AudioTrack.cpp revision cfe2ba6b01a258e39f9c215ffc7b750e0b68f708 
1/* //device/extlibs/pv/android/AudioTrack.cpp
2**
3** Copyright 2007, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18
19//#define LOG_NDEBUG 0
20#define LOG_TAG "AudioTrack"
21
22#include <stdint.h>
23#include <sys/types.h>
24#include <limits.h>
25
26#include <sched.h>
27#include <sys/resource.h>
28
29#include <private/media/AudioTrackShared.h>
30
31#include <media/AudioSystem.h>
32#include <media/AudioTrack.h>
33
34#include <utils/Log.h>
35#include <binder/Parcel.h>
36#include <binder/IPCThreadState.h>
37#include <utils/Timers.h>
38#include <utils/Atomic.h>
39
40#include <cutils/bitops.h>
41
42#include <system/audio.h>
43#include <system/audio_policy.h>
44
45#define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
46#define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
47
48namespace android {
49// ---------------------------------------------------------------------------
50
51// static
52status_t AudioTrack::getMinFrameCount(
53        int* frameCount,
54        int streamType,
55        uint32_t sampleRate)
56{
57    int afSampleRate;
58    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
59        return NO_INIT;
60    }
61    int afFrameCount;
62    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
63        return NO_INIT;
64    }
65    uint32_t afLatency;
66    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
67        return NO_INIT;
68    }
69
70    // Ensure that buffer depth covers at least audio hardware latency
71    uint32_t minBufCount = afLatency / ((1000 * afFrameCount) / afSampleRate);
72    if (minBufCount < 2) minBufCount = 2;
73
74    *frameCount = (sampleRate == 0) ? afFrameCount * minBufCount :
75              afFrameCount * minBufCount * sampleRate / afSampleRate;
76    return NO_ERROR;
77}
78
79// ---------------------------------------------------------------------------
80
81AudioTrack::AudioTrack()
82    : mStatus(NO_INIT)
83{
84}
85
86AudioTrack::AudioTrack(
87        int streamType,
88        uint32_t sampleRate,
89        int format,
90        int channelMask,
91        int frameCount,
92        uint32_t flags,
93        callback_t cbf,
94        void* user,
95        int notificationFrames,
96        int sessionId)
97    : mStatus(NO_INIT)
98{
99    mStatus = set(streamType, sampleRate, format, channelMask,
100            frameCount, flags, cbf, user, notificationFrames,
101            0, false, sessionId);
102}
103
104AudioTrack::AudioTrack(
105        int streamType,
106        uint32_t sampleRate,
107        int format,
108        int channelMask,
109        const sp<IMemory>& sharedBuffer,
110        uint32_t flags,
111        callback_t cbf,
112        void* user,
113        int notificationFrames,
114        int sessionId)
115    : mStatus(NO_INIT)
116{
117    mStatus = set(streamType, sampleRate, format, channelMask,
118            0, flags, cbf, user, notificationFrames,
119            sharedBuffer, false, sessionId);
120}
121
122AudioTrack::~AudioTrack()
123{
124    LOGV_IF(mSharedBuffer != 0, "Destructor sharedBuffer: %p", mSharedBuffer->pointer());
125
126    if (mStatus == NO_ERROR) {
127        // Make sure that callback function exits in the case where
128        // it is looping on buffer full condition in obtainBuffer().
129        // Otherwise the callback thread will never exit.
130        stop();
131        if (mAudioTrackThread != 0) {
132            mAudioTrackThread->requestExitAndWait();
133            mAudioTrackThread.clear();
134        }
135        mAudioTrack.clear();
136        IPCThreadState::self()->flushCommands();
137        AudioSystem::releaseAudioSessionId(mSessionId);
138    }
139}
140
141status_t AudioTrack::set(
142        int streamType,
143        uint32_t sampleRate,
144        int format,
145        int channelMask,
146        int frameCount,
147        uint32_t flags,
148        callback_t cbf,
149        void* user,
150        int notificationFrames,
151        const sp<IMemory>& sharedBuffer,
152        bool threadCanCallJava,
153        int sessionId)
154{
155
156    LOGV_IF(sharedBuffer != 0, "sharedBuffer: %p, size: %d", sharedBuffer->pointer(), sharedBuffer->size());
157
158    AutoMutex lock(mLock);
159    if (mAudioTrack != 0) {
160        LOGE("Track already in use");
161        return INVALID_OPERATION;
162    }
163
164    int afSampleRate;
165    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
166        return NO_INIT;
167    }
168    uint32_t afLatency;
169    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
170        return NO_INIT;
171    }
172
173    // handle default values first.
174    if (streamType == AUDIO_STREAM_DEFAULT) {
175        streamType = AUDIO_STREAM_MUSIC;
176    }
177    if (sampleRate == 0) {
178        sampleRate = afSampleRate;
179    }
180    // these below should probably come from the audioFlinger too...
