AudioTrack.cpp revision d8d6185c978c9b27ca69e7791785e0983ed9e8b8 
1/*
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#include <cutils/compiler.h>
42
43#include <system/audio.h>
44#include <system/audio_policy.h>
45
46#include <audio_utils/primitives.h>
47
48namespace android {
49// ---------------------------------------------------------------------------
50
51// static
52status_t AudioTrack::getMinFrameCount(
53        int* frameCount,
54        audio_stream_type_t 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      mIsTimed(false),
84      mPreviousPriority(ANDROID_PRIORITY_NORMAL),
85      mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
86{
87}
88
89AudioTrack::AudioTrack(
90        audio_stream_type_t streamType,
91        uint32_t sampleRate,
92        audio_format_t format,
93        int channelMask,
94        int frameCount,
95        uint32_t flags,
96        callback_t cbf,
97        void* user,
98        int notificationFrames,
99        int sessionId)
100    : mStatus(NO_INIT),
101      mIsTimed(false),
102      mPreviousPriority(ANDROID_PRIORITY_NORMAL),
103      mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
104{
105    mStatus = set(streamType, sampleRate, format, channelMask,
106            frameCount, flags, cbf, user, notificationFrames,
107            0, false, sessionId);
108}
109
110AudioTrack::AudioTrack(
111        int streamType,
112        uint32_t sampleRate,
113        int format,
114        int channelMask,
115        int frameCount,
116        uint32_t flags,
117        callback_t cbf,
118        void* user,
119        int notificationFrames,
120        int sessionId)
121    : mStatus(NO_INIT),
122      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
123{
124    mStatus = set((audio_stream_type_t)streamType, sampleRate, (audio_format_t)format, channelMask,
125            frameCount, flags, cbf, user, notificationFrames,
126            0, false, sessionId);
127}
128
129AudioTrack::AudioTrack(
130        audio_stream_type_t streamType,
131        uint32_t sampleRate,
132        audio_format_t format,
133        int channelMask,
134        const sp<IMemory>& sharedBuffer,
135        uint32_t flags,
136        callback_t cbf,
137        void* user,
138        int notificationFrames,
139        int sessionId)
140    : mStatus(NO_INIT),
141      mIsTimed(false),
142      mPreviousPriority(ANDROID_PRIORITY_NORMAL),
143      mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
144{
145    mStatus = set(streamType, sampleRate, format, channelMask,
146            0, flags, cbf, user, notificationFrames,
147            sharedBuffer, false, sessionId);
148}
149
150AudioTrack::~AudioTrack()
151{
152    ALOGV_IF(mSharedBuffer != 0, "Destructor sharedBuffer: %p", mSharedBuffer->pointer());
153
154    if (mStatus == NO_ERROR) {
155        // Make sure that callback function exits in the case where
156        // it is looping on buffer full condition in obtainBuffer().
157        // Otherwise the callback thread will never exit.
158        stop();
159        if (mAudioTrackThread != 0) {
160            mAudioTrackThread->requestExitAndWait();
161            mAudioTrackThread.clear();
162        }
163        mAudioTrack.clear();
164        IPCThreadState::self()->flushCommands();
165        AudioSystem::releaseAudioSessionId(mSessionId);
166    }
167}
168
169status_t AudioTrack::set(
170        audio_stream_type_t streamType,
171        uint32_t sampleRate,
172        audio_format_t format,
173        int channelMask,
174        int frameCount,
175        uint32_t flags,
176        callback_t cbf,
177        void* user,
178        int notificationFrames,
179        const sp<IMemory>& sharedBuffer,
180        bool threadCanCallJava,
181        int sessionId)
182{
183
184    ALOGV_IF(sharedBuffer != 0, "sharedBuffer: %p, size: %d", sharedBuffer->pointer(), sharedBuffer->size());
185
186    AutoMutex lock(mLock);
187    if (mAudioTrack != 0) {
188        ALOGE("Track already in use");
189        return INVALID_OPERATION;
190    }
191
192    int afSampleRate;
193    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
194        return NO_INIT;
195    }
196    uint32_t afLatency;
197    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
198        return NO_INIT;
199    }
200
201    // handle default values first.
202    if (streamType == AUDIO_STREAM_DEFAULT) {
203        streamType = AUDIO_STREAM_MUSIC;
204    }
205    if (sampleRate == 0) {
206        sampleRate = afSampleRate;
207    }
208    // these below should probably come from the audioFlinger too...
