AudioFlinger.h revision d054c32443a493513ab63529b0c8b1aca290278c 
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#ifndef ANDROID_AUDIO_FLINGER_H
19#define ANDROID_AUDIO_FLINGER_H
20
21#include <stdint.h>
22#include <sys/types.h>
23#include <limits.h>
24
25#include <common_time/cc_helper.h>
26
27#include <cutils/compiler.h>
28
29#include <media/IAudioFlinger.h>
30#include <media/IAudioFlingerClient.h>
31#include <media/IAudioTrack.h>
32#include <media/IAudioRecord.h>
33#include <media/AudioSystem.h>
34#include <media/AudioTrack.h>
35
36#include <utils/Atomic.h>
37#include <utils/Errors.h>
38#include <utils/threads.h>
39#include <utils/SortedVector.h>
40#include <utils/TypeHelpers.h>
41#include <utils/Vector.h>
42
43#include <binder/BinderService.h>
44#include <binder/MemoryDealer.h>
45
46#include <system/audio.h>
47#include <hardware/audio.h>
48#include <hardware/audio_policy.h>
49
50#include <media/AudioBufferProvider.h>
51#include <media/ExtendedAudioBufferProvider.h>
52#include "FastMixer.h"
53#include <media/nbaio/NBAIO.h>
54#include "AudioWatchdog.h"
55
56#include <powermanager/IPowerManager.h>
57
58#include <media/nbaio/NBLog.h>
59#include <private/media/AudioTrackShared.h>
60
61namespace android {
62
63class audio_track_cblk_t;
64class effect_param_cblk_t;
65class AudioMixer;
66class AudioBuffer;
67class AudioResampler;
68class FastMixer;
69class ServerProxy;
70
71// ----------------------------------------------------------------------------
72
73// AudioFlinger has a hard-coded upper limit of 2 channels for capture and playback.
74// There is support for > 2 channel tracks down-mixed to 2 channel output via a down-mix effect.
75// Adding full support for > 2 channel capture or playback would require more than simply changing
76// this #define.  There is an independent hard-coded upper limit in AudioMixer;
77// removing that AudioMixer limit would be necessary but insufficient to support > 2 channels.
78// The macro FCC_2 highlights some (but not all) places where there is are 2-channel assumptions.
79// Search also for "2", "left", "right", "[0]", "[1]", ">> 16", "<< 16", etc.
80#define FCC_2 2     // FCC_2 = Fixed Channel Count 2
81
82static const nsecs_t kDefaultStandbyTimeInNsecs = seconds(3);
83
84#define MAX_GAIN 4096.0f
85#define MAX_GAIN_INT 0x1000
86
87#define INCLUDING_FROM_AUDIOFLINGER_H
88
89class AudioFlinger :
90    public BinderService<AudioFlinger>,
91    public BnAudioFlinger
92{
93    friend class BinderService<AudioFlinger>;   // for AudioFlinger()
94public:
95    static const char* getServiceName() ANDROID_API { return "media.audio_flinger"; }
96
97    virtual     status_t    dump(int fd, const Vector<String16>& args);
98
99    // IAudioFlinger interface, in binder opcode order
100    virtual sp<IAudioTrack> createTrack(
101                                audio_stream_type_t streamType,
102                                uint32_t sampleRate,
103                                audio_format_t format,
104                                audio_channel_mask_t channelMask,
105                                size_t frameCount,
106                                IAudioFlinger::track_flags_t *flags,
107                                const sp<IMemory>& sharedBuffer,
108                                audio_io_handle_t output,
109                                pid_t tid,
110                                int *sessionId,
111                                String8& name,
112                                status_t *status);
113
114    virtual sp<IAudioRecord> openRecord(
115                                audio_io_handle_t input,
116                                uint32_t sampleRate,
117                                audio_format_t format,
118                                audio_channel_mask_t channelMask,
119                                size_t frameCount,
120                                IAudioFlinger::track_flags_t flags,
121                                pid_t tid,
122                                int *sessionId,
123                                status_t *status);
124
125    virtual     uint32_t    sampleRate(audio_io_handle_t output) const;
126    virtual     int         channelCount(audio_io_handle_t output) const;
