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1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 // <IMPORTANT_WARNING>
18 // Design rules for threadLoop() are given in the comments at section "Fast mixer thread" of
19 // StateQueue.h.  In particular, avoid library and system calls except at well-known points.
20 // The design rules are only for threadLoop(), and don't apply to FastMixerDumpState methods.
21 // </IMPORTANT_WARNING>
22 
23 #define LOG_TAG "FastMixer"
24 //#define LOG_NDEBUG 0
25 
26 #define ATRACE_TAG ATRACE_TAG_AUDIO
27 
28 #include "Configuration.h"
29 #include <time.h>
30 #include <utils/Debug.h>
31 #include <utils/Log.h>
32 #include <utils/Trace.h>
33 #include <system/audio.h>
34 #ifdef FAST_THREAD_STATISTICS
35 #include <audio_utils/Statistics.h>
36 #ifdef CPU_FREQUENCY_STATISTICS
37 #include <cpustats/ThreadCpuUsage.h>
38 #endif
39 #endif
40 #include <audio_utils/channels.h>
41 #include <audio_utils/format.h>
42 #include <audio_utils/mono_blend.h>
43 #include <media/AudioMixer.h>
44 #include "FastMixer.h"
45 #include "TypedLogger.h"
46 
47 namespace android {
48 
49 /*static*/ const FastMixerState FastMixer::sInitial;
50 
FastMixer(audio_io_handle_t parentIoHandle)51 FastMixer::FastMixer(audio_io_handle_t parentIoHandle)
52     : FastThread("cycle_ms", "load_us"),
53     // mFastTrackNames
54     // mGenerations
55     mOutputSink(NULL),
56     mOutputSinkGen(0),
57     mMixer(NULL),
58     mSinkBuffer(NULL),
59     mSinkBufferSize(0),
60     mSinkChannelCount(FCC_2),
61     mMixerBuffer(NULL),
62     mMixerBufferSize(0),
63     mMixerBufferState(UNDEFINED),
64     mFormat(Format_Invalid),
65     mSampleRate(0),
66     mFastTracksGen(0),
67     mTotalNativeFramesWritten(0),
68     // timestamp
69     mNativeFramesWrittenButNotPresented(0),   // the = 0 is to silence the compiler
70     mMasterMono(false),
71     mThreadIoHandle(parentIoHandle)
72 {
73     (void)mThreadIoHandle; // prevent unused warning, see C++17 [[maybe_unused]]
74 
75     // FIXME pass sInitial as parameter to base class constructor, and make it static local
76     mPrevious = &sInitial;
77     mCurrent = &sInitial;
78 
79     mDummyDumpState = &mDummyFastMixerDumpState;
80     // TODO: Add channel mask to NBAIO_Format.
81     // We assume that the channel mask must be a valid positional channel mask.
82     mSinkChannelMask = audio_channel_out_mask_from_count(mSinkChannelCount);
83 
84     unsigned i;
85     for (i = 0; i < FastMixerState::sMaxFastTracks; ++i) {
86         mGenerations[i] = 0;
87     }
88 #ifdef FAST_THREAD_STATISTICS
89     mOldLoad.tv_sec = 0;
90     mOldLoad.tv_nsec = 0;
91 #endif
92 }
93 
~FastMixer()94 FastMixer::~FastMixer()
95 {
96 }
97 
sq()98 FastMixerStateQueue* FastMixer::sq()
99 {
100     return &mSQ;
101 }
102 
poll()103 const FastThreadState *FastMixer::poll()
104 {
105     return mSQ.poll();
106 }
107 
setNBLogWriter(NBLog::Writer * logWriter)108 void FastMixer::setNBLogWriter(NBLog::Writer *logWriter)
109 {
110     // FIXME If mMixer is set or changed prior to this, we don't inform correctly.
111     //       Should cache logWriter and re-apply it at the assignment to mMixer.