181    if (format == 0) {
182        format = AUDIO_FORMAT_PCM_16_BIT;
183    }
184    if (channelMask == 0) {
185        channelMask = AUDIO_CHANNEL_OUT_STEREO;
186    }
187
188    // validate parameters
189    if (!audio_is_valid_format(format)) {
190        LOGE("Invalid format");
191        return BAD_VALUE;
192    }
193
194    // force direct flag if format is not linear PCM
195    if (!audio_is_linear_pcm(format)) {
196        flags |= AUDIO_POLICY_OUTPUT_FLAG_DIRECT;
197    }
198
199    if (!audio_is_output_channel(channelMask)) {
200        LOGE("Invalid channel mask");
201        return BAD_VALUE;
202    }
203    uint32_t channelCount = popcount(channelMask);
204
205    audio_io_handle_t output = AudioSystem::getOutput(
206                                    (audio_stream_type_t)streamType,
207                                    sampleRate,format, channelMask,
208                                    (audio_policy_output_flags_t)flags);
209
210    if (output == 0) {
211        LOGE("Could not get audio output for stream type %d", streamType);
212        return BAD_VALUE;
213    }
214
215    mVolume[LEFT] = 1.0f;
216    mVolume[RIGHT] = 1.0f;
217    mSendLevel = 0;
218    mFrameCount = frameCount;
219    mNotificationFramesReq = notificationFrames;
220    mSessionId = sessionId;
221    mAuxEffectId = 0;
222
223    // create the IAudioTrack
224    status_t status = createTrack_l(streamType,
225                                  sampleRate,
226                                  (uint32_t)format,
227                                  (uint32_t)channelMask,
228                                  frameCount,
229                                  flags,
230                                  sharedBuffer,
231                                  output,
232                                  true);
233
234    if (status != NO_ERROR) {
235        return status;
236    }
237
238    if (cbf != 0) {
239        mAudioTrackThread = new AudioTrackThread(*this, threadCanCallJava);
240        if (mAudioTrackThread == 0) {
241          LOGE("Could not create callback thread");
242          return NO_INIT;
243        }
244    }
245
246    mStatus = NO_ERROR;
247
248    mStreamType = streamType;
249    mFormat = (uint32_t)format;
250    mChannelMask = (uint32_t)channelMask;
251    mChannelCount = channelCount;
252    mSharedBuffer = sharedBuffer;
253    mMuted = false;
254    mActive = 0;
255    mCbf = cbf;
256    mUserData = user;
257    mLoopCount = 0;
258    mMarkerPosition = 0;
259    mMarkerReached = false;
260    mNewPosition = 0;
261    mUpdatePeriod = 0;
262    mFlushed = false;
263    mFlags = flags;
264    AudioSystem::acquireAudioSessionId(mSessionId);
265    mRestoreStatus = NO_ERROR;
266    return NO_ERROR;
267}
268
269status_t AudioTrack::initCheck() const
270{
271    return mStatus;
272}
273
274// -------------------------------------------------------------------------
275
276uint32_t AudioTrack::latency() const
277{
278    return mLatency;
279}
280
281int AudioTrack::streamType() const
282{
283    return mStreamType;
284}
285
286int AudioTrack::format() const
287{
288    return mFormat;
289}
290
291int AudioTrack::channelCount() const
292{
293    return mChannelCount;
294}
295
296uint32_t AudioTrack::frameCount() const
297{
298    return mCblk->frameCount;
299}
300
301int AudioTrack::frameSize() const
302{
303    if (audio_is_linear_pcm(mFormat)) {
304        return channelCount()*audio_bytes_per_sample(mFormat);
305    } else {
306        return sizeof(uint8_t);
307    }
308}
309
310sp<IMemory>& AudioTrack::sharedBuffer()
311{
312    return mSharedBuffer;
313}
314
315// -------------------------------------------------------------------------
316
317void AudioTrack::start()
318{
319    sp<AudioTrackThread> t = mAudioTrackThread;
320    status_t status = NO_ERROR;
321
322    LOGV("start %p", this);
323    if (t != 0) {
324        if (t->exitPending()) {
325            if (t->requestExitAndWait() == WOULD_BLOCK) {
326                LOGE("AudioTrack::start called from thread");
327                return;
328            }
329        }
330        t->mLock.lock();
331     }
332
333    AutoMutex lock(mLock);
334    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
335    // while we are accessing the cblk
336    sp <IAudioTrack> audioTrack = mAudioTrack;
337    sp <IMemory> iMem = mCblkMemory;
338    audio_track_cblk_t* cblk = mCblk;
339
340    if (mActive == 0) {
341        mFlushed = false;
342        mActive = 1;
343        mNewPosition = cblk->server + mUpdatePeriod;
344        cblk->lock.lock();
345        cblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
346        cblk->waitTimeMs = 0;
347        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
348        if (t != 0) {
349           t->run("AudioTrackThread", ANDROID_PRIORITY_AUDIO);
350        } else {
351            setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_AUDIO);
352        }
353
354        LOGV("start %p before lock cblk %p", this, mCblk);
355        if (!(cblk->flags & CBLK_INVALID_MSK)) {
356            cblk->lock.unlock();
357            status = mAudioTrack->start();
358            cblk->lock.lock();
359            if (status == DEAD_OBJECT) {
360                android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
361            }
362        }
363        if (cblk->flags & CBLK_INVALID_MSK) {
364            status = restoreTrack_l(cblk, true);
365        }
366        cblk->lock.unlock();
367        if (status != NO_ERROR) {
368            LOGV("start() failed");
369            mActive = 0;
370            if (t != 0) {
371                t->requestExit();
372            } else {
373                setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
374            }
375        }
376    }
377
378    if (t != 0) {
379        t->mLock.unlock();
380    }
381}
382
383void AudioTrack::stop()
384{
385    sp<AudioTrackThread> t = mAudioTrackThread;
386
387    LOGV("stop %p", this);
388    if (t != 0) {
389        t->mLock.lock();
390    }
391
392    AutoMutex lock(mLock);
393    if (mActive == 1) {
394        mActive = 0;
395        mCblk->cv.signal();
396        mAudioTrack->stop();
397        // Cancel loops (If we are in the middle of a loop, playback
398        // would not stop until loopCount reaches 0).
399        setLoop_l(0, 0, 0);
400        // the playback head position will reset to 0, so if a marker is set, we need
401        // to activate it again
402        mMarkerReached = false;
403        // Force flush if a shared buffer is used otherwise audioflinger
404        // will not stop before end of buffer is reached.