209    if (format == AUDIO_FORMAT_DEFAULT) {
210        format = AUDIO_FORMAT_PCM_16_BIT;
211    }
212    if (channelMask == 0) {
213        channelMask = AUDIO_CHANNEL_OUT_STEREO;
214    }
215
216    // validate parameters
217    if (!audio_is_valid_format(format)) {
218        ALOGE("Invalid format");
219        return BAD_VALUE;
220    }
221
222    // force direct flag if format is not linear PCM
223    if (!audio_is_linear_pcm(format)) {
224        flags |= AUDIO_POLICY_OUTPUT_FLAG_DIRECT;
225    }
226
227    if (!audio_is_output_channel(channelMask)) {
228        ALOGE("Invalid channel mask");
229        return BAD_VALUE;
230    }
231    uint32_t channelCount = popcount(channelMask);
232
233    audio_io_handle_t output = AudioSystem::getOutput(
234                                    streamType,
235                                    sampleRate, format, channelMask,
236                                    (audio_policy_output_flags_t)flags);
237
238    if (output == 0) {
239        ALOGE("Could not get audio output for stream type %d", streamType);
240        return BAD_VALUE;
241    }
242
243    mVolume[LEFT] = 1.0f;
244    mVolume[RIGHT] = 1.0f;
245    mSendLevel = 0.0f;
246    mFrameCount = frameCount;
247    mNotificationFramesReq = notificationFrames;
248    mSessionId = sessionId;
249    mAuxEffectId = 0;
250
251    // create the IAudioTrack
252    status_t status = createTrack_l(streamType,
253                                  sampleRate,
254                                  format,
255                                  (uint32_t)channelMask,
256                                  frameCount,
257                                  flags,
258                                  sharedBuffer,
259                                  output,
260                                  true);
261
262    if (status != NO_ERROR) {
263        return status;
264    }
265
266    if (cbf != NULL) {
267        mAudioTrackThread = new AudioTrackThread(*this, threadCanCallJava);
268    }
269
270    mStatus = NO_ERROR;
271
272    mStreamType = streamType;
273    mFormat = format;
274    mChannelMask = (uint32_t)channelMask;
275    mChannelCount = channelCount;
276    mSharedBuffer = sharedBuffer;
277    mMuted = false;
278    mActive = false;
279    mCbf = cbf;
280    mUserData = user;
281    mLoopCount = 0;
282    mMarkerPosition = 0;
283    mMarkerReached = false;
284    mNewPosition = 0;
285    mUpdatePeriod = 0;
286    mFlushed = false;
287    mFlags = flags;
288    AudioSystem::acquireAudioSessionId(mSessionId);
289    mRestoreStatus = NO_ERROR;
290    return NO_ERROR;
291}
292
293status_t AudioTrack::initCheck() const
294{
295    return mStatus;
296}
297
298// -------------------------------------------------------------------------
299
300uint32_t AudioTrack::latency() const
301{
302    return mLatency;
303}
304
305audio_stream_type_t AudioTrack::streamType() const
306{
307    return mStreamType;
308}
309
310audio_format_t AudioTrack::format() const
311{
312    return mFormat;
313}
314
315int AudioTrack::channelCount() const
316{
317    return mChannelCount;
318}
319
320uint32_t AudioTrack::frameCount() const
321{
322    return mCblk->frameCount;
323}
324
325size_t AudioTrack::frameSize() const
326{
327    if (audio_is_linear_pcm(mFormat)) {
328        return channelCount()*audio_bytes_per_sample(mFormat);
329    } else {
330        return sizeof(uint8_t);
331    }
332}
333
334sp<IMemory>& AudioTrack::sharedBuffer()
335{
336    return mSharedBuffer;
337}
338
339// -------------------------------------------------------------------------
340
341void AudioTrack::start()
342{
343    sp<AudioTrackThread> t = mAudioTrackThread;
344    status_t status = NO_ERROR;
345
346    ALOGV("start %p", this);
347    if (t != 0) {
348        if (t->exitPending()) {
349            if (t->requestExitAndWait() == WOULD_BLOCK) {
350                ALOGE("AudioTrack::start called from thread");
351                return;
352            }
353        }
354     }
355
356    AutoMutex lock(mLock);
357    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
358    // while we are accessing the cblk
359    sp <IAudioTrack> audioTrack = mAudioTrack;
360    sp <IMemory> iMem = mCblkMemory;
361    audio_track_cblk_t* cblk = mCblk;
362
363    if (!mActive) {
364        mFlushed = false;
365        mActive = true;
366        mNewPosition = cblk->server + mUpdatePeriod;
367        cblk->lock.lock();
368        cblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
369        cblk->waitTimeMs = 0;
370        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
371        pid_t tid;
372        if (t != 0) {
373            t->run("AudioTrack", ANDROID_PRIORITY_AUDIO);
374            tid = t->getTid();  // pid_t is unknown until run()
375            ALOGV("getTid=%d", tid);
376            if (tid == -1) {
377                tid = 0;
378            }
379        } else {
380            mPreviousPriority = getpriority(PRIO_PROCESS, 0);
381            mPreviousSchedulingGroup = androidGetThreadSchedulingGroup(0);
382            androidSetThreadPriority(0, ANDROID_PRIORITY_AUDIO);
383            tid = 0;    // not gettid()
384        }
385
386        ALOGV("start %p before lock cblk %p", this, mCblk);
387        if (!(cblk->flags & CBLK_INVALID_MSK)) {
388            cblk->lock.unlock();
389            ALOGV("mAudioTrack->start(tid=%d)", tid);
390            status = mAudioTrack->start(tid);
391            cblk->lock.lock();
392            if (status == DEAD_OBJECT) {
393                android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
394            }
395        }
396        if (cblk->flags & CBLK_INVALID_MSK) {
397            status = restoreTrack_l(cblk, true);
398        }
399        cblk->lock.unlock();
400        if (status != NO_ERROR) {
401            ALOGV("start() failed");
402            mActive = false;
403            if (t != 0) {
404                t->requestExit();
405            } else {
406                setpriority(PRIO_PROCESS, 0, mPreviousPriority);
407                androidSetThreadSchedulingGroup(0, mPreviousSchedulingGroup);
408            }
409        }
410    }
411
412}
413
414void AudioTrack::stop()
415{
416    sp<AudioTrackThread> t = mAudioTrackThread;
417
418    ALOGV("stop %p", this);
419
420    AutoMutex lock(mLock);
421    if (mActive) {
422        mActive = false;
423        mCblk->cv.signal();
424        mAudioTrack->stop();
425        // Cancel loops (If we are in the middle of a loop, playback
426        // would not stop until loopCount reaches 0).
427        setLoop_l(0, 0, 0);
428        // the playback head position will reset to 0, so if a marker is set, we need
429        // to activate it again
430        mMarkerReached = false;
431        // Force flush if a shared buffer is used otherwise audioflinger
432        // will not stop before end of buffer is reached.