112     if (mMixer != NULL) {
113         mMixer->setNBLogWriter(logWriter);
114     }
115 }
116 
onIdle()117 void FastMixer::onIdle()
118 {
119     mPreIdle = *(const FastMixerState *)mCurrent;
120     mCurrent = &mPreIdle;
121 }
122 
onExit()123 void FastMixer::onExit()
124 {
125     delete mMixer;
126     free(mMixerBuffer);
127     free(mSinkBuffer);
128 }
129 
isSubClassCommand(FastThreadState::Command command)130 bool FastMixer::isSubClassCommand(FastThreadState::Command command)
131 {
132     switch ((FastMixerState::Command) command) {
133     case FastMixerState::MIX:
134     case FastMixerState::WRITE:
135     case FastMixerState::MIX_WRITE:
136         return true;
137     default:
138         return false;
139     }
140 }
141 
updateMixerTrack(int index,Reason reason)142 void FastMixer::updateMixerTrack(int index, Reason reason) {
143     const FastMixerState * const current = (const FastMixerState *) mCurrent;
144     const FastTrack * const fastTrack = &current->mFastTracks[index];
145 
146     // check and update generation
147     if (reason == REASON_MODIFY && mGenerations[index] == fastTrack->mGeneration) {
148         return; // no change on an already configured track.
149     }
150     mGenerations[index] = fastTrack->mGeneration;
151 
152     // mMixer == nullptr on configuration failure (check done after generation update).
153     if (mMixer == nullptr) {
154         return;
155     }
156 
157     switch (reason) {
158     case REASON_REMOVE:
159         mMixer->destroy(index);
160         break;
161     case REASON_ADD: {
162         const status_t status = mMixer->create(
163                 index, fastTrack->mChannelMask, fastTrack->mFormat, AUDIO_SESSION_OUTPUT_MIX);
164         LOG_ALWAYS_FATAL_IF(status != NO_ERROR,
165                 "%s: cannot create fast track index"
166                 " %d, mask %#x, format %#x in AudioMixer",
167                 __func__, index, fastTrack->mChannelMask, fastTrack->mFormat);
168     }
169         [[fallthrough]];  // now fallthrough to update the newly created track.
170     case REASON_MODIFY:
171         mMixer->setBufferProvider(index, fastTrack->mBufferProvider);
172 
173         float vlf, vrf;
174         if (fastTrack->mVolumeProvider != nullptr) {
175             const gain_minifloat_packed_t vlr = fastTrack->mVolumeProvider->getVolumeLR();
176             vlf = float_from_gain(gain_minifloat_unpack_left(vlr));
177             vrf = float_from_gain(gain_minifloat_unpack_right(vlr));
178         } else {
179             vlf = vrf = AudioMixer::UNITY_GAIN_FLOAT;
180         }
181 
182         // set volume to avoid ramp whenever the track is updated (or created).
183         // Note: this does not distinguish from starting fresh or
184         // resuming from a paused state.
185         mMixer->setParameter(index, AudioMixer::VOLUME, AudioMixer::VOLUME0, &vlf);
186         mMixer->setParameter(index, AudioMixer::VOLUME, AudioMixer::VOLUME1, &vrf);
187 
188         mMixer->setParameter(index, AudioMixer::RESAMPLE, AudioMixer::REMOVE, nullptr);
189         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::MAIN_BUFFER,
190                 (void *)mMixerBuffer);
191         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::MIXER_FORMAT,
192                 (void *)(uintptr_t)mMixerBufferFormat);
193         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::FORMAT,
194                 (void *)(uintptr_t)fastTrack->mFormat);
195         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK,
196                 (void *)(uintptr_t)fastTrack->mChannelMask);
197         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::MIXER_CHANNEL_MASK,
198                 (void *)(uintptr_t)mSinkChannelMask);
199         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::HAPTIC_ENABLED,
200                 (void *)(uintptr_t)fastTrack->mHapticPlaybackEnabled);
201         mMixer->setParameter(index, AudioMixer::TRACK, AudioMixer::HAPTIC_INTENSITY,
202                 (void *)(uintptr_t)fastTrack->mHapticIntensity);
203 
204         mMixer->enable(index);
205         break;
206     default:
207         LOG_ALWAYS_FATAL("%s: invalid update reason %d", __func__, reason);
208     }
209 }
210 
onStateChange()211 void FastMixer::onStateChange()
212 {