405        if (mSharedBuffer != 0) {
406            flush_l();
407        }
408        if (t != 0) {
409            t->requestExit();
410        } else {
411            setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_NORMAL);
412        }
413    }
414
415    if (t != 0) {
416        t->mLock.unlock();
417    }
418}
419
420bool AudioTrack::stopped() const
421{
422    return !mActive;
423}
424
425void AudioTrack::flush()
426{
427    AutoMutex lock(mLock);
428    flush_l();
429}
430
431// must be called with mLock held
432void AudioTrack::flush_l()
433{
434    LOGV("flush");
435
436    // clear playback marker and periodic update counter
437    mMarkerPosition = 0;
438    mMarkerReached = false;
439    mUpdatePeriod = 0;
440
441    if (!mActive) {
442        mFlushed = true;
443        mAudioTrack->flush();
444        // Release AudioTrack callback thread in case it was waiting for new buffers
445        // in AudioTrack::obtainBuffer()
446        mCblk->cv.signal();
447    }
448}
449
450void AudioTrack::pause()
451{
452    LOGV("pause");
453    AutoMutex lock(mLock);
454    if (mActive == 1) {
455        mActive = 0;
456        mAudioTrack->pause();
457    }
458}
459
460void AudioTrack::mute(bool e)
461{
462    mAudioTrack->mute(e);
463    mMuted = e;
464}
465
466bool AudioTrack::muted() const
467{
468    return mMuted;
469}
470
471status_t AudioTrack::setVolume(float left, float right)
472{
473    if (left > 1.0f || right > 1.0f) {
474        return BAD_VALUE;
475    }
476
477    AutoMutex lock(mLock);
478    mVolume[LEFT] = left;
479    mVolume[RIGHT] = right;
480
481    // write must be atomic
482    mCblk->volumeLR = (uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000);
483
484    return NO_ERROR;
485}
486
487void AudioTrack::getVolume(float* left, float* right)
488{
489    if (left != NULL) {
490        *left  = mVolume[LEFT];
491    }
492    if (right != NULL) {
493        *right = mVolume[RIGHT];
494    }
495}
496
497status_t AudioTrack::setAuxEffectSendLevel(float level)
498{
499    LOGV("setAuxEffectSendLevel(%f)", level);
500    if (level > 1.0f) {
501        return BAD_VALUE;
502    }
503    AutoMutex lock(mLock);
504
505    mSendLevel = level;
506
507    mCblk->sendLevel = uint16_t(level * 0x1000);
508
509    return NO_ERROR;
510}
511
512void AudioTrack::getAuxEffectSendLevel(float* level)
513{
514    if (level != NULL) {
515        *level  = mSendLevel;
516    }
517}
518
519status_t AudioTrack::setSampleRate(int rate)
520{
521    int afSamplingRate;
522
523    if (AudioSystem::getOutputSamplingRate(&afSamplingRate, mStreamType) != NO_ERROR) {
524        return NO_INIT;
525    }
526    // Resampler implementation limits input sampling rate to 2 x output sampling rate.
527    if (rate <= 0 || rate > afSamplingRate*2 ) return BAD_VALUE;
528
529    AutoMutex lock(mLock);
530    mCblk->sampleRate = rate;
531    return NO_ERROR;
532}
533
534uint32_t AudioTrack::getSampleRate()
535{
536    AutoMutex lock(mLock);
537    return mCblk->sampleRate;
538}
539
540status_t AudioTrack::setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount)
541{
542    AutoMutex lock(mLock);
543    return setLoop_l(loopStart, loopEnd, loopCount);
544}
545
546// must be called with mLock held
547status_t AudioTrack::setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount)
548{
549    audio_track_cblk_t* cblk = mCblk;
550
551    Mutex::Autolock _l(cblk->lock);
552
553    if (loopCount == 0) {
554        cblk->loopStart = UINT_MAX;
555        cblk->loopEnd = UINT_MAX;
556        cblk->loopCount = 0;
557        mLoopCount = 0;
558        return NO_ERROR;
559    }
560
561    if (loopStart >= loopEnd ||
562        loopEnd - loopStart > cblk->frameCount ||
563        cblk->server > loopStart) {
564        LOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, cblk->frameCount, cblk->user);
565        return BAD_VALUE;
566    }
567
568    if ((mSharedBuffer != 0) && (loopEnd > cblk->frameCount)) {
569        LOGE("setLoop invalid value: loop markers beyond data: loopStart %d, loopEnd %d, framecount %d",
570            loopStart, loopEnd, cblk->frameCount);
571        return BAD_VALUE;
572    }
573
574    cblk->loopStart = loopStart;
575    cblk->loopEnd = loopEnd;
576    cblk->loopCount = loopCount;
577    mLoopCount = loopCount;
578
579    return NO_ERROR;
580}
581
582status_t AudioTrack::getLoop(uint32_t *loopStart, uint32_t *loopEnd, int *loopCount)
583{
584    AutoMutex lock(mLock);
585    if (loopStart != 0) {
586        *loopStart = mCblk->loopStart;
587    }
588    if (loopEnd != 0) {
589        *loopEnd = mCblk->loopEnd;
590    }
591    if (loopCount != 0) {
592        if (mCblk->loopCount < 0) {
593            *loopCount = -1;
594        } else {
595            *loopCount = mCblk->loopCount;
596        }
597    }
598
599    return NO_ERROR;
600}
601
602status_t AudioTrack::setMarkerPosition(uint32_t marker)
603{
604    if (mCbf == 0) return INVALID_OPERATION;
605
606    mMarkerPosition = marker;
607    mMarkerReached = false;
608
609    return NO_ERROR;
610}
611
612status_t AudioTrack::getMarkerPosition(uint32_t *marker)
613{
614    if (marker == 0) return BAD_VALUE;
615
616    *marker = mMarkerPosition;
617
618    return NO_ERROR;
619}
620
621status_t AudioTrack::setPositionUpdatePeriod(uint32_t updatePeriod)
622{
623    if (mCbf == 0) return INVALID_OPERATION;
624
625    uint32_t curPosition;
626    getPosition(&curPosition);
627    mNewPosition = curPosition + updatePeriod;
628    mUpdatePeriod = updatePeriod;
629
630    return NO_ERROR;
631}
632
633status_t AudioTrack::getPositionUpdatePeriod(uint32_t *updatePeriod)
634{
635    if (updatePeriod == 0) return BAD_VALUE;
636
637    *updatePeriod = mUpdatePeriod;
638
639    return NO_ERROR;
640}
641
642status_t AudioTrack::setPosition(uint32_t position)
643{
644    AutoMutex lock(mLock);
645    Mutex::Autolock _l(mCblk->lock);
646
647    if (!stopped()) return INVALID_OPERATION;
648
649    if (position > mCblk->user) return BAD_VALUE;
650
651    mCblk->server = position;
