Improvements for issue 2197683: English IME key-press latency is noticeably higher on passion than sholes
This change goes with a kernel driver change that reduces the audio buffer size from 4800 bytes (~27ms) to 3072 bytes (~17ms).
- The AudioFlinger modifcations in change 0bca68cfff161abbc992fec82dc7c88079dd1a36 have been removed: the short sleep period was counter productive when the AudioTrack is using the call back thread as it causes to many preemptions.
- AudioFlinger mixer thread now detects long standby exit time and in this case anticipates start by writing 0s as soon as a track is enabled even if not ready for mixing.
- AudioTrack::start() is modified to start call back thread before starting the IAudioTrack so that thread startup time is masked by IAudioTrack start and mixer thread wakeup time.
diff --git a/libs/audioflinger/AudioFlinger.cpp b/libs/audioflinger/AudioFlinger.cpp
index ebd470f4..d918998 100644
--- a/libs/audioflinger/AudioFlinger.cpp
+++ b/libs/audioflinger/AudioFlinger.cpp
@@ -1185,7 +1185,6 @@
mFrameSize = mOutput->frameSize();
mFrameCount = mOutput->bufferSize() / mFrameSize;
- mMinBytesToWrite = (mOutput->latency() * mSampleRate * mFrameSize) / 1000;
// FIXME - Current mixer implementation only supports stereo output: Always
// Allocate a stereo buffer even if HW output is mono.
if (mMixBuffer != NULL) delete mMixBuffer;
@@ -1215,23 +1214,25 @@
bool AudioFlinger::MixerThread::threadLoop()
{
- uint32_t sleepTime = 1000;
- uint32_t maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
int16_t* curBuf = mMixBuffer;
Vector< sp<Track> > tracksToRemove;
- size_t enabledTracks = 0;
+ uint32_t mixerStatus = MIXER_IDLE;
nsecs_t standbyTime = systemTime();
size_t mixBufferSize = mFrameCount * mFrameSize;
// FIXME: Relaxed timing because of a certain device that can't meet latency
// Should be reduced to 2x after the vendor fixes the driver issue
nsecs_t maxPeriod = seconds(mFrameCount) / mSampleRate * 3;
nsecs_t lastWarning = 0;
+ bool longStandbyExit = false;
+ uint32_t activeSleepTime = activeSleepTimeUs();
+ uint32_t idleSleepTime = idleSleepTimeUs();
+ uint32_t sleepTime = idleSleepTime;
while (!exitPending())
{
processConfigEvents();
- enabledTracks = 0;
+ mixerStatus = MIXER_IDLE;
{ // scope for mLock
Mutex::Autolock _l(mLock);
@@ -1241,7 +1242,8 @@
// FIXME: Relaxed timing because of a certain device that can't meet latency
// Should be reduced to 2x after the vendor fixes the driver issue
maxPeriod = seconds(mFrameCount) / mSampleRate * 3;
- maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
+ activeSleepTime = activeSleepTimeUs();
+ idleSleepTime = idleSleepTimeUs();
}
const SortedVector< wp<Track> >& activeTracks = mActiveTracks;
@@ -1277,15 +1279,15 @@
}
standbyTime = systemTime() + kStandbyTimeInNsecs;
- sleepTime = 1000;
+ sleepTime = idleSleepTime;
continue;
}
}
- enabledTracks = prepareTracks_l(activeTracks, &tracksToRemove);
+ mixerStatus = prepareTracks_l(activeTracks, &tracksToRemove);
}
- if (LIKELY(enabledTracks)) {
+ if (LIKELY(mixerStatus == MIXER_TRACKS_READY)) {
// mix buffers...
