1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ANDROID_AUDIO_TRACK_SHARED_H 18 #define ANDROID_AUDIO_TRACK_SHARED_H 19 20 #include <stdint.h> 21 #include <sys/types.h> 22 23 #include <utils/threads.h> 24 #include <utils/Log.h> 25 #include <utils/RefBase.h> 26 #include <media/nbaio/roundup.h> 27 #include <media/SingleStateQueue.h> 28 #include <private/media/StaticAudioTrackState.h> 29 30 namespace android { 31 32 // ---------------------------------------------------------------------------- 33 34 // for audio_track_cblk_t::mFlags 35 #define CBLK_UNDERRUN 0x01 // set by server immediately on output underrun, cleared by client 36 #define CBLK_FORCEREADY 0x02 // set: track is considered ready immediately by AudioFlinger, 37 // clear: track is ready when buffer full 38 #define CBLK_INVALID 0x04 // track buffer invalidated by AudioFlinger, need to re-create 39 #define CBLK_DISABLED 0x08 // output track disabled by AudioFlinger due to underrun, 40 // need to re-start. Unlike CBLK_UNDERRUN, this is not set 41 // immediately, but only after a long string of underruns. 42 // 0x10 unused 43 #define CBLK_LOOP_CYCLE 0x20 // set by server each time a loop cycle other than final one completes 44 #define CBLK_LOOP_FINAL 0x40 // set by server when the final loop cycle completes 45 #define CBLK_BUFFER_END 0x80 // set by server when the position reaches end of buffer if not looping 46 #define CBLK_OVERRUN 0x100 // set by server immediately on input overrun, cleared by client 47 #define CBLK_INTERRUPT 0x200 // set by client on interrupt(), cleared by client in obtainBuffer() 48 #define CBLK_STREAM_END_DONE 0x400 // set by server on render completion, cleared by client 49 50 //EL_FIXME 20 seconds may not be enough and must be reconciled with new obtainBuffer implementation 51 #define MAX_RUN_OFFLOADED_TIMEOUT_MS 20000 //assuming upto a maximum of 20 seconds of offloaded 52 53 struct AudioTrackSharedStreaming { 54 // similar to NBAIO MonoPipe 55 // in continuously incrementing frame units, take modulo buffer size, which must be a power of 2 56 volatile int32_t mFront; // read by server 57 volatile int32_t mRear; // write by client 58 volatile int32_t mFlush; // incremented by client to indicate a request to flush; 59 // server notices and discards all data between mFront and mRear 60 volatile uint32_t mUnderrunFrames; // server increments for each unavailable but desired frame 61 }; 62 63 typedef SingleStateQueue<StaticAudioTrackState> StaticAudioTrackSingleStateQueue; 64 65 struct AudioTrackSharedStatic { 66 StaticAudioTrackSingleStateQueue::Shared 67 mSingleStateQueue; 68 size_t mBufferPosition; // updated asynchronously by server, 69 // "for entertainment purposes only" 70 }; 71 72 // ---------------------------------------------------------------------------- 73 74 // Important: do not add any virtual methods, including ~ 75 struct audio_track_cblk_t 76 { 77 // Since the control block is always located in shared memory, this constructor 78 // is only used for placement new(). It is never used for regular new() or stack. 79 audio_track_cblk_t(); ~audio_track_cblk_taudio_track_cblk_t80 /*virtual*/ ~audio_track_cblk_t() { } 81 82 friend class Proxy; 83 friend class ClientProxy; 84 friend class AudioTrackClientProxy; 85 friend class AudioRecordClientProxy; 86 friend class ServerProxy; 87 friend class AudioTrackServerProxy; 88 friend class AudioRecordServerProxy; 89 90 // The data members are grouped so that members accessed frequently and in the same context 91 // are in the same line of data cache. 92 93 uint32_t mServer; // Number of filled frames consumed by server (mIsOut), 94 // or filled frames provided by server (!mIsOut). 95 // It is updated asynchronously by server without a barrier. 96 // The value should be used "for entertainment purposes only", 97 // which means don't make important decisions based on it. 98 99 size_t frameCount_; // used during creation to pass actual track buffer size 100 // from AudioFlinger to client, and not referenced again 101 // FIXME remove here and replace by createTrack() in/out 102 // parameter 103 // renamed to "_" to detect incorrect use 104 105 volatile int32_t mFutex; // event flag: down (P) by client, 106 // up (V) by server or binderDied() or interrupt() 107 #define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending 108 109 private: 110 111 size_t mMinimum; // server wakes up client if available >= mMinimum 112 113 // Channel volumes are fixed point U4.12, so 0x1000 means 1.0. 114 // Left channel is in [0:15], right channel is in [16:31]. 115 // Always read and write the combined pair atomically. 116 // For AudioTrack only, not used by AudioRecord. 117 uint32_t mVolumeLR; 118 119 uint32_t mSampleRate; // AudioTrack only: client's requested sample rate in Hz 120 // or 0 == default. Write-only client, read-only server. 