433        if (mSharedBuffer != 0) {
434            flush_l();
435        }
436        if (t != 0) {
437            t->requestExit();
438        } else {
439            setpriority(PRIO_PROCESS, 0, mPreviousPriority);
440            androidSetThreadSchedulingGroup(0, mPreviousSchedulingGroup);
441        }
442    }
443
444}
445
446bool AudioTrack::stopped() const
447{
448    AutoMutex lock(mLock);
449    return stopped_l();
450}
451
452void AudioTrack::flush()
453{
454    AutoMutex lock(mLock);
455    flush_l();
456}
457
458// must be called with mLock held
459void AudioTrack::flush_l()
460{
461    ALOGV("flush");
462
463    // clear playback marker and periodic update counter
464    mMarkerPosition = 0;
465    mMarkerReached = false;
466    mUpdatePeriod = 0;
467
468    if (!mActive) {
469        mFlushed = true;
470        mAudioTrack->flush();
471        // Release AudioTrack callback thread in case it was waiting for new buffers
472        // in AudioTrack::obtainBuffer()
473        mCblk->cv.signal();
474    }
475}
476
477void AudioTrack::pause()
478{
479    ALOGV("pause");
480    AutoMutex lock(mLock);
481    if (mActive) {
482        mActive = false;
483        mAudioTrack->pause();
484    }
485}
486
487void AudioTrack::mute(bool e)
488{
489    mAudioTrack->mute(e);
490    mMuted = e;
491}
492
493bool AudioTrack::muted() const
494{
495    return mMuted;
496}
497
498status_t AudioTrack::setVolume(float left, float right)
499{
500    if (left < 0.0f || left > 1.0f || right < 0.0f || right > 1.0f) {
501        return BAD_VALUE;
502    }
503
504    AutoMutex lock(mLock);
505    mVolume[LEFT] = left;
506    mVolume[RIGHT] = right;
507
508    mCblk->setVolumeLR((uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000));
509
510    return NO_ERROR;
511}
512
513void AudioTrack::getVolume(float* left, float* right) const
514{
515    if (left != NULL) {
516        *left  = mVolume[LEFT];
517    }
518    if (right != NULL) {
519        *right = mVolume[RIGHT];
520    }
521}
522
523status_t AudioTrack::setAuxEffectSendLevel(float level)
524{
525    ALOGV("setAuxEffectSendLevel(%f)", level);
526    if (level < 0.0f || level > 1.0f) {
527        return BAD_VALUE;
528    }
529    AutoMutex lock(mLock);
530
531    mSendLevel = level;
532
533    mCblk->setSendLevel(level);
534
535    return NO_ERROR;
536}
537
538void AudioTrack::getAuxEffectSendLevel(float* level) const
539{
540    if (level != NULL) {
541        *level  = mSendLevel;
542    }
543}
544
545status_t AudioTrack::setSampleRate(int rate)
546{
547    int afSamplingRate;
548
549    if (mIsTimed) {
550        return INVALID_OPERATION;
551    }
552
553    if (AudioSystem::getOutputSamplingRate(&afSamplingRate, mStreamType) != NO_ERROR) {
554        return NO_INIT;
555    }
556    // Resampler implementation limits input sampling rate to 2 x output sampling rate.
557    if (rate <= 0 || rate > afSamplingRate*2 ) return BAD_VALUE;
558
559    AutoMutex lock(mLock);
560    mCblk->sampleRate = rate;
561    return NO_ERROR;
562}
563
564uint32_t AudioTrack::getSampleRate() const
565{
566    if (mIsTimed) {
567        return INVALID_OPERATION;
568    }
569
570    AutoMutex lock(mLock);
571    return mCblk->sampleRate;
572}
573
574status_t AudioTrack::setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount)
575{
576    AutoMutex lock(mLock);
577    return setLoop_l(loopStart, loopEnd, loopCount);
578}
579
580// must be called with mLock held
581status_t AudioTrack::setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount)
582{
583    audio_track_cblk_t* cblk = mCblk;
584
585    Mutex::Autolock _l(cblk->lock);
586
587    if (loopCount == 0) {
588        cblk->loopStart = UINT_MAX;
589        cblk->loopEnd = UINT_MAX;
590        cblk->loopCount = 0;
591        mLoopCount = 0;
592        return NO_ERROR;
593    }
594
595    if (mIsTimed) {
596        return INVALID_OPERATION;
597    }
598
599    if (loopStart >= loopEnd ||
600        loopEnd - loopStart > cblk->frameCount ||
601        cblk->server > loopStart) {
602        ALOGE("setLoop invalid value: loopStart %d, loopEnd %d, loopCount %d, framecount %d, user %d", loopStart, loopEnd, loopCount, cblk->frameCount, cblk->user);
603        return BAD_VALUE;
604    }
605
606    if ((mSharedBuffer != 0) && (loopEnd > cblk->frameCount)) {
607        ALOGE("setLoop invalid value: loop markers beyond data: loopStart %d, loopEnd %d, framecount %d",
608            loopStart, loopEnd, cblk->frameCount);
609        return BAD_VALUE;
610    }
611
612    cblk->loopStart = loopStart;
613    cblk->loopEnd = loopEnd;
614    cblk->loopCount = loopCount;
615    mLoopCount = loopCount;
616
617    return NO_ERROR;
618}
619
620status_t AudioTrack::setMarkerPosition(uint32_t marker)
621{
622    if (mCbf == NULL) return INVALID_OPERATION;
623
624    mMarkerPosition = marker;
625    mMarkerReached = false;
626
627    return NO_ERROR;
628}
629
630status_t AudioTrack::getMarkerPosition(uint32_t *marker) const
631{
632    if (marker == NULL) return BAD_VALUE;
633
634    *marker = mMarkerPosition;
635
636    return NO_ERROR;
637}
638
639status_t AudioTrack::setPositionUpdatePeriod(uint32_t updatePeriod)
640{
641    if (mCbf == NULL) return INVALID_OPERATION;
642
643    uint32_t curPosition;
644    getPosition(&curPosition);
645    mNewPosition = curPosition + updatePeriod;
646    mUpdatePeriod = updatePeriod;
647
648    return NO_ERROR;
649}
650
651status_t AudioTrack::getPositionUpdatePeriod(uint32_t *updatePeriod) const
652{
653    if (updatePeriod == NULL) return BAD_VALUE;
654
655    *updatePeriod = mUpdatePeriod;
656
657    return NO_ERROR;
658}
659
660status_t AudioTrack::setPosition(uint32_t position)
661{
662    if (mIsTimed) return INVALID_OPERATION;
663
664    AutoMutex lock(mLock);
665
666    if (!stopped_l()) return INVALID_OPERATION;
667
668    Mutex::Autolock _l(mCblk->lock);
669
670    if (position > mCblk->user) return BAD_VALUE;
671
672    mCblk->server = position;
673    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
674
675    return NO_ERROR;
676}
677
678status_t AudioTrack::getPosition(uint32_t *position)
679{
680    if (position == NULL) return BAD_VALUE;
681    AutoMutex lock(mLock);
682    *position = mFlushed ? 0 : mCblk->server;
683
684    return NO_ERROR;
685}
686
687status_t AudioTrack::reload()
688{
689    AutoMutex lock(mLock);
690
691    if (!stopped_l()) return INVALID_OPERATION;
692
693    flush_l();
694
695    mCblk->stepUser(mCblk->frameCount);
696
697    return NO_ERROR;
698}
699
700audio_io_handle_t AudioTrack::getOutput()
701{
702    AutoMutex lock(mLock);
703    return getOutput_l();
704}
705
706// must be called with mLock held
707audio_io_handle_t AudioTrack::getOutput_l()
708{
709    return AudioSystem::getOutput(mStreamType,
710            mCblk->sampleRate, mFormat, mChannelMask, (audio_policy_output_flags_t)mFlags);
711}
712
713int AudioTrack::getSessionId() const
714{
715    return mSessionId;
716}
717
718status_t AudioTrack::attachAuxEffect(int effectId)
719{
720    ALOGV("attachAuxEffect(%d)", effectId);
721    status_t status = mAudioTrack->attachAuxEffect(effectId);
