AudioRecord.cpp revision 83bc7f3cf78b28a818417f40a4f0c00593993366 
1/*
2**
3** Copyright 2008, 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//#define LOG_NDEBUG 0
19#define LOG_TAG "AudioRecord"
20
21#include <stdint.h>
22#include <sys/types.h>
23
24#include <sched.h>
25#include <sys/resource.h>
26
27#include <private/media/AudioTrackShared.h>
28
29#include <media/AudioSystem.h>
30#include <media/AudioRecord.h>
31#include <media/mediarecorder.h>
32
33#include <binder/IServiceManager.h>
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 <system/audio.h>
41#include <cutils/bitops.h>
42#include <cutils/compiler.h>
43
44namespace android {
45// ---------------------------------------------------------------------------
46
47// static
48status_t AudioRecord::getMinFrameCount(
49        int* frameCount,
50        uint32_t sampleRate,
51        int format,
52        int channelCount)
53{
54    size_t size = 0;
55    if (AudioSystem::getInputBufferSize(sampleRate, format, channelCount, &size)
56            != NO_ERROR) {
57        ALOGE("AudioSystem could not query the input buffer size.");
58        return NO_INIT;
59    }
60
61    if (size == 0) {
62        ALOGE("Unsupported configuration: sampleRate %d, format %d, channelCount %d",
63            sampleRate, format, channelCount);
64        return BAD_VALUE;
65    }
66
67    // We double the size of input buffer for ping pong use of record buffer.
68    size <<= 1;
69
70    if (audio_is_linear_pcm(format)) {
71        size /= channelCount * audio_bytes_per_sample(format);
72    }
73
74    *frameCount = size;
75    return NO_ERROR;
76}
77
78// ---------------------------------------------------------------------------
79
80AudioRecord::AudioRecord()
81    : mStatus(NO_INIT), mSessionId(0),
82      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
83{
84}
85
86AudioRecord::AudioRecord(
87        int inputSource,
88        uint32_t sampleRate,
89        int format,
90        uint32_t channelMask,
91        int frameCount,
92        uint32_t flags,
93        callback_t cbf,
94        void* user,
95        int notificationFrames,
96        int sessionId)
97    : mStatus(NO_INIT), mSessionId(0),
98      mPreviousPriority(ANDROID_PRIORITY_NORMAL), mPreviousSchedulingGroup(ANDROID_TGROUP_DEFAULT)
99{
100    mStatus = set(inputSource, sampleRate, format, channelMask,
101            frameCount, flags, cbf, user, notificationFrames, sessionId);
102}
103
104AudioRecord::~AudioRecord()
105{
106    if (mStatus == NO_ERROR) {
107        // Make sure that callback function exits in the case where
108        // it is looping on buffer empty condition in obtainBuffer().
109        // Otherwise the callback thread will never exit.
110        stop();
111        if (mClientRecordThread != 0) {
112            mClientRecordThread->requestExitAndWait();
113            mClientRecordThread.clear();
114        }
115        mAudioRecord.clear();
116        IPCThreadState::self()->flushCommands();
117        AudioSystem::releaseAudioSessionId(mSessionId);
118    }
119}
120
121status_t AudioRecord::set(
122        int inputSource,
123        uint32_t sampleRate,
124        int format,
125        uint32_t channelMask,
126        int frameCount,
127        uint32_t flags,
128        callback_t cbf,
129        void* user,
130        int notificationFrames,
131        bool threadCanCallJava,
132        int sessionId)
133{
134
135    ALOGV("set(): sampleRate %d, channelMask %d, frameCount %d",sampleRate, channelMask, frameCount);
136
137    AutoMutex lock(mLock);
138
139    if (mAudioRecord != 0) {
140        return INVALID_OPERATION;
141    }
142
143    if (inputSource == AUDIO_SOURCE_DEFAULT) {
144        inputSource = AUDIO_SOURCE_MIC;
145    }
146
147    if (sampleRate == 0) {
148        sampleRate = DEFAULT_SAMPLE_RATE;
149    }
150    // these below should probably come from the audioFlinger too...