652    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
653
654    return NO_ERROR;
655}
656
657status_t AudioTrack::getPosition(uint32_t *position)
658{
659    if (position == 0) return BAD_VALUE;
660    AutoMutex lock(mLock);
661    *position = mFlushed ? 0 : mCblk->server;
662
663    return NO_ERROR;
664}
665
666status_t AudioTrack::reload()
667{
668    AutoMutex lock(mLock);
669
670    if (!stopped()) return INVALID_OPERATION;
671
672    flush_l();
673
674    mCblk->stepUser(mCblk->frameCount);
675
676    return NO_ERROR;
677}
678
679audio_io_handle_t AudioTrack::getOutput()
680{
681    AutoMutex lock(mLock);
682    return getOutput_l();
683}
684
685// must be called with mLock held
686audio_io_handle_t AudioTrack::getOutput_l()
687{
688    return AudioSystem::getOutput((audio_stream_type_t)mStreamType,
689            mCblk->sampleRate, mFormat, mChannelMask, (audio_policy_output_flags_t)mFlags);
690}
691
692int AudioTrack::getSessionId()
693{
694    return mSessionId;
695}
696
697status_t AudioTrack::attachAuxEffect(int effectId)
698{
699    LOGV("attachAuxEffect(%d)", effectId);
700    status_t status = mAudioTrack->attachAuxEffect(effectId);
701    if (status == NO_ERROR) {
702        mAuxEffectId = effectId;
703    }
704    return status;
705}
706
707// -------------------------------------------------------------------------
708
709// must be called with mLock held
710status_t AudioTrack::createTrack_l(
711        int streamType,
712        uint32_t sampleRate,
713        uint32_t format,
714        uint32_t channelMask,
715        int frameCount,
716        uint32_t flags,
717        const sp<IMemory>& sharedBuffer,
718        audio_io_handle_t output,
719        bool enforceFrameCount)
720{
721    status_t status;
722    const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
723    if (audioFlinger == 0) {
724       LOGE("Could not get audioflinger");
725       return NO_INIT;
726    }
727
728    int afSampleRate;
729    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
730        return NO_INIT;
731    }
732    int afFrameCount;
733    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
734        return NO_INIT;
735    }
736    uint32_t afLatency;
737    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
738        return NO_INIT;
739    }
740
741    mNotificationFramesAct = mNotificationFramesReq;
742    if (!audio_is_linear_pcm(format)) {
743        if (sharedBuffer != 0) {
744            frameCount = sharedBuffer->size();
745        }
746    } else {
747        // Ensure that buffer depth covers at least audio hardware latency
748        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
749        if (minBufCount < 2) minBufCount = 2;
750
751        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
752
753        if (sharedBuffer == 0) {
754            if (frameCount == 0) {
755                frameCount = minFrameCount;
756            }
757            if (mNotificationFramesAct == 0) {
758                mNotificationFramesAct = frameCount/2;
759            }
760            // Make sure that application is notified with sufficient margin
761            // before underrun
762            if (mNotificationFramesAct > (uint32_t)frameCount/2) {
763                mNotificationFramesAct = frameCount/2;
764            }
765            if (frameCount < minFrameCount) {
766                if (enforceFrameCount) {
767                    LOGE("Invalid buffer size: minFrameCount %d, frameCount %d", minFrameCount, frameCount);
768                    return BAD_VALUE;
769                } else {
770                    frameCount = minFrameCount;
771                }
772            }
773        } else {
774            // Ensure that buffer alignment matches channelcount
775            int channelCount = popcount(channelMask);
776            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
777                LOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
778                return BAD_VALUE;
779            }
780            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
781        }
782    }
783
784    sp<IAudioTrack> track = audioFlinger->createTrack(getpid(),
785                                                      streamType,
786                                                      sampleRate,
787                                                      format,
788                                                      channelMask,
789                                                      frameCount,
790                                                      ((uint16_t)flags) << 16,
791                                                      sharedBuffer,
792                                                      output,
793                                                      &mSessionId,
794                                                      &status);
795
796    if (track == 0) {
797        LOGE("AudioFlinger could not create track, status: %d", status);
798        return status;
799    }
800    sp<IMemory> cblk = track->getCblk();
801    if (cblk == 0) {
802        LOGE("Could not get control block");
803        return NO_INIT;
804    }
805    mAudioTrack.clear();
806    mAudioTrack = track;
807    mCblkMemory.clear();
808    mCblkMemory = cblk;
809    mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
810    android_atomic_or(CBLK_DIRECTION_OUT, &mCblk->flags);
811    if (sharedBuffer == 0) {
812        mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
813    } else {
814        mCblk->buffers = sharedBuffer->pointer();
815         // Force buffer full condition as data is already present in shared memory
816        mCblk->stepUser(mCblk->frameCount);
817    }
818
819    mCblk->volumeLR = (uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000);
820    mCblk->sendLevel = uint16_t(mSendLevel * 0x1000);
821    mAudioTrack->attachAuxEffect(mAuxEffectId);
822    mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
823    mCblk->waitTimeMs = 0;
