AudioTrack.cpp revision c5ac4cb3a5124860ccfc7e4ff66251c55a5595ca 
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      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
84{
85}
86
87AudioTrack::AudioTrack(
88        int streamType,
89        uint32_t sampleRate,
90        int format,
91        int channelMask,
92        int frameCount,
93        uint32_t flags,
94        callback_t cbf,
95        void* user,
96        int notificationFrames,
97        int sessionId)
98    : mStatus(NO_INIT),
99      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
100{
101    mStatus = set(streamType, sampleRate, format, channelMask,
102            frameCount, flags, cbf, user, notificationFrames,
103            0, false, sessionId);
104}
105
106AudioTrack::AudioTrack(
107        int streamType,
108        uint32_t sampleRate,
109        int format,
110        int channelMask,
111        const sp<IMemory>& sharedBuffer,
112        uint32_t flags,
113        callback_t cbf,
114        void* user,
115        int notificationFrames,
116        int sessionId)
117    : mStatus(NO_INIT),
118      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
119{
120    mStatus = set(streamType, sampleRate, format, channelMask,
121            0, flags, cbf, user, notificationFrames,
122            sharedBuffer, false, sessionId);
123}
124
125AudioTrack::~AudioTrack()
126{
127    ALOGV_IF(mSharedBuffer != 0, "Destructor sharedBuffer: %p", mSharedBuffer->pointer());
128
129    if (mStatus == NO_ERROR) {
130        // Make sure that callback function exits in the case where
131        // it is looping on buffer full condition in obtainBuffer().
132        // Otherwise the callback thread will never exit.
133        stop();
134        if (mAudioTrackThread != 0) {
135            mAudioTrackThread->requestExitAndWait();
136            mAudioTrackThread.clear();
137        }
138        mAudioTrack.clear();
139        IPCThreadState::self()->flushCommands();
140        AudioSystem::releaseAudioSessionId(mSessionId);
141    }
142}
143
144status_t AudioTrack::set(
145        int streamType,
146        uint32_t sampleRate,
147        int format,
148        int channelMask,
149        int frameCount,
150        uint32_t flags,
151        callback_t cbf,
152        void* user,
153        int notificationFrames,
154        const sp<IMemory>& sharedBuffer,
155        bool threadCanCallJava,
156        int sessionId)
157{
158
159    ALOGV_IF(sharedBuffer != 0, "sharedBuffer: %p, size: %d", sharedBuffer->pointer(), sharedBuffer->size());
160
161    AutoMutex lock(mLock);
162    if (mAudioTrack != 0) {
163        LOGE("Track already in use");
164        return INVALID_OPERATION;
165    }
166
167    int afSampleRate;
168    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
169        return NO_INIT;
170    }
171    uint32_t afLatency;
172    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
173        return NO_INIT;
174    }
175
176    // handle default values first.
177    if (streamType == AUDIO_STREAM_DEFAULT) {
178        streamType = AUDIO_STREAM_MUSIC;
179    }
180    if (sampleRate == 0) {
181        sampleRate = afSampleRate;
182    }
183    // these below should probably come from the audioFlinger too...
184    if (format == 0) {
185        format = AUDIO_FORMAT_PCM_16_BIT;
186    }
187    if (channelMask == 0) {
188        channelMask = AUDIO_CHANNEL_OUT_STEREO;
189    }
190
191    // validate parameters
192    if (!audio_is_valid_format(format)) {
193        LOGE("Invalid format");
194        return BAD_VALUE;
195    }
196
197    // force direct flag if format is not linear PCM
198    if (!audio_is_linear_pcm(format)) {
199        flags |= AUDIO_POLICY_OUTPUT_FLAG_DIRECT;
200    }
201
202    if (!audio_is_output_channel(channelMask)) {
203        LOGE("Invalid channel mask");
204        return BAD_VALUE;
205    }
206    uint32_t channelCount = popcount(channelMask);
207
208    audio_io_handle_t output = AudioSystem::getOutput(
209                                    (audio_stream_type_t)streamType,
210                                    sampleRate,format, channelMask,
211                                    (audio_policy_output_flags_t)flags);
212
213    if (output == 0) {
214        LOGE("Could not get audio output for stream type %d", streamType);
215        return BAD_VALUE;
216    }
217
218    mVolume[LEFT] = 1.0f;
219    mVolume[RIGHT] = 1.0f;
220    mSendLevel = 0;
221    mFrameCount = frameCount;
222    mNotificationFramesReq = notificationFrames;
223    mSessionId = sessionId;
224    mAuxEffectId = 0;
225
226    // create the IAudioTrack
227    status_t status = createTrack_l(streamType,
228                                  sampleRate,
229                                  (uint32_t)format,
230                                  (uint32_t)channelMask,
231                                  frameCount,
232                                  flags,
233                                  sharedBuffer,
234                                  output,
235                                  true);