213     const FastMixerState * const current = (const FastMixerState *) mCurrent;
214     const FastMixerState * const previous = (const FastMixerState *) mPrevious;
215     FastMixerDumpState * const dumpState = (FastMixerDumpState *) mDumpState;
216     const size_t frameCount = current->mFrameCount;
217 
218     // update boottime offset, in case it has changed
219     mTimestamp.mTimebaseOffset[ExtendedTimestamp::TIMEBASE_BOOTTIME] =
220             mBoottimeOffset.load();
221 
222     // handle state change here, but since we want to diff the state,
223     // we're prepared for previous == &sInitial the first time through
224     unsigned previousTrackMask;
225 
226     // check for change in output HAL configuration
227     NBAIO_Format previousFormat = mFormat;
228     if (current->mOutputSinkGen != mOutputSinkGen) {
229         mOutputSink = current->mOutputSink;
230         mOutputSinkGen = current->mOutputSinkGen;
231         mSinkChannelMask = current->mSinkChannelMask;
232         mBalance.setChannelMask(mSinkChannelMask);
233         if (mOutputSink == NULL) {
234             mFormat = Format_Invalid;
235             mSampleRate = 0;
236             mSinkChannelCount = 0;
237             mSinkChannelMask = AUDIO_CHANNEL_NONE;
238             mAudioChannelCount = 0;
239         } else {
240             mFormat = mOutputSink->format();
241             mSampleRate = Format_sampleRate(mFormat);
242             mSinkChannelCount = Format_channelCount(mFormat);
243             LOG_ALWAYS_FATAL_IF(mSinkChannelCount > AudioMixer::MAX_NUM_CHANNELS);
244 
245             if (mSinkChannelMask == AUDIO_CHANNEL_NONE) {
246                 mSinkChannelMask = audio_channel_out_mask_from_count(mSinkChannelCount);
247             }
248             mAudioChannelCount = mSinkChannelCount - audio_channel_count_from_out_mask(
249                     mSinkChannelMask & AUDIO_CHANNEL_HAPTIC_ALL);
250         }
251         dumpState->mSampleRate = mSampleRate;
252     }
253 
254     if ((!Format_isEqual(mFormat, previousFormat)) || (frameCount != previous->mFrameCount)) {
255         // FIXME to avoid priority inversion, don't delete here
256         delete mMixer;
257         mMixer = NULL;
258         free(mMixerBuffer);
259         mMixerBuffer = NULL;
260         free(mSinkBuffer);
261         mSinkBuffer = NULL;
262         if (frameCount > 0 && mSampleRate > 0) {
263             // FIXME new may block for unbounded time at internal mutex of the heap
264             //       implementation; it would be better to have normal mixer allocate for us
265             //       to avoid blocking here and to prevent possible priority inversion
266             mMixer = new AudioMixer(frameCount, mSampleRate);
267             // FIXME See the other FIXME at FastMixer::setNBLogWriter()
268             NBLog::thread_params_t params;
269             params.frameCount = frameCount;
270             params.sampleRate = mSampleRate;
271             LOG_THREAD_PARAMS(params);
272             const size_t mixerFrameSize = mSinkChannelCount
273                     * audio_bytes_per_sample(mMixerBufferFormat);
274             mMixerBufferSize = mixerFrameSize * frameCount;
275             (void)posix_memalign(&mMixerBuffer, 32, mMixerBufferSize);
276             const size_t sinkFrameSize = mSinkChannelCount
277                     * audio_bytes_per_sample(mFormat.mFormat);
278             if (sinkFrameSize > mixerFrameSize) { // need a sink buffer
279                 mSinkBufferSize = sinkFrameSize * frameCount;
280                 (void)posix_memalign(&mSinkBuffer, 32, mSinkBufferSize);
281             }
282             mPeriodNs = (frameCount * 1000000000LL) / mSampleRate;    // 1.00
283             mUnderrunNs = (frameCount * 1750000000LL) / mSampleRate;  // 1.75
284             mOverrunNs = (frameCount * 500000000LL) / mSampleRate;    // 0.50
285             mForceNs = (frameCount * 950000000LL) / mSampleRate;      // 0.95
286             mWarmupNsMin = (frameCount * 750000000LL) / mSampleRate;  // 0.75
287             mWarmupNsMax = (frameCount * 1250000000LL) / mSampleRate; // 1.25
288         } else {
289             mPeriodNs = 0;
290             mUnderrunNs = 0;
291             mOverrunNs = 0;
292             mForceNs = 0;
293             mWarmupNsMin = 0;