824    mRemainingFrames = mNotificationFramesAct;
825    mLatency = afLatency + (1000*mCblk->frameCount) / sampleRate;
826    return NO_ERROR;
827}
828
829status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
830{
831    AutoMutex lock(mLock);
832    int active;
833    status_t result = NO_ERROR;
834    audio_track_cblk_t* cblk = mCblk;
835    uint32_t framesReq = audioBuffer->frameCount;
836    uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;
837
838    audioBuffer->frameCount  = 0;
839    audioBuffer->size = 0;
840
841    uint32_t framesAvail = cblk->framesAvailable();
842
843    cblk->lock.lock();
844    if (cblk->flags & CBLK_INVALID_MSK) {
845        goto create_new_track;
846    }
847    cblk->lock.unlock();
848
849    if (framesAvail == 0) {
850        cblk->lock.lock();
851        goto start_loop_here;
852        while (framesAvail == 0) {
853            active = mActive;
854            if (UNLIKELY(!active)) {
855                LOGV("Not active and NO_MORE_BUFFERS");
856                cblk->lock.unlock();
857                return NO_MORE_BUFFERS;
858            }
859            if (UNLIKELY(!waitCount)) {
860                cblk->lock.unlock();
861                return WOULD_BLOCK;
862            }
863            if (!(cblk->flags & CBLK_INVALID_MSK)) {
864                mLock.unlock();
865                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
866                cblk->lock.unlock();
867                mLock.lock();
868                if (mActive == 0) {
869                    return status_t(STOPPED);
870                }
871                cblk->lock.lock();
872            }
873
874            if (cblk->flags & CBLK_INVALID_MSK) {
875                goto create_new_track;
876            }
877            if (__builtin_expect(result!=NO_ERROR, false)) {
878                cblk->waitTimeMs += waitTimeMs;
879                if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
880                    // timing out when a loop has been set and we have already written upto loop end
881                    // is a normal condition: no need to wake AudioFlinger up.
882                    if (cblk->user < cblk->loopEnd) {
883                        LOGW(   "obtainBuffer timed out (is the CPU pegged?) %p "
884                                "user=%08x, server=%08x", this, cblk->user, cblk->server);
885                        //unlock cblk mutex before calling mAudioTrack->start() (see issue #1617140)
886                        cblk->lock.unlock();
887                        result = mAudioTrack->start();
888                        cblk->lock.lock();
889                        if (result == DEAD_OBJECT) {
890                            android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
891create_new_track:
892                            result = restoreTrack_l(cblk, false);
893                        }
894                        if (result != NO_ERROR) {
895                            LOGW("obtainBuffer create Track error %d", result);
896                            cblk->lock.unlock();
897                            return result;
898                        }
899                    }
900                    cblk->waitTimeMs = 0;
901                }
902
903                if (--waitCount == 0) {
904                    cblk->lock.unlock();
905                    return TIMED_OUT;
906                }
907            }
908            // read the server count again
909        start_loop_here:
910            framesAvail = cblk->framesAvailable_l();
911        }
912        cblk->lock.unlock();
913    }
914
915    // restart track if it was disabled by audioflinger due to previous underrun
916    if (mActive && (cblk->flags & CBLK_DISABLED_MSK)) {
917        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
918        LOGW("obtainBuffer() track %p disabled, restarting", this);
919        mAudioTrack->start();
920    }
921
922    cblk->waitTimeMs = 0;
923
924    if (framesReq > framesAvail) {
925        framesReq = framesAvail;
926    }
927
928    uint32_t u = cblk->user;
929    uint32_t bufferEnd = cblk->userBase + cblk->frameCount;
930
931    if (u + framesReq > bufferEnd) {
932        framesReq = bufferEnd - u;
933    }
934
935    audioBuffer->flags = mMuted ? Buffer::MUTE : 0;
936    audioBuffer->channelCount = mChannelCount;
937    audioBuffer->frameCount = framesReq;
938    audioBuffer->size = framesReq * cblk->frameSize;
939    if (audio_is_linear_pcm(mFormat)) {
940        audioBuffer->format = AUDIO_FORMAT_PCM_16_BIT;
941    } else {
942        audioBuffer->format = mFormat;
943    }
944    audioBuffer->raw = (int8_t *)cblk->buffer(u);
945    active = mActive;
946    return active ? status_t(NO_ERROR) : status_t(STOPPED);
947}
948
949void AudioTrack::releaseBuffer(Buffer* audioBuffer)
950{
951    AutoMutex lock(mLock);
952    mCblk->stepUser(audioBuffer->frameCount);
953}
954
955// -------------------------------------------------------------------------
956
957ssize_t AudioTrack::write(const void* buffer, size_t userSize)
958{
959
960    if (mSharedBuffer != 0) return INVALID_OPERATION;
961
962    if (ssize_t(userSize) < 0) {
963        // sanity-check. user is most-likely passing an error code.
964        LOGE("AudioTrack::write(buffer=%p, size=%u (%d)",
965                buffer, userSize, userSize);
966        return BAD_VALUE;
967    }
968
969    LOGV("write %p: %d bytes, mActive=%d", this, userSize, mActive);
970
971    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
972    // while we are accessing the cblk
973    mLock.lock();
974    sp <IAudioTrack> audioTrack = mAudioTrack;
975    sp <IMemory> iMem = mCblkMemory;
976    mLock.unlock();
977
978    ssize_t written = 0;
979    const int8_t *src = (const int8_t *)buffer;
980    Buffer audioBuffer;
981    size_t frameSz = (size_t)frameSize();
982
983    do {
984        audioBuffer.frameCount = userSize/frameSz;
985
986        // Calling obtainBuffer() with a negative wait count causes
987        // an (almost) infinite wait time.
