audio: Fix race condition in AudioTrack underrun.
When audio flinger mixer removes an AudioTrack from the
active list in case of underrun, it is possible that the
client has written a full buffer just after the underrun detection and
is blocked waiting for more space to write. In this case, the client
will never detect the DISABLED flag and the track never be restarted.
Also implement missing DISABLE flag detection in server side audio tracks
(OutputTrack and PatchTrack).
bug: 27567768
Change-Id: I8d0753429d4113498258b1f61bd8ac5939a612f0
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 423273d..ab18c27 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -1532,6 +1532,10 @@
}
oldSequence = newSequence;
+ if (status == NOT_ENOUGH_DATA) {
+ restartIfDisabled();
+ }
+
// Keep the extra references
proxy = mProxy;
iMem = mCblkMemory;
@@ -1554,8 +1558,7 @@
buffer.mFrameCount = audioBuffer->frameCount;
// FIXME starts the requested timeout and elapsed over from scratch
status = proxy->obtainBuffer(&buffer, requested, elapsed);
-
- } while ((status == DEAD_OBJECT) && (tryCounter-- > 0));
+ } while (((status == DEAD_OBJECT) || (status == NOT_ENOUGH_DATA)) && (tryCounter-- > 0));
audioBuffer->frameCount = buffer.mFrameCount;
audioBuffer->size = buffer.mFrameCount * mFrameSize;
@@ -1588,13 +1591,16 @@
mProxy->releaseBuffer(&buffer);
// restart track if it was disabled by audioflinger due to previous underrun
- if (mState == STATE_ACTIVE) {
- audio_track_cblk_t* cblk = mCblk;
- if (android_atomic_and(~CBLK_DISABLED, &cblk->mFlags) & CBLK_DISABLED) {
- ALOGW("releaseBuffer() track %p disabled due to previous underrun, restarting", this);
- // FIXME ignoring status
- mAudioTrack->start();
- }
+ restartIfDisabled();
+}
+
+void AudioTrack::restartIfDisabled()
+{
+ int32_t flags = android_atomic_and(~CBLK_DISABLED, &mCblk->mFlags);
+ if ((mState == STATE_ACTIVE) && (flags & CBLK_DISABLED)) {
+ ALOGW("releaseBuffer() track %p disabled due to previous underrun, restarting", this);
+ // FIXME ignoring status
+ mAudioTrack->start();
}
}