236
237    if (status != NO_ERROR) {
238        return status;
239    }
240
241    if (cbf != 0) {
242        mAudioTrackThread = new AudioTrackThread(*this, threadCanCallJava);
243        if (mAudioTrackThread == 0) {
244          LOGE("Could not create callback thread");
245          return NO_INIT;
246        }
247    }
248
249    mStatus = NO_ERROR;
250
251    mStreamType = streamType;
252    mFormat = (uint32_t)format;
253    mChannelMask = (uint32_t)channelMask;
254    mChannelCount = channelCount;
255    mSharedBuffer = sharedBuffer;
256    mMuted = false;
257    mActive = 0;
258    mCbf = cbf;
259    mUserData = user;
260    mLoopCount = 0;
261    mMarkerPosition = 0;
262    mMarkerReached = false;
263    mNewPosition = 0;
264    mUpdatePeriod = 0;
265    mFlushed = false;
266    mFlags = flags;
267    AudioSystem::acquireAudioSessionId(mSessionId);
268    mRestoreStatus = NO_ERROR;
269    return NO_ERROR;
270}
271
272status_t AudioTrack::initCheck() const
273{
274    return mStatus;
275}
276
277// -------------------------------------------------------------------------
278
279uint32_t AudioTrack::latency() const
280{
281    return mLatency;
282}
283
284int AudioTrack::streamType() const
285{
286    return mStreamType;
287}
288
289int AudioTrack::format() const
290{
291    return mFormat;
292}
293
294int AudioTrack::channelCount() const
295{
296    return mChannelCount;
297}
298
299uint32_t AudioTrack::frameCount() const
300{
301    return mCblk->frameCount;
302}
303
304int AudioTrack::frameSize() const
305{
306    if (audio_is_linear_pcm(mFormat)) {
307        return channelCount()*audio_bytes_per_sample(mFormat);
308    } else {
309        return sizeof(uint8_t);
310    }
311}
312
313sp<IMemory>& AudioTrack::sharedBuffer()
314{
315    return mSharedBuffer;
316}
317
318// -------------------------------------------------------------------------
319
320void AudioTrack::start()
321{
322    sp<AudioTrackThread> t = mAudioTrackThread;
323    status_t status = NO_ERROR;
324
325    ALOGV("start %p", this);
326    if (t != 0) {
327        if (t->exitPending()) {
328            if (t->requestExitAndWait() == WOULD_BLOCK) {
329                LOGE("AudioTrack::start called from thread");
330                return;
331            }
332        }
333        t->mLock.lock();
334     }
335
336    AutoMutex lock(mLock);
337    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
338    // while we are accessing the cblk
339    sp <IAudioTrack> audioTrack = mAudioTrack;
340    sp <IMemory> iMem = mCblkMemory;
341    audio_track_cblk_t* cblk = mCblk;
342
343    if (mActive == 0) {
344        mFlushed = false;
345        mActive = 1;
346        mNewPosition = cblk->server + mUpdatePeriod;
347        cblk->lock.lock();
348        cblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
349        cblk->waitTimeMs = 0;
350        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
351        if (t != 0) {
352            t->run("AudioTrackThread", ANDROID_PRIORITY_AUDIO);
353        } else {
354            mPreviousPriority = getpriority(PRIO_PROCESS, 0);
355            mPreviousSchedulingGroup = androidGetThreadSchedulingGroup(0);
356            androidSetThreadPriority(0, ANDROID_PRIORITY_AUDIO);
357        }
358
359        ALOGV("start %p before lock cblk %p", this, mCblk);
360        if (!(cblk->flags & CBLK_INVALID_MSK)) {
361            cblk->lock.unlock();
362            status = mAudioTrack->start();
363            cblk->lock.lock();
364            if (status == DEAD_OBJECT) {
365                android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
366            }
367        }
368        if (cblk->flags & CBLK_INVALID_MSK) {
369            status = restoreTrack_l(cblk, true);
370        }
371        cblk->lock.unlock();
372        if (status != NO_ERROR) {
373            ALOGV("start() failed");
374            mActive = 0;
375            if (t != 0) {
376                t->requestExit();
377            } else {
378                setpriority(PRIO_PROCESS, 0, mPreviousPriority);
379                androidSetThreadSchedulingGroup(0, mPreviousSchedulingGroup);
380            }
381        }
382    }
383
384    if (t != 0) {
385        t->mLock.unlock();
386    }
387}
388
389void AudioTrack::stop()
390{
391    sp<AudioTrackThread> t = mAudioTrackThread;
392
393    ALOGV("stop %p", this);
394    if (t != 0) {
395        t->mLock.lock();
396    }
397
398    AutoMutex lock(mLock);
399    if (mActive == 1) {
400        mActive = 0;
401        mCblk->cv.signal();
402        mAudioTrack->stop();
403        // Cancel loops (If we are in the middle of a loop, playback
404        // would not stop until loopCount reaches 0).
405        setLoop_l(0, 0, 0);
406        // the playback head position will reset to 0, so if a marker is set, we need
407        // to activate it again
408        mMarkerReached = false;
409        // Force flush if a shared buffer is used otherwise audioflinger
410        // will not stop before end of buffer is reached.