988        status_t err = obtainBuffer(&audioBuffer, -1);
989        if (err < 0) {
990            // out of buffers, return #bytes written
991            if (err == status_t(NO_MORE_BUFFERS))
992                break;
993            return ssize_t(err);
994        }
995
996        size_t toWrite;
997
998        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
999            // Divide capacity by 2 to take expansion into account
1000            toWrite = audioBuffer.size>>1;
1001            // 8 to 16 bit conversion
1002            int count = toWrite;
1003            int16_t *dst = (int16_t *)(audioBuffer.i8);
1004            while(count--) {
1005                *dst++ = (int16_t)(*src++^0x80) << 8;
1006            }
1007        } else {
1008            toWrite = audioBuffer.size;
1009            memcpy(audioBuffer.i8, src, toWrite);
1010            src += toWrite;
1011        }
1012        userSize -= toWrite;
1013        written += toWrite;
1014
1015        releaseBuffer(&audioBuffer);
1016    } while (userSize >= frameSz);
1017
1018    return written;
1019}
1020
1021// -------------------------------------------------------------------------
1022
1023bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
1024{
1025    Buffer audioBuffer;
1026    uint32_t frames;
1027    size_t writtenSize;
1028
1029    mLock.lock();
1030    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
1031    // while we are accessing the cblk
1032    sp <IAudioTrack> audioTrack = mAudioTrack;
1033    sp <IMemory> iMem = mCblkMemory;
1034    audio_track_cblk_t* cblk = mCblk;
1035    mLock.unlock();
1036
1037    // Manage underrun callback
1038    if (mActive && (cblk->framesAvailable() == cblk->frameCount)) {
1039        LOGV("Underrun user: %x, server: %x, flags %04x", cblk->user, cblk->server, cblk->flags);
1040        if (!(android_atomic_or(CBLK_UNDERRUN_ON, &cblk->flags) & CBLK_UNDERRUN_MSK)) {
1041            mCbf(EVENT_UNDERRUN, mUserData, 0);
1042            if (cblk->server == cblk->frameCount) {
1043                mCbf(EVENT_BUFFER_END, mUserData, 0);
1044            }
1045            if (mSharedBuffer != 0) return false;
1046        }
1047    }
1048
1049    // Manage loop end callback
1050    while (mLoopCount > cblk->loopCount) {
1051        int loopCount = -1;
1052        mLoopCount--;
1053        if (mLoopCount >= 0) loopCount = mLoopCount;
1054
1055        mCbf(EVENT_LOOP_END, mUserData, (void *)&loopCount);
1056    }
1057
1058    // Manage marker callback
1059    if (!mMarkerReached && (mMarkerPosition > 0)) {
1060        if (cblk->server >= mMarkerPosition) {
1061            mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
1062            mMarkerReached = true;
1063        }
1064    }
1065
1066    // Manage new position callback
1067    if (mUpdatePeriod > 0) {
1068        while (cblk->server >= mNewPosition) {
1069            mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
1070            mNewPosition += mUpdatePeriod;
1071        }
1072    }
1073
1074    // If Shared buffer is used, no data is requested from client.
1075    if (mSharedBuffer != 0) {
1076        frames = 0;
1077    } else {
1078        frames = mRemainingFrames;
1079    }
1080
1081    int32_t waitCount = -1;
1082    if (mUpdatePeriod || (!mMarkerReached && mMarkerPosition) || mLoopCount) {
1083        waitCount = 1;
1084    }
1085
1086    do {
1087
1088        audioBuffer.frameCount = frames;
1089
1090        // Calling obtainBuffer() with a wait count of 1
1091        // limits wait time to WAIT_PERIOD_MS. This prevents from being
1092        // stuck here not being able to handle timed events (position, markers, loops).
1093        status_t err = obtainBuffer(&audioBuffer, waitCount);
1094        if (err < NO_ERROR) {
1095            if (err != TIMED_OUT) {
1096                LOGE_IF(err != status_t(NO_MORE_BUFFERS), "Error obtaining an audio buffer, giving up.");
1097                return false;
1098            }
1099            break;
1100        }
1101        if (err == status_t(STOPPED)) return false;
1102
1103        // Divide buffer size by 2 to take into account the expansion
1104        // due to 8 to 16 bit conversion: the callback must fill only half
1105        // of the destination buffer
1106        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1107            audioBuffer.size >>= 1;
1108        }
1109
1110        size_t reqSize = audioBuffer.size;
1111        mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
1112        writtenSize = audioBuffer.size;
1113
1114        // Sanity check on returned size
1115        if (ssize_t(writtenSize) <= 0) {
1116            // The callback is done filling buffers
1117            // Keep this thread going to handle timed events and
1118            // still try to get more data in intervals of WAIT_PERIOD_MS
1119            // but don't just loop and block the CPU, so wait
1120            usleep(WAIT_PERIOD_MS*1000);
1121            break;
1122        }
1123        if (writtenSize > reqSize) writtenSize = reqSize;
1124
1125        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1126            // 8 to 16 bit conversion
1127            const int8_t *src = audioBuffer.i8 + writtenSize-1;
1128            int count = writtenSize;
1129            int16_t *dst = audioBuffer.i16 + writtenSize-1;
1130            while(count--) {
1131                *dst-- = (int16_t)(*src--^0x80) << 8;
1132            }
1133            writtenSize <<= 1;
1134        }
1135
1136        audioBuffer.size = writtenSize;
1137        // NOTE: mCblk->frameSize is not equal to AudioTrack::frameSize() for
1138        // 8 bit PCM data: in this case,  mCblk->frameSize is based on a sampel size of
1139        // 16 bit.