mAudioMixer->process(curBuf);
sleepTime = 0;
@@ -1294,15 +1296,22 @@
// If no tracks are ready, sleep once for the duration of an output
// buffer size, then write 0s to the output
if (sleepTime == 0) {
- sleepTime = maxBufferRecoveryInUsecs;
- } else if (mBytesWritten != 0) {
+ if (mixerStatus == MIXER_TRACKS_ENABLED) {
+ sleepTime = activeSleepTime;
+ } else {
+ sleepTime = idleSleepTime;
+ }
+ } else if (mBytesWritten != 0 ||
+ (mixerStatus == MIXER_TRACKS_ENABLED && longStandbyExit)) {
+ LOGV("NO DATA READY, %p", this);
memset (curBuf, 0, mixBufferSize);
sleepTime = 0;
+ LOGV_IF((mBytesWritten == 0 && (mixerStatus == MIXER_TRACKS_ENABLED && longStandbyExit)), "anticipated start");
}
}
if (mSuspended) {
- sleepTime = maxBufferRecoveryInUsecs;
+ sleepTime = idleSleepTime;
}
// sleepTime == 0 means we must write to audio hardware
if (sleepTime == 0) {
@@ -1312,7 +1321,6 @@
if (bytesWritten > 0) mBytesWritten += bytesWritten;
mNumWrites++;
mInWrite = false;
- mStandby = false;
nsecs_t now = systemTime();
nsecs_t delta = now - mLastWriteTime;
if (delta > maxPeriod) {
@@ -1322,7 +1330,11 @@
ns2ms(delta), mNumDelayedWrites, this);
lastWarning = now;
}
+ if (mStandby) {
+ longStandbyExit = true;
+ }
}
+ mStandby = false;
} else {
usleep(sleepTime);
}
@@ -1342,10 +1354,10 @@
}
// prepareTracks_l() must be called with ThreadBase::mLock held
-size_t AudioFlinger::MixerThread::prepareTracks_l(const SortedVector< wp<Track> >& activeTracks, Vector< sp<Track> > *tracksToRemove)
+uint32_t AudioFlinger::MixerThread::prepareTracks_l(const SortedVector< wp<Track> >& activeTracks, Vector< sp<Track> > *tracksToRemove)
{
- size_t enabledTracks = 0;
+ uint32_t mixerStatus = MIXER_IDLE;
// find out which tracks need to be processed
size_t count = activeTracks.size();
for (size_t i=0 ; i<count ; i++) {
@@ -1415,7 +1427,7 @@
// reset retry count
track->mRetryCount = kMaxTrackRetries;
- enabledTracks++;
+ mixerStatus = MIXER_TRACKS_READY;
} else {
//LOGV("track %d u=%08x, s=%08x [NOT READY]", track->name(), cblk->user, cblk->server);
if (track->isStopped()) {
@@ -1432,16 +1444,11 @@
if (--(track->mRetryCount) <= 0) {
LOGV("BUFFER TIMEOUT: remove(%d) from active list on thread %p", track->name(), this);
tracksToRemove->add(track);
+ } else if (mixerStatus != MIXER_TRACKS_READY) {
+ mixerStatus = MIXER_TRACKS_ENABLED;
}
- // For tracks using static shared memory buffer, make sure that we have
- // written enough data to audio hardware before disabling the track
- // NOTE: this condition with arrive before track->mRetryCount <= 0 so we
- // don't care about code removing track from active list above.