121 122 // client write-only, server read-only 123 uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 124 125 uint16_t mPad2; // unused 126 127 public: 128 129 volatile int32_t mFlags; // combinations of CBLK_* 130 131 // Cache line boundary (32 bytes) 132 133 public: 134 union { 135 AudioTrackSharedStreaming mStreaming; 136 AudioTrackSharedStatic mStatic; 137 int mAlign[8]; 138 } u; 139 140 // Cache line boundary (32 bytes) 141 }; 142 143 // ---------------------------------------------------------------------------- 144 145 // Proxy for shared memory control block, to isolate callers from needing to know the details. 146 // There is exactly one ClientProxy and one ServerProxy per shared memory control block. 147 // The proxies are located in normal memory, and are not multi-thread safe within a given side. 148 class Proxy : public RefBase { 149 protected: 150 Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, 151 bool clientInServer); ~Proxy()152 virtual ~Proxy() { } 153 154 public: 155 struct Buffer { 156 size_t mFrameCount; // number of frames available in this buffer 157 void* mRaw; // pointer to first frame 158 size_t mNonContig; // number of additional non-contiguous frames available 159 }; 160 161 protected: 162 // These refer to shared memory, and are virtual addresses with respect to the current process. 163 // They may have different virtual addresses within the other process. 164 audio_track_cblk_t* const mCblk; // the control block 165 void* const mBuffers; // starting address of buffers 166 167 const size_t mFrameCount; // not necessarily a power of 2 168 const size_t mFrameSize; // in bytes 169 const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode 170 const bool mIsOut; // true for AudioTrack, false for AudioRecord 171 const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord 172 bool mIsShutdown; // latch set to true when shared memory corruption detected 173 size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer 174 }; 175 176 // ---------------------------------------------------------------------------- 177 178 // Proxy seen by AudioTrack client and AudioRecord client 179 class ClientProxy : public Proxy { 180 protected: 181 ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 182 bool isOut, bool clientInServer); ~ClientProxy()183 virtual ~ClientProxy() { } 184 185 public: 186 static const struct timespec kForever; 187 static const struct timespec kNonBlocking; 188 189 // Obtain a buffer with filled frames (reading) or empty frames (writing). 190 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 191 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 192 // sets or extends the unreleased frame count. 193 // On entry: 194 // buffer->mFrameCount should be initialized to maximum number of desired frames, 195 // which must be > 0. 196 // buffer->mNonContig is unused. 197 // buffer->mRaw is unused. 198 // requested is the requested timeout in local monotonic delta time units: 199 // NULL or &kNonBlocking means non-blocking (zero timeout). 200 // &kForever means block forever (infinite timeout). 201 // Other values mean a specific timeout in local monotonic delta time units. 202 // elapsed is a pointer to a location that will hold the total local monotonic time that 203 // elapsed while blocked, or NULL if not needed. 204 // On exit: 205 // buffer->mFrameCount has the actual number of contiguous available frames, 206 // which is always 0 when the return status != NO_ERROR. 207 // buffer->mNonContig is the number of additional non-contiguous available frames. 208 // buffer->mRaw is a pointer to the first available frame, 209 // or NULL when buffer->mFrameCount == 0. 210 // The return status is one of: 211 // NO_ERROR Success, buffer->mFrameCount > 0. 212 // WOULD_BLOCK Non-blocking mode and no frames are available. 213 // TIMED_OUT Timeout occurred before any frames became available. 214 // This can happen even for infinite timeout, due to a spurious wakeup. 215 // In this case, the caller should investigate and then re-try as appropriate. 216 // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. 217 // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. 218 // NO_INIT Shared memory is corrupt. 219 // Assertion failure on entry, if buffer == NULL or buffer->mFrameCount == 0. 220 status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, 221 struct timespec *elapsed = NULL); 222 223 // Release (some of) the frames last obtained. 