151    if (format == 0) {
152        format = AUDIO_FORMAT_PCM_16_BIT;
153    }
154    // validate parameters
155    if (!audio_is_valid_format(format)) {
156        ALOGE("Invalid format");
157        return BAD_VALUE;
158    }
159
160    if (!audio_is_input_channel(channelMask)) {
161        return BAD_VALUE;
162    }
163
164    int channelCount = popcount(channelMask);
165
166    if (sessionId == 0 ) {
167        mSessionId = AudioSystem::newAudioSessionId();
168    } else {
169        mSessionId = sessionId;
170    }
171    ALOGV("set(): mSessionId %d", mSessionId);
172
173    audio_io_handle_t input = AudioSystem::getInput(inputSource,
174                                                    sampleRate,
175                                                    format,
176                                                    channelMask,
177                                                    (audio_in_acoustics_t)flags,
178                                                    mSessionId);
179    if (input == 0) {
180        ALOGE("Could not get audio input for record source %d", inputSource);
181        return BAD_VALUE;
182    }
183
184    // validate framecount
185    int minFrameCount = 0;
186    status_t status = getMinFrameCount(&minFrameCount, sampleRate, format, channelCount);
187    if (status != NO_ERROR) {
188        return status;
189    }
190    ALOGV("AudioRecord::set() minFrameCount = %d", minFrameCount);
191
192    if (frameCount == 0) {
193        frameCount = minFrameCount;
194    } else if (frameCount < minFrameCount) {
195        return BAD_VALUE;
196    }
197
198    if (notificationFrames == 0) {
199        notificationFrames = frameCount/2;
200    }
201
202    // create the IAudioRecord
203    status = openRecord_l(sampleRate, format, channelMask,
204                        frameCount, flags, input);
205    if (status != NO_ERROR) {
206        return status;
207    }
208
209    if (cbf != 0) {
210        mClientRecordThread = new ClientRecordThread(*this, threadCanCallJava);
211    }
212
213    mStatus = NO_ERROR;
214
215    mFormat = format;
216    // Update buffer size in case it has been limited by AudioFlinger during track creation
217    mFrameCount = mCblk->frameCount;
218    mChannelCount = (uint8_t)channelCount;
219    mChannelMask = channelMask;
220    mActive = 0;
221    mCbf = cbf;
222    mNotificationFrames = notificationFrames;
223    mRemainingFrames = notificationFrames;
224    mUserData = user;
225    // TODO: add audio hardware input latency here
226    mLatency = (1000*mFrameCount) / sampleRate;
227    mMarkerPosition = 0;
228    mMarkerReached = false;
229    mNewPosition = 0;
230    mUpdatePeriod = 0;
231    mInputSource = (uint8_t)inputSource;
232    mFlags = flags;
233    mInput = input;
234    AudioSystem::acquireAudioSessionId(mSessionId);
235
236    return NO_ERROR;
237}
238
239status_t AudioRecord::initCheck() const
240{
241    return mStatus;
242}
243
244// -------------------------------------------------------------------------
245
246uint32_t AudioRecord::latency() const
247{
248    return mLatency;
249}
250
251int AudioRecord::format() const
252{
253    return mFormat;
254}
255
256int AudioRecord::channelCount() const
257{
258    return mChannelCount;
259}
260
261uint32_t AudioRecord::frameCount() const
262{
263    return mFrameCount;
264}
265
266int AudioRecord::frameSize() const
267{
268    if (audio_is_linear_pcm(mFormat)) {
269        return channelCount()*audio_bytes_per_sample(mFormat);
270    } else {
271        return sizeof(uint8_t);
272    }
273}
274
275int AudioRecord::inputSource() const
276{
277    return (int)mInputSource;
278}
279
280// -------------------------------------------------------------------------
281
282status_t AudioRecord::start()
283{
284    status_t ret = NO_ERROR;
285    sp<ClientRecordThread> t = mClientRecordThread;
286
287    ALOGV("start");
288
289    if (t != 0) {
290        if (t->exitPending()) {
291            if (t->requestExitAndWait() == WOULD_BLOCK) {
292                ALOGE("AudioRecord::start called from thread");
293                return WOULD_BLOCK;
294            }
295        }
296        t->mLock.lock();
297     }
298
299    AutoMutex lock(mLock);
300    // acquire a strong reference on the IAudioRecord and IMemory so that they cannot be destroyed
301    // while we are accessing the cblk
302    sp <IAudioRecord> audioRecord = mAudioRecord;
303    sp <IMemory> iMem = mCblkMemory;
304    audio_track_cblk_t* cblk = mCblk;
305    if (mActive == 0) {
306        mActive = 1;
307
308        cblk->lock.lock();
309        if (!(cblk->flags & CBLK_INVALID_MSK)) {
310            cblk->lock.unlock();
311            ret = mAudioRecord->start();
312            cblk->lock.lock();
313            if (ret == DEAD_OBJECT) {
314                android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