411        if (mSharedBuffer != 0) {
412            flush_l();
413        }
414        if (t != 0) {
415            t->requestExit();
416        } else {
417            setpriority(PRIO_PROCESS, 0, mPreviousPriority);
418            androidSetThreadSchedulingGroup(0, mPreviousSchedulingGroup);
419        }
420    }
421
422    if (t != 0) {
423        t->mLock.unlock();
424    }
425}
426
427bool AudioTrack::stopped() const
428{
429    return !mActive;
430}
431
432void AudioTrack::flush()
433{
434    AutoMutex lock(mLock);
435    flush_l();
436}
437
438// must be called with mLock held
439void AudioTrack::flush_l()
440{
441    ALOGV("flush");
442
443    // clear playback marker and periodic update counter
444    mMarkerPosition = 0;
445    mMarkerReached = false;
446    mUpdatePeriod = 0;
447
448    if (!mActive) {
449        mFlushed = true;
450        mAudioTrack->flush();
451        // Release AudioTrack callback thread in case it was waiting for new buffers
452        // in AudioTrack::obtainBuffer()
453        mCblk->cv.signal();
454    }
455}
456
457void AudioTrack::pause()
458{
459    ALOGV("pause");
460    AutoMutex lock(mLock);
461    if (mActive == 1) {
462        mActive = 0;
463        mAudioTrack->pause();
464    }
465}
466
467void AudioTrack::mute(bool e)
468{
469    mAudioTrack->mute(e);
470    mMuted = e;
471}
472
473bool AudioTrack::muted() const
474{
475    return mMuted;
476}
477
478status_t AudioTrack::setVolume(float left, float right)
479{
480    if (left > 1.0f || right > 1.0f) {
481        return BAD_VALUE;
482    }
483
484    AutoMutex lock(mLock);
485    mVolume[LEFT] = left;
486    mVolume[RIGHT] = right;
487
488    // write must be atomic
489    mCblk->volumeLR = (uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000);
490
491    return NO_ERROR;
492}
493
494void AudioTrack::getVolume(float* left, float* right)
495{
496    if (left != NULL) {
497        *left  = mVolume[LEFT];
498    }
499    if (right != NULL) {
500        *right = mVolume[RIGHT];
501    }
502}
503
504status_t AudioTrack::setAuxEffectSendLevel(float level)
505{
506    ALOGV("setAuxEffectSendLevel(%f)", level);
507    if (level > 1.0f) {
508        return BAD_VALUE;
509    }
510    AutoMutex lock(mLock);
511
512    mSendLevel = level;
513
514    mCblk->sendLevel = uint16_t(level * 0x1000);
515
516    return NO_ERROR;
517}
518
519void AudioTrack::getAuxEffectSendLevel(float* level)
520{
521    if (level != NULL) {
522        *level  = mSendLevel;
523    }
524}
525
526status_t AudioTrack::setSampleRate(int rate)
527{
528    int afSamplingRate;
529
530    if (AudioSystem::getOutputSamplingRate(&afSamplingRate, mStreamType) != NO_ERROR) {
531        return NO_INIT;
532    }
533    // Resampler implementation limits input sampling rate to 2 x output sampling rate.
534    if (rate <= 0 || rate > afSamplingRate*2 ) return BAD_VALUE;
535
536    AutoMutex lock(mLock);
537    mCblk->sampleRate = rate;
538    return NO_ERROR;
539}
540
541uint32_t AudioTrack::getSampleRate()
542{
543    AutoMutex lock(mLock);
544    return mCblk->sampleRate;
545}
546
547status_t AudioTrack::setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount)
548{
549    AutoMutex lock(mLock);
550    return setLoop_l(loopStart, loopEnd, loopCount);
551}
552
553// must be called with mLock held
554status_t AudioTrack::setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount)
555{
556    audio_track_cblk_t* cblk = mCblk;
557
558    Mutex::Autolock _l(cblk->lock);
559
560    if (loopCount == 0) {
561        cblk->loopStart = UINT_MAX;
562        cblk->loopEnd = UINT_MAX;
563        cblk->loopCount = 0;
564        mLoopCount = 0;
565        return NO_ERROR;
566    }
567
568    if (loopStart >= loopEnd ||
569        loopEnd - loopStart > cblk->frameCount ||
570        cblk->server > loopStart) {
571        LOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, cblk->frameCount, cblk->user);
572        return BAD_VALUE;
573    }
574
575    if ((mSharedBuffer != 0) && (loopEnd > cblk->frameCount)) {
576        LOGE("setLoop invalid value: loop markers beyond data: loopStart %d, loopEnd %d, framecount %d",
577            loopStart, loopEnd, cblk->frameCount);
578        return BAD_VALUE;
579    }
580
581    cblk->loopStart = loopStart;
582    cblk->loopEnd = loopEnd;
583    cblk->loopCount = loopCount;
584    mLoopCount = loopCount;
585
586    return NO_ERROR;
587}
588
589status_t AudioTrack::getLoop(uint32_t *loopStart, uint32_t *loopEnd, int *loopCount)
590{
591    AutoMutex lock(mLock);
592    if (loopStart != 0) {
593        *loopStart = mCblk->loopStart;
594    }
595    if (loopEnd != 0) {
596        *loopEnd = mCblk->loopEnd;
597    }
598    if (loopCount != 0) {
599        if (mCblk->loopCount < 0) {
600            *loopCount = -1;
601        } else {
602            *loopCount = mCblk->loopCount;
603        }
604    }
605
606    return NO_ERROR;
607}
608
609status_t AudioTrack::setMarkerPosition(uint32_t marker)
610{
611    if (mCbf == 0) return INVALID_OPERATION;
612
613    mMarkerPosition = marker;
614    mMarkerReached = false;
615
616    return NO_ERROR;
617}
618
619status_t AudioTrack::getMarkerPosition(uint32_t *marker)
620{
621    if (marker == 0) return BAD_VALUE;
622
623    *marker = mMarkerPosition;
624
625    return NO_ERROR;
626}
627
628status_t AudioTrack::setPositionUpdatePeriod(uint32_t updatePeriod)
629{
630    if (mCbf == 0) return INVALID_OPERATION;
631
632    uint32_t curPosition;
633    getPosition(&curPosition);
634    mNewPosition = curPosition + updatePeriod;
635    mUpdatePeriod = updatePeriod;
636
637    return NO_ERROR;
638}
639
640status_t AudioTrack::getPositionUpdatePeriod(uint32_t *updatePeriod)
641{
642    if (updatePeriod == 0) return BAD_VALUE;
643
644    *updatePeriod = mUpdatePeriod;
645
646    return NO_ERROR;
647}
648
649status_t AudioTrack::setPosition(uint32_t position)
650{
651    AutoMutex lock(mLock);
652    Mutex::Autolock _l(mCblk->lock);
653
654    if (!stopped()) return INVALID_OPERATION;
655
656    if (position > mCblk->user) return BAD_VALUE;
657
658    mCblk->server = position;
659    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
660
661    return NO_ERROR;
662}
663
664status_t AudioTrack::getPosition(uint32_t *position)
665{
666    if (position == 0) return BAD_VALUE;
667    AutoMutex lock(mLock);
668    *position = mFlushed ? 0 : mCblk->server;
669
670    return NO_ERROR;
671}
672
673status_t AudioTrack::reload()
674{
675    AutoMutex lock(mLock);
676
677    if (!stopped()) return INVALID_OPERATION;
678
679    flush_l();
680
681    mCblk->stepUser(mCblk->frameCount);
682
683    return NO_ERROR;
684}
685
686audio_io_handle_t AudioTrack::getOutput()
687{
688    AutoMutex lock(mLock);
689    return getOutput_l();
690}
691
692// must be called with mLock held
693audio_io_handle_t AudioTrack::getOutput_l()
694{
695    return AudioSystem::getOutput((audio_stream_type_t)mStreamType,
696            mCblk->sampleRate, mFormat, mChannelMask, (audio_policy_output_flags_t)mFlags);
697}
698
699int AudioTrack::getSessionId()
700{
701    return mSessionId;
702}
703