- if ((track->mSharedBuffer == 0) || (mBytesWritten >= mMinBytesToWrite)) {
- mAudioMixer->disable(AudioMixer::MIXING);
- } else {
- enabledTracks++;
- }
+
+ mAudioMixer->disable(AudioMixer::MIXING);
}
}
}
@@ -1459,7 +1466,7 @@
}
}
- return enabledTracks;
+ return mixerStatus;
}
void AudioFlinger::MixerThread::getTracks(
@@ -1621,14 +1628,14 @@
return NO_ERROR;
}
-uint32_t AudioFlinger::MixerThread::getMaxBufferRecoveryInUsecs()
+uint32_t AudioFlinger::MixerThread::activeSleepTimeUs()
{
- uint32_t time = ((mFrameCount * 1000) / mSampleRate) * 1000;
- // Add some margin with regard to scheduling precision
- if (time > 10000) {
- time -= 10000;
- }
- return time;
+ return (uint32_t)(mOutput->latency() * 1000) / 2;
+}
+
+uint32_t AudioFlinger::MixerThread::idleSleepTimeUs()
+{
+ return (uint32_t)((mFrameCount * 1000) / mSampleRate) * 1000;
}
// ----------------------------------------------------------------------------
@@ -1646,25 +1653,31 @@
bool AudioFlinger::DirectOutputThread::threadLoop()
{
- uint32_t sleepTime = 1000;
- uint32_t maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
+ uint32_t mixerStatus = MIXER_IDLE;
sp<Track> trackToRemove;
sp<Track> activeTrack;
nsecs_t standbyTime = systemTime();
int8_t *curBuf;
size_t mixBufferSize = mFrameCount*mFrameSize;
+ uint32_t activeSleepTime = activeSleepTimeUs();
+ uint32_t idleSleepTime = idleSleepTimeUs();
+ uint32_t sleepTime = idleSleepTime;
+
while (!exitPending())
{
processConfigEvents();
+ mixerStatus = MIXER_IDLE;
+
{ // scope for the mLock
Mutex::Autolock _l(mLock);
if (checkForNewParameters_l()) {
mixBufferSize = mFrameCount*mFrameSize;
- maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
+ activeSleepTime = activeSleepTimeUs();
+ idleSleepTime = idleSleepTimeUs();
}
// put audio hardware into standby after short delay
@@ -1698,7 +1711,7 @@
}
standbyTime = systemTime() + kStandbyTimeInNsecs;
- sleepTime = 1000;
+ sleepTime = idleSleepTime;
continue;
}
}
@@ -1753,6 +1766,7 @@
// reset retry count
track->mRetryCount = kMaxTrackRetries;
activeTrack = t;
+ mixerStatus = MIXER_TRACKS_READY;
} else {
//LOGV("track %d u=%08x, s=%08x [NOT READY]", track->name(), cblk->user, cblk->server);
if (track->isStopped()) {
@@ -1768,16 +1782,10 @@
if (--(track->mRetryCount) <= 0) {
LOGV("BUFFER TIMEOUT: remove(%d) from active list", track->name());
trackToRemove = track;
+ } else {
+ mixerStatus = MIXER_TRACKS_ENABLED;
}
-
- // For tracks using static shared memry buffer, make sure that we have
- // written enough data to audio hardware before disabling the track
- // NOTE: this condition with arrive before track->mRetryCount <= 0 so we
- // don't care about code removing track from active list above.
- if ((track->mSharedBuffer != 0) && (mBytesWritten < mMinBytesToWrite)) {
- activeTrack = t;
- }
- }
+ }
}
}
@@ -1791,7 +1799,7 @@
}
}
- if (activeTrack != 0) {