315            }
316        }
317        if (cblk->flags & CBLK_INVALID_MSK) {
318            ret = restoreRecord_l(cblk);
319        }
320        cblk->lock.unlock();
321        if (ret == NO_ERROR) {
322            mNewPosition = cblk->user + mUpdatePeriod;
323            cblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
324            cblk->waitTimeMs = 0;
325            if (t != 0) {
326                t->run("ClientRecordThread", ANDROID_PRIORITY_AUDIO);
327            } else {
328                mPreviousPriority = getpriority(PRIO_PROCESS, 0);
329                mPreviousSchedulingGroup = androidGetThreadSchedulingGroup(0);
330                androidSetThreadPriority(0, ANDROID_PRIORITY_AUDIO);
331            }
332        } else {
333            mActive = 0;
334        }
335    }
336
337    if (t != 0) {
338        t->mLock.unlock();
339    }
340
341    return ret;
342}
343
344status_t AudioRecord::stop()
345{
346    sp<ClientRecordThread> t = mClientRecordThread;
347
348    ALOGV("stop");
349
350    if (t != 0) {
351        t->mLock.lock();
352    }
353
354    AutoMutex lock(mLock);
355    if (mActive == 1) {
356        mActive = 0;
357        mCblk->cv.signal();
358        mAudioRecord->stop();
359        // the record head position will reset to 0, so if a marker is set, we need
360        // to activate it again
361        mMarkerReached = false;
362        if (t != 0) {
363            t->requestExit();
364        } else {
365            setpriority(PRIO_PROCESS, 0, mPreviousPriority);
366            androidSetThreadSchedulingGroup(0, mPreviousSchedulingGroup);
367        }
368    }
369
370    if (t != 0) {
371        t->mLock.unlock();
372    }
373
374    return NO_ERROR;
375}
376
377bool AudioRecord::stopped() const
378{
379    return !mActive;
380}
381
382uint32_t AudioRecord::getSampleRate()
383{
384    AutoMutex lock(mLock);
385    return mCblk->sampleRate;
386}
387
388status_t AudioRecord::setMarkerPosition(uint32_t marker)
389{
390    if (mCbf == 0) return INVALID_OPERATION;
391
392    mMarkerPosition = marker;
393    mMarkerReached = false;
394
395    return NO_ERROR;
396}
397
398status_t AudioRecord::getMarkerPosition(uint32_t *marker)
399{
400    if (marker == 0) return BAD_VALUE;
401
402    *marker = mMarkerPosition;
403
404    return NO_ERROR;
405}
406
407status_t AudioRecord::setPositionUpdatePeriod(uint32_t updatePeriod)
408{
409    if (mCbf == 0) return INVALID_OPERATION;
410
411    uint32_t curPosition;
412    getPosition(&curPosition);
413    mNewPosition = curPosition + updatePeriod;
414    mUpdatePeriod = updatePeriod;
415
416    return NO_ERROR;
417}
418
419status_t AudioRecord::getPositionUpdatePeriod(uint32_t *updatePeriod)
420{
421    if (updatePeriod == 0) return BAD_VALUE;
422
423    *updatePeriod = mUpdatePeriod;
424
425    return NO_ERROR;
426}
427
428status_t AudioRecord::getPosition(uint32_t *position)
429{
430    if (position == 0) return BAD_VALUE;
431
432    AutoMutex lock(mLock);
433    *position = mCblk->user;
434
435    return NO_ERROR;
436}
437
438unsigned int AudioRecord::getInputFramesLost()
439{
440    if (mActive)
441        return AudioSystem::getInputFramesLost(mInput);
442    else
443        return 0;
444}
445
446// -------------------------------------------------------------------------
447
448// must be called with mLock held
449status_t AudioRecord::openRecord_l(
450        uint32_t sampleRate,
451        uint32_t format,
452        uint32_t channelMask,
453        int frameCount,
454        uint32_t flags,
455        audio_io_handle_t input)
456{
457    status_t status;
458    const sp<IAudioFlinger>& audioFlinger = AudioSystem::get_audio_flinger();
459    if (audioFlinger == 0) {
460        return NO_INIT;
461    }
462
463    sp<IAudioRecord> record = audioFlinger->openRecord(getpid(), input,
464                                                       sampleRate, format,
465                                                       channelMask,
466                                                       frameCount,
467                                                       ((uint16_t)flags) << 16,
468                                                       &mSessionId,
469                                                       &status);
470
471    if (record == 0) {
472        ALOGE("AudioFlinger could not create record track, status: %d", status);
473        return status;
474    }
475    sp<IMemory> cblk = record->getCblk();
476    if (cblk == 0) {
477        ALOGE("Could not get control block");
478        return NO_INIT;
479    }
480    mAudioRecord.clear();
481    mAudioRecord = record;
482    mCblkMemory.clear();
483    mCblkMemory = cblk;
484    mCblk = static_cast<audio_track_cblk_t*>(cblk->pointer());
485    mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
