Fix race condition in AudioTrack::releaseBuffer()
Ignore releaseBuffer() if it is for a different IAudioTrack than was
used for obtainBuffer().
Bug: 136268149
Test: at bug comments #32 and #45
Change-Id: I2e1955c60479edcba6e7d66c98b9faef088b65d9
diff --git a/media/libaudioclient/AudioTrack.cpp b/media/libaudioclient/AudioTrack.cpp
index eda9426..d5690fb 100644
--- a/media/libaudioclient/AudioTrack.cpp
+++ b/media/libaudioclient/AudioTrack.cpp
@@ -1777,7 +1777,6 @@
{
// previous and new IAudioTrack sequence numbers are used to detect track re-creation
uint32_t oldSequence = 0;
- uint32_t newSequence;
Proxy::Buffer buffer;
status_t status = NO_ERROR;
@@ -1794,7 +1793,7 @@
{ // start of lock scope
AutoMutex lock(mLock);
- newSequence = mSequence;
+ uint32_t newSequence = mSequence;
// did previous obtainBuffer() fail due to media server death or voluntary invalidation?
if (status == DEAD_OBJECT) {
// re-create track, unless someone else has already done so
@@ -1841,6 +1840,7 @@
audioBuffer->frameCount = buffer.mFrameCount;
audioBuffer->size = buffer.mFrameCount * mFrameSize;
audioBuffer->raw = buffer.mRaw;
+ audioBuffer->sequence = oldSequence;
if (nonContig != NULL) {
*nonContig = buffer.mNonContig;
}
@@ -1864,6 +1864,12 @@
buffer.mRaw = audioBuffer->raw;
AutoMutex lock(mLock);
+ if (audioBuffer->sequence != mSequence) {
+ // This Buffer came from a different IAudioTrack instance, so ignore the releaseBuffer
+ ALOGD("%s is no-op due to IAudioTrack sequence mismatch %u != %u",
+ __func__, audioBuffer->sequence, mSequence);
+ return;
+ }
mReleased += stepCount;
mInUnderrun = false;
mProxy->releaseBuffer(&buffer);