294             mWarmupNsMax = LONG_MAX;
295         }
296         mMixerBufferState = UNDEFINED;
297         // we need to reconfigure all active tracks
298         previousTrackMask = 0;
299         mFastTracksGen = current->mFastTracksGen - 1;
300         dumpState->mFrameCount = frameCount;
301 #ifdef TEE_SINK
302         mTee.set(mFormat, NBAIO_Tee::TEE_FLAG_OUTPUT_THREAD);
303         mTee.setId(std::string("_") + std::to_string(mThreadIoHandle) + "_F");
304 #endif
305     } else {
306         previousTrackMask = previous->mTrackMask;
307     }
308 
309     // check for change in active track set
310     const unsigned currentTrackMask = current->mTrackMask;
311     dumpState->mTrackMask = currentTrackMask;
312     dumpState->mNumTracks = popcount(currentTrackMask);
313     if (current->mFastTracksGen != mFastTracksGen) {
314 
315         // process removed tracks first to avoid running out of track names
316         unsigned removedTracks = previousTrackMask & ~currentTrackMask;
317         while (removedTracks != 0) {
318             int i = __builtin_ctz(removedTracks);
319             removedTracks &= ~(1 << i);
320             updateMixerTrack(i, REASON_REMOVE);
321             // don't reset track dump state, since other side is ignoring it
322         }
323 
324         // now process added tracks
325         unsigned addedTracks = currentTrackMask & ~previousTrackMask;
326         while (addedTracks != 0) {
327             int i = __builtin_ctz(addedTracks);
328             addedTracks &= ~(1 << i);
329             updateMixerTrack(i, REASON_ADD);
330         }
331 
332         // finally process (potentially) modified tracks; these use the same slot
333         // but may have a different buffer provider or volume provider
334         unsigned modifiedTracks = currentTrackMask & previousTrackMask;
335         while (modifiedTracks != 0) {
336             int i = __builtin_ctz(modifiedTracks);
337             modifiedTracks &= ~(1 << i);
338             updateMixerTrack(i, REASON_MODIFY);
339         }
340 
341         mFastTracksGen = current->mFastTracksGen;
342     }
343 }
344 
onWork()345 void FastMixer::onWork()
346 {
347     // TODO: pass an ID parameter to indicate which time series we want to write to in NBLog.cpp
348     // Or: pass both of these into a single call with a boolean
349     const FastMixerState * const current = (const FastMixerState *) mCurrent;
350     FastMixerDumpState * const dumpState = (FastMixerDumpState *) mDumpState;
351 
352     if (mIsWarm) {
353         // Logging timestamps for FastMixer is currently disabled to make memory room for logging
354         // other statistics in FastMixer.
355         // To re-enable, delete the #ifdef FASTMIXER_LOG_HIST_TS lines (and the #endif lines).
356 #ifdef FASTMIXER_LOG_HIST_TS
357         LOG_HIST_TS();
358 #endif
359         //ALOGD("Eric FastMixer::onWork() mIsWarm");
360     } else {
361         dumpState->mTimestampVerifier.discontinuity();
362         // See comment in if block.
363 #ifdef FASTMIXER_LOG_HIST_TS
364         LOG_AUDIO_STATE();
365 #endif
366     }
367     const FastMixerState::Command command = mCommand;
368     const size_t frameCount = current->mFrameCount;
369 
370     if ((command & FastMixerState::MIX) && (mMixer != NULL) && mIsWarm) {
371         ALOG_ASSERT(mMixerBuffer != NULL);
372 
373         // AudioMixer::mState.enabledTracks is undefined if mState.hook == process__validate,
374         // so we keep a side copy of enabledTracks
375         bool anyEnabledTracks = false;
376 
377         // for each track, update volume and check for underrun
378         unsigned currentTrackMask = current->mTrackMask;
379         while (currentTrackMask != 0) {
380             int i = __builtin_ctz(currentTrackMask);
381             currentTrackMask &= ~(1 << i);
382             const FastTrack* fastTrack = &current->mFastTracks[i];
383 
384             const int64_t trackFramesWrittenButNotPresented =
385                 mNativeFramesWrittenButNotPresented;
386             const int64_t trackFramesWritten = fastTrack->mBufferProvider->framesReleased();
387             ExtendedTimestamp perTrackTimestamp(mTimestamp);
388 
389             // Can't provide an ExtendedTimestamp before first frame presented.