486    android_atomic_and(~CBLK_DIRECTION_MSK, &mCblk->flags);
487    mCblk->bufferTimeoutMs = MAX_RUN_TIMEOUT_MS;
488    mCblk->waitTimeMs = 0;
489    return NO_ERROR;
490}
491
492status_t AudioRecord::obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
493{
494    AutoMutex lock(mLock);
495    int active;
496    status_t result = NO_ERROR;
497    audio_track_cblk_t* cblk = mCblk;
498    uint32_t framesReq = audioBuffer->frameCount;
499    uint32_t waitTimeMs = (waitCount < 0) ? cblk->bufferTimeoutMs : WAIT_PERIOD_MS;
500
501    audioBuffer->frameCount  = 0;
502    audioBuffer->size        = 0;
503
504    uint32_t framesReady = cblk->framesReady();
505
506    if (framesReady == 0) {
507        cblk->lock.lock();
508        goto start_loop_here;
509        while (framesReady == 0) {
510            active = mActive;
511            if (CC_UNLIKELY(!active)) {
512                cblk->lock.unlock();
513                return NO_MORE_BUFFERS;
514            }
515            if (CC_UNLIKELY(!waitCount)) {
516                cblk->lock.unlock();
517                return WOULD_BLOCK;
518            }
519            if (!(cblk->flags & CBLK_INVALID_MSK)) {
520                mLock.unlock();
521                result = cblk->cv.waitRelative(cblk->lock, milliseconds(waitTimeMs));
522                cblk->lock.unlock();
523                mLock.lock();
524                if (mActive == 0) {
525                    return status_t(STOPPED);
526                }
527                cblk->lock.lock();
528            }
529            if (cblk->flags & CBLK_INVALID_MSK) {
530                goto create_new_record;
531            }
532            if (CC_UNLIKELY(result != NO_ERROR)) {
533                cblk->waitTimeMs += waitTimeMs;
534                if (cblk->waitTimeMs >= cblk->bufferTimeoutMs) {
535                    ALOGW(   "obtainBuffer timed out (is the CPU pegged?) "
536                            "user=%08x, server=%08x", cblk->user, cblk->server);
537                    cblk->lock.unlock();
538                    result = mAudioRecord->start();
539                    cblk->lock.lock();
540                    if (result == DEAD_OBJECT) {
541                        android_atomic_or(CBLK_INVALID_ON, &cblk->flags);
542create_new_record:
543                        result = AudioRecord::restoreRecord_l(cblk);
544                    }
545                    if (result != NO_ERROR) {
546                        ALOGW("obtainBuffer create Track error %d", result);
547                        cblk->lock.unlock();
548                        return result;
549                    }
550                    cblk->waitTimeMs = 0;
551                }
552                if (--waitCount == 0) {
553                    cblk->lock.unlock();
554                    return TIMED_OUT;
555                }
556            }
557            // read the server count again
558        start_loop_here:
559            framesReady = cblk->framesReady();
560        }
561        cblk->lock.unlock();
562    }
563
564    cblk->waitTimeMs = 0;
565
566    if (framesReq > framesReady) {
567        framesReq = framesReady;
568    }
569
570    uint32_t u = cblk->user;
571    uint32_t bufferEnd = cblk->userBase + cblk->frameCount;
572
573    if (u + framesReq > bufferEnd) {
574        framesReq = bufferEnd - u;
575    }
576
577    audioBuffer->flags       = 0;
578    audioBuffer->channelCount= mChannelCount;
579    audioBuffer->format      = mFormat;
580    audioBuffer->frameCount  = framesReq;
581    audioBuffer->size        = framesReq*cblk->frameSize;
582    audioBuffer->raw         = (int8_t*)cblk->buffer(u);
583    active = mActive;
584    return active ? status_t(NO_ERROR) : status_t(STOPPED);
585}
586
587void AudioRecord::releaseBuffer(Buffer* audioBuffer)
588{
589    AutoMutex lock(mLock);
590    mCblk->stepUser(audioBuffer->frameCount);
591}
592
593audio_io_handle_t AudioRecord::getInput()
594{
595    AutoMutex lock(mLock);
596    return mInput;
597}
598
599// must be called with mLock held
600audio_io_handle_t AudioRecord::getInput_l()
601{
602    mInput = AudioSystem::getInput(mInputSource,
603                                mCblk->sampleRate,
604                                mFormat,
605                                mChannelMask,
606                                (audio_in_acoustics_t)mFlags,
607                                mSessionId);
608    return mInput;
609}
610
611int AudioRecord::getSessionId()
612{
613    return mSessionId;
614}
615
616// -------------------------------------------------------------------------
617
618ssize_t AudioRecord::read(void* buffer, size_t userSize)
619{
620    ssize_t read = 0;
621    Buffer audioBuffer;
622    int8_t *dst = static_cast<int8_t*>(buffer);
623
624    if (ssize_t(userSize) < 0) {
625        // sanity-check. user is most-likely passing an error code.