127    virtual     audio_format_t format(audio_io_handle_t output) const;
128    virtual     size_t      frameCount(audio_io_handle_t output) const;
129    virtual     uint32_t    latency(audio_io_handle_t output) const;
130
131    virtual     status_t    setMasterVolume(float value);
132    virtual     status_t    setMasterMute(bool muted);
133
134    virtual     float       masterVolume() const;
135    virtual     bool        masterMute() const;
136
137    virtual     status_t    setStreamVolume(audio_stream_type_t stream, float value,
138                                            audio_io_handle_t output);
139    virtual     status_t    setStreamMute(audio_stream_type_t stream, bool muted);
140
141    virtual     float       streamVolume(audio_stream_type_t stream,
142                                         audio_io_handle_t output) const;
143    virtual     bool        streamMute(audio_stream_type_t stream) const;
144
145    virtual     status_t    setMode(audio_mode_t mode);
146
147    virtual     status_t    setMicMute(bool state);
148    virtual     bool        getMicMute() const;
149
150    virtual     status_t    setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs);
151    virtual     String8     getParameters(audio_io_handle_t ioHandle, const String8& keys) const;
152
153    virtual     void        registerClient(const sp<IAudioFlingerClient>& client);
154
155    virtual     size_t      getInputBufferSize(uint32_t sampleRate, audio_format_t format,
156                                               audio_channel_mask_t channelMask) const;
157
158    virtual audio_io_handle_t openOutput(audio_module_handle_t module,
159                                         audio_devices_t *pDevices,
160                                         uint32_t *pSamplingRate,
161                                         audio_format_t *pFormat,
162                                         audio_channel_mask_t *pChannelMask,
163                                         uint32_t *pLatencyMs,
164                                         audio_output_flags_t flags,
165                                         const audio_offload_info_t *offloadInfo);
166
167    virtual audio_io_handle_t openDuplicateOutput(audio_io_handle_t output1,
168                                                  audio_io_handle_t output2);
169
170    virtual status_t closeOutput(audio_io_handle_t output);
171
172    virtual status_t suspendOutput(audio_io_handle_t output);
173
174    virtual status_t restoreOutput(audio_io_handle_t output);
175
176    virtual audio_io_handle_t openInput(audio_module_handle_t module,
177                                        audio_devices_t *pDevices,
178                                        uint32_t *pSamplingRate,
179                                        audio_format_t *pFormat,
180                                        audio_channel_mask_t *pChannelMask);
181
182    virtual status_t closeInput(audio_io_handle_t input);
183
184    virtual status_t setStreamOutput(audio_stream_type_t stream, audio_io_handle_t output);
185
186    virtual status_t setVoiceVolume(float volume);
187
188    virtual status_t getRenderPosition(size_t *halFrames, size_t *dspFrames,
189                                       audio_io_handle_t output) const;
190
191    virtual     unsigned int  getInputFramesLost(audio_io_handle_t ioHandle) const;
192
193    virtual int newAudioSessionId();
194
195    virtual void acquireAudioSessionId(int audioSession);
196
197    virtual void releaseAudioSessionId(int audioSession);
198
199    virtual status_t queryNumberEffects(uint32_t *numEffects) const;
200
201    virtual status_t queryEffect(uint32_t index, effect_descriptor_t *descriptor) const;
202
203    virtual status_t getEffectDescriptor(const effect_uuid_t *pUuid,
204                                         effect_descriptor_t *descriptor) const;
205
206    virtual sp<IEffect> createEffect(
207                        effect_descriptor_t *pDesc,
208                        const sp<IEffectClient>& effectClient,
209                        int32_t priority,
210                        audio_io_handle_t io,
211                        int sessionId,