1140        audioBuffer.frameCount = writtenSize/mCblk->frameSize;
1141
1142        frames -= audioBuffer.frameCount;
1143
1144        releaseBuffer(&audioBuffer);
1145    }
1146    while (frames);
1147
1148    if (frames == 0) {
1149        mRemainingFrames = mNotificationFramesAct;
1150    } else {
1151        mRemainingFrames = frames;
1152    }
1153    return true;
1154}
1155
1156// must be called with mLock and cblk.lock held. Callers must also hold strong references on
1157// the IAudioTrack and IMemory in case they are recreated here.
1158// If the IAudioTrack is successfully restored, the cblk pointer is updated
1159status_t AudioTrack::restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart)
1160{
1161    status_t result;
1162
1163    if (!(android_atomic_or(CBLK_RESTORING_ON, &cblk->flags) & CBLK_RESTORING_MSK)) {
1164        LOGW("dead IAudioTrack, creating a new one from %s TID %d",
1165             fromStart ? "start()" : "obtainBuffer()", gettid());
1166
1167        // signal old cblk condition so that other threads waiting for available buffers stop
1168        // waiting now
1169        cblk->cv.broadcast();
1170        cblk->lock.unlock();
1171
1172        // refresh the audio configuration cache in this process to make sure we get new
1173        // output parameters in getOutput_l() and createTrack_l()
1174        AudioSystem::clearAudioConfigCache();
1175
1176        // if the new IAudioTrack is created, createTrack_l() will modify the
1177        // following member variables: mAudioTrack, mCblkMemory and mCblk.
1178        // It will also delete the strong references on previous IAudioTrack and IMemory
1179        result = createTrack_l(mStreamType,
1180                               cblk->sampleRate,
1181                               mFormat,
1182                               mChannelMask,
1183                               mFrameCount,
1184                               mFlags,
1185                               mSharedBuffer,
1186                               getOutput_l(),
1187                               false);
1188
1189        if (result == NO_ERROR) {
1190            uint32_t user = cblk->user;
1191            uint32_t server = cblk->server;
1192            // restore write index and set other indexes to reflect empty buffer status
1193            mCblk->user = user;
1194            mCblk->server = user;
1195            mCblk->userBase = user;
1196            mCblk->serverBase = user;
1197            // restore loop: this is not guaranteed to succeed if new frame count is not
1198            // compatible with loop length
1199            setLoop_l(cblk->loopStart, cblk->loopEnd, cblk->loopCount);
1200            if (!fromStart) {
1201                mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1202                // Make sure that a client relying on callback events indicating underrun or
1203                // the actual amount of audio frames played (e.g SoundPool) receives them.
1204                if (mSharedBuffer == 0) {
1205                    uint32_t frames = 0;
1206                    if (user > server) {
1207                        frames = ((user - server) > mCblk->frameCount) ?
1208                                mCblk->frameCount : (user - server);
1209                        memset(mCblk->buffers, 0, frames * mCblk->frameSize);
1210                    }
1211                    // restart playback even if buffer is not completely filled.
1212                    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
1213                    // stepUser() clears CBLK_UNDERRUN_ON flag enabling underrun callbacks to
1214                    // the client
1215                    mCblk->stepUser(frames);
1216                }
1217            }
1218            if (mActive) {
1219                result = mAudioTrack->start();
1220                LOGW_IF(result != NO_ERROR, "restoreTrack_l() start() failed status %d", result);
1221            }
1222            if (fromStart && result == NO_ERROR) {
1223                mNewPosition = mCblk->server + mUpdatePeriod;
1224            }
1225        }
1226        if (result != NO_ERROR) {
1227            android_atomic_and(~CBLK_RESTORING_ON, &cblk->flags);
1228            LOGW_IF(result != NO_ERROR, "restoreTrack_l() failed status %d", result);
1229        }
1230        mRestoreStatus = result;
1231        // signal old cblk condition for other threads waiting for restore completion
1232        android_atomic_or(CBLK_RESTORED_ON, &cblk->flags);
1233        cblk->cv.broadcast();
1234    } else {
1235        if (!(cblk->flags & CBLK_RESTORED_MSK)) {
1236            LOGW("dead IAudioTrack, waiting for a new one TID %d", gettid());
1237            mLock.unlock();
1238            result = cblk->cv.waitRelative(cblk->lock, milliseconds(RESTORE_TIMEOUT_MS));
1239            if (result == NO_ERROR) {
1240                result = mRestoreStatus;
1241            }
1242            cblk->lock.unlock();
1243            mLock.lock();
1244        } else {
1245            LOGW("dead IAudioTrack, already restored TID %d", gettid());
1246            result = mRestoreStatus;
1247            cblk->lock.unlock();
1248        }
1249    }
1250    LOGV("restoreTrack_l() status %d mActive %d cblk %p, old cblk %p flags %08x old flags %08x",
1251         result, mActive, mCblk, cblk, mCblk->flags, cblk->flags);
1252
1253    if (result == NO_ERROR) {
1254        // from now on we switch to the newly created cblk
1255        cblk = mCblk;
1256    }
1257    cblk->lock.lock();
1258
1259    LOGW_IF(result != NO_ERROR, "restoreTrack_l() error %d TID %d", result, gettid());
1260
1261    return result;
1262}
1263
1264status_t AudioTrack::dump(int fd, const Vector<String16>& args) const
1265{
1266
1267    const size_t SIZE = 256;
1268    char buffer[SIZE];
1269    String8 result;
1270
1271    result.append(" AudioTrack::dump\n");
1272    snprintf(buffer, 255, "  stream type(%d), left - right volume(%f, %f)\n", mStreamType, mVolume[0], mVolume[1]);
1273    result.append(buffer);
