AudioTrackShared.h revision 74935e44734c1ec235c2b6677db3e0dbefa5ddb8
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 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 63typedef SingleStateQueue<StaticAudioTrackState> StaticAudioTrackSingleStateQueue; 64 65struct 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 ~ 75struct 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(); 80 /*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 uint32_t mPad1; // unused 100 101 volatile int32_t mFutex; // event flag: down (P) by client, 102 // up (V) by server or binderDied() or interrupt() 103#define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending 104 105private: 106 107 size_t mMinimum; // server wakes up client if available >= mMinimum 108 109 // Channel volumes are fixed point U4.12, so 0x1000 means 1.0. 110 // Left channel is in [0:15], right channel is in [16:31]. 111 // Always read and write the combined pair atomically. 112 // For AudioTrack only, not used by AudioRecord. 113 uint32_t mVolumeLR; 114 115 uint32_t mSampleRate; // AudioTrack only: client's requested sample rate in Hz 116 // or 0 == default. Write-only client, read-only server. 117 118 // client write-only, server read-only 119 uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 120 121 uint16_t mPad2; // unused 122 123public: 124 125 volatile int32_t mFlags; // combinations of CBLK_* 126 127 // Cache line boundary (32 bytes) 128 129public: 130 union { 131 AudioTrackSharedStreaming mStreaming; 132 AudioTrackSharedStatic mStatic; 133 int mAlign[8]; 134 } u; 135 136 // Cache line boundary (32 bytes) 137}; 138 139// ---------------------------------------------------------------------------- 140 141// Proxy for shared memory control block, to isolate callers from needing to know the details. 142// There is exactly one ClientProxy and one ServerProxy per shared memory control block. 143// The proxies are located in normal memory, and are not multi-thread safe within a given side. 144class Proxy : public RefBase { 145protected: 146 Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, 147 bool clientInServer); 148 virtual ~Proxy() { } 149 150public: 151 struct Buffer { 152 size_t mFrameCount; // number of frames available in this buffer 153 void* mRaw; // pointer to first frame 154 size_t mNonContig; // number of additional non-contiguous frames available 155 }; 156 157protected: 158 // These refer to shared memory, and are virtual addresses with respect to the current process. 159 // They may have different virtual addresses within the other process. 160 audio_track_cblk_t* const mCblk; // the control block 161 void* const mBuffers; // starting address of buffers 162 163 const size_t mFrameCount; // not necessarily a power of 2 164 const size_t mFrameSize; // in bytes 165 const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode 166 const bool mIsOut; // true for AudioTrack, false for AudioRecord 167 const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord 168 bool mIsShutdown; // latch set to true when shared memory corruption detected 169 size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer 170}; 171 172// ---------------------------------------------------------------------------- 173 174// Proxy seen by AudioTrack client and AudioRecord client 175class ClientProxy : public Proxy { 176protected: 177 ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 178 bool isOut, bool clientInServer); 179 virtual ~ClientProxy() { } 180 181public: 182 static const struct timespec kForever; 183 static const struct timespec kNonBlocking; 184 185 // Obtain a buffer with filled frames (reading) or empty frames (writing). 186 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 187 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 188 // sets or extends the unreleased frame count. 189 // On entry: 190 // buffer->mFrameCount should be initialized to maximum number of desired frames, 191 // which must be > 0. 192 // buffer->mNonContig is unused. 193 // buffer->mRaw is unused. 194 // requested is the requested timeout in local monotonic delta time units: 195 // NULL or &kNonBlocking means non-blocking (zero timeout). 196 // &kForever means block forever (infinite timeout). 197 // Other values mean a specific timeout in local monotonic delta time units. 198 // elapsed is a pointer to a location that will hold the total local monotonic time that 199 // elapsed while blocked, or NULL if not needed. 200 // On exit: 201 // buffer->mFrameCount has the actual number of contiguous available frames, 202 // which is always 0 when the return status != NO_ERROR. 203 // buffer->mNonContig is the number of additional non-contiguous available frames. 204 // buffer->mRaw is a pointer to the first available frame, 205 // or NULL when buffer->mFrameCount == 0. 206 // The return status is one of: 207 // NO_ERROR Success, buffer->mFrameCount > 0. 