224 // On entry, buffer->mFrameCount should have the number of frames to release, 225 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 226 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 227 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 228 // On exit: 229 // buffer->mFrameCount is zero. 230 // buffer->mRaw is NULL. 231 void releaseBuffer(Buffer* buffer); 232 233 // Call after detecting server's death 234 void binderDied(); 235 236 // Call to force an obtainBuffer() to return quickly with -EINTR 237 void interrupt(); 238 getPosition()239 size_t getPosition() { 240 return mEpoch + mCblk->mServer; 241 } 242 setEpoch(size_t epoch)243 void setEpoch(size_t epoch) { 244 mEpoch = epoch; 245 } 246 setMinimum(size_t minimum)247 void setMinimum(size_t minimum) { 248 mCblk->mMinimum = minimum; 249 } 250 251 // Return the number of frames that would need to be obtained and released 252 // in order for the client to be aligned at start of buffer 253 virtual size_t getMisalignment(); 254 getEpoch()255 size_t getEpoch() const { 256 return mEpoch; 257 } 258 259 size_t getFramesFilled(); 260 261 private: 262 size_t mEpoch; 263 }; 264 265 // ---------------------------------------------------------------------------- 266 267 // Proxy used by AudioTrack client, which also includes AudioFlinger::PlaybackThread::OutputTrack 268 class AudioTrackClientProxy : public ClientProxy { 269 public: 270 AudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 271 size_t frameSize, bool clientInServer = false) ClientProxy(cblk,buffers,frameCount,frameSize,true,clientInServer)272 : ClientProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, 273 clientInServer) { } ~AudioTrackClientProxy()274 virtual ~AudioTrackClientProxy() { } 275 276 // No barriers on the following operations, so the ordering of loads/stores 277 // with respect to other parameters is UNPREDICTABLE. That's considered safe. 278 279 // caller must limit to 0.0 <= sendLevel <= 1.0 setSendLevel(float sendLevel)280 void setSendLevel(float sendLevel) { 281 mCblk->mSendLevel = uint16_t(sendLevel * 0x1000); 282 } 283 284 // caller must limit to 0 <= volumeLR <= 0x10001000 setVolumeLR(uint32_t volumeLR)285 void setVolumeLR(uint32_t volumeLR) { 286 mCblk->mVolumeLR = volumeLR; 287 } 288 setSampleRate(uint32_t sampleRate)289 void setSampleRate(uint32_t sampleRate) { 290 mCblk->mSampleRate = sampleRate; 291 } 292 293 virtual void flush(); 294 getUnderrunFrames()295 virtual uint32_t getUnderrunFrames() const { 296 return mCblk->u.mStreaming.mUnderrunFrames; 297 } 298 299 bool clearStreamEndDone(); // and return previous value 300 301 bool getStreamEndDone() const; 302 303 status_t waitStreamEndDone(const struct timespec *requested); 304 }; 305 306 class StaticAudioTrackClientProxy : public AudioTrackClientProxy { 307 public: 308 StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 309 size_t frameSize); ~StaticAudioTrackClientProxy()310 virtual ~StaticAudioTrackClientProxy() { } 311 312 virtual void flush(); 313 314 #define MIN_LOOP 16 // minimum length of each loop iteration in frames 315 void setLoop(size_t loopStart, size_t loopEnd, int loopCount); 316 size_t getBufferPosition(); 317 getMisalignment()318 virtual size_t getMisalignment() { 319 return 0; 320 } 321 getUnderrunFrames()322 virtual uint32_t getUnderrunFrames() const { 323 return 0; 324 } 325 326 private: 327 StaticAudioTrackSingleStateQueue::Mutator mMutator; 328 size_t mBufferPosition; // so that getBufferPosition() appears to be synchronous 329 }; 330 331 // ---------------------------------------------------------------------------- 332 333 // Proxy used by AudioRecord client 334 class AudioRecordClientProxy : public ClientProxy { 335 public: AudioRecordClientProxy(audio_track_cblk_t * cblk,void * buffers,size_t frameCount,size_t frameSize)336 AudioRecordClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 337 size_t frameSize) 338 : ClientProxy(cblk, buffers, frameCount, frameSize, 339 false /*isOut*/, false /*clientInServer*/) { } ~AudioRecordClientProxy()340 ~AudioRecordClientProxy() { } 341 }; 342 343 // ---------------------------------------------------------------------------- 344 345 // Proxy used by AudioFlinger server 346 class ServerProxy : public Proxy { 347 protected: 348 ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 349 bool isOut, bool clientInServer); 350 public: ~ServerProxy()351 virtual ~ServerProxy() { } 352 353 // Obtain a buffer with filled frames (writing) or empty frames (reading). 354 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 355 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 356 // sets or extends the unreleased frame count. 357 // Always non-blocking. 358 // On entry: 359 // buffer->mFrameCount should be initialized to maximum number of desired frames, 360 // which must be > 0. 361 // buffer->mNonContig is unused. 362 // buffer->mRaw is unused. 363 // ackFlush is true iff being called from Track::start to acknowledge a pending flush. 364 // On exit: 365 // buffer->mFrameCount has the actual number of contiguous available frames, 366 // which is always 0 when the return status != NO_ERROR. 