722    if (status == NO_ERROR) {
723        mAuxEffectId = effectId;
724    }
725    return status;
726}
727
728// -------------------------------------------------------------------------
729
730// must be called with mLock held
731status_t AudioTrack::createTrack_l(
732        audio_stream_type_t streamType,
733        uint32_t sampleRate,
734        audio_format_t format,
735        uint32_t channelMask,
736        int frameCount,
737        uint32_t flags,
738        const sp<IMemory>& sharedBuffer,
739        audio_io_handle_t output,
740        bool enforceFrameCount)
741{
742    status_t status;
743    const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
744    if (audioFlinger == 0) {
745       ALOGE("Could not get audioflinger");
746       return NO_INIT;
747    }
748
749    int afSampleRate;
750    if (AudioSystem::getOutputSamplingRate(&afSampleRate, streamType) != NO_ERROR) {
751        return NO_INIT;
752    }
753    int afFrameCount;
754    if (AudioSystem::getOutputFrameCount(&afFrameCount, streamType) != NO_ERROR) {
755        return NO_INIT;
756    }
757    uint32_t afLatency;
758    if (AudioSystem::getOutputLatency(&afLatency, streamType) != NO_ERROR) {
759        return NO_INIT;
760    }
761
762    mNotificationFramesAct = mNotificationFramesReq;
763    if (!audio_is_linear_pcm(format)) {
764        if (sharedBuffer != 0) {
765            frameCount = sharedBuffer->size();
766        }
767    } else {
768        // Ensure that buffer depth covers at least audio hardware latency
769        uint32_t minBufCount = afLatency / ((1000 * afFrameCount)/afSampleRate);
770        if (minBufCount < 2) minBufCount = 2;
771
772        int minFrameCount = (afFrameCount*sampleRate*minBufCount)/afSampleRate;
773
774        if (sharedBuffer == 0) {
775            if (frameCount == 0) {
776                frameCount = minFrameCount;
777            }
778            if (mNotificationFramesAct == 0) {
779                mNotificationFramesAct = frameCount/2;
780            }
781            // Make sure that application is notified with sufficient margin
782            // before underrun
783            if (mNotificationFramesAct > (uint32_t)frameCount/2) {
784                mNotificationFramesAct = frameCount/2;
785            }
786            if (frameCount < minFrameCount) {
787                ALOGW_IF(enforceFrameCount, "Minimum buffer size corrected from %d to %d",
788                         frameCount, minFrameCount);
789                frameCount = minFrameCount;
790            }
791        } else {
792            // Ensure that buffer alignment matches channelCount
793            int channelCount = popcount(channelMask);
794            if (((uint32_t)sharedBuffer->pointer() & (channelCount | 1)) != 0) {
795                ALOGE("Invalid buffer alignement: address %p, channelCount %d", sharedBuffer->pointer(), channelCount);
796                return BAD_VALUE;
797            }
798            frameCount = sharedBuffer->size()/channelCount/sizeof(int16_t);
799        }
800    }
801
802    sp<IAudioTrack> track = audioFlinger->createTrack(getpid(),
803                                                      streamType,
804                                                      sampleRate,
805                                                      format,
806                                                      channelMask,
807                                                      frameCount,
808                                                      ((uint16_t)flags) << 16,
809                                                      sharedBuffer,
810                                                      output,
811                                                      mIsTimed,
812                                                      &mSessionId,
813                                                      &status);
814
815    if (track == 0) {
816        ALOGE("AudioFlinger could not create track, status: %d", status);
817        return status;
818    }
819    sp<IMemory> cblk = track->getCblk();
820    if (cblk == 0) {
821        ALOGE("Could not get control block");
822        return NO_INIT;
823    }
824    mAudioTrack = track;
825    mCblkMemory = cblk;
826    mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
827    android_atomic_or(CBLK_DIRECTION_OUT, &mCblk->flags);
828    if (sharedBuffer == 0) {
829        mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
830    } else {
831        mCblk->buffers = sharedBuffer->pointer();
832         // Force buffer full condition as data is already present in shared memory
833        mCblk->stepUser(mCblk->frameCount);
834    }
835
836    mCblk->setVolumeLR((uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000));
837    mCblk->setSendLevel(mSendLevel);
838    mAudioTrack->attachAuxEffect(mAuxEffectId);
839    mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
840    mCblk->waitTimeMs = 0;
841    mRemainingFrames = mNotificationFramesAct;
842    mLatency = afLatency + (1000*mCblk->frameCount) / sampleRate;
843    return NO_ERROR;
844}
845
846status_t AudioTrack::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
847{
848    AutoMutex lock(mLock);
849    bool active;
850    status_t result = NO_ERROR;
851    audio_track_cblk_t* cblk = mCblk;
852    uint32_t framesReq = audioBuffer->frameCount;
853    uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;
854
855    audioBuffer->frameCount  = 0;
856    audioBuffer->size = 0;
857
858    uint32_t framesAvail = cblk->framesAvailable();
859
860    cblk->lock.lock();
861    if (cblk->flags & CBLK_INVALID_MSK) {
862        goto create_new_track;
863    }
864    cblk->lock.unlock();
865
866    if (framesAvail == 0) {
867        cblk->lock.lock();
868        goto start_loop_here;
869        while (framesAvail == 0) {
870            active = mActive;
871            if (CC_UNLIKELY(!active)) {
872                ALOGV("Not active and NO_MORE_BUFFERS");
873                cblk->lock.unlock();
874                return NO_MORE_BUFFERS;
875            }
876            if (CC_UNLIKELY(!waitCount)) {
877                cblk->lock.unlock();
878                return WOULD_BLOCK;
879            }
880            if (!(cblk->flags & CBLK_INVALID_MSK)) {
881                mLock.unlock();
882                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
883                cblk->lock.unlock();
884                mLock.lock();
885                if (!mActive) {
886                    return status_t(STOPPED);
887                }
888                cblk->lock.lock();
889            }
890
891            if (cblk->flags & CBLK_INVALID_MSK) {
892                goto create_new_track;
893            }
894            if (CC_UNLIKELY(result != NO_ERROR)) {
895                cblk->waitTimeMs += waitTimeMs;
896                if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
897                    // timing out when a loop has been set and we have already written upto loop end
898                    // is a normal condition: no need to wake AudioFlinger up.