+ if (LIKELY(mixerStatus == MIXER_TRACKS_READY)) {
AudioBufferProvider::Buffer buffer;
size_t frameCount = mFrameCount;
curBuf = (int8_t *)mMixBuffer;
@@ -1812,7 +1820,11 @@
standbyTime = systemTime() + kStandbyTimeInNsecs;
} else {
if (sleepTime == 0) {
- sleepTime = maxBufferRecoveryInUsecs;
+ if (mixerStatus == MIXER_TRACKS_ENABLED) {
+ sleepTime = activeSleepTime;
+ } else {
+ sleepTime = idleSleepTime;
+ }
} else if (mBytesWritten != 0 && AudioSystem::isLinearPCM(mFormat)) {
memset (mMixBuffer, 0, mFrameCount * mFrameSize);
sleepTime = 0;
@@ -1820,7 +1832,7 @@
}
if (mSuspended) {
- sleepTime = maxBufferRecoveryInUsecs;
+ sleepTime = idleSleepTime;
}
// sleepTime == 0 means we must write to audio hardware
if (sleepTime == 0) {
@@ -1905,15 +1917,22 @@
return reconfig;
}
-uint32_t AudioFlinger::DirectOutputThread::getMaxBufferRecoveryInUsecs()
+uint32_t AudioFlinger::DirectOutputThread::activeSleepTimeUs()
{
uint32_t time;
if (AudioSystem::isLinearPCM(mFormat)) {
- time = ((mFrameCount * 1000) / mSampleRate) * 1000;
- // Add some margin with regard to scheduling precision
- if (time > 10000) {
- time -= 10000;
- }
+ time = (uint32_t)(mOutput->latency() * 1000) / 2;
+ } else {
+ time = 10000;
+ }
+ return time;
+}
+
+uint32_t AudioFlinger::DirectOutputThread::idleSleepTimeUs()
+{
+ uint32_t time;
+ if (AudioSystem::isLinearPCM(mFormat)) {
+ time = (uint32_t)((mFrameCount * 1000) / mSampleRate) * 1000;
} else {
time = 10000;
}
@@ -1936,28 +1955,30 @@
bool AudioFlinger::DuplicatingThread::threadLoop()
{
- uint32_t sleepTime = 1000;
- uint32_t maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
int16_t* curBuf = mMixBuffer;
Vector< sp<Track> > tracksToRemove;
- size_t enabledTracks = 0;
+ uint32_t mixerStatus = MIXER_IDLE;
nsecs_t standbyTime = systemTime();
size_t mixBufferSize = mFrameCount*mFrameSize;
SortedVector< sp<OutputTrack> > outputTracks;
uint32_t writeFrames = 0;
+ uint32_t activeSleepTime = activeSleepTimeUs();
+ uint32_t idleSleepTime = idleSleepTimeUs();
+ uint32_t sleepTime = idleSleepTime;
while (!exitPending())
{
processConfigEvents();
- enabledTracks = 0;
+ mixerStatus = MIXER_IDLE;
{ // scope for the mLock
Mutex::Autolock _l(mLock);
if (checkForNewParameters_l()) {
mixBufferSize = mFrameCount*mFrameSize;
- maxBufferRecoveryInUsecs = getMaxBufferRecoveryInUsecs();
+ activeSleepTime = activeSleepTimeUs();
+ idleSleepTime = idleSleepTimeUs();
}
const SortedVector< wp<Track> >& activeTracks = mActiveTracks;
@@ -1997,22 +2018,26 @@
}
standbyTime = systemTime() + kStandbyTimeInNsecs;
- sleepTime = 1000;
+ sleepTime = idleSleepTime;
continue;
}
}
- enabledTracks = prepareTracks_l(activeTracks, &tracksToRemove);
+ mixerStatus = prepareTracks_l(activeTracks, &tracksToRemove);
}
- if (LIKELY(enabledTracks)) {
+ if (LIKELY(mixerStatus == MIXER_TRACKS_READY)) {
// mix buffers...