626        ALOGE("AudioRecord::read(buffer=%p, size=%u (%d)",
627                buffer, userSize, userSize);
628        return BAD_VALUE;
629    }
630
631    mLock.lock();
632    // acquire a strong reference on the IAudioRecord and IMemory so that they cannot be destroyed
633    // while we are accessing the cblk
634    sp <IAudioRecord> audioRecord = mAudioRecord;
635    sp <IMemory> iMem = mCblkMemory;
636    mLock.unlock();
637
638    do {
639
640        audioBuffer.frameCount = userSize/frameSize();
641
642        // By using a wait count corresponding to twice the timeout period in
643        // obtainBuffer() we give a chance to recover once for a read timeout
644        // (if media_server crashed for instance) before returning a length of
645        // 0 bytes read to the client
646        status_t err = obtainBuffer(&audioBuffer, ((2 * MAX_RUN_TIMEOUT_MS) / WAIT_PERIOD_MS));
647        if (err < 0) {
648            // out of buffers, return #bytes written
649            if (err == status_t(NO_MORE_BUFFERS))
650                break;
651            if (err == status_t(TIMED_OUT))
652                err = 0;
653            return ssize_t(err);
654        }
655
656        size_t bytesRead = audioBuffer.size;
657        memcpy(dst, audioBuffer.i8, bytesRead);
658
659        dst += bytesRead;
660        userSize -= bytesRead;
661        read += bytesRead;
662
663        releaseBuffer(&audioBuffer);
664    } while (userSize);
665
666    return read;
667}
668
669// -------------------------------------------------------------------------
670
671bool AudioRecord::processAudioBuffer(const sp<ClientRecordThread>& thread)
672{
673    Buffer audioBuffer;
674    uint32_t frames = mRemainingFrames;
675    size_t readSize;
676
677    mLock.lock();
678    // acquire a strong reference on the IAudioRecord and IMemory so that they cannot be destroyed
679    // while we are accessing the cblk
680    sp <IAudioRecord> audioRecord = mAudioRecord;
681    sp <IMemory> iMem = mCblkMemory;
682    audio_track_cblk_t* cblk = mCblk;
683    mLock.unlock();
684
685    // Manage marker callback
686    if (!mMarkerReached && (mMarkerPosition > 0)) {
687        if (cblk->user >= mMarkerPosition) {
688            mCbf(EVENT_MARKER, mUserData, (void *)&mMarkerPosition);
689            mMarkerReached = true;
690        }
691    }
692
693    // Manage new position callback
694    if (mUpdatePeriod > 0) {
695        while (cblk->user >= mNewPosition) {
696            mCbf(EVENT_NEW_POS, mUserData, (void *)&mNewPosition);
697            mNewPosition += mUpdatePeriod;
698        }
699    }
700
701    do {
702        audioBuffer.frameCount = frames;
703        // Calling obtainBuffer() with a wait count of 1
704        // limits wait time to WAIT_PERIOD_MS. This prevents from being
705        // stuck here not being able to handle timed events (position, markers).