899                    if (cblk->user < cblk->loopEnd) {
900                        ALOGW(   "obtainBuffer timed out (is the CPU pegged?) %p "
901                                "user=%08x, server=%08x", this, cblk->user, cblk->server);
902                        //unlock cblk mutex before calling mAudioTrack->start() (see issue #1617140)
903                        cblk->lock.unlock();
904                        result = mAudioTrack->start(0); // callback thread hasn't changed
905                        cblk->lock.lock();
906                        if (result == DEAD_OBJECT) {
907                            android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
908create_new_track:
909                            result = restoreTrack_l(cblk, false);
910                        }
911                        if (result != NO_ERROR) {
912                            ALOGW("obtainBuffer create Track error %d", result);
913                            cblk->lock.unlock();
914                            return result;
915                        }
916                    }
917                    cblk->waitTimeMs = 0;
918                }
919
920                if (--waitCount == 0) {
921                    cblk->lock.unlock();
922                    return TIMED_OUT;
923                }
924            }
925            // read the server count again
926        start_loop_here:
927            framesAvail = cblk->framesAvailable_l();
928        }
929        cblk->lock.unlock();
930    }
931
932    // restart track if it was disabled by audioflinger due to previous underrun
933    if (mActive && (cblk->flags & CBLK_DISABLED_MSK)) {
934        android_atomic_and(~CBLK_DISABLED_ON, &cblk->flags);
935        ALOGW("obtainBuffer() track %p disabled, restarting", this);
936        mAudioTrack->start(0);  // callback thread hasn't changed
937    }
938
939    cblk->waitTimeMs = 0;
940
941    if (framesReq > framesAvail) {
942        framesReq = framesAvail;
943    }
944
945    uint32_t u = cblk->user;
946    uint32_t bufferEnd = cblk->userBase + cblk->frameCount;
947
948    if (u + framesReq > bufferEnd) {
949        framesReq = bufferEnd - u;
950    }
951
952    audioBuffer->flags = mMuted ? Buffer::MUTE : 0;
953    audioBuffer->channelCount = mChannelCount;
954    audioBuffer->frameCount = framesReq;
955    audioBuffer->size = framesReq * cblk->frameSize;
956    if (audio_is_linear_pcm(mFormat)) {
957        audioBuffer->format = AUDIO_FORMAT_PCM_16_BIT;
958    } else {
959        audioBuffer->format = mFormat;
960    }
961    audioBuffer->raw = (int8_t *)cblk->buffer(u);
962    active = mActive;
963    return active ? status_t(NO_ERROR) : status_t(STOPPED);
964}
965
966void AudioTrack::releaseBuffer(Buffer* audioBuffer)
967{
968    AutoMutex lock(mLock);
969    mCblk->stepUser(audioBuffer->frameCount);
970}
971
972// -------------------------------------------------------------------------
973
974ssize_t AudioTrack::write(const void* buffer, size_t userSize)
975{
976
977    if (mSharedBuffer != 0) return INVALID_OPERATION;
978    if (mIsTimed) return INVALID_OPERATION;
979
980    if (ssize_t(userSize) < 0) {
981        // Sanity-check: user is most-likely passing an error code, and it would
982        // make the return value ambiguous (actualSize vs error).
983        ALOGE("AudioTrack::write(buffer=%p, size=%u (%d)",
984                buffer, userSize, userSize);
985        return BAD_VALUE;
986    }
987
988    ALOGV("write %p: %d bytes, mActive=%d", this, userSize, mActive);
989
990    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
991    // while we are accessing the cblk
992    mLock.lock();
993    sp <IAudioTrack> audioTrack = mAudioTrack;
994    sp <IMemory> iMem = mCblkMemory;
995    mLock.unlock();
996
997    ssize_t written = 0;
998    const int8_t *src = (const int8_t *)buffer;
999    Buffer audioBuffer;
1000    size_t frameSz = frameSize();
1001
1002    do {
1003        audioBuffer.frameCount = userSize/frameSz;
1004
1005        status_t err = obtainBuffer(&audioBuffer, -1);
1006        if (err < 0) {
1007            // out of buffers, return #bytes written
1008            if (err == status_t(NO_MORE_BUFFERS))
1009                break;
1010            return ssize_t(err);
1011        }
1012
1013        size_t toWrite;
1014
1015        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1016            // Divide capacity by 2 to take expansion into account
1017            toWrite = audioBuffer.size>>1;
1018            memcpy_to_i16_from_u8(audioBuffer.i16, (const uint8_t *) src, toWrite);
1019        } else {
1020            toWrite = audioBuffer.size;
1021            memcpy(audioBuffer.i8, src, toWrite);
1022            src += toWrite;
1023        }
1024        userSize -= toWrite;
1025        written += toWrite;
1026
1027        releaseBuffer(&audioBuffer);
1028    } while (userSize >= frameSz);
1029
1030    return written;
1031}
1032
1033// -------------------------------------------------------------------------
1034
1035TimedAudioTrack::TimedAudioTrack() {
1036    mIsTimed = true;
1037}
1038
1039status_t TimedAudioTrack::allocateTimedBuffer(size_t size, sp<IMemory>* buffer)
1040{
1041    status_t result = UNKNOWN_ERROR;
1042
1043    // If the track is not invalid already, try to allocate a buffer.  alloc
1044    // fails indicating that the server is dead, flag the track as invalid so
1045    // we can attempt to restore in in just a bit.