367 // buffer->mNonContig is the number of additional non-contiguous available frames. 368 // buffer->mRaw is a pointer to the first available frame, 369 // or NULL when buffer->mFrameCount == 0. 370 // The return status is one of: 371 // NO_ERROR Success, buffer->mFrameCount > 0. 372 // WOULD_BLOCK No frames are available. 373 // NO_INIT Shared memory is corrupt. 374 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush = false); 375 376 // Release (some of) the frames last obtained. 377 // On entry, buffer->mFrameCount should have the number of frames to release, 378 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 379 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 380 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 381 // On exit: 382 // buffer->mFrameCount is zero. 383 // buffer->mRaw is NULL. 384 virtual void releaseBuffer(Buffer* buffer); 385 386 protected: 387 size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() 388 int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only 389 }; 390 391 // Proxy used by AudioFlinger for servicing AudioTrack 392 class AudioTrackServerProxy : public ServerProxy { 393 public: 394 AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 395 size_t frameSize, bool clientInServer = false) ServerProxy(cblk,buffers,frameCount,frameSize,true,clientInServer)396 : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } 397 protected: ~AudioTrackServerProxy()398 virtual ~AudioTrackServerProxy() { } 399 400 public: 401 // return value of these methods must be validated by the caller getSampleRate()402 uint32_t getSampleRate() const { return mCblk->mSampleRate; } getSendLevel_U4_12()403 uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } getVolumeLR()404 uint32_t getVolumeLR() const { return mCblk->mVolumeLR; } 405 406 // estimated total number of filled frames available to server to read, 407 // which may include non-contiguous frames 408 virtual size_t framesReady(); 409 410 // Currently AudioFlinger will call framesReady() for a fast track from two threads: 411 // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended 412 // to be called from at most one thread of server, and one thread of client. 413 // As a temporary workaround, this method informs the proxy implementation that it 414 // should avoid doing a state queue poll from within framesReady(). 415 // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. framesReadyIsCalledByMultipleThreads()416 virtual void framesReadyIsCalledByMultipleThreads() { } 417 418 bool setStreamEndDone(); // and return previous value 419 420 // Add to the tally of underrun frames, and inform client of underrun 421 virtual void tallyUnderrunFrames(uint32_t frameCount); 422 423 // Return the total number of frames which AudioFlinger desired but were unavailable, 424 // and thus which resulted in an underrun. getUnderrunFrames()425 virtual uint32_t getUnderrunFrames() const { return mCblk->u.mStreaming.mUnderrunFrames; } 426 427 // Return the total number of frames that AudioFlinger has obtained and released framesReleased()428 virtual size_t framesReleased() const { return mCblk->mServer; } 429 }; 430 431 class StaticAudioTrackServerProxy : public AudioTrackServerProxy { 432 public: 433 StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 434 size_t frameSize); 435 protected: ~StaticAudioTrackServerProxy()436 virtual ~StaticAudioTrackServerProxy() { } 437 438 public: 439 virtual size_t framesReady(); 440 virtual void framesReadyIsCalledByMultipleThreads(); 441 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush); 442 virtual void releaseBuffer(Buffer* buffer); 443 virtual void tallyUnderrunFrames(uint32_t frameCount); getUnderrunFrames()444 virtual uint32_t getUnderrunFrames() const { return 0; } 445 446 private: 447 ssize_t pollPosition(); // poll for state queue update, and return current position 448 StaticAudioTrackSingleStateQueue::Observer mObserver; 449 size_t mPosition; // server's current play position in frames, relative to 0 450 size_t mEnd; // cached value computed from mState, safe for asynchronous read 451 bool mFramesReadyIsCalledByMultipleThreads; 452 StaticAudioTrackState mState; 453 }; 454 455 // Proxy used by AudioFlinger for servicing AudioRecord 456 class AudioRecordServerProxy : public ServerProxy { 457 public: AudioRecordServerProxy(audio_track_cblk_t * cblk,void * buffers,size_t frameCount,size_t frameSize)458 AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 459 size_t frameSize) 460 : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, 461 false /*clientInServer*/) { } 462 protected: ~AudioRecordServerProxy()463 virtual ~AudioRecordServerProxy() { } 464 }; 465 466 // ---------------------------------------------------------------------------- 467 468 }; // namespace android 469 470 #endif // ANDROID_AUDIO_TRACK_SHARED_H 471