Prevent ANR when AudioTrack is paused or re-routed
If ClientProxy was interrupted by AudioTrack::pause() just before futex syscall() in obtainBuffer() was called,
It will not call releaseBuffer to wake up AudioTrackThread.
It puts the AudioTrackThread to sleep and then a deadlock occurs.
In this case, CBLK_INTERRUPT flags can't prevent a deadlock,
so this patch set mFutex to FUTEX_WAKE during interrupt() to avoid deadlock.
A similar problem could occur due to re-route or recovery after mediaserver death.
Bug: 18641665
Change-Id: I66fcae43af9a91eb55f6cdb52c644ee6c0999772
diff --git a/media/libmedia/AudioTrackShared.cpp b/media/libmedia/AudioTrackShared.cpp
index 4a783b3..ff24475 100644
--- a/media/libmedia/AudioTrackShared.cpp
+++ b/media/libmedia/AudioTrackShared.cpp
@@ -307,6 +307,7 @@
{
audio_track_cblk_t* cblk = mCblk;
if (!(android_atomic_or(CBLK_INVALID, &cblk->mFlags) & CBLK_INVALID)) {
+ android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
// it seems that a FUTEX_WAKE_PRIVATE will not wake a FUTEX_WAIT, even within same process
(void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE,
1);
@@ -317,6 +318,7 @@
{
audio_track_cblk_t* cblk = mCblk;
if (!(android_atomic_or(CBLK_INTERRUPT, &cblk->mFlags) & CBLK_INTERRUPT)) {
+ android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
(void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE,
1);
}