706        status_t err = obtainBuffer(&audioBuffer, 1);
707        if (err < NO_ERROR) {
708            if (err != TIMED_OUT) {
709                ALOGE_IF(err != status_t(NO_MORE_BUFFERS), "Error obtaining an audio buffer, giving up.");
710                return false;
711            }
712            break;
713        }
714        if (err == status_t(STOPPED)) return false;
715
716        size_t reqSize = audioBuffer.size;
717        mCbf(EVENT_MORE_DATA, mUserData, &audioBuffer);
718        readSize = audioBuffer.size;
719
720        // Sanity check on returned size
721        if (ssize_t(readSize) <= 0) {
722            // The callback is done filling buffers
723            // Keep this thread going to handle timed events and
724            // still try to get more data in intervals of WAIT_PERIOD_MS
725            // but don't just loop and block the CPU, so wait
726            usleep(WAIT_PERIOD_MS*1000);
727            break;
728        }
729        if (readSize > reqSize) readSize = reqSize;
730
731        audioBuffer.size = readSize;
732        audioBuffer.frameCount = readSize/frameSize();
733        frames -= audioBuffer.frameCount;
734
735        releaseBuffer(&audioBuffer);
736
737    } while (frames);
738
739
740    // Manage overrun callback
741    if (mActive && (cblk->framesAvailable() == 0)) {
742        ALOGV("Overrun user: %x, server: %x, flags %04x", cblk->user, cblk->server, cblk->flags);
743        if (!(android_atomic_or(CBLK_UNDERRUN_ON, &cblk->flags) & CBLK_UNDERRUN_MSK)) {
744            mCbf(EVENT_OVERRUN, mUserData, 0);
745        }
746    }
747
748    if (frames == 0) {
749        mRemainingFrames = mNotificationFrames;
750    } else {
751        mRemainingFrames = frames;
752    }
753    return true;
754}
755
756// must be called with mLock and cblk.lock held. Callers must also hold strong references on
757// the IAudioRecord and IMemory in case they are recreated here.
758// If the IAudioRecord is successfully restored, the cblk pointer is updated
759status_t AudioRecord::restoreRecord_l(audio_track_cblk_t*& cblk)
760{
761    status_t result;
762
763    if (!(android_atomic_or(CBLK_RESTORING_ON, &cblk->flags) & CBLK_RESTORING_MSK)) {
764        ALOGW("dead IAudioRecord, creating a new one");
765        // signal old cblk condition so that other threads waiting for available buffers stop
766        // waiting now
767        cblk->cv.broadcast();
768        cblk->lock.unlock();
769
770        // if the new IAudioRecord is created, openRecord_l() will modify the
771        // following member variables: mAudioRecord, mCblkMemory and mCblk.
772        // It will also delete the strong references on previous IAudioRecord and IMemory
773        result = openRecord_l(cblk->sampleRate, mFormat, mChannelMask,
774                mFrameCount, mFlags, getInput_l());
775        if (result == NO_ERROR) {
776            result = mAudioRecord->start();
777        }
778        if (result != NO_ERROR) {
779            mActive = false;
780        }
781
782        // signal old cblk condition for other threads waiting for restore completion
783        android_atomic_or(CBLK_RESTORED_ON, &cblk->flags);
784        cblk->cv.broadcast();
785    } else {
786        if (!(cblk->flags & CBLK_RESTORED_MSK)) {
787            ALOGW("dead IAudioRecord, waiting for a new one to be created");
788            mLock.unlock();
789            result = cblk->cv.waitRelative(cblk->lock, milliseconds(RESTORE_TIMEOUT_MS));
790            cblk->lock.unlock();
791            mLock.lock();
792        } else {
793            ALOGW("dead IAudioRecord, already restored");
794            result = NO_ERROR;
795            cblk->lock.unlock();
796        }
797        if (result != NO_ERROR || mActive == 0) {
798            result = status_t(STOPPED);
799        }
800    }
801    ALOGV("restoreRecord_l() status %d mActive %d cblk %p, old cblk %p flags %08x old flags %08x",
802         result, mActive, mCblk, cblk, mCblk->flags, cblk->flags);
803
804    if (result == NO_ERROR) {
805        // from now on we switch to the newly created cblk
806        cblk = mCblk;
807    }
808    cblk->lock.lock();
809
810    ALOGW_IF(result != NO_ERROR, "restoreRecord_l() error %d", result);
811
812    return result;
813}
814
815// =========================================================================
816
817AudioRecord::ClientRecordThread::ClientRecordThread(AudioRecord& receiver, bool bCanCallJava)
818    : Thread(bCanCallJava), mReceiver(receiver)
819{
820}
821
822bool AudioRecord::ClientRecordThread::threadLoop()
823{
824    return mReceiver.processAudioBuffer(this);
825}
826
827// -------------------------------------------------------------------------
828
829}; // namespace android
830
831