1046    if (!(mCblk->flags & CBLK_INVALID_MSK)) {
1047        result = mAudioTrack->allocateTimedBuffer(size, buffer);
1048        if (result == DEAD_OBJECT) {
1049            android_atomic_or(CBLK_INVALID_ON, &mCblk->flags);
1050        }
1051    }
1052
1053    // If the track is invalid at this point, attempt to restore it. and try the
1054    // allocation one more time.
1055    if (mCblk->flags & CBLK_INVALID_MSK) {
1056        mCblk->lock.lock();
1057        result = restoreTrack_l(mCblk, false);
1058        mCblk->lock.unlock();
1059
1060        if (result == OK)
1061            result = mAudioTrack->allocateTimedBuffer(size, buffer);
1062    }
1063
1064    return result;
1065}
1066
1067status_t TimedAudioTrack::queueTimedBuffer(const sp<IMemory>& buffer,
1068                                           int64_t pts)
1069{
1070    // restart track if it was disabled by audioflinger due to previous underrun
1071    if (mActive && (mCblk->flags & CBLK_DISABLED_MSK)) {
1072        android_atomic_and(~CBLK_DISABLED_ON, &mCblk->flags);
1073        ALOGW("queueTimedBuffer() track %p disabled, restarting", this);
1074        mAudioTrack->start(0);
1075    }
1076
1077    return mAudioTrack->queueTimedBuffer(buffer, pts);
1078}
1079
1080status_t TimedAudioTrack::setMediaTimeTransform(const LinearTransform& xform,
1081                                                TargetTimeline target)
1082{
1083    return mAudioTrack->setMediaTimeTransform(xform, target);
1084}
1085
1086// -------------------------------------------------------------------------
1087
1088bool AudioTrack::processAudioBuffer(const sp<AudioTrackThread>& thread)
1089{
1090    Buffer audioBuffer;
1091    uint32_t frames;
1092    size_t writtenSize;
1093
1094    mLock.lock();
1095    // acquire a strong reference on the IMemory and IAudioTrack so that they cannot be destroyed
1096    // while we are accessing the cblk
1097    sp <IAudioTrack> audioTrack = mAudioTrack;
1098    sp <IMemory> iMem = mCblkMemory;
1099    audio_track_cblk_t* cblk = mCblk;
1100    bool active = mActive;
1101    mLock.unlock();
1102
1103    // Manage underrun callback
1104    if (active && (cblk->framesAvailable() == cblk->frameCount)) {
1105        ALOGV("Underrun user: %x, server: %x, flags %04x", cblk->user, cblk->server, cblk->flags);
1106        if (!(android_atomic_or(CBLK_UNDERRUN_ON, &cblk->flags) & CBLK_UNDERRUN_MSK)) {
1107            mCbf(EVENT_UNDERRUN, mUserData, 0);
1108            if (cblk->server == cblk->frameCount) {
1109                mCbf(EVENT_BUFFER_END, mUserData, 0);
1110            }
1111            if (mSharedBuffer != 0) return false;
1112        }
1113    }
1114
1115    // Manage loop end callback
1116    while (mLoopCount > cblk->loopCount) {
1117        int loopCount = -1;
1118        mLoopCount--;
1119        if (mLoopCount >= 0) loopCount = mLoopCount;
1120
1121        mCbf(EVENT_LOOP_END, mUserData, (void *)&loopCount);
1122    }
1123
1124    // Manage marker callback
1125    if (!mMarkerReached && (mMarkerPosition > 0)) {
1126        if (cblk->server >= mMarkerPosition) {
1127            mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
1128            mMarkerReached = true;
1129        }
1130    }
1131
1132    // Manage new position callback
1133    if (mUpdatePeriod > 0) {
1134        while (cblk->server >= mNewPosition) {
1135            mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
1136            mNewPosition += mUpdatePeriod;
1137        }
1138    }
1139
1140    // If Shared buffer is used, no data is requested from client.
1141    if (mSharedBuffer != 0) {
1142        frames = 0;
1143    } else {
1144        frames = mRemainingFrames;
1145    }
1146
1147    // See description of waitCount parameter at declaration of obtainBuffer().
1148    // The logic below prevents us from being stuck below at obtainBuffer()
1149    // not being able to handle timed events (position, markers, loops).
1150    int32_t waitCount = -1;
1151    if (mUpdatePeriod || (!mMarkerReached && mMarkerPosition) || mLoopCount) {
1152        waitCount = 1;
1153    }
1154
1155    do {
1156
1157        audioBuffer.frameCount = frames;
1158
1159        status_t err = obtainBuffer(&audioBuffer, waitCount);
1160        if (err < NO_ERROR) {
1161            if (err != TIMED_OUT) {
1162                ALOGE_IF(err != status_t(NO_MORE_BUFFERS), "Error obtaining an audio buffer, giving up.");
1163                return false;
1164            }
1165            break;
1166        }
1167        if (err == status_t(STOPPED)) return false;
1168
1169        // Divide buffer size by 2 to take into account the expansion
1170        // due to 8 to 16 bit conversion: the callback must fill only half
1171        // of the destination buffer
1172        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1173            audioBuffer.size >>= 1;
1174        }
1175
1176        size_t reqSize = audioBuffer.size;
1177        mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
1178        writtenSize = audioBuffer.size;
1179
1180        // Sanity check on returned size
1181        if (ssize_t(writtenSize) <= 0) {
1182            // The callback is done filling buffers
1183            // Keep this thread going to handle timed events and
1184            // still try to get more data in intervals of WAIT_PERIOD_MS
1185            // but don't just loop and block the CPU, so wait
1186            usleep(WAIT_PERIOD_MS*1000);
1187            break;
1188        }
1189        if (writtenSize > reqSize) writtenSize = reqSize;
1190
1191        if (mFormat == AUDIO_FORMAT_PCM_8_BIT && !(mFlags & AUDIO_POLICY_OUTPUT_FLAG_DIRECT)) {
1192            // 8 to 16 bit conversion, note that source and destination are the same address
1193            memcpy_to_i16_from_u8(audioBuffer.i16, (const uint8_t *) audioBuffer.i8, writtenSize);
1194            writtenSize <<= 1;
1195        }
1196
1197        audioBuffer.size = writtenSize;
1198        // NOTE: mCblk->frameSize is not equal to AudioTrack::frameSize() for
1199        // 8 bit PCM data: in this case,  mCblk->frameSize is based on a sample size of
1200        // 16 bit.