704status_t AudioTrack::attachAuxEffect(int effectId)
705{
706    ALOGV("attachAuxEffect(%d)", effectId);
707    status_t status = mAudioTrack->attachAuxEffect(effectId);
708    if (status == NO_ERROR) {
709        mAuxEffectId = effectId;
710    }
711    return status;
712}
713
714// -------------------------------------------------------------------------
715
716// must be called with mLock held
717status_t AudioTrack::createTrack_l(
718        int streamType,
719        uint32_t sampleRate,
720        uint32_t format,
721        uint32_t channelMask,
722        int frameCount,
723        uint32_t flags,
724        const sp<IMemory>& sharedBuffer,
725        audio_io_handle_t output,
726        bool enforceFrameCount)
727{
728    status_t status;
729    const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
730    if (audioFlinger == 0) {
731       LOGE("Could not get audioflinger");
732       return NO_INIT;
733    }
734
735    int afSampleRate;
736    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
737        return NO_INIT;
738    }
739    int afFrameCount;
740    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
741        return NO_INIT;
742    }
743    uint32_t afLatency;
744    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
745        return NO_INIT;
746    }
747
748    mNotificationFramesAct = mNotificationFramesReq;
749    if (!audio_is_linear_pcm(format)) {
750        if (sharedBuffer != 0) {
751            frameCount = sharedBuffer->size();
752        }
753    } else {
754        // Ensure that buffer depth covers at least audio hardware latency
755        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
756        if (minBufCount < 2) minBufCount = 2;
757
758        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
759
760        if (sharedBuffer == 0) {
761            if (frameCount == 0) {
762                frameCount = minFrameCount;
763            }
764            if (mNotificationFramesAct == 0) {
765                mNotificationFramesAct = frameCount/2;
766            }
767            // Make sure that application is notified with sufficient margin
768            // before underrun
769            if (mNotificationFramesAct > (uint32_t)frameCount/2) {
770                mNotificationFramesAct = frameCount/2;
771            }
772            if (frameCount < minFrameCount) {
773                if (enforceFrameCount) {
774                    LOGE("Invalid buffer size: minFrameCount %d, frameCount %d", minFrameCount, frameCount);
775                    return BAD_VALUE;
776                } else {
777                    frameCount = minFrameCount;
778                }
779            }
780        } else {
781            // Ensure that buffer alignment matches channelcount
782            int channelCount = popcount(channelMask);
783            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
784                LOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
785                return BAD_VALUE;
786            }
787            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
788        }
789    }
790
791    sp<IAudioTrack> track = audioFlinger->createTrack(getpid(),
792                                                      streamType,
793                                                      sampleRate,
794                                                      format,
795                                                      channelMask,
796                                                      frameCount,
797                                                      ((uint16_t)flags) << 16,
798                                                      sharedBuffer,
799                                                      output,
800                                                      &mSessionId,
801                                                      &status);
802
803    if (track == 0) {
804        LOGE("AudioFlinger could not create track, status: %d", status);
805        return status;
806    }
807    sp<IMemory> cblk = track->getCblk();
808    if (cblk == 0) {
809        LOGE("Could not get control block");
810        return NO_INIT;
811    }
812    mAudioTrack.clear();
813    mAudioTrack = track;
814    mCblkMemory.clear();
815    mCblkMemory = cblk;
816    mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
817    android_atomic_or(CBLK_DIRECTION_OUT, &mCblk->flags);
818    if (sharedBuffer == 0) {
819        mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
820    } else {
821        mCblk->buffers = sharedBuffer->pointer();
822         // Force buffer full condition as data is already present in shared memory
823        mCblk->stepUser(mCblk->frameCount);
824    }
825
826    mCblk->volumeLR = (uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000);
827    mCblk->sendLevel = uint16_t(mSendLevel * 0x1000);
828    mAudioTrack->attachAuxEffect(mAuxEffectId);
829    mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
830    mCblk->waitTimeMs = 0;
831    mRemainingFrames = mNotificationFramesAct;
832    mLatency = afLatency + (1000*mCblk->frameCount) / sampleRate;
833    return NO_ERROR;
834}
835
836status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
837{
838    AutoMutex lock(mLock);
839    int active;
840    status_t result = NO_ERROR;
841    audio_track_cblk_t* cblk = mCblk;
842    uint32_t framesReq = audioBuffer->frameCount;
843    uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;
844
845    audioBuffer->frameCount  = 0;
846    audioBuffer->size = 0;
847
848    uint32_t framesAvail = cblk->framesAvailable();
849
850    cblk->lock.lock();
851    if (cblk->flags & CBLK_INVALID_MSK) {
852        goto create_new_track;
853    }
854    cblk->lock.unlock();
855
856    if (framesAvail == 0) {
857        cblk->lock.lock();
858        goto start_loop_here;
859        while (framesAvail == 0) {
860            active = mActive;
861            if (UNLIKELY(!active)) {
862                ALOGV("Not active and NO_MORE_BUFFERS");
863                cblk->lock.unlock();
864                return NO_MORE_BUFFERS;
865            }
866            if (UNLIKELY(!waitCount)) {
867                cblk->lock.unlock();
868                return WOULD_BLOCK;
869            }
870            if (!(cblk->flags & CBLK_INVALID_MSK)) {
871                mLock.unlock();
872                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
873                cblk->lock.unlock();
874                mLock.lock();
875                if (mActive == 0) {
876                    return status_t(STOPPED);
877                }
878                cblk->lock.lock();
879            }
880
881            if (cblk->flags & CBLK_INVALID_MSK) {
882                goto create_new_track;
883            }
884            if (__builtin_expect(result!=NO_ERROR, false)) {
885                cblk->waitTimeMs += waitTimeMs;
886                if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
887                    // timing out when a loop has been set and we have already written upto loop end
888                    // is a normal condition: no need to wake AudioFlinger up.