390             // Also, timestamp may not go to very last frame on stop().
391             if (trackFramesWritten >= trackFramesWrittenButNotPresented &&
392                     perTrackTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL] > 0) {
393                 perTrackTimestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL] =
394                         trackFramesWritten - trackFramesWrittenButNotPresented;
395             } else {
396                 perTrackTimestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL] = 0;
397                 perTrackTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL] = -1;
398             }
399             perTrackTimestamp.mPosition[ExtendedTimestamp::LOCATION_SERVER] = trackFramesWritten;
400             fastTrack->mBufferProvider->onTimestamp(perTrackTimestamp);
401 
402             const int name = i;
403             if (fastTrack->mVolumeProvider != NULL) {
404                 gain_minifloat_packed_t vlr = fastTrack->mVolumeProvider->getVolumeLR();
405                 float vlf = float_from_gain(gain_minifloat_unpack_left(vlr));
406                 float vrf = float_from_gain(gain_minifloat_unpack_right(vlr));
407 
408                 mMixer->setParameter(name, AudioMixer::RAMP_VOLUME, AudioMixer::VOLUME0, &vlf);
409                 mMixer->setParameter(name, AudioMixer::RAMP_VOLUME, AudioMixer::VOLUME1, &vrf);
410             }
411             // FIXME The current implementation of framesReady() for fast tracks
412             // takes a tryLock, which can block
413             // up to 1 ms.  If enough active tracks all blocked in sequence, this would result
414             // in the overall fast mix cycle being delayed.  Should use a non-blocking FIFO.
415             size_t framesReady = fastTrack->mBufferProvider->framesReady();
416             if (ATRACE_ENABLED()) {
417                 // I wish we had formatted trace names
418                 char traceName[16];
419                 strcpy(traceName, "fRdy");
420                 traceName[4] = i + (i < 10 ? '0' : 'A' - 10);
421                 traceName[5] = '\0';
422                 ATRACE_INT(traceName, framesReady);
423             }
424             FastTrackDump *ftDump = &dumpState->mTracks[i];
425             FastTrackUnderruns underruns = ftDump->mUnderruns;
426             if (framesReady < frameCount) {
427                 if (framesReady == 0) {
428                     underruns.mBitFields.mEmpty++;
429                     underruns.mBitFields.mMostRecent = UNDERRUN_EMPTY;
430                     mMixer->disable(name);
431                 } else {
432                     // allow mixing partial buffer
433                     underruns.mBitFields.mPartial++;
434                     underruns.mBitFields.mMostRecent = UNDERRUN_PARTIAL;
435                     mMixer->enable(name);
436                     anyEnabledTracks = true;
437                 }
438             } else {
439                 underruns.mBitFields.mFull++;
440                 underruns.mBitFields.mMostRecent = UNDERRUN_FULL;
441                 mMixer->enable(name);
442                 anyEnabledTracks = true;
443             }
444             ftDump->mUnderruns = underruns;
445             ftDump->mFramesReady = framesReady;
446             ftDump->mFramesWritten = trackFramesWritten;
447         }
448 
449         if (anyEnabledTracks) {
450             // process() is CPU-bound
451             mMixer->process();
452             mMixerBufferState = MIXED;
453         } else if (mMixerBufferState != ZEROED) {
454             mMixerBufferState = UNDEFINED;
455         }
456 
457     } else if (mMixerBufferState == MIXED) {
458         mMixerBufferState = UNDEFINED;
459     }
460     //bool didFullWrite = false;    // dumpsys could display a count of partial writes
461     if ((command & FastMixerState::WRITE) && (mOutputSink != NULL) && (mMixerBuffer != NULL)) {
462         if (mMixerBufferState == UNDEFINED) {
463             memset(mMixerBuffer, 0, mMixerBufferSize);
464             mMixerBufferState = ZEROED;
465         }
466 
467         if (mMasterMono.load()) {  // memory_order_seq_cst
468             mono_blend(mMixerBuffer, mMixerBufferFormat, Format_channelCount(mFormat), frameCount,
469                     true /*limit*/);
470         }
471 
472         // Balance must take effect after mono conversion.