1201        audioBuffer.frameCount = writtenSize/mCblk->frameSize;
1202
1203        frames -= audioBuffer.frameCount;
1204
1205        releaseBuffer(&audioBuffer);
1206    }
1207    while (frames);
1208
1209    if (frames == 0) {
1210        mRemainingFrames = mNotificationFramesAct;
1211    } else {
1212        mRemainingFrames = frames;
1213    }
1214    return true;
1215}
1216
1217// must be called with mLock and cblk.lock held. Callers must also hold strong references on
1218// the IAudioTrack and IMemory in case they are recreated here.
1219// If the IAudioTrack is successfully restored, the cblk pointer is updated
1220status_t AudioTrack::restoreTrack_l(audio_track_cblk_t*& cblk, bool fromStart)
1221{
1222    status_t result;
1223
1224    if (!(android_atomic_or(CBLK_RESTORING_ON, &cblk->flags) & CBLK_RESTORING_MSK)) {
1225        ALOGW("dead IAudioTrack, creating a new one from %s TID %d",
1226             fromStart ? "start()" : "obtainBuffer()", gettid());
1227
1228        // signal old cblk condition so that other threads waiting for available buffers stop
1229        // waiting now
1230        cblk->cv.broadcast();
1231        cblk->lock.unlock();
1232
1233        // refresh the audio configuration cache in this process to make sure we get new
1234        // output parameters in getOutput_l() and createTrack_l()
1235        AudioSystem::clearAudioConfigCache();
1236
1237        // if the new IAudioTrack is created, createTrack_l() will modify the
1238        // following member variables: mAudioTrack, mCblkMemory and mCblk.
1239        // It will also delete the strong references on previous IAudioTrack and IMemory
1240        result = createTrack_l(mStreamType,
1241                               cblk->sampleRate,
1242                               mFormat,
1243                               mChannelMask,
1244                               mFrameCount,
1245                               mFlags,
1246                               mSharedBuffer,
1247                               getOutput_l(),
1248                               false);
1249
1250        if (result == NO_ERROR) {
1251            uint32_t user = cblk->user;
1252            uint32_t server = cblk->server;
1253            // restore write index and set other indexes to reflect empty buffer status
1254            mCblk->user = user;
1255            mCblk->server = user;
1256            mCblk->userBase = user;
1257            mCblk->serverBase = user;
1258            // restore loop: this is not guaranteed to succeed if new frame count is not
1259            // compatible with loop length
1260            setLoop_l(cblk->loopStart, cblk->loopEnd, cblk->loopCount);
1261            if (!fromStart) {
1262                mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1263                // Make sure that a client relying on callback events indicating underrun or
1264                // the actual amount of audio frames played (e.g SoundPool) receives them.
1265                if (mSharedBuffer == 0) {
1266                    uint32_t frames = 0;
1267                    if (user > server) {
1268                        frames = ((user - server) > mCblk->frameCount) ?
1269                                mCblk->frameCount : (user - server);
1270                        memset(mCblk->buffers, 0, frames * mCblk->frameSize);
1271                    }
1272                    // restart playback even if buffer is not completely filled.
1273                    android_atomic_or(CBLK_FORCEREADY_ON, &mCblk->flags);
1274                    // stepUser() clears CBLK_UNDERRUN_ON flag enabling underrun callbacks to
1275                    // the client
1276                    mCblk->stepUser(frames);
1277                }
1278            }
1279            if (mActive) {
1280                result = mAudioTrack->start(0); // callback thread hasn't changed
1281                ALOGW_IF(result != NO_ERROR, "restoreTrack_l() start() failed status %d", result);
1282            }
1283            if (fromStart && result == NO_ERROR) {
1284                mNewPosition = mCblk->server + mUpdatePeriod;
1285            }
1286        }
1287        if (result != NO_ERROR) {
1288            android_atomic_and(~CBLK_RESTORING_ON, &cblk->flags);
1289            ALOGW_IF(result != NO_ERROR, "restoreTrack_l() failed status %d", result);
1290        }
1291        mRestoreStatus = result;
1292        // signal old cblk condition for other threads waiting for restore completion
1293        android_atomic_or(CBLK_RESTORED_ON, &cblk->flags);
1294        cblk->cv.broadcast();
1295    } else {
1296        if (!(cblk->flags & CBLK_RESTORED_MSK)) {
1297            ALOGW("dead IAudioTrack, waiting for a new one TID %d", gettid());
1298            mLock.unlock();
1299            result = cblk->cv.waitRelative(cblk->lock, milliseconds(RESTORE_TIMEOUT_MS));
1300            if (result == NO_ERROR) {
1301                result = mRestoreStatus;
1302            }
1303            cblk->lock.unlock();
1304            mLock.lock();
1305        } else {
1306            ALOGW("dead IAudioTrack, already restored TID %d", gettid());
1307            result = mRestoreStatus;
1308            cblk->lock.unlock();
1309        }
1310    }
1311    ALOGV("restoreTrack_l() status %d mActive %d cblk %p, old cblk %p flags %08x old flags %08x",
1312         result, mActive, mCblk, cblk, mCblk->flags, cblk->flags);
1313
1314    if (result == NO_ERROR) {
1315        // from now on we switch to the newly created cblk
1316        cblk = mCblk;
1317    }
1318    cblk->lock.lock();
1319
1320    ALOGW_IF(result != NO_ERROR, "restoreTrack_l() error %d TID %d", result, gettid());
1321
1322    return result;
1323}
1324
1325status_t AudioTrack::dump(int fd, const Vector<String16>& args) const
1326{
1327
1328    const size_t SIZE = 256;
1329    char buffer[SIZE];
1330    String8 result;
1331
1332    result.append(" AudioTrack::dump\n");
1333    snprintf(buffer, 255, "  stream type(%d), left - right volume(%f, %f)\n", mStreamType, mVolume[0], mVolume[1]);
