AudioTrackShared.h revision 9b4615887c23548438fd0d8e3d8f04ac21912850
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 <audio_utils/minifloat.h> 24#include <utils/threads.h> 25#include <utils/Log.h> 26#include <utils/RefBase.h> 27#include <media/nbaio/roundup.h> 28#include <media/SingleStateQueue.h> 29 30namespace 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 up to a maximum of 20 seconds of offloaded 52 53struct 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// Represents a single state of an AudioTrack that was created in static mode (shared memory buffer 64// supplied by the client). This state needs to be communicated from the client to server. As this 65// state is too large to be updated atomically without a mutex, and mutexes aren't allowed here, the 66// state is wrapped by a SingleStateQueue. 67struct StaticAudioTrackState { 68 // Do not define constructors, destructors, or virtual methods as this is part of a 69 // union in shared memory and they will not get called properly. 70 71 // These fields should both be size_t, but since they are located in shared memory we 72 // force to 32-bit. The client and server may have different typedefs for size_t. 73 74 // The state has a sequence counter to indicate whether changes are made to loop or position. 75 // The sequence counter also currently indicates whether loop or position is first depending 76 // on which is greater; it jumps by max(mLoopSequence, mPositionSequence) + 1. 77 78 uint32_t mLoopStart; 79 uint32_t mLoopEnd; 80 int32_t mLoopCount; 81 uint32_t mLoopSequence; // a sequence counter to indicate changes to loop 82 uint32_t mPosition; 83 uint32_t mPositionSequence; // a sequence counter to indicate changes to position 84}; 85 86typedef SingleStateQueue<StaticAudioTrackState> StaticAudioTrackSingleStateQueue; 87 88struct AudioTrackSharedStatic { 89 StaticAudioTrackSingleStateQueue::Shared 90 mSingleStateQueue; 91 // This field should be a size_t, but since it is located in shared memory we 92 // force to 32-bit. The client and server may have different typedefs for size_t. 93 uint32_t mBufferPosition; // updated asynchronously by server, 94 // "for entertainment purposes only" 95}; 96 97// ---------------------------------------------------------------------------- 98 99// Important: do not add any virtual methods, including ~ 100struct audio_track_cblk_t 101{ 102 // Since the control block is always located in shared memory, this constructor 103 // is only used for placement new(). It is never used for regular new() or stack. 104 audio_track_cblk_t(); 105 /*virtual*/ ~audio_track_cblk_t() { } 106 107 friend class Proxy; 108 friend class ClientProxy; 109 friend class AudioTrackClientProxy; 110 friend class AudioRecordClientProxy; 111 friend class ServerProxy; 112 friend class AudioTrackServerProxy; 113 friend class AudioRecordServerProxy; 114 115 // The data members are grouped so that members accessed frequently and in the same context 116 // are in the same line of data cache. 117 118 uint32_t mServer; // Number of filled frames consumed by server (mIsOut), 119 // or filled frames provided by server (!mIsOut). 120 // It is updated asynchronously by server without a barrier. 121 // The value should be used 122 // "for entertainment purposes only", 123 // which means don't make important decisions based on it. 124 125 uint32_t mPad1; // unused 126 127 volatile int32_t mFutex; // event flag: down (P) by client, 128 // up (V) by server or binderDied() or interrupt() 129#define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending 130 131private: 132 133 // This field should be a size_t, but since it is located in shared memory we 134 // force to 32-bit. The client and server may have different typedefs for size_t. 135 uint32_t mMinimum; // server wakes up client if available >= mMinimum 136 137 // Stereo gains for AudioTrack only, not used by AudioRecord. 138 gain_minifloat_packed_t mVolumeLR; 139 140 uint32_t mSampleRate; // AudioTrack only: client's requested sample rate in Hz 141 // or 0 == default. Write-only client, read-only server. 142 143 // client write-only, server read-only 144 uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 145 146 uint16_t mPad2; // unused 147 148public: 149 150 volatile int32_t mFlags; // combinations of CBLK_* 151 152 // Cache line boundary (32 bytes) 153 154public: 155 union { 156 AudioTrackSharedStreaming mStreaming; 157 AudioTrackSharedStatic mStatic; 158 int mAlign[8]; 159 } u; 160 161 // Cache line boundary (32 bytes) 162}; 163 164// ---------------------------------------------------------------------------- 165 166// Proxy for shared memory control block, to isolate callers from needing to know the details. 167// There is exactly one ClientProxy and one ServerProxy per shared memory control block. 