1274    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mCblk->frameCount);
1275    result.append(buffer);
1276    snprintf(buffer, 255, "  sample rate(%d), status(%d), muted(%d)\n", (mCblk == 0) ? 0 : mCblk->sampleRate, mStatus, mMuted);
1277    result.append(buffer);
1278    snprintf(buffer, 255, "  active(%d), latency (%d)\n", mActive, mLatency);
1279    result.append(buffer);
1280    ::write(fd, result.string(), result.size());
1281    return NO_ERROR;
1282}
1283
1284// =========================================================================
1285
1286AudioTrack::AudioTrackThread::AudioTrackThread(AudioTrack& receiver, bool bCanCallJava)
1287    : Thread(bCanCallJava), mReceiver(receiver)
1288{
1289}
1290
1291bool AudioTrack::AudioTrackThread::threadLoop()
1292{
1293    return mReceiver.processAudioBuffer(this);
1294}
1295
1296status_t AudioTrack::AudioTrackThread::readyToRun()
1297{
1298    return NO_ERROR;
1299}
1300
1301void AudioTrack::AudioTrackThread::onFirstRef()
1302{
1303}
1304
1305// =========================================================================
1306
1307
1308audio_track_cblk_t::audio_track_cblk_t()
1309    : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
1310    userBase(0), serverBase(0), buffers(0), frameCount(0),
1311    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0),
1312    sendLevel(0), flags(0)
1313{
1314}
1315
1316uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
1317{
1318    uint32_t u = this->user;
1319
1320    u += frameCount;
1321    // Ensure that user is never ahead of server for AudioRecord
1322    if (flags & CBLK_DIRECTION_MSK) {
1323        // If stepServer() has been called once, switch to normal obtainBuffer() timeout period
1324        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS-1) {
1325            bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1326        }
1327    } else if (u > this->server) {
1328        LOGW("stepServer occured after track reset");
1329        u = this->server;
1330    }
1331
1332    if (u >= userBase + this->frameCount) {
1333        userBase += this->frameCount;
1334    }
1335
1336    this->user = u;
1337
1338    // Clear flow control error condition as new data has been written/read to/from buffer.
1339    if (flags & CBLK_UNDERRUN_MSK) {
1340        android_atomic_and(~CBLK_UNDERRUN_MSK, &flags);
1341    }
1342
1343    return u;
1344}
1345
1346bool audio_track_cblk_t::stepServer(uint32_t frameCount)
1347{
1348    if (!tryLock()) {
1349        LOGW("stepServer() could not lock cblk");
1350        return false;
1351    }
1352
1353    uint32_t s = this->server;
1354
1355    s += frameCount;
1356    if (flags & CBLK_DIRECTION_MSK) {
1357        // Mark that we have read the first buffer so that next time stepUser() is called
1358        // we switch to normal obtainBuffer() timeout period
1359        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS) {
1360            bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS - 1;
1361        }
1362        // It is possible that we receive a flush()
1363        // while the mixer is processing a block: in this case,
1364        // stepServer() is called After the flush() has reset u & s and
1365        // we have s > u
1366        if (s > this->user) {
1367            LOGW("stepServer occured after track reset");
1368            s = this->user;
1369        }
1370    }
1371
1372    if (s >= loopEnd) {
1373        LOGW_IF(s > loopEnd, "stepServer: s %u > loopEnd %u", s, loopEnd);
1374        s = loopStart;
1375        if (--loopCount == 0) {
1376            loopEnd = UINT_MAX;
1377            loopStart = UINT_MAX;
1378        }
1379    }
1380    if (s >= serverBase + this->frameCount) {
1381        serverBase += this->frameCount;
1382    }
1383
1384    this->server = s;
1385
1386    if (!(flags & CBLK_INVALID_MSK)) {
1387        cv.signal();
1388    }
1389    lock.unlock();
1390    return true;
1391}
1392
1393void* audio_track_cblk_t::buffer(uint32_t offset) const
1394{
1395    return (int8_t *)this->buffers + (offset - userBase) * this->frameSize;
1396}
1397
1398uint32_t audio_track_cblk_t::framesAvailable()
1399{
1400    Mutex::Autolock _l(lock);
1401    return framesAvailable_l();
1402}
1403
1404uint32_t audio_track_cblk_t::framesAvailable_l()
1405{
1406    uint32_t u = this->user;
1407    uint32_t s = this->server;
1408
1409    if (flags & CBLK_DIRECTION_MSK) {
1410        uint32_t limit = (s < loopStart) ? s : loopStart;
1411        return limit + frameCount - u;
1412    } else {
1413        return frameCount + u - s;
1414    }
1415}
1416
1417uint32_t audio_track_cblk_t::framesReady()
1418{
1419    uint32_t u = this->user;
1420    uint32_t s = this->server;
1421
1422    if (flags & CBLK_DIRECTION_MSK) {
1423        if (u < loopEnd) {
1424            return u - s;
1425        } else {
1426            // do not block on mutex shared with client on AudioFlinger side
1427            if (!tryLock()) {
1428                LOGW("framesReady() could not lock cblk");
1429                return 0;
1430            }
1431            uint32_t frames = UINT_MAX;
1432            if (loopCount >= 0) {
1433                frames = (loopEnd - loopStart)*loopCount + u - s;
1434            }
1435            lock.unlock();
1436            return frames;
1437        }
1438    } else {
1439        return s - u;
1440    }
1441}
1442
1443bool audio_track_cblk_t::tryLock()
1444{
1445    // the code below simulates lock-with-timeout
1446    // we MUST do this to protect the AudioFlinger server
1447    // as this lock is shared with the client.
1448    status_t err;
1449
1450    err = lock.tryLock();
1451    if (err == -EBUSY) { // just wait a bit
1452        usleep(1000);
1453        err = lock.tryLock();
1454    }
1455    if (err != NO_ERROR) {
1456        // probably, the client just died.
1457        return false;
1458    }
1459    return true;
1460}
1461
1462// -------------------------------------------------------------------------
1463
1464}; // namespace android
1465
1466