212                        status_t *status,
213                        int *id,
214                        int *enabled);
215
216    virtual status_t moveEffects(int sessionId, audio_io_handle_t srcOutput,
217                        audio_io_handle_t dstOutput);
218
219    virtual audio_module_handle_t loadHwModule(const char *name);
220
221    virtual uint32_t getPrimaryOutputSamplingRate();
222    virtual size_t getPrimaryOutputFrameCount();
223
224    virtual status_t setLowRamDevice(bool isLowRamDevice);
225
226    virtual     status_t    onTransact(
227                                uint32_t code,
228                                const Parcel& data,
229                                Parcel* reply,
230                                uint32_t flags);
231
232    // end of IAudioFlinger interface
233
234    sp<NBLog::Writer>   newWriter_l(size_t size, const char *name);
235    void                unregisterWriter(const sp<NBLog::Writer>& writer);
236private:
237    static const size_t kLogMemorySize = 10 * 1024;
238    sp<MemoryDealer>    mLogMemoryDealer;   // == 0 when NBLog is disabled
239public:
240
241    class SyncEvent;
242
243    typedef void (*sync_event_callback_t)(const wp<SyncEvent>& event) ;
244
245    class SyncEvent : public RefBase {
246    public:
247        SyncEvent(AudioSystem::sync_event_t type,
248                  int triggerSession,
249                  int listenerSession,
250                  sync_event_callback_t callBack,
251                  void *cookie)
252        : mType(type), mTriggerSession(triggerSession), mListenerSession(listenerSession),
253          mCallback(callBack), mCookie(cookie)
254        {}
255
256        virtual ~SyncEvent() {}
257
258        void trigger() { Mutex::Autolock _l(mLock); if (mCallback) mCallback(this); }
259        bool isCancelled() const { Mutex::Autolock _l(mLock); return (mCallback == NULL); }
260        void cancel() { Mutex::Autolock _l(mLock); mCallback = NULL; }
261        AudioSystem::sync_event_t type() const { return mType; }
262        int triggerSession() const { return mTriggerSession; }
263        int listenerSession() const { return mListenerSession; }
264        void *cookie() const { return mCookie; }
265
266    private:
267          const AudioSystem::sync_event_t mType;
268          const int mTriggerSession;
269          const int mListenerSession;
270          sync_event_callback_t mCallback;
271          void * const mCookie;
272          mutable Mutex mLock;
273    };
274
275    sp<SyncEvent> createSyncEvent(AudioSystem::sync_event_t type,
276                                        int triggerSession,
277                                        int listenerSession,
278                                        sync_event_callback_t callBack,
279                                        void *cookie);
280
281private:
282    class AudioHwDevice;    // fwd declaration for findSuitableHwDev_l
283
284               audio_mode_t getMode() const { return mMode; }
285
286                bool        btNrecIsOff() const { return mBtNrecIsOff; }
287
288                            AudioFlinger() ANDROID_API;
289    virtual                 ~AudioFlinger();
290
291    // call in any IAudioFlinger method that accesses mPrimaryHardwareDev
292    status_t                initCheck() const { return mPrimaryHardwareDev == NULL ?
293                                                        NO_INIT : NO_ERROR; }
294
295    // RefBase
296    virtual     void        onFirstRef();
297
298    AudioHwDevice*          findSuitableHwDev_l(audio_module_handle_t module,
299                                                audio_devices_t devices);
300    void                    purgeStaleEffects_l();
301
302    // standby delay for MIXER and DUPLICATING playback threads is read from property
303    // ro.audio.flinger_standbytime_ms or defaults to kDefaultStandbyTimeInNsecs
304    static nsecs_t          mStandbyTimeInNsecs;
305
306    // incremented by 2 when screen state changes, bit 0 == 1 means "off"
307    // AudioFlinger::setParameters() updates, other threads read w/o lock
308    static uint32_t         mScreenState;
309
310    // Internal dump utilities.
