diff options
Diffstat (limited to 'media/libmedia/AudioTrackShared.cpp')
| -rw-r--r-- | media/libmedia/AudioTrackShared.cpp | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/media/libmedia/AudioTrackShared.cpp b/media/libmedia/AudioTrackShared.cpp index eec025e..561cb24 100644 --- a/media/libmedia/AudioTrackShared.cpp +++ b/media/libmedia/AudioTrackShared.cpp @@ -348,7 +348,13 @@ size_t ClientProxy::getFramesFilled() { void AudioTrackClientProxy::flush() { - mCblk->u.mStreaming.mFlush++; + // This works for mFrameCountP2 <= 2^30 + size_t increment = mFrameCountP2 << 1; + size_t mask = increment - 1; + audio_track_cblk_t* cblk = mCblk; + int32_t newFlush = (cblk->u.mStreaming.mRear & mask) | + ((cblk->u.mStreaming.mFlush & ~mask) + increment); + android_atomic_release_store(newFlush, &cblk->u.mStreaming.mFlush); } bool AudioTrackClientProxy::clearStreamEndDone() { @@ -536,17 +542,27 @@ status_t ServerProxy::obtainBuffer(Buffer* buffer, bool ackFlush) rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); front = cblk->u.mStreaming.mFront; if (flush != mFlush) { - mFlush = flush; // effectively obtain then release whatever is in the buffer - android_atomic_release_store(rear, &cblk->u.mStreaming.mFront); - if (front != rear) { + size_t mask = (mFrameCountP2 << 1) - 1; + int32_t newFront = (front & ~mask) | (flush & mask); + ssize_t filled = rear - newFront; + // Rather than shutting down on a corrupt flush, just treat it as a full flush + if (!(0 <= filled && (size_t) filled <= mFrameCount)) { + ALOGE("mFlush %#x -> %#x, front %#x, rear %#x, mask %#x, newFront %#x, filled %d=%#x", + mFlush, flush, front, rear, mask, newFront, filled, filled); + newFront = rear; + } + mFlush = flush; + android_atomic_release_store(newFront, &cblk->u.mStreaming.mFront); + // There is no danger from a false positive, so err on the side of caution + if (true /*front != newFront*/) { int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); if (!(old & CBLK_FUTEX_WAKE)) { (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); } } - front = rear; + front = newFront; } } else { front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); @@ -668,6 +684,7 @@ size_t AudioTrackServerProxy::framesReady() int32_t flush = cblk->u.mStreaming.mFlush; if (flush != mFlush) { + // FIXME should return an accurate value, but over-estimate is better than under-estimate return mFrameCount; } // the acquire might not be necessary since not doing a subsequent read |