168// The proxies are located in normal memory, and are not multi-thread safe within a given side. 169class Proxy : public RefBase { 170protected: 171 Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, 172 bool clientInServer); 173 virtual ~Proxy() { } 174 175public: 176 struct Buffer { 177 size_t mFrameCount; // number of frames available in this buffer 178 void* mRaw; // pointer to first frame 179 size_t mNonContig; // number of additional non-contiguous frames available 180 }; 181 182protected: 183 // These refer to shared memory, and are virtual addresses with respect to the current process. 184 // They may have different virtual addresses within the other process. 185 audio_track_cblk_t* const mCblk; // the control block 186 void* const mBuffers; // starting address of buffers 187 188 const size_t mFrameCount; // not necessarily a power of 2 189 const size_t mFrameSize; // in bytes 190 const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode 191 const bool mIsOut; // true for AudioTrack, false for AudioRecord 192 const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord 193 bool mIsShutdown; // latch set to true when shared memory corruption detected 194 size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer 195}; 196 197// ---------------------------------------------------------------------------- 198 199// Proxy seen by AudioTrack client and AudioRecord client 200class ClientProxy : public Proxy { 201public: 202 ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 203 bool isOut, bool clientInServer); 204 virtual ~ClientProxy() { } 205 206 static const struct timespec kForever; 207 static const struct timespec kNonBlocking; 208 209 // Obtain a buffer with filled frames (reading) or empty frames (writing). 210 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 211 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 212 // sets or extends the unreleased frame count. 213 // On entry: 214 // buffer->mFrameCount should be initialized to maximum number of desired frames, 215 // which must be > 0. 216 // buffer->mNonContig is unused. 217 // buffer->mRaw is unused. 218 // requested is the requested timeout in local monotonic delta time units: 219 // NULL or &kNonBlocking means non-blocking (zero timeout). 220 // &kForever means block forever (infinite timeout). 221 // Other values mean a specific timeout in local monotonic delta time units. 222 // elapsed is a pointer to a location that will hold the total local monotonic time that 223 // elapsed while blocked, or NULL if not needed. 224 // On exit: 225 // buffer->mFrameCount has the actual number of contiguous available frames, 226 // which is always 0 when the return status != NO_ERROR. 227 // buffer->mNonContig is the number of additional non-contiguous available frames. 228 // buffer->mRaw is a pointer to the first available frame, 229 // or NULL when buffer->mFrameCount == 0. 230 // The return status is one of: 231 // NO_ERROR Success, buffer->mFrameCount > 0. 232 // WOULD_BLOCK Non-blocking mode and no frames are available. 233 // TIMED_OUT Timeout occurred before any frames became available. 234 // This can happen even for infinite timeout, due to a spurious wakeup. 235 // In this case, the caller should investigate and then re-try as appropriate. 236 // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. 237 // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. 238 // NO_INIT Shared memory is corrupt. 239 // Assertion failure on entry, if buffer == NULL or buffer->mFrameCount == 0. 240 status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, 241 struct timespec *elapsed = NULL); 242 243 // Release (some of) the frames last obtained. 244 // On entry, buffer->mFrameCount should have the number of frames to release, 245 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 246 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 247 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 248 // On exit: 249 // buffer->mFrameCount is zero. 250 // buffer->mRaw is NULL. 251 void releaseBuffer(Buffer* buffer); 252 253 // Call after detecting server's death 254 void binderDied(); 255 256 // Call to force an obtainBuffer() to return quickly with -EINTR 257 void interrupt(); 258 259 size_t getPosition() { 260 return mEpoch + mCblk->mServer; 261 } 262 263 void setEpoch(size_t epoch) { 264 mEpoch = epoch; 265 } 266 267 void setMinimum(size_t minimum) { 268 // This can only happen on a 64-bit client 269 if (minimum > UINT32_MAX) { 270 minimum = UINT32_MAX; 271 } 272 mCblk->mMinimum = (uint32_t) minimum; 273 } 274 275 // Return the number of frames that would need to be obtained and released 276 // in order for the client to be aligned at start of buffer 277 virtual size_t getMisalignment(); 278 279 size_t getEpoch() const { 280 return mEpoch; 281 } 282 283 size_t getFramesFilled(); 284 285private: 286 