/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef ANDROID_AUDIO_TRACK_SHARED_H #define ANDROID_AUDIO_TRACK_SHARED_H #include #include #include #include #include #include #include #include namespace android { // ---------------------------------------------------------------------------- // for audio_track_cblk_t::mFlags #define CBLK_UNDERRUN 0x01 // set by server immediately on output underrun, cleared by client #define CBLK_FORCEREADY 0x02 // set: track is considered ready immediately by AudioFlinger, // clear: track is ready when buffer full #define CBLK_INVALID 0x04 // track buffer invalidated by AudioFlinger, need to re-create #define CBLK_DISABLED 0x08 // output track disabled by AudioFlinger due to underrun, // need to re-start. Unlike CBLK_UNDERRUN, this is not set // immediately, but only after a long string of underruns. // 0x10 unused #define CBLK_LOOP_CYCLE 0x20 // set by server each time a loop cycle other than final one completes #define CBLK_LOOP_FINAL 0x40 // set by server when the final loop cycle completes #define CBLK_BUFFER_END 0x80 // set by server when the position reaches end of buffer if not looping #define CBLK_OVERRUN 0x100 // set by server immediately on input overrun, cleared by client #define CBLK_INTERRUPT 0x200 // set by client on interrupt(), cleared by client in obtainBuffer() #define CBLK_STREAM_END_DONE 0x400 // set by server on render completion, cleared by client //EL_FIXME 20 seconds may not be enough and must be reconciled with new obtainBuffer implementation #define MAX_RUN_OFFLOADED_TIMEOUT_MS 20000 //assuming upto a maximum of 20 seconds of offloaded struct AudioTrackSharedStreaming { // similar to NBAIO MonoPipe // in continuously incrementing frame units, take modulo buffer size, which must be a power of 2 volatile int32_t mFront; // read by server volatile int32_t mRear; // write by client volatile int32_t mFlush; // incremented by client to indicate a request to flush; // server notices and discards all data between mFront and mRear volatile uint32_t mUnderrunFrames; // server increments for each unavailable but desired frame }; typedef SingleStateQueue StaticAudioTrackSingleStateQueue; struct AudioTrackSharedStatic { StaticAudioTrackSingleStateQueue::Shared mSingleStateQueue; size_t mBufferPosition; // updated asynchronously by server, // "for entertainment purposes only" }; // ---------------------------------------------------------------------------- // Important: do not add any virtual methods, including ~ struct audio_track_cblk_t { // Since the control block is always located in shared memory, this constructor // is only used for placement new(). It is never used for regular new() or stack. audio_track_cblk_t(); /*virtual*/ ~audio_track_cblk_t() { } friend class Proxy; friend class ClientProxy; friend class AudioTrackClientProxy; friend class AudioRecordClientProxy; friend class ServerProxy; friend class AudioTrackServerProxy; friend class AudioRecordServerProxy; // The data members are grouped so that members accessed frequently and in the same context // are in the same line of data cache. uint32_t mServer; // Number of filled frames consumed by server (mIsOut), // or filled frames provided by server (!mIsOut). // It is updated asynchronously by server without a barrier. // The value should be used "for entertainment purposes only", // which means don't make important decisions based on it. size_t frameCount_; // used during creation to pass actual track buffer size // from AudioFlinger to client, and not referenced again // FIXME remove here and replace by createTrack() in/out // parameter // renamed to "_" to detect incorrect use volatile int32_t mFutex; // event flag: down (P) by client, // up (V) by server or binderDied() or interrupt() #define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending private: size_t mMinimum; // server wakes up client if available >= mMinimum // Channel volumes are fixed point U4.12, so 0x1000 means 1.0. // Left channel is in [0:15], right channel is in [16:31]. // Always read and write the combined pair atomically. // For AudioTrack only, not used by AudioRecord. uint32_t mVolumeLR; uint32_t mSampleRate; // AudioTrack only: client's requested sample rate in Hz // or 0 == default. Write-only client, read-only server. // client write-only, server read-only uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 uint16_t mPad2; // unused public: volatile int32_t mFlags; // combinations of CBLK_* // Cache line boundary (32 bytes) public: union { AudioTrackSharedStreaming mStreaming; AudioTrackSharedStatic mStatic; int mAlign[8]; } u; // Cache line boundary (32 bytes) }; // ---------------------------------------------------------------------------- // Proxy for shared memory control block, to isolate callers from needing to know the details. // There is exactly one ClientProxy and one ServerProxy per shared memory control block. // The proxies are located in normal memory, and are not multi-thread safe within a given side. class Proxy : public RefBase { protected: Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, bool clientInServer); virtual ~Proxy() { } public: struct Buffer { size_t mFrameCount; // number of frames available in this buffer void* mRaw; // pointer to first frame size_t mNonContig; // number of additional non-contiguous frames available }; protected: // These refer to shared memory, and are virtual addresses with