889                    if (cblk->user < cblk->loopEnd) {
890                        LOGW(   "obtainBuffer timed out (is the CPU pegged?) %p "
891                                "user=%08x, server=%08x", this, cblk->user, cblk->server);
892                        //unlock cblk mutex before calling mAudioTrack->start() (see issue #1617140)
893                        cblk->lock.unlock();
894                        result = mAudioTrack->start();
895                        cblk->lock.lock();
896                        if (result == DEAD_OBJECT) {
897                            android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
898create_new_track:
899                            result = restoreTrack_l(cblk, false);
900                        }
901                        if (result != NO_ERROR) {
902                            LOGW("obtainBuffer create Track error %d", result);
903                            cblk->lock.unlock();
904                            return result;
905                        }
906                    }
907                    cblk->waitTimeMs = 0;
908                }
909
910                if (--waitCount == 0) {
911                    cblk->lock.unlock();
912                    return TIMED_OUT;
913                }
914            }
915            // read the server count again
916        start_loop_here:
917            framesAvail = cblk->framesAvailable_l();
918        }
919        cblk->lock.unlock();
920    }
921
922    // restart track if it was disabled by audioflinger due to previous underrun
923    if (mActive && (cblk->flags & CBLK_DISABLED_MSK)) {
924        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
925        LOGW("obtainBuffer() track %p disabled, restarting", this);
926        mAudioTrack->start();
927    }
928
929    cblk->waitTimeMs = 0;
930
931    if (framesReq > framesAvail) {
932        framesReq = framesAvail;
933    }
934
935    uint32_t u = cblk->user;
936    uint32_t bufferEnd = cblk->userBase + cblk->frameCount;
937
938    if (u + framesReq > bufferEnd) {
939        framesReq = bufferEnd - u;
940    }
941
942    audioBuffer->flags = mMuted ? Buffer::MUTE : 0;
943    audioBuffer->channelCount = mChannelCount;
944    audioBuffer->frameCount = framesReq;
945    audioBuffer->size = framesReq * cblk->frameSize;
946    if (audio_is_linear_pcm(mFormat)) {
947        audioBuffer->format = AUDIO_FORMAT_PCM_16_BIT;
948    } else {
949        audioBuffer->format = mFormat;
950    }
951    audioBuffer->raw = (int8_t *)cblk->buffer(u);
952    active = mActive;
953    return active ? status_t(NO_ERROR) : status_t(STOPPED);
954}
955
956void AudioTrack::releaseBuffer(Buffer* audioBuffer)
957{
958    AutoMutex lock(mLock);
959    mCblk->stepUser(audioBuffer->frameCount);
960}
961
962// -------------------------------------------------------------------------
963
964ssize_t AudioTrack::write(const void* buffer, size_t userSize)
965{
966
967    if (mSharedBuffer != 0) return INVALID_OPERATION;
968
969    if (ssize_t(userSize) < 0) {
970        // sanity-check. user is most-likely passing an error code.
971        LOGE("AudioTrack::write(buffer=%p, size=%u (%d)",
972                buffer, userSize, userSize);
973        return BAD_VALUE;
974    }
975
976    ALOGV("write %p: %d bytes, mActive=%d", this, userSize, mActive);
977
978    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
979    // while we are accessing the cblk
980    mLock.lock();
981    sp <IAudioTrack> audioTrack = mAudioTrack;
982    sp <IMemory> iMem = mCblkMemory;
983    mLock.unlock();
984
985    ssize_t written = 0;
986    const int8_t *src = (const int8_t *)buffer;
987    Buffer audioBuffer;
988    size_t frameSz = (size_t)frameSize();
989
990    do {
991        audioBuffer.frameCount = userSize/frameSz;
992
993        // Calling obtainBuffer() with a negative wait count causes
994        // an (almost) infinite wait time.
