Fix uncertainty of one normal mix buffer in AudioTrack::getTimestamp
The per-thread timestamp latch was not synchronized with the per-track
released frames. Now the value of each track's released frames is
latched along with the timestamp.
Bug: 17531839
Bug: 17669342
Change-Id: I96252782911bd42a2534cc4030521b7eeb99a7b9
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 818bb05..fe258ae 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -2126,6 +2126,7 @@
size_t totalFramesWritten = mNormalSink->framesWritten();
if (totalFramesWritten >= mLatchD.mTimestamp.mPosition) {
mLatchD.mUnpresentedFrames = totalFramesWritten - mLatchD.mTimestamp.mPosition;
+ // mLatchD.mFramesReleased is set in threadloop_mix()
mLatchDValid = true;
}
}
@@ -3091,6 +3092,18 @@
sleepTime = 0;
standbyTime = systemTime() + standbyDelay;
//TODO: delay standby when effects have a tail
+
+ mLatchD.mFramesReleased.clear();
+ {
+ Mutex::Autolock _l(mLock);
+ size_t size = mActiveTracks.size();
+ for (size_t i = 0; i < size; i++) {
+ sp<Track> t = mActiveTracks[i].promote();
+ if (t != 0) {
+ mLatchD.mFramesReleased.add(t.get(), t->mAudioTrackServerProxy->framesReleased());
+ }
+ }
+ }
}
void AudioFlinger::MixerThread::threadLoop_sleepTime()
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index fd025b5..cda8095 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -819,6 +819,7 @@
struct {
AudioTimestamp mTimestamp;
uint32_t mUnpresentedFrames;
+ KeyedVector<Track *, uint32_t> mFramesReleased;
} mLatchD, mLatchQ;
bool mLatchDValid; // true means mLatchD is valid, and clock it into latch at next opportunity
bool mLatchQValid; // true means mLatchQ is valid
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index c0a75b9..8c2bee4 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -894,7 +894,15 @@
uint32_t unpresentedFrames =
((int64_t) playbackThread->mLatchQ.mUnpresentedFrames * mSampleRate) /
playbackThread->mSampleRate;
- uint32_t framesWritten = mAudioTrackServerProxy->framesReleased();
+ // FIXME Since we're using a raw pointer as the key, it is theoretically possible
+ // for a brand new track to share the same address as a recently destroyed
+ // track, and thus for us to get the frames released of the wrong track.
+ // It is unlikely that we would be able to call getTimestamp() so quickly
+ // right after creating a new track. Nevertheless, the index here should
+ // be changed to something that is unique. Or use a completely different strategy.
+ ssize_t i = playbackThread->mLatchQ.mFramesReleased.indexOfKey(this);
+ uint32_t framesWritten = i >= 0 ?
+ playbackThread->mLatchQ.mFramesReleased[i] : mAudioTrackServerProxy->framesReleased();
bool checkPreviousTimestamp = mPreviousValid && framesWritten >= mPreviousFramesWritten;
if (framesWritten < unpresentedFrames) {
mPreviousValid = false;