size_t mEpoch; 287}; 288 289// ---------------------------------------------------------------------------- 290 291// Proxy used by AudioTrack client, which also includes AudioFlinger::PlaybackThread::OutputTrack 292class AudioTrackClientProxy : public ClientProxy { 293public: 294 AudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 295 size_t frameSize, bool clientInServer = false) 296 : ClientProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, 297 clientInServer) { } 298 virtual ~AudioTrackClientProxy() { } 299 300 // No barriers on the following operations, so the ordering of loads/stores 301 // with respect to other parameters is UNPREDICTABLE. That's considered safe. 302 303 // caller must limit to 0.0 <= sendLevel <= 1.0 304 void setSendLevel(float sendLevel) { 305 mCblk->mSendLevel = uint16_t(sendLevel * 0x1000); 306 } 307 308 // set stereo gains 309 void setVolumeLR(gain_minifloat_packed_t volumeLR) { 310 mCblk->mVolumeLR = volumeLR; 311 } 312 313 void setSampleRate(uint32_t sampleRate) { 314 mCblk->mSampleRate = sampleRate; 315 } 316 317 virtual void flush(); 318 319 virtual uint32_t getUnderrunFrames() const { 320 return mCblk->u.mStreaming.mUnderrunFrames; 321 } 322 323 bool clearStreamEndDone(); // and return previous value 324 325 bool getStreamEndDone() const; 326 327 status_t waitStreamEndDone(const struct timespec *requested); 328}; 329 330class StaticAudioTrackClientProxy : public AudioTrackClientProxy { 331public: 332 StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 333 size_t frameSize); 334 virtual ~StaticAudioTrackClientProxy() { } 335 336 virtual void flush(); 337 338#define MIN_LOOP 16 // minimum length of each loop iteration in frames 339 340 // setLoop(), setBufferPosition(), and setBufferPositionAndLoop() set the 341 // static buffer position and looping parameters. These commands are not 342 // synchronous (they do not wait or block); instead they take effect at the 343 // next buffer data read from the server side. However, the client side 344 // getters will read a cached version of the position and loop variables 345 // until the setting takes effect. 346 // 347 // setBufferPositionAndLoop() is equivalent to calling, in order, setLoop() and 348 // setBufferPosition(). 349 // 350 // The functions should not be relied upon to do parameter or state checking. 351 // That is done at the AudioTrack level. 352 353 void setLoop(size_t loopStart, size_t loopEnd, int loopCount); 354 void setBufferPosition(size_t position); 355 void setBufferPositionAndLoop(size_t position, size_t loopStart, size_t loopEnd, 356 int loopCount); 357 size_t getBufferPosition(); 358 359 virtual size_t getMisalignment() { 360 return 0; 361 } 362 363 virtual uint32_t getUnderrunFrames() const { 364 return 0; 365 } 366 367private: 368 StaticAudioTrackSingleStateQueue::Mutator mMutator; 369 StaticAudioTrackState mState; // last communicated state to server 370 size_t mBufferPosition; // so that getBufferPosition() appears to be synchronous 371}; 372 373// ---------------------------------------------------------------------------- 374 375// Proxy used by AudioRecord client 376class AudioRecordClientProxy : public ClientProxy { 377public: 378 AudioRecordClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 379 size_t frameSize) 380 : ClientProxy(cblk, buffers, frameCount, frameSize, 381 false /*isOut*/, false /*clientInServer*/) { } 382 ~AudioRecordClientProxy() { } 383}; 384 385// ---------------------------------------------------------------------------- 386 387// Proxy used by AudioFlinger server 388class ServerProxy : public Proxy { 389protected: 390 ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 391 bool isOut, bool clientInServer); 392public: 393 virtual ~ServerProxy() { } 394 395 // Obtain a buffer with filled frames (writing) or empty frames (reading). 396 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 397 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 398 // sets or extends the unreleased frame count. 399 // Always non-blocking. 400 // On entry: 401 // buffer->mFrameCount should be initialized to maximum number of desired frames, 402 // which must be > 0. 403 // buffer->mNonContig is unused. 404 // buffer->mRaw is unused. 405 // ackFlush is true iff being called from Track::start to acknowledge a pending flush. 406 // On exit: 407 // buffer->mFrameCount has the actual number of contiguous available frames, 408 // which is always 0 when the return status != NO_ERROR. 409 // buffer->mNonContig is the number of additional non-contiguous available frames. 410 // buffer->mRaw is a pointer to the first available frame, 411 // or NULL when buffer->mFrameCount == 0. 412 // The return status is one of: 413 // NO_ERROR Success, buffer->mFrameCount > 0. 414 // WOULD_BLOCK No frames are available. 415 // NO_INIT Shared memory is corrupt. 