995        status_t err = obtainBuffer(&audioBuffer, -1);
996        if (err < 0) {
997            // out of buffers, return #bytes written
998            if (err == status_t(NO_MORE_BUFFERS))
999                break;
1000            return ssize_t(err);
1001        }
1002
1003        size_t toWrite;
1004
1005        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1006            // Divide capacity by 2 to take expansion into account
1007            toWrite = audioBuffer.size>>1;
1008            // 8 to 16 bit conversion
1009            int count = toWrite;
1010            int16_t *dst = (int16_t *)(audioBuffer.i8);
1011            while(count--) {
1012                *dst++ = (int16_t)(*src++^0x80) << 8;
1013            }
1014        } else {
1015            toWrite = audioBuffer.size;
1016            memcpy(audioBuffer.i8, src, toWrite);
1017            src += toWrite;
1018        }
1019        userSize -= toWrite;
1020        written += toWrite;
1021
1022        releaseBuffer(&audioBuffer);
1023    } while (userSize >= frameSz);
1024
1025    return written;
1026}
1027
1028// -------------------------------------------------------------------------
1029
1030bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
1031{
1032    Buffer audioBuffer;
1033    uint32_t frames;
1034    size_t writtenSize;
1035
1036    mLock.lock();
1037    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
1038    // while we are accessing the cblk
1039    sp <IAudioTrack> audioTrack = mAudioTrack;
1040    sp <IMemory> iMem = mCblkMemory;
1041    audio_track_cblk_t* cblk = mCblk;
1042    mLock.unlock();
1043
1044    // Manage underrun callback
1045    if (mActive && (cblk->framesAvailable() == cblk->frameCount)) {
1046        ALOGV("Underrun user: %x, server: %x, flags %04x", cblk->user, cblk->server, cblk->flags);
1047        if (!(android_atomic_or(CBLK_UNDERRUN_ON, &cblk->flags) & CBLK_UNDERRUN_MSK)) {
1048            mCbf(EVENT_UNDERRUN, mUserData, 0);
1049            if (cblk->server == cblk->frameCount) {
1050                mCbf(EVENT_BUFFER_END, mUserData, 0);
1051            }
1052            if (mSharedBuffer != 0) return false;
1053        }
1054    }
1055
1056    // Manage loop end callback
1057    while (mLoopCount > cblk->loopCount) {
1058        int loopCount = -1;
1059        mLoopCount--;
1060        if (mLoopCount >= 0) loopCount = mLoopCount;
1061
1062        mCbf(EVENT_LOOP_END, mUserData, (void *)&loopCount);
1063    }
1064
1065    // Manage marker callback
1066    if (!mMarkerReached && (mMarkerPosition > 0)) {
1067        if (cblk->server >= mMarkerPosition) {
1068            mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
1069            mMarkerReached = true;
1070        }
1071    }
1072
1073    // Manage new position callback
1074    if (mUpdatePeriod > 0) {
1075        while (cblk->server >= mNewPosition) {
1076            mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
1077            mNewPosition += mUpdatePeriod;
1078        }
1079    }
1080
1081    // If Shared buffer is used, no data is requested from client.
1082    if (mSharedBuffer != 0) {
1083        frames = 0;
1084    } else {
1085        frames = mRemainingFrames;
1086    }
1087
1088    int32_t waitCount = -1;
1089    if (mUpdatePeriod || (!mMarkerReached && mMarkerPosition) || mLoopCount) {
1090        waitCount = 1;
1091    }
1092
1093    do {
1094
1095        audioBuffer.frameCount = frames;
1096
1097        // Calling obtainBuffer() with a wait count of 1
1098        // limits wait time to WAIT_PERIOD_MS. This prevents from being
1099        // stuck here not being able to handle timed events (position, markers, loops).
1100        status_t err = obtainBuffer(&audioBuffer, waitCount);
1101        if (err < NO_ERROR) {
1102            if (err != TIMED_OUT) {
1103                LOGE_IF(err != status_t(NO_MORE_BUFFERS), "Error obtaining an audio buffer, giving up.");
1104                return false;
1105            }
1106            break;
1107        }
1108        if (err == status_t(STOPPED)) return false;
1109
1110        // Divide buffer size by 2 to take into account the expansion
1111        // due to 8 to 16 bit conversion: the callback must fill only half
1112        // of the destination buffer
1113        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1114            audioBuffer.size >>= 1;
1115        }
1116
1117        size_t reqSize = audioBuffer.size;
1118        mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
1119        writtenSize = audioBuffer.size;
1120
1121        // Sanity check on returned size
1122        if (ssize_t(writtenSize) <= 0) {
1123            // The callback is done filling buffers
1124            // Keep this thread going to handle timed events and
1125            // still try to get more data in intervals of WAIT_PERIOD_MS
1126            // but don't just loop and block the CPU, so wait
1127            usleep(WAIT_PERIOD_MS*1000);
1128            break;
1129        }
1130        if (writtenSize > reqSize) writtenSize = reqSize;
1131
1132        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1133            // 8 to 16 bit conversion
1134            const int8_t *src = audioBuffer.i8 + writtenSize-1;
1135            int count = writtenSize;
1136            int16_t *dst = audioBuffer.i16 + writtenSize-1;
1137            while(count--) {
1138                *dst-- = (int16_t)(*src--^0x80) << 8;
1139            }
1140            writtenSize <<= 1;
1141        }
1142
1143        audioBuffer.size = writtenSize;
1144        // NOTE: mCblk->frameSize is not equal to AudioTrack::frameSize() for
1145        // 8 bit PCM data: in this case,  mCblk->frameSize is based on a sampel size of
1146        // 16 bit.
1147        audioBuffer.frameCount = writtenSize/mCblk->frameSize;
1148
1149        frames -= audioBuffer.frameCount;
1150
1151        releaseBuffer(&audioBuffer);
1152    }
1153    while (frames);
1154
1155    if (frames == 0) {
1156        mRemainingFrames = mNotificationFramesAct;
1157    } else {
1158        mRemainingFrames = frames;
1159    }
1160    return true;
1161}
1162
1163// must be called with mLock and cblk.lock held. Callers must also hold strong references on
1164// the IAudioTrack and IMemory in case they are recreated here.