respect to the current process. // They may have different virtual addresses within the other process. audio_track_cblk_t* const mCblk; // the control block void* const mBuffers; // starting address of buffers const size_t mFrameCount; // not necessarily a power of 2 const size_t mFrameSize; // in bytes const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode const bool mIsOut; // true for AudioTrack, false for AudioRecord const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord bool mIsShutdown; // latch set to true when shared memory corruption detected size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer }; // ---------------------------------------------------------------------------- // Proxy seen by AudioTrack client and AudioRecord client class ClientProxy : public Proxy { protected: ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, bool clientInServer); virtual ~ClientProxy() { } public: static const struct timespec kForever; static const struct timespec kNonBlocking; // Obtain a buffer with filled frames (reading) or empty frames (writing). // It is permitted to call obtainBuffer() multiple times in succession, without any intervening // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively // sets or extends the unreleased frame count. // On entry: // buffer->mFrameCount should be initialized to maximum number of desired frames, // which must be > 0. // buffer->mNonContig is unused. // buffer->mRaw is unused. // requested is the requested timeout in local monotonic delta time units: // NULL or &kNonBlocking means non-blocking (zero timeout). // &kForever means block forever (infinite timeout). // Other values mean a specific timeout in local monotonic delta time units. // elapsed is a pointer to a location that will hold the total local monotonic time that // elapsed while blocked, or NULL if not needed. // On exit: // buffer->mFrameCount has the actual number of contiguous available frames, // which is always 0 when the return status != NO_ERROR. // buffer->mNonContig is the number of additional non-contiguous available frames. // buffer->mRaw is a pointer to the first available frame, // or NULL when buffer->mFrameCount == 0. // The return status is one of: // NO_ERROR Success, buffer->mFrameCount > 0. // WOULD_BLOCK Non-blocking mode and no frames are available. // TIMED_OUT Timeout occurred before any frames became available. // This can happen even for infinite timeout, due to a spurious wakeup. // In this case, the caller should investigate and then re-try as appropriate. // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. // NO_INIT Shared memory is corrupt. // Assertion failure on entry, if buffer == NULL or buffer->mFrameCount == 0. status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, struct timespec *elapsed = NULL); // Release (some of) the frames last obtained. // On entry, buffer->mFrameCount should have the number of frames to release, // which must (cumulatively) be <= the number of frames last obtained but not yet released. // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. // On exit: // buffer->mFrameCount is zero. // buffer->mRaw is NULL. void releaseBuffer(Buffer* buffer); // Call after detecting server's death void binderDied(); // Call to force an obtainBuffer() to return quickly with -EINTR void interrupt(); size_t getPosition() { return mEpoch + mCblk->mServer; } void setEpoch(size_t epoch) { mEpoch = epoch; } void setMinimum(size_t minimum) { mCblk->mMinimum = minimum; } // Return the number of frames that would need to be obtained and released // in order for the client to be aligned at start of buffer virtual size_t getMisalignment(); size_t getEpoch() const { return mEpoch; } size_t getFramesFilled(); private: size_t mEpoch; }; // ---------------------------------------------------------------------------- // Proxy used by AudioTrack client, which also includes AudioFlinger::PlaybackThread::OutputTrack class AudioTrackClientProxy : public ClientProxy { public: AudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool clientInServer = false) : ClientProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } virtual ~AudioTrackClientProxy() { } // No barriers on the following operations, so the ordering of loads/stores // with respect to other parameters is UNPREDICTABLE. That's considered safe. // caller must limit to 0.0 <= sendLevel <= 1.0 void setSendLevel(float sendLevel) { mCblk->mSendLevel = uint16_t(sendLevel * 0x1000); } // caller must limit to 0 <= volumeLR <= 0x10001000 void setVolumeLR(uint32_t volumeLR) { mCblk->mVolumeLR = volumeLR; } void setSampleRate(uint32_t sampleRate) { mCblk->mSampleRate = sampleRate; } virtual void flush(); virtual uint32_t getUnderrunFrames() const { return mCblk->u.mStreaming.mUnderrunFrames; } bool clearStreamEndDone(); // and return previous value bool getStreamEndDone() const; status_t waitStreamEndDone(const struct timespec *requested); }; class StaticAudioTrackClientProxy : public AudioTrackClientProxy { public: StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize); virtual ~StaticAudioTrackClientProxy() { } virtual void flush(); #define MIN_LOOP 16 // minimum length of each loop iteration in frames void setLoop(size_t loopStart, size_t loopEnd, int loopCount); size_t getBufferPosition(); virtual size_t getMisalignment() { return 0; } virtual uint32_t getUnderrunFrames() const { return 0; } private: StaticAudioTrackSingleStateQueue::Mutator mMutator; size_t mBufferPosition; // so that getBufferPosition() appears to be synchronous }; // ---------------------------------------------------------------------------- // Proxy used by AudioRecord client class AudioRecordClientProxy : public ClientProxy { public: AudioRecordClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize) : ClientProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, false /*clientInServer*/) { } ~AudioRecordClientProxy() { } }; // ---------------------------------------------------------------------------- // Proxy used by AudioFlinger server class ServerProxy : public Proxy { protected: ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, bool clientInServer); public: virtual ~ServerProxy() { } // Obtain a buffer with filled frames (writing) or empty frames (reading). // It is permitted to call obtainBuffer() multiple times in succession, without any intervening // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively // sets or extends the unreleased frame count. // Always non-blocking. // On entry: // buffer->mFrameCount should be initialized to maximum number of desired frames, // which must be > 0. // buffer->mNonContig is unused. // buffer->mRaw is unused. // ackFlush is true iff being called from Track::start to acknowledge a pending flush. // On exit: // buffer->mFrameCount has the actual number of contiguous available frames, // which is always 0 when the return status != NO_ERROR. // buffer->mNonContig is the number of additional non-contiguous available frames. // buffer->mRaw is a pointer to the first available frame, // or NULL when buffer->mFrameCount == 0. // The return status is one of: // NO_ERROR Success, buffer->mFrameCount > 0. // WOULD_BLOCK No frames are available. // NO_INIT Shared memory is corrupt. virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush = false); // Release (some of) the frames last obtained. // On entry, buffer->mFrameCount should have the number of frames to release, // which must (cumulatively) be <= the number of frames last obtained but not yet released. // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). // On exit: // buffer->mFrameCount is zero. // buffer->mRaw is NULL. virtual void releaseBuffer(Buffer* buffer); protected: size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only }; // Proxy used by AudioFlinger for servicing AudioTrack class AudioTrackServerProxy : public ServerProxy { public: AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool clientInServer = false) : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } protected: virtual ~AudioTrackServerProxy() { } public: // return value of these methods must be validated by the caller uint32_t getSampleRate() const { return mCblk->mSampleRate; } uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } uint32_t getVolumeLR() const { return mCblk->mVolumeLR; } // estimated total number of filled frames available to server to read, // which may include non-contiguous frames virtual size_t framesReady(); // Currently AudioFlinger will call framesReady() for a fast track from two threads: // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended // to be called from at most one thread of server, and one thread of client. // As a temporary workaround, this method informs the proxy implementation that it // should avoid doing a state queue poll from within framesReady(). // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. virtual void framesReadyIsCalledByMultipleThreads() { } bool setStreamEndDone(); // and return previous value // Add to the tally of underrun frames, and inform client of underrun virtual void tallyUnderrunFrames(uint32_t frameCount); // Return the total number of frames which AudioFlinger desired but were unavailable, // and thus which resulted in an underrun. virtual uint32_t getUnderrunFrames() const { return mCblk->u.mStreaming.mUnderrunFrames; } // Return the total number of frames that AudioFlinger has obtained and released virtual size_t framesReleased() const { return mCblk->mServer; } }; class StaticAudioTrackServerProxy : public AudioTrackServerProxy { public: StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize); protected: virtual ~StaticAudioTrackServerProxy() { } public: virtual size_t framesReady(); virtual void framesReadyIsCalledByMultipleThreads(); virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush); virtual void releaseBuffer(Buffer* buffer); virtual void tallyUnderrunFrames(uint32_t frameCount); virtual uint32_t getUnderrunFrames() const { return 0; } private: ssize_t pollPosition(); // poll for state queue update, and return current position StaticAudioTrackSingleStateQueue::Observer mObserver; size_t mPosition; // server's current play position in frames, relative to 0 size_t mEnd; // cached value computed from mState, safe for asynchronous read bool mFramesReadyIsCalledByMultipleThreads; StaticAudioTrackState mState; }; // Proxy used by AudioFlinger for servicing AudioRecord class AudioRecordServerProxy : public ServerProxy { public: AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize) : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, false /*clientInServer*/) { } protected: virtual ~AudioRecordServerProxy() { } }; // ---------------------------------------------------------------------------- }; // namespace android #endif // ANDROID_AUDIO_TRACK_SHARED_H