208 // WOULD_BLOCK Non-blocking mode and no frames are available. 209 // TIMED_OUT Timeout occurred before any frames became available. 210 // This can happen even for infinite timeout, due to a spurious wakeup. 211 // In this case, the caller should investigate and then re-try as appropriate. 212 // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. 213 // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. 214 // NO_INIT Shared memory is corrupt. 215 // Assertion failure on entry, if buffer == NULL or buffer->mFrameCount == 0. 216 status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, 217 struct timespec *elapsed = NULL); 218 219 // Release (some of) the frames last obtained. 220 // On entry, buffer->mFrameCount should have the number of frames to release, 221 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 222 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 223 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 224 // On exit: 225 // buffer->mFrameCount is zero. 226 // buffer->mRaw is NULL. 227 void releaseBuffer(Buffer* buffer); 228 229 // Call after detecting server's death 230 void binderDied(); 231 232 // Call to force an obtainBuffer() to return quickly with -EINTR 233 void interrupt(); 234 235 size_t getPosition() { 236 return mEpoch + mCblk->mServer; 237 } 238 239 void setEpoch(size_t epoch) { 240 mEpoch = epoch; 241 } 242 243 void setMinimum(size_t minimum) { 244 mCblk->mMinimum = minimum; 245 } 246 247 // Return the number of frames that would need to be obtained and released 248 // in order for the client to be aligned at start of buffer 249 virtual size_t getMisalignment(); 250 251 size_t getEpoch() const { 252 return mEpoch; 253 } 254 255 size_t getFramesFilled(); 256 257private: 258 size_t mEpoch; 259}; 260 261// ---------------------------------------------------------------------------- 262 263// Proxy used by AudioTrack client, which also includes AudioFlinger::PlaybackThread::OutputTrack 264class AudioTrackClientProxy : public ClientProxy { 265public: 266 AudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 267 size_t frameSize, bool clientInServer = false) 268 : ClientProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, 269 clientInServer) { } 270 virtual ~AudioTrackClientProxy() { } 271 272 // No barriers on the following operations, so the ordering of loads/stores 273 // with respect to other parameters is UNPREDICTABLE. That's considered safe. 274 275 // caller must limit to 0.0 <= sendLevel <= 1.0 276 void setSendLevel(float sendLevel) { 277 mCblk->mSendLevel = uint16_t(sendLevel * 0x1000); 278 } 279 280 // caller must limit to 0 <= volumeLR <= 0x10001000 281 void setVolumeLR(uint32_t volumeLR) { 282 mCblk->mVolumeLR = volumeLR; 283 } 284 285 void setSampleRate(uint32_t sampleRate) { 286 mCblk->mSampleRate = sampleRate; 287 } 288 289 virtual void flush(); 290 291 virtual uint32_t getUnderrunFrames() const { 292 return mCblk->u.mStreaming.mUnderrunFrames; 293 } 294 295 bool clearStreamEndDone(); // and return previous value 296 297 bool getStreamEndDone() const; 298 299 status_t waitStreamEndDone(const struct timespec *requested); 300}; 301 302class StaticAudioTrackClientProxy : public AudioTrackClientProxy { 303public: 304 StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 305 size_t frameSize); 306 virtual ~StaticAudioTrackClientProxy() { } 307 308 virtual void flush(); 309 310#define MIN_LOOP 16 // minimum length of each loop iteration in frames 311 void setLoop(size_t loopStart, size_t loopEnd, int loopCount); 312 size_t getBufferPosition(); 313 314 virtual size_t getMisalignment() { 315 return 0; 316 } 317 318 virtual uint32_t getUnderrunFrames() const { 319 return 0; 320 } 321 322private: 323 StaticAudioTrackSingleStateQueue::Mutator mMutator; 324 size_t mBufferPosition; // so that getBufferPosition() appears to be synchronous 325}; 326 327// ---------------------------------------------------------------------------- 328 329// Proxy used by AudioRecord client 330class AudioRecordClientProxy : public ClientProxy { 331public: 332 AudioRecordClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 333 size_t frameSize) 334 : ClientProxy(cblk, buffers, frameCount, frameSize, 335 false /*isOut*/, false /*clientInServer*/) { } 336 ~AudioRecordClientProxy() { } 337}; 338 339// ---------------------------------------------------------------------------- 340 341// Proxy used by AudioFlinger server 342class ServerProxy : public Proxy { 343protected: 344 ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 345 bool isOut, bool clientInServer); 346public: 347 virtual ~ServerProxy() { } 348 349 // Obtain a buffer with filled frames (writing) or empty frames (reading). 350 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 351 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 352 // sets or extends the unreleased frame count. 353 // Always non-blocking. 354 // On entry: 355 // buffer->mFrameCount should be initialized to maximum number of desired frames, 356 // which must be > 0. 357 // buffer->mNonContig is unused. 358 // buffer->mRaw is unused. 359 // ackFlush is true iff being called from Track::start to acknowledge a pending flush. 360 // On exit: 361 // buffer->mFrameCount has the actual number of contiguous available frames, 362 // which is always 0 when the return status != NO_ERROR. 363 // buffer->mNonContig is the number of additional non-contiguous available frames. 364 // buffer->mRaw is a pointer to the first available frame, 365 // or NULL when buffer->mFrameCount == 0. 366 // The return status is one of: 367 // NO_ERROR Success, buffer->mFrameCount > 0. 368 // WOULD_BLOCK No frames are available. 369 // NO_INIT Shared memory is corrupt. 370 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush = false); 371 372 // Release (some of) the frames last obtained. 373 // On entry, buffer->mFrameCount should have the number of frames to release, 374 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 375 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 376 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 377 // On exit: 378 // buffer->mFrameCount is zero. 379 // buffer->mRaw is NULL. 380 virtual void releaseBuffer(Buffer* buffer); 381 382protected: 383 size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() 384 int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only 385}; 386 387// Proxy used by AudioFlinger for servicing AudioTrack 388class AudioTrackServerProxy : public ServerProxy { 389public: 390 AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 391 size_t frameSize, bool clientInServer = false) 392 : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } 393protected: 394 virtual ~AudioTrackServerProxy() { } 395 396public: 397 // return value of these methods must be validated by the caller 398 uint32_t getSampleRate() const { return mCblk->mSampleRate; } 399 uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } 400 uint32_t getVolumeLR() const { return mCblk->mVolumeLR; } 401 402 // estimated total number of filled frames available to server to read, 403 // which may include non-contiguous frames 404 virtual size_t framesReady(); 405 406 // Currently AudioFlinger will call framesReady() for a fast track from two threads: 407 // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended 408 // to be called from at most one thread of server, and one thread of client. 409 // As a temporary workaround, this method informs the proxy implementation that it 410 // should avoid doing a state queue poll from within framesReady(). 411 // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. 412 virtual void framesReadyIsCalledByMultipleThreads() { } 413 414 bool setStreamEndDone(); // and return previous value 415 416 // Add to the tally of underrun frames, and inform client of underrun 417 virtual void tallyUnderrunFrames(uint32_t frameCount); 418 419 // Return the total number of frames which AudioFlinger desired but were unavailable, 420 // and thus which resulted in an underrun. 421 virtual uint32_t getUnderrunFrames() const { return mCblk->u.mStreaming.mUnderrunFrames; } 422 423 // Return the total number of frames that AudioFlinger has obtained and released 424 virtual size_t framesReleased() const { return mCblk->mServer; } 425}; 426 427class StaticAudioTrackServerProxy : public AudioTrackServerProxy { 428public: 429 StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 430 size_t frameSize); 431protected: 432 virtual ~StaticAudioTrackServerProxy() { } 433 434public: 435 virtual size_t framesReady(); 436 virtual void framesReadyIsCalledByMultipleThreads(); 437 virtual status_t obtainBuffer(Buffer* buffer, bool ackFlush); 438 virtual void releaseBuffer(Buffer* buffer); 439 virtual void tallyUnderrunFrames(uint32_t frameCount); 440 virtual uint32_t getUnderrunFrames() const { return 0; } 441 442private: 443 ssize_t pollPosition(); // poll for state queue update, and return current position 444 StaticAudioTrackSingleStateQueue::Observer mObserver; 445 size_t mPosition; // server's current play position in frames, relative to 0 446 size_t mEnd; // cached value computed from mState, safe for asynchronous read 447 bool mFramesReadyIsCalledByMultipleThreads; 448 StaticAudioTrackState mState; 449}; 450 451// Proxy used by AudioFlinger for servicing AudioRecord 452class AudioRecordServerProxy : public ServerProxy { 453public: 454 AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 455 size_t frameSize) 456 : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, 457 false /*clientInServer*/) { } 458protected: 459 virtual ~AudioRecordServerProxy() { } 460}; 461 462// ---------------------------------------------------------------------------- 463 464}; // namespace android 465 466#endif // ANDROID_AUDIO_TRACK_SHARED_H 467