1165// If the IAudioTrack is successfully restored, the cblk pointer is updated
1166status_t AudioTrack::restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart)
1167{
1168    status_t result;
1169
1170    if (!(android_atomic_or(CBLK_RESTORING_ON, &cblk->flags) & CBLK_RESTORING_MSK)) {
1171        LOGW("dead IAudioTrack, creating a new one from %s TID %d",
1172             fromStart ? "start()" : "obtainBuffer()", gettid());
1173
1174        // signal old cblk condition so that other threads waiting for available buffers stop
1175        // waiting now
1176        cblk->cv.broadcast();
1177        cblk->lock.unlock();
1178
1179        // refresh the audio configuration cache in this process to make sure we get new
1180        // output parameters in getOutput_l() and createTrack_l()
1181        AudioSystem::clearAudioConfigCache();
1182
1183        // if the new IAudioTrack is created, createTrack_l() will modify the
1184        // following member variables: mAudioTrack, mCblkMemory and mCblk.
1185        // It will also delete the strong references on previous IAudioTrack and IMemory
1186        result = createTrack_l(mStreamType,
1187                               cblk->sampleRate,
1188                               mFormat,
1189                               mChannelMask,
1190                               mFrameCount,
1191                               mFlags,
1192                               mSharedBuffer,
1193                               getOutput_l(),
1194                               false);
1195
1196        if (result == NO_ERROR) {
1197            uint32_t user = cblk->user;
1198            uint32_t server = cblk->server;
1199            // restore write index and set other indexes to reflect empty buffer status
1200            mCblk->user = user;
1201            mCblk->server = user;
1202            mCblk->userBase = user;
1203            mCblk->serverBase = user;
1204            // restore loop: this is not guaranteed to succeed if new frame count is not
1205            // compatible with loop length
1206            setLoop_l(cblk->loopStart, cblk->loopEnd, cblk->loopCount);
1207            if (!fromStart) {
1208                mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1209                // Make sure that a client relying on callback events indicating underrun or
1210                // the actual amount of audio frames played (e.g SoundPool) receives them.
1211                if (mSharedBuffer == 0) {
1212                    uint32_t frames = 0;
1213                    if (user > server) {
1214                        frames = ((user - server) > mCblk->frameCount) ?
1215                                mCblk->frameCount : (user - server);
1216                        memset(mCblk->buffers, 0, frames * mCblk->frameSize);
1217                    }
1218                    // restart playback even if buffer is not completely filled.
1219                    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
1220                    // stepUser() clears CBLK_UNDERRUN_ON flag enabling underrun callbacks to
1221                    // the client
1222                    mCblk->stepUser(frames);
1223                }
1224            }
1225            if (mActive) {
1226                result = mAudioTrack->start();
1227                LOGW_IF(result != NO_ERROR, "restoreTrack_l() start() failed status %d", result);
1228            }
1229            if (fromStart && result == NO_ERROR) {
1230                mNewPosition = mCblk->server + mUpdatePeriod;
1231            }
1232        }
1233        if (result != NO_ERROR) {
1234            android_atomic_and(~CBLK_RESTORING_ON, &cblk->flags);
1235            LOGW_IF(result != NO_ERROR, "restoreTrack_l() failed status %d", result);
1236        }
1237        mRestoreStatus = result;
1238        // signal old cblk condition for other threads waiting for restore completion
1239        android_atomic_or(CBLK_RESTORED_ON, &cblk->flags);
1240        cblk->cv.broadcast();
1241    } else {
1242        if (!(cblk->flags & CBLK_RESTORED_MSK)) {
1243            LOGW("dead IAudioTrack, waiting for a new one TID %d", gettid());
1244            mLock.unlock();
1245            result = cblk->cv.waitRelative(cblk->lock, milliseconds(RESTORE_TIMEOUT_MS));
1246            if (result == NO_ERROR) {
1247                result = mRestoreStatus;
1248            }
1249            cblk->lock.unlock();
1250            mLock.lock();
1251        } else {
1252            LOGW("dead IAudioTrack, already restored TID %d", gettid());
1253            result = mRestoreStatus;
1254            cblk->lock.unlock();
1255        }
1256    }
1257    ALOGV("restoreTrack_l() status %d mActive %d cblk %p, old cblk %p flags %08x old flags %08x",
1258         result, mActive, mCblk, cblk, mCblk->flags, cblk->flags);
1259
1260    if (result == NO_ERROR) {
1261        // from now on we switch to the newly created cblk
1262        cblk = mCblk;
1263    }
1264    cblk->lock.lock();
1265
1266    LOGW_IF(result != NO_ERROR, "restoreTrack_l() error %d TID %d", result, gettid());
1267
1268    return result;
1269}
1270
1271status_t AudioTrack::dump(int fd, const Vector<String16>& args) const
1272{
1273
1274    const size_t SIZE = 256;
1275    char buffer[SIZE];
1276    String8 result;
1277
1278    result.append(" AudioTrack::dump\n");
1279    snprintf(buffer, 255, "  stream type(%d), left - right volume(%f, %f)\n", mStreamType, mVolume[0], mVolume[1]);
1280    result.append(buffer);
1281    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mCblk->frameCount);
1282    result.append(buffer);
1283    snprintf(buffer, 255, "  sample rate(%d), status(%d), muted(%d)\n", (mCblk == 0) ? 0 : mCblk->sampleRate, mStatus, mMuted);
1284    result.append(buffer);