311    static const int kDumpLockRetries = 50;
312    static const int kDumpLockSleepUs = 20000;
313    static bool dumpTryLock(Mutex& mutex);
314    void dumpPermissionDenial(int fd, const Vector<String16>& args);
315    void dumpClients(int fd, const Vector<String16>& args);
316    void dumpInternals(int fd, const Vector<String16>& args);
317
318    // --- Client ---
319    class Client : public RefBase {
320    public:
321                            Client(const sp<AudioFlinger>& audioFlinger, pid_t pid);
322        virtual             ~Client();
323        sp<MemoryDealer>    heap() const;
324        pid_t               pid() const { return mPid; }
325        sp<AudioFlinger>    audioFlinger() const { return mAudioFlinger; }
326
327        bool reserveTimedTrack();
328        void releaseTimedTrack();
329
330    private:
331                            Client(const Client&);
332                            Client& operator = (const Client&);
333        const sp<AudioFlinger> mAudioFlinger;
334        const sp<MemoryDealer> mMemoryDealer;
335        const pid_t         mPid;
336
337        Mutex               mTimedTrackLock;
338        int                 mTimedTrackCount;
339    };
340
341    // --- Notification Client ---
342    class NotificationClient : public IBinder::DeathRecipient {
343    public:
344                            NotificationClient(const sp<AudioFlinger>& audioFlinger,
345                                                const sp<IAudioFlingerClient>& client,
346                                                pid_t pid);
347        virtual             ~NotificationClient();
348
349                sp<IAudioFlingerClient> audioFlingerClient() const { return mAudioFlingerClient; }
350
351                // IBinder::DeathRecipient
352                virtual     void        binderDied(const wp<IBinder>& who);
353
354    private:
355                            NotificationClient(const NotificationClient&);
356                            NotificationClient& operator = (const NotificationClient&);
357
358        const sp<AudioFlinger>  mAudioFlinger;
359        const pid_t             mPid;
360        const sp<IAudioFlingerClient> mAudioFlingerClient;
361    };
362
363    class TrackHandle;
364    class RecordHandle;
365    class RecordThread;
366    class PlaybackThread;
367    class MixerThread;
368    class DirectOutputThread;
369    class OffloadThread;
370    class DuplicatingThread;
371    class AsyncCallbackThread;
372    class Track;
373    class RecordTrack;
374    class EffectModule;
375    class EffectHandle;
376    class EffectChain;
377    struct AudioStreamOut;
378    struct AudioStreamIn;
379
380    struct  stream_type_t {
381        stream_type_t()
382            :   volume(1.0f),
383                mute(false)
384        {
385        }
386        float       volume;
387        bool        mute;
388    };
389
390    // --- PlaybackThread ---
391
392#include "Threads.h"
393
394#include "Effects.h"
395
396    // server side of the client's IAudioTrack
397    class TrackHandle : public android::BnAudioTrack {
398    public:
399                            TrackHandle(const sp<PlaybackThread::Track>& track);
400        virtual             ~TrackHandle();
401        virtual sp<IMemory> getCblk() const;
402        virtual status_t    start();
403        virtual void        stop();
404        virtual void        flush();
405        virtual void        pause();
406        virtual status_t    attachAuxEffect(int effectId);
407        virtual status_t    allocateTimedBuffer(size_t size,
408                                                sp<IMemory>* buffer);
409        virtual status_t    queueTimedBuffer(const sp<IMemory>& buffer,
410                                             int64_t pts);
411        virtual status_t    setMediaTimeTransform(const LinearTransform& xform,
412                                                  int target);
413        virtual status_t    setParameters(const String8& keyValuePairs);
414
415        virtual status_t onTransact(
416            uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags);
417
418    private:
419        const sp<PlaybackThread::Track> mTrack;
420    };
421
422    // server side of the client's IAudioRecord
423    class RecordHandle : public android::BnAudioRecord {
424    public:
425        RecordHandle(const sp<RecordThread::RecordTrack>& recordTrack);
426        virtual             ~RecordHandle();
427        virtual sp<IMemory> getCblk() const;
428        virtual status_t    start(int /*AudioSystem::sync_event_t*/ event, int triggerSession);
429        virtual void        stop();
430        virtual status_t onTransact(
431            uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags);
432    private:
433        const sp<RecordThread::RecordTrack> mRecordTrack;
434
435        // for use from destructor