1334    result.append(buffer);
1335    snprintf(buffer, 255, "  format(%d), channel count(%d), frame count(%d)\n", mFormat, mChannelCount, mCblk->frameCount);
1336    result.append(buffer);
1337    snprintf(buffer, 255, "  sample rate(%d), status(%d), muted(%d)\n", (mCblk == 0) ? 0 : mCblk->sampleRate, mStatus, mMuted);
1338    result.append(buffer);
1339    snprintf(buffer, 255, "  active(%d), latency (%d)\n", mActive, mLatency);
1340    result.append(buffer);
1341    ::write(fd, result.string(), result.size());
1342    return NO_ERROR;
1343}
1344
1345// =========================================================================
1346
1347AudioTrack::AudioTrackThread::AudioTrackThread(AudioTrack& receiver, bool bCanCallJava)
1348    : Thread(bCanCallJava), mReceiver(receiver)
1349{
1350}
1351
1352bool AudioTrack::AudioTrackThread::threadLoop()
1353{
1354    return mReceiver.processAudioBuffer(this);
1355}
1356
1357status_t AudioTrack::AudioTrackThread::readyToRun()
1358{
1359    return NO_ERROR;
1360}
1361
1362void AudioTrack::AudioTrackThread::onFirstRef()
1363{
1364}
1365
1366// =========================================================================
1367
1368
1369audio_track_cblk_t::audio_track_cblk_t()
1370    : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
1371    userBase(0), serverBase(0), buffers(NULL), frameCount(0),
1372    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), mVolumeLR(0x10001000),
1373    mSendLevel(0), flags(0)
1374{
1375}
1376
1377uint32_t audio_track_cblk_t::stepUser(uint32_t frameCount)
1378{
1379    uint32_t u = user;
1380
1381    u += frameCount;
1382    // Ensure that user is never ahead of server for AudioRecord
1383    if (flags & CBLK_DIRECTION_MSK) {
1384        // If stepServer() has been called once, switch to normal obtainBuffer() timeout period
1385        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS-1) {
1386            bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
1387        }
1388    } else if (u > server) {
1389        ALOGW("stepServer occurred after track reset");
1390        u = server;
1391    }
1392
1393    if (u >= userBase + this->frameCount) {
1394        userBase += this->frameCount;
1395    }
1396
1397    user = u;
1398
1399    // Clear flow control error condition as new data has been written/read to/from buffer.
1400    if (flags & CBLK_UNDERRUN_MSK) {
1401        android_atomic_and(~CBLK_UNDERRUN_MSK, &flags);
1402    }
1403
1404    return u;
1405}
1406
1407bool audio_track_cblk_t::stepServer(uint32_t frameCount)
1408{
1409    if (!tryLock()) {
1410        ALOGW("stepServer() could not lock cblk");
1411        return false;
1412    }
1413
1414    uint32_t s = server;
1415
1416    s += frameCount;
1417    if (flags & CBLK_DIRECTION_MSK) {
1418        // Mark that we have read the first buffer so that next time stepUser() is called
1419        // we switch to normal obtainBuffer() timeout period
1420        if (bufferTimeoutMs == MAX_STARTUP_TIMEOUT_MS) {
1421            bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS - 1;
1422        }
1423        // It is possible that we receive a flush()
1424        // while the mixer is processing a block: in this case,
1425        // stepServer() is called After the flush() has reset u & s and
1426        // we have s > u
1427        if (s > user) {
1428            ALOGW("stepServer occurred after track reset");
1429            s = user;
1430        }
1431    }
1432
1433    if (s >= loopEnd) {
1434        ALOGW_IF(s > loopEnd, "stepServer: s %u > loopEnd %u", s, loopEnd);
1435        s = loopStart;
1436        if (--loopCount == 0) {
1437            loopEnd = UINT_MAX;
1438            loopStart = UINT_MAX;
1439        }
1440    }
1441    if (s >= serverBase + this->frameCount) {
1442        serverBase += this->frameCount;
1443    }
1444
1445    server = s;
1446
1447    if (!(flags & CBLK_INVALID_MSK)) {
1448        cv.signal();
1449    }
1450    lock.unlock();
1451    return true;
1452}
1453
1454void* audio_track_cblk_t::buffer(uint32_t offset) const
1455{
1456    return (int8_t *)buffers + (offset - userBase) * frameSize;
1457}
1458
1459uint32_t audio_track_cblk_t::framesAvailable()
1460{
1461    Mutex::Autolock _l(lock);
1462    return framesAvailable_l();
1463}
1464
1465uint32_t audio_track_cblk_t::framesAvailable_l()
1466{
1467    uint32_t u = user;
1468    uint32_t s = server;
1469
1470    if (flags & CBLK_DIRECTION_MSK) {
1471        uint32_t limit = (s < loopStart) ? s : loopStart;
1472        return limit + frameCount - u;
1473    } else {
1474        return frameCount + u - s;
1475    }
1476}
1477
1478uint32_t audio_track_cblk_t::framesReady()
1479{
1480    uint32_t u = user;
1481    uint32_t s = server;
1482
1483    if (flags & CBLK_DIRECTION_MSK) {
1484        if (u < loopEnd) {
1485            return u - s;
1486        } else {
1487            // do not block on mutex shared with client on AudioFlinger side
1488            if (!tryLock()) {
1489                ALOGW("framesReady() could not lock cblk");
1490                return 0;
1491            }
1492            uint32_t frames = UINT_MAX;
1493            if (loopCount >= 0) {
1494                frames = (loopEnd - loopStart)*loopCount + u - s;
1495            }
1496            lock.unlock();
1497            return frames;
1498        }
1499    } else {
1500        return s - u;
1501    }
1502}
1503
1504bool audio_track_cblk_t::tryLock()
1505{
1506    // the code below simulates lock-with-timeout
1507    // we MUST do this to protect the AudioFlinger server
1508    // as this lock is shared with the client.
1509    status_t err;
1510
1511    err = lock.tryLock();
1512    if (err == -EBUSY) { // just wait a bit
1513        usleep(1000);
1514        err = lock.tryLock();
1515    }
1516    if (err != NO_ERROR) {
1517        // probably, the client just died.
1518        return false;
1519    }
1520    return true;
1521}
1522
1523// -------------------------------------------------------------------------
1524
1525}; // namespace android
1526