416 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush = false); 417 418 // Release (some of) the frames last obtained. 419 // On entry, buffer->mFrameCount should have the number of frames to release, 420 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 421 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 422 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 423 // On exit: 424 // buffer->mFrameCount is zero. 425 // buffer->mRaw is NULL. 426 virtual void releaseBuffer(Buffer* buffer); 427 428protected: 429 size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() 430 int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only 431}; 432 433// Proxy used by AudioFlinger for servicing AudioTrack 434class AudioTrackServerProxy : public ServerProxy { 435public: 436 AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 437 size_t frameSize, bool clientInServer = false, uint32_t sampleRate = 0) 438 : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { 439 mCblk->mSampleRate = sampleRate; 440 } 441protected: 442 virtual ~AudioTrackServerProxy() { } 443 444public: 445 // return value of these methods must be validated by the caller 446 uint32_t getSampleRate() const { return mCblk->mSampleRate; } 447 uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } 448 gain_minifloat_packed_t getVolumeLR() const { return mCblk->mVolumeLR; } 449 450 // estimated total number of filled frames available to server to read, 451 // which may include non-contiguous frames 452 virtual size_t framesReady(); 453 454 // Currently AudioFlinger will call framesReady() for a fast track from two threads: 455 // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended 456 // to be called from at most one thread of server, and one thread of client. 457 // As a temporary workaround, this method informs the proxy implementation that it 458 // should avoid doing a state queue poll from within framesReady(). 459 // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. 460 virtual void framesReadyIsCalledByMultipleThreads() { } 461 462 bool setStreamEndDone(); // and return previous value 463 464 // Add to the tally of underrun frames, and inform client of underrun 465 virtual void tallyUnderrunFrames(uint32_t frameCount); 466 467 // Return the total number of frames which AudioFlinger desired but were unavailable, 468 // and thus which resulted in an underrun. 469 virtual uint32_t getUnderrunFrames() const { return mCblk->u.mStreaming.mUnderrunFrames; } 470 471 // Return the total number of frames that AudioFlinger has obtained and released 472 virtual size_t framesReleased() const { return mCblk->mServer; } 473}; 474 475class StaticAudioTrackServerProxy : public AudioTrackServerProxy { 476public: 477 StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 478 size_t frameSize); 479protected: 480 virtual ~StaticAudioTrackServerProxy() { } 481 482public: 483 virtual size_t framesReady(); 484 virtual void framesReadyIsCalledByMultipleThreads(); 485 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush); 486 virtual void releaseBuffer(Buffer* buffer); 487 virtual void tallyUnderrunFrames(uint32_t frameCount); 488 virtual uint32_t getUnderrunFrames() const { return 0; } 489 490private: 491 status_t updateStateWithLoop(StaticAudioTrackState *localState, 492 const StaticAudioTrackState &update) const; 493 status_t updateStateWithPosition(StaticAudioTrackState *localState, 494 const StaticAudioTrackState &update) const; 495 ssize_t pollPosition(); // poll for state queue update, and return current position 496 StaticAudioTrackSingleStateQueue::Observer mObserver; 497 size_t mPosition; // server's current play position in frames, relative to 0 498 499 size_t mFramesReadySafe; // Assuming size_t read/writes are atomic on 32 / 64 bit 500 // processors, this is a thread-safe version of 501 // mFramesReady. 502 int64_t mFramesReady; // The number of frames ready in the static buffer 503 // including loops. This is 64 bits since loop mode 504 // can cause a track to appear to have a large number 505 // of frames. INT64_MAX means an infinite loop. 506 bool mFramesReadyIsCalledByMultipleThreads; 507 StaticAudioTrackState mState; // Server side state. Any updates from client must be 508 // passed by the mObserver SingleStateQueue. 509}; 510 511// Proxy used by AudioFlinger for servicing AudioRecord 512class AudioRecordServerProxy : public ServerProxy { 513public: 514 AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 515 size_t frameSize, bool clientInServer) 516 : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, clientInServer) { } 517protected: 518 virtual ~AudioRecordServerProxy() { } 519}; 520 521// ---------------------------------------------------------------------------- 522 523}; // namespace android 524 525#endif // ANDROID_AUDIO_TRACK_SHARED_H 526