Merge "Fix race condition in IMediaSource" into rvc-dev

        data.writeInterfaceToken(BpMediaSource::getInterfaceDescriptor());

        status_t ret = remote()->transact(GETFORMAT, data, &reply);

        if (ret == NO_ERROR) {

            AutoMutex _l(mLock);

            AutoMutex _l(mBpLock);

            mMetaData = MetaData::createFromParcel(reply);

            return mMetaData;

        }

    // XXX: could we use this for caching, or does metadata change on the fly?

    sp<MetaData> mMetaData;

    // ensure synchronize access to mMetaData

    Mutex mLock;

    Mutex mBpLock;

    // Cache all IMemory objects received from MediaExtractor.

    // We gc IMemory objects that are no longer active (referenced by a MediaBuffer).

            CHECK_INTERFACE(IMediaSource, data, reply);

            mGroup->signalBufferReturned(nullptr);

            status_t status = stop();

            AutoMutex _l(mBnLock);

            mIndexCache.reset();

            mBuffersSinceStop = 0;

            return status;

                    && len == sizeof(opts)

                    && data.read((void *)&opts, len) == NO_ERROR;

            AutoMutex _l(mBnLock);

            mGroup->signalBufferReturned(nullptr);

            mIndexCache.gc();

            size_t inlineTransferSize = 0;

private:

    uint32_t mBuffersSinceStop; // Buffer tracking variable

    Mutex mBnLock; // to guard readMultiple against concurrent access to the buffer cache

    std::unique_ptr<MediaBufferGroup> mGroup;