AudioTrackShared.h revision b1a270d1e926fb9a01b4265a7675ed0c2c8f4868
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#define CBLK_UNDERRUN 0x01 // set by server immediately on output underrun, cleared by client 35#define CBLK_FORCEREADY 0x02 // set: track is considered ready immediately by AudioFlinger, 36 // clear: track is ready when buffer full 37#define CBLK_INVALID 0x04 // track buffer invalidated by AudioFlinger, need to re-create 38#define CBLK_DISABLED 0x08 // output track disabled by AudioFlinger due to underrun, 39 // need to re-start. Unlike CBLK_UNDERRUN, this is not set 40 // immediately, but only after a long string of underruns. 41// 0x10 unused 42#define CBLK_LOOP_CYCLE 0x20 // set by server each time a loop cycle other than final one completes 43#define CBLK_LOOP_FINAL 0x40 // set by server when the final loop cycle completes 44#define CBLK_BUFFER_END 0x80 // set by server when the position reaches end of buffer if not looping 45#define CBLK_OVERRUN 0x100 // set by server immediately on input overrun, cleared by client 46#define CBLK_INTERRUPT 0x200 // set by client on interrupt(), cleared by client in obtainBuffer() 47#define CBLK_STREAM_END_DONE 0x400 // set by server on render completion, cleared by client 48 49//EL_FIXME 20 seconds may not be enough and must be reconciled with new obtainBuffer implementation 50#define MAX_RUN_OFFLOADED_TIMEOUT_MS 20000 //assuming upto a maximum of 20 seconds of offloaded 51 52struct AudioTrackSharedStreaming { 53 // similar to NBAIO MonoPipe 54 // in continuously incrementing frame units, take modulo buffer size, which must be a power of 2 55 volatile int32_t mFront; // read by server 56 volatile int32_t mRear; // write by client 57 volatile int32_t mFlush; // incremented by client to indicate a request to flush; 58 // server notices and discards all data between mFront and mRear 59 volatile uint32_t mUnderrunFrames; // server increments for each unavailable but desired frame 60}; 61 62typedef SingleStateQueue<StaticAudioTrackState> StaticAudioTrackSingleStateQueue; 63 64struct AudioTrackSharedStatic { 65 StaticAudioTrackSingleStateQueue::Shared 66 mSingleStateQueue; 67 size_t mBufferPosition; // updated asynchronously by server, 68 // "for entertainment purposes only" 69}; 70 71// ---------------------------------------------------------------------------- 72 73// Important: do not add any virtual methods, including ~ 74struct audio_track_cblk_t 75{ 76 // Since the control block is always located in shared memory, this constructor 77 // is only used for placement new(). It is never used for regular new() or stack. 78 audio_track_cblk_t(); 79 /*virtual*/ ~audio_track_cblk_t() { } 80 81 friend class Proxy; 82 friend class ClientProxy; 83 friend class AudioTrackClientProxy; 84 friend class AudioRecordClientProxy; 85 friend class ServerProxy; 86 friend class AudioTrackServerProxy; 87 friend class AudioRecordServerProxy; 88 89 // The data members are grouped so that members accessed frequently and in the same context 90 // are in the same line of data cache. 91 92 volatile uint32_t server; // updated asynchronously by server, 93 // "for entertainment purposes only" 94 95 size_t frameCount_; // used during creation to pass actual track buffer size 96 // from AudioFlinger to client, and not referenced again 97 // FIXME remove here and replace by createTrack() in/out 98 // parameter 99 // renamed to "_" to detect incorrect use 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 uint8_t mPad2; // unused 122 123public: 124 // read-only for client, server writes once at initialization and is then read-only 125 uint8_t mName; // normal tracks: track name, fast tracks: track index 126 127 volatile int32_t flags; 128 129 // Cache line boundary (32 bytes) 130 131public: 132 union { 133 AudioTrackSharedStreaming mStreaming; 134 AudioTrackSharedStatic mStatic; 135 int mAlign[8]; 136 } u; 137 138 // Cache line boundary (32 bytes) 139}; 140 141// ---------------------------------------------------------------------------- 142 143// Proxy for shared memory control block, to isolate callers from needing to know the details. 144// There is exactly one ClientProxy and one ServerProxy per shared memory control block. 145// The proxies are located in normal memory, and are not multi-thread safe within a given side. 146class Proxy : public RefBase { 147protected: 148 Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, 149 bool clientInServer); 150 virtual ~Proxy() { } 151 152public: 153 struct Buffer { 154 size_t mFrameCount; // number of frames available in this buffer 155 void* mRaw; // pointer to first frame 156 size_t mNonContig; // number of additional non-contiguous frames available 157 }; 158 159protected: 160 // These refer to shared memory, and are virtual addresses with respect to the current process. 161 // They may have different virtual addresses within the other process. 