436        void                stop_nonvirtual();
437    };
438
439
440              PlaybackThread *checkPlaybackThread_l(audio_io_handle_t output) const;
441              MixerThread *checkMixerThread_l(audio_io_handle_t output) const;
442              RecordThread *checkRecordThread_l(audio_io_handle_t input) const;
443              // no range check, AudioFlinger::mLock held
444              bool streamMute_l(audio_stream_type_t stream) const
445                                { return mStreamTypes[stream].mute; }
446              // no range check, doesn't check per-thread stream volume, AudioFlinger::mLock held
447              float streamVolume_l(audio_stream_type_t stream) const
448                                { return mStreamTypes[stream].volume; }
449              void audioConfigChanged_l(int event, audio_io_handle_t ioHandle, const void *param2);
450
451              // allocate an audio_io_handle_t, session ID, or effect ID
452              uint32_t nextUniqueId();
453
454              status_t moveEffectChain_l(int sessionId,
455                                     PlaybackThread *srcThread,
456                                     PlaybackThread *dstThread,
457                                     bool reRegister);
458              // return thread associated with primary hardware device, or NULL
459              PlaybackThread *primaryPlaybackThread_l() const;
460              audio_devices_t primaryOutputDevice_l() const;
461
462              sp<PlaybackThread> getEffectThread_l(int sessionId, int EffectId);
463
464
465                void        removeClient_l(pid_t pid);
466                void        removeNotificationClient(pid_t pid);
467
468    class AudioHwDevice {
469    public:
470        enum Flags {
471            AHWD_CAN_SET_MASTER_VOLUME  = 0x1,
472            AHWD_CAN_SET_MASTER_MUTE    = 0x2,
473        };
474
475        AudioHwDevice(const char *moduleName,
476                      audio_hw_device_t *hwDevice,
477                      Flags flags)
478            : mModuleName(strdup(moduleName))
479            , mHwDevice(hwDevice)
480            , mFlags(flags) { }
481        /*virtual*/ ~AudioHwDevice() { free((void *)mModuleName); }
482
483        bool canSetMasterVolume() const {
484            return (0 != (mFlags & AHWD_CAN_SET_MASTER_VOLUME));
485        }
486
487        bool canSetMasterMute() const {
488            return (0 != (mFlags & AHWD_CAN_SET_MASTER_MUTE));
489        }
490
491        const char *moduleName() const { return mModuleName; }
492        audio_hw_device_t *hwDevice() const { return mHwDevice; }
493    private:
494        const char * const mModuleName;
495        audio_hw_device_t * const mHwDevice;
496        Flags mFlags;
497    };
498
499    // AudioStreamOut and AudioStreamIn are immutable, so their fields are const.
500    // For emphasis, we could also make all pointers to them be "const *",
501    // but that would clutter the code unnecessarily.
502
503    struct AudioStreamOut {
504        AudioHwDevice* const audioHwDev;
505        audio_stream_out_t* const stream;
506        audio_output_flags_t flags;
507
508        audio_hw_device_t* hwDev() const { return audioHwDev->hwDevice(); }
509
510        AudioStreamOut(AudioHwDevice *dev, audio_stream_out_t *out, audio_output_flags_t flags) :
511            audioHwDev(dev), stream(out), flags(flags) {}
512    };
513
514    struct AudioStreamIn {
515        AudioHwDevice* const audioHwDev;
516        audio_stream_in_t* const stream;
517
518        audio_hw_device_t* hwDev() const { return audioHwDev->hwDevice(); }
519
520        AudioStreamIn(AudioHwDevice *dev, audio_stream_in_t *in) :
521            audioHwDev(dev), stream(in) {}
522    };
523
524    // for mAudioSessionRefs only
525    struct AudioSessionRef {
526        AudioSessionRef(int sessionid, pid_t pid) :
527            mSessionid(sessionid), mPid(pid), mCnt(1) {}
528        const int   mSessionid;
529        const pid_t mPid;
530        int         mCnt;
531    };
532
533    mutable     Mutex                               mLock;
534
535                DefaultKeyedVector< pid_t, wp<Client> >     mClients;   // see ~Client()
536
537                mutable     Mutex                   mHardwareLock;
538                // NOTE: If both mLock and mHardwareLock mutexes must be held,
539                // always take mLock before mHardwareLock
540
541                // These two fields are immutable after onFirstRef(), so no lock needed to access
542                AudioHwDevice*                      mPrimaryHardwareDev; // mAudioHwDevs[0] or NULL
543                DefaultKeyedVector<audio_module_handle_t, AudioHwDevice*>  mAudioHwDevs;
544
545    // for dump, indicates which hardware operation is currently in progress (but not stream ops)
546    enum hardware_call_state {
547        AUDIO_HW_IDLE = 0,              // no operation in progress