1285    snprintf(buffer, 255, "  active(%d), latency (%d)\n", mActive, mLatency);
1286    result.append(buffer);
1287    ::write(fd, result.string(), result.size());
1288    return NO_ERROR;
1289}
1290
1291// =========================================================================
1292
1293AudioTrack::AudioTrackThread::AudioTrackThread(AudioTrack& receiver, bool bCanCallJava)
1294    : Thread(bCanCallJava), mReceiver(receiver)
1295{
1296}
1297
1298bool AudioTrack::AudioTrackThread::threadLoop()
1299{
1300    return mReceiver.processAudioBuffer(this);
1301}
1302
1303status_t AudioTrack::AudioTrackThread::readyToRun()
1304{
1305    return NO_ERROR;
1306}
1307
1308void AudioTrack::AudioTrackThread::onFirstRef()
1309{
1310}
1311
1312// =========================================================================
1313
1314
1315audio_track_cblk_t::audio_track_cblk_t()
1316    : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
1317    userBase(0), serverBase(0), buffers(0), frameCount(0),
1318    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0),
1319    sendLevel(0), flags(0)
1320{
1321}
1322
1323uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
1324{
1325    uint32_t u = this->user;
1326
1327    u += frameCount;
1328    // Ensure that user is never ahead of server for AudioRecord
1329    if (flags & CBLK_DIRECTION_MSK) {
1330        // If stepServer() has been called once, switch to normal obtainBuffer() timeout period
1331        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS-1) {
1332            bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1333        }
1334    } else if (u > this->server) {
1335        LOGW("stepServer occured after track reset");
1336        u = this->server;
1337    }
1338
1339    if (u >= userBase + this->frameCount) {
1340        userBase += this->frameCount;
1341    }
1342
1343    this->user = u;
1344
1345    // Clear flow control error condition as new data has been written/read to/from buffer.
1346    if (flags & CBLK_UNDERRUN_MSK) {
1347        android_atomic_and(~CBLK_UNDERRUN_MSK, &flags);
1348    }
1349
1350    return u;
1351}
1352
1353bool audio_track_cblk_t::stepServer(uint32_t frameCount)
1354{
1355    if (!tryLock()) {
1356        LOGW("stepServer() could not lock cblk");
1357        return false;
1358    }
1359
1360    uint32_t s = this->server;
1361
1362    s += frameCount;
1363    if (flags & CBLK_DIRECTION_MSK) {
1364        // Mark that we have read the first buffer so that next time stepUser() is called
1365        // we switch to normal obtainBuffer() timeout period
1366        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS) {
1367            bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS - 1;
1368        }
1369        // It is possible that we receive a flush()
1370        // while the mixer is processing a block: in this case,
1371        // stepServer() is called After the flush() has reset u & s and
1372        // we have s > u
1373        if (s > this->user) {
1374            LOGW("stepServer occured after track reset");
1375            s = this->user;
1376        }
1377    }
1378
1379    if (s >= loopEnd) {
1380        LOGW_IF(s > loopEnd, "stepServer: s %u > loopEnd %u", s, loopEnd);
1381        s = loopStart;
1382        if (--loopCount == 0) {
1383            loopEnd = UINT_MAX;
1384            loopStart = UINT_MAX;
1385        }
1386    }
1387    if (s >= serverBase + this->frameCount) {
1388        serverBase += this->frameCount;
1389    }
1390
1391    this->server = s;
1392
1393    if (!(flags & CBLK_INVALID_MSK)) {
1394        cv.signal();
1395    }
1396    lock.unlock();
1397    return true;
1398}
1399
1400void* audio_track_cblk_t::buffer(uint32_t offset) const
1401{
1402    return (int8_t *)this->buffers + (offset - userBase) * this->frameSize;
1403}
1404
1405uint32_t audio_track_cblk_t::framesAvailable()
1406{
1407    Mutex::Autolock _l(lock);
1408    return framesAvailable_l();
1409}
1410
1411uint32_t audio_track_cblk_t::framesAvailable_l()
1412{
1413    uint32_t u = this->user;
1414    uint32_t s = this->server;
1415
1416    if (flags & CBLK_DIRECTION_MSK) {
1417        uint32_t limit = (s < loopStart) ? s : loopStart;
1418        return limit + frameCount - u;
1419    } else {
1420        return frameCount + u - s;
1421    }
1422}
1423
1424uint32_t audio_track_cblk_t::framesReady()
1425{
1426    uint32_t u = this->user;
1427    uint32_t s = this->server;
1428
1429    if (flags & CBLK_DIRECTION_MSK) {
1430        if (u < loopEnd) {
1431            return u - s;
1432        } else {
1433            // do not block on mutex shared with client on AudioFlinger side
1434            if (!tryLock()) {
1435                LOGW("framesReady() could not lock cblk");
1436                return 0;
1437            }
1438            uint32_t frames = UINT_MAX;
1439            if (loopCount >= 0) {
1440                frames = (loopEnd - loopStart)*loopCount + u - s;
1441            }
1442            lock.unlock();
1443            return frames;
1444        }
1445    } else {
1446        return s - u;
1447    }
1448}
1449
1450bool audio_track_cblk_t::tryLock()
1451{
1452    // the code below simulates lock-with-timeout
1453    // we MUST do this to protect the AudioFlinger server
1454    // as this lock is shared with the client.
1455    status_t err;
1456
1457    err = lock.tryLock();
1458    if (err == -EBUSY) { // just wait a bit
1459        usleep(1000);
1460        err = lock.tryLock();
1461    }
1462    if (err != NO_ERROR) {
1463        // probably, the client just died.
1464        return false;
1465    }
1466    return true;
1467}
1468
1469// -------------------------------------------------------------------------
1470
1471}; // namespace android
1472