mAudioMixer->process(curBuf);
sleepTime = 0;
writeFrames = mFrameCount;
} else {
if (sleepTime == 0) {
- sleepTime = maxBufferRecoveryInUsecs;
+ if (mixerStatus == MIXER_TRACKS_ENABLED) {
+ sleepTime = activeSleepTime;
+ } else {
+ sleepTime = idleSleepTime;
+ }
} else if (mBytesWritten != 0) {
// flush remaining overflow buffers in output tracks
for (size_t i = 0; i < outputTracks.size(); i++) {
@@ -2026,7 +2051,7 @@
}
if (mSuspended) {
- sleepTime = maxBufferRecoveryInUsecs;
+ sleepTime = idleSleepTime;
}
// sleepTime == 0 means we must write to audio hardware
if (sleepTime == 0) {
diff --git a/libs/audioflinger/AudioFlinger.h b/libs/audioflinger/AudioFlinger.h
index 22d15c9..594d878 100644
--- a/libs/audioflinger/AudioFlinger.h
+++ b/libs/audioflinger/AudioFlinger.h
@@ -361,6 +361,12 @@
DUPLICATING
};
+ enum mixer_state {
+ MIXER_IDLE,
+ MIXER_TRACKS_ENABLED,
+ MIXER_TRACKS_READY
+ };
+
// playback track
class Track : public TrackBase {
public:
@@ -530,7 +536,8 @@
virtual int getTrackName_l() = 0;
virtual void deleteTrackName_l(int name) = 0;
- virtual uint32_t getMaxBufferRecoveryInUsecs() = 0;
+ virtual uint32_t activeSleepTimeUs() = 0;
+ virtual uint32_t idleSleepTimeUs() = 0;
private:
@@ -562,7 +569,6 @@
int mNumWrites;
int mNumDelayedWrites;
bool mInWrite;
- int mMinBytesToWrite;
};
class MixerThread : public PlaybackThread {
@@ -582,10 +588,11 @@
virtual status_t dumpInternals(int fd, const Vector<String16>& args);
protected:
- size_t prepareTracks_l(const SortedVector< wp<Track> >& activeTracks, Vector< sp<Track> > *tracksToRemove);
+ uint32_t prepareTracks_l(const SortedVector< wp<Track> >& activeTracks, Vector< sp<Track> > *tracksToRemove);
virtual int getTrackName_l();
virtual void deleteTrackName_l(int name);
- virtual uint32_t getMaxBufferRecoveryInUsecs();
+ virtual uint32_t activeSleepTimeUs();
+ virtual uint32_t idleSleepTimeUs();
AudioMixer* mAudioMixer;
};
@@ -604,7 +611,8 @@
protected:
virtual int getTrackName_l();
virtual void deleteTrackName_l(int name);
- virtual uint32_t getMaxBufferRecoveryInUsecs();
+ virtual uint32_t activeSleepTimeUs();
+ virtual uint32_t idleSleepTimeUs();
private:
float mLeftVolume;
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 8529a8e..cedd79d 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -318,26 +318,35 @@
}
if (android_atomic_or(1, &mActive) == 0) {
- audio_io_handle_t output = AudioTrack::getOutput();
+ audio_io_handle_t output = getOutput();
+ AudioSystem::startOutput(output, (AudioSystem::stream_type)mStreamType);
+ mNewPosition = mCblk->server + mUpdatePeriod;
+ mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
+ mCblk->waitTimeMs = 0;
+ if (t != 0) {
+ t->run("AudioTrackThread", THREAD_PRIORITY_AUDIO_CLIENT);
+ } else {
+ setpriority(PRIO_PROCESS, 0, THREAD_PRIORITY_AUDIO_CLIENT);
+ }
+
status_t status = mAudioTrack->start();
if (status == DEAD_OBJECT) {
LOGV("start() dead IAudioTrack: creating a new one");
status = createTrack(mStreamType, mCblk->sampleRate, mFormat, mChannelCount,
mFrameCount, mFlags, mSharedBuffer, output);
- }
- if (status == NO_ERROR) {
- AudioSystem::startOutput(output, (AudioSystem::stream_type)mStreamType);
mNewPosition = mCblk->server + mUpdatePeriod;
mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
mCblk->waitTimeMs = 0;
- if (t != 0) {
- t->run("AudioTrackThread", THREAD_PRIORITY_AUDIO_CLIENT);
- } else {
- setpriority(PRIO_PROCESS, 0, THREAD_PRIORITY_AUDIO_CLIENT);
- }
- } else {
+ }
+ if (status != NO_ERROR) {
LOGV("start() failed");
android_atomic_and(~1, &mActive);
+ if (t != 0) {
+ t->requestExit();
+ } else {
+ setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
+ }
+ AudioSystem::stopOutput(output, (AudioSystem::stream_type)mStreamType);
}
}