548        AUDIO_HW_INIT,                  // init_check
549        AUDIO_HW_OUTPUT_OPEN,           // open_output_stream
550        AUDIO_HW_OUTPUT_CLOSE,          // unused
551        AUDIO_HW_INPUT_OPEN,            // unused
552        AUDIO_HW_INPUT_CLOSE,           // unused
553        AUDIO_HW_STANDBY,               // unused
554        AUDIO_HW_SET_MASTER_VOLUME,     // set_master_volume
555        AUDIO_HW_GET_ROUTING,           // unused
556        AUDIO_HW_SET_ROUTING,           // unused
557        AUDIO_HW_GET_MODE,              // unused
558        AUDIO_HW_SET_MODE,              // set_mode
559        AUDIO_HW_GET_MIC_MUTE,          // get_mic_mute
560        AUDIO_HW_SET_MIC_MUTE,          // set_mic_mute
561        AUDIO_HW_SET_VOICE_VOLUME,      // set_voice_volume
562        AUDIO_HW_SET_PARAMETER,         // set_parameters
563        AUDIO_HW_GET_INPUT_BUFFER_SIZE, // get_input_buffer_size
564        AUDIO_HW_GET_MASTER_VOLUME,     // get_master_volume
565        AUDIO_HW_GET_PARAMETER,         // get_parameters
566        AUDIO_HW_SET_MASTER_MUTE,       // set_master_mute
567        AUDIO_HW_GET_MASTER_MUTE,       // get_master_mute
568    };
569
570    mutable     hardware_call_state                 mHardwareStatus;    // for dump only
571
572
573                DefaultKeyedVector< audio_io_handle_t, sp<PlaybackThread> >  mPlaybackThreads;
574                stream_type_t                       mStreamTypes[AUDIO_STREAM_CNT];
575
576                // member variables below are protected by mLock
577                float                               mMasterVolume;
578                bool                                mMasterMute;
579                // end of variables protected by mLock
580
581                DefaultKeyedVector< audio_io_handle_t, sp<RecordThread> >    mRecordThreads;
582
583                DefaultKeyedVector< pid_t, sp<NotificationClient> >    mNotificationClients;
584                volatile int32_t                    mNextUniqueId;  // updated by android_atomic_inc
585                audio_mode_t                        mMode;
586                bool                                mBtNrecIsOff;
587
588                // protected by mLock
589                Vector<AudioSessionRef*> mAudioSessionRefs;
590
591                float       masterVolume_l() const;
592                bool        masterMute_l() const;
593                audio_module_handle_t loadHwModule_l(const char *name);
594
595                Vector < sp<SyncEvent> > mPendingSyncEvents; // sync events awaiting for a session
596                                                             // to be created
597
598private:
599    sp<Client>  registerPid_l(pid_t pid);    // always returns non-0
600
601    // for use from destructor
602    status_t    closeOutput_nonvirtual(audio_io_handle_t output);
603    status_t    closeInput_nonvirtual(audio_io_handle_t input);
604
605#ifdef TEE_SINK
606    // all record threads serially share a common tee sink, which is re-created on format change
607    sp<NBAIO_Sink>   mRecordTeeSink;
608    sp<NBAIO_Source> mRecordTeeSource;
609#endif
610
611public:
612
613#ifdef TEE_SINK
614    // tee sink, if enabled by property, allows dumpsys to write most recent audio to .wav file
615    static void dumpTee(int fd, const sp<NBAIO_Source>& source, audio_io_handle_t id = 0);
616
617    // whether tee sink is enabled by property
618    static bool mTeeSinkInputEnabled;
619    static bool mTeeSinkOutputEnabled;
620    static bool mTeeSinkTrackEnabled;
621
622    // runtime configured size of each tee sink pipe, in frames
623    static size_t mTeeSinkInputFrames;
624    static size_t mTeeSinkOutputFrames;
625    static size_t mTeeSinkTrackFrames;
626
627    // compile-time default size of tee sink pipes, in frames
628    // 0x200000 stereo 16-bit PCM frames = 47.5 seconds at 44.1 kHz, 8 megabytes
629    static const size_t kTeeSinkInputFramesDefault = 0x200000;
630    static const size_t kTeeSinkOutputFramesDefault = 0x200000;
631    static const size_t kTeeSinkTrackFramesDefault = 0x1000;
632#endif
633
634    // This method reads from a variable without mLock, but the variable is updated under mLock.  So
635    // we might read a stale value, or a value that's inconsistent with respect to other variables.
636    // In this case, it's safe because the return value isn't used for making an important decision.
637    // The reason we don't want to take mLock is because it could block the caller for a long time.
638    bool    isLowRamDevice() const { return mIsLowRamDevice; }
639
640private:
641    bool    mIsLowRamDevice;
642    bool    mIsDeviceTypeKnown;
643};
644
645#undef INCLUDING_FROM_AUDIOFLINGER_H
646
647// ----------------------------------------------------------------------------
648
649}; // namespace android
650
651#endif // ANDROID_AUDIO_FLINGER_H
652