMemory;

            if (mState == STATE_STOPPING) {

                status = -EINTR;

    buffer.mFrameCount = stepCount;

    buffer.mRaw = audioBuffer->raw;

    sp<IMemory> tempMemory;

    sp<AudioTrackClientProxy> tempProxy;

    AutoMutex lock(mLock);

    if (audioBuffer->sequence != mSequence) {

        // This Buffer came from a different IAudioTrack instance, so ignore the releaseBuffer

    }

    mReleased += stepCount;

    mInUnderrun = false;

    mProxy->releaseBuffer(&buffer);

    mProxyObtainBufferRef->releaseBuffer(&buffer);

    // The extra reference of shared memory and proxy from `obtainBuffer` is not used after

    // calling `releaseBuffer`. Move the extra reference to a temp strong pointer so that it

    // will be cleared outside `releaseBuffer`.

    tempMemory = std::move(mCblkMemoryObtainBufferRef);

    tempProxy = std::move(mProxyObtainBufferRef);

    // restart track if it was disabled by audioflinger due to previous underrun

    restartIfDisabled();

    audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()

    audio_io_handle_t       mOutput = AUDIO_IO_HANDLE_NONE; // from AudioSystem::getOutputForAttr()

    // A copy of shared memory and proxy between obtainBuffer and releaseBuffer to keep the

    // shared memory valid when processing data.

    sp<IMemory>               mCblkMemoryObtainBufferRef GUARDED_BY(mLock);

    sp<AudioTrackClientProxy> mProxyObtainBufferRef GUARDED_BY(mLock);

    sp<AudioTrackThread>    mAudioTrackThread;

    bool                    mThreadCanCallJava;