473         // mBalance detects zero balance within the class for speed (not needed here).
474         mBalance.setBalance(mMasterBalance.load());
475         mBalance.process((float *)mMixerBuffer, frameCount);
476 
477         // prepare the buffer used to write to sink
478         void *buffer = mSinkBuffer != NULL ? mSinkBuffer : mMixerBuffer;
479         if (mFormat.mFormat != mMixerBufferFormat) { // sink format not the same as mixer format
480             memcpy_by_audio_format(buffer, mFormat.mFormat, mMixerBuffer, mMixerBufferFormat,
481                     frameCount * Format_channelCount(mFormat));
482         }
483         if (mSinkChannelMask & AUDIO_CHANNEL_HAPTIC_ALL) {
484             // When there are haptic channels, the sample data is partially interleaved.
485             // Make the sample data fully interleaved here.
486             adjust_channels_non_destructive(buffer, mAudioChannelCount, buffer, mSinkChannelCount,
487                     audio_bytes_per_sample(mFormat.mFormat),
488                     frameCount * audio_bytes_per_frame(mAudioChannelCount, mFormat.mFormat));
489         }
490         // if non-NULL, then duplicate write() to this non-blocking sink
491 #ifdef TEE_SINK
492         mTee.write(buffer, frameCount);
493 #endif
494         // FIXME write() is non-blocking and lock-free for a properly implemented NBAIO sink,
495         //       but this code should be modified to handle both non-blocking and blocking sinks
496         dumpState->mWriteSequence++;
497         ATRACE_BEGIN("write");
498         ssize_t framesWritten = mOutputSink->write(buffer, frameCount);
499         ATRACE_END();
500         dumpState->mWriteSequence++;
501         if (framesWritten >= 0) {
502             ALOG_ASSERT((size_t) framesWritten <= frameCount);
503             mTotalNativeFramesWritten += framesWritten;
504             dumpState->mFramesWritten = mTotalNativeFramesWritten;
505             //if ((size_t) framesWritten == frameCount) {
506             //    didFullWrite = true;
507             //}
508         } else {
509             dumpState->mWriteErrors++;
510         }
511         mAttemptedWrite = true;
512         // FIXME count # of writes blocked excessively, CPU usage, etc. for dump
513 
514         if (mIsWarm) {
515             ExtendedTimestamp timestamp; // local
516             status_t status = mOutputSink->getTimestamp(timestamp);
517             if (status == NO_ERROR) {
518                 dumpState->mTimestampVerifier.add(
519                         timestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL],
520                         timestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL],
521                         mSampleRate);
522                 const int64_t totalNativeFramesPresented =
523                         timestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL];
524                 if (totalNativeFramesPresented <= mTotalNativeFramesWritten) {
525                     mNativeFramesWrittenButNotPresented =
526                         mTotalNativeFramesWritten - totalNativeFramesPresented;
527                     mTimestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL] =
528                             timestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL];
529                     mTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL] =
530                             timestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL];
531                     // We don't compensate for server - kernel time difference and
532                     // only update latency if we have valid info.
533                     const double latencyMs =
534                             (double)mNativeFramesWrittenButNotPresented * 1000 / mSampleRate;
535                     dumpState->mLatencyMs = latencyMs;
536                     LOG_LATENCY(latencyMs);
537                 } else {
538                     // HAL reported that more frames were presented than were written
539                     mNativeFramesWrittenButNotPresented = 0;
540                     status = INVALID_OPERATION;
541                 }
542             } else {
543                 dumpState->mTimestampVerifier.error();
544             }
545             if (status == NO_ERROR) {
546                 mTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_SERVER] =
547                         mTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL];
548             } else {
549                 // fetch server time if we can't get timestamp
550                 mTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_SERVER] =
551                         systemTime(SYSTEM_TIME_MONOTONIC);
552                 // clear out kernel cached position as this may get rapidly stale
553                 // if we never get a new valid timestamp
554                 mTimestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL] = 0;
555                 mTimestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL] = -1;
556             }
557         }
558     }
559 }
560 
561 }   // namespace android
562