diff options
-rw-r--r-- | include/private/media/AudioTrackShared.h | 3 | ||||
-rw-r--r-- | media/libmedia/AudioTrackShared.cpp | 11 |
2 files changed, 7 insertions, 7 deletions
diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h index 681f557..ef5bb8d 100644 --- a/include/private/media/AudioTrackShared.h +++ b/include/private/media/AudioTrackShared.h @@ -94,8 +94,9 @@ struct audio_track_cblk_t // parameter // renamed to "_" to detect incorrect use - volatile int32_t mFutex; // semaphore: down (P) by client, + volatile int32_t mFutex; // event flag: down (P) by client, // up (V) by server or binderDied() or interrupt() +#define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending private: diff --git a/media/libmedia/AudioTrackShared.cpp b/media/libmedia/AudioTrackShared.cpp index f034164..4b7f368 100644 --- a/media/libmedia/AudioTrackShared.cpp +++ b/media/libmedia/AudioTrackShared.cpp @@ -207,15 +207,15 @@ status_t ClientProxy::obtainBuffer(Buffer* buffer, const struct timespec *reques ts = NULL; break; } - int32_t old = android_atomic_dec(&cblk->mFutex); - if (old <= 0) { + int32_t old = android_atomic_and(~CBLK_FUTEX_WAKE, &cblk->mFutex); + if (!(old & CBLK_FUTEX_WAKE)) { int rc; if (measure && !beforeIsValid) { clock_gettime(CLOCK_MONOTONIC, &before); beforeIsValid = true; } int ret = __futex_syscall4(&cblk->mFutex, - mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old - 1, ts); + mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts); // update total elapsed time spent waiting if (measure) { struct timespec after; @@ -484,9 +484,8 @@ void ServerProxy::releaseBuffer(Buffer* buffer) } if (!mDeferWake && mAvailToClient + stepCount >= minimum) { ALOGV("mAvailToClient=%u stepCount=%u minimum=%u", mAvailToClient, stepCount, minimum); - // could client be sleeping, or not need this increment and counter overflows? - int32_t old = android_atomic_inc(&cblk->mFutex); - if (old == -1) { + int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); + if (!(old & CBLK_FUTEX_WAKE)) { (void) __futex_syscall3(&cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); } |