162 audio_track_cblk_t* const mCblk; // the control block 163 void* const mBuffers; // starting address of buffers 164 165 const size_t mFrameCount; // not necessarily a power of 2 166 const size_t mFrameSize; // in bytes 167 const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode 168 const bool mIsOut; // true for AudioTrack, false for AudioRecord 169 const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord 170 bool mIsShutdown; // latch set to true when shared memory corruption detected 171 size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer 172}; 173 174// ---------------------------------------------------------------------------- 175 176// Proxy seen by AudioTrack client and AudioRecord client 177class ClientProxy : public Proxy { 178protected: 179 ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 180 bool isOut, bool clientInServer); 181 virtual ~ClientProxy() { } 182 183public: 184 static const struct timespec kForever; 185 static const struct timespec kNonBlocking; 186 187 // Obtain a buffer with filled frames (reading) or empty frames (writing). 188 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 189 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 190 // sets or extends the unreleased frame count. 191 // On entry: 192 // buffer->mFrameCount should be initialized to maximum number of desired frames, 193 // which must be > 0. 194 // buffer->mNonContig is unused. 195 // buffer->mRaw is unused. 196 // requested is the requested timeout in local monotonic delta time units: 197 // NULL or &kNonBlocking means non-blocking (zero timeout). 198 // &kForever means block forever (infinite timeout). 199 // Other values mean a specific timeout in local monotonic delta time units. 200 // elapsed is a pointer to a location that will hold the total local monotonic time that 201 // elapsed while blocked, or NULL if not needed. 202 // On exit: 203 // buffer->mFrameCount has the actual number of contiguous available frames, 204 // which is always 0 when the return status != NO_ERROR. 205 // buffer->mNonContig is the number of additional non-contiguous available frames. 206 // buffer->mRaw is a pointer to the first available frame, 207 // or NULL when buffer->mFrameCount == 0. 208 // The return status is one of: 209 // NO_ERROR Success, buffer->mFrameCount > 0. 210 // WOULD_BLOCK Non-blocking mode and no frames are available. 211 // TIMED_OUT Timeout occurred before any frames became available. 212 // This can happen even for infinite timeout, due to a spurious wakeup. 213 // In this case, the caller should investigate and then re-try as appropriate. 214 // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. 215 // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. 216 // NO_INIT Shared memory is corrupt. 217 // Assertion failure on entry, if buffer == NULL or buffer->mFrameCount == 0. 218 status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, 219 struct timespec *elapsed = NULL); 220 221 // Release (some of) the frames last obtained. 222 // On entry, buffer->mFrameCount should have the number of frames to release, 223 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 224 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 225 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 226 // On exit: 227 // buffer->mFrameCount is zero. 228 // buffer->mRaw is NULL. 229 void releaseBuffer(Buffer* buffer); 230 231 // Call after detecting server's death 232 void binderDied(); 233 234 // Call to force an obtainBuffer() to return quickly with -EINTR 235 void interrupt(); 236 237 size_t getPosition() { 238 return mEpoch + mCblk->server; 239 } 240 241 void setEpoch(size_t epoch) { 242 mEpoch = epoch; 243 } 244 245 void setMinimum(size_t minimum) { 246 mCblk->mMinimum = minimum; 247 } 248 249 // Return the number of frames that would need to be obtained and released 250 // in order for the client to be aligned at start of buffer 251 virtual size_t getMisalignment(); 252 253 size_t getEpoch() const { 254 return mEpoch; 255 } 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 // On exit: 360 // buffer->mFrameCount has the actual number of contiguous available frames, 361 // which is always 0 when the return status != NO_ERROR. 362 // buffer->mNonContig is the number of additional non-contiguous available frames. 363 // buffer->mRaw is a pointer to the first available frame, 364 // or NULL when buffer->mFrameCount == 0. 365 // The return status is one of: 366 // NO_ERROR Success, buffer->mFrameCount > 0. 367 // WOULD_BLOCK No frames are available. 368 // NO_INIT Shared memory is corrupt. 369 virtual status_t obtainBuffer(Buffer* buffer); 370 371 // Release (some of) the frames last obtained. 372 // On entry, buffer->mFrameCount should have the number of frames to release, 373 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 374 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 375 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 376 // On exit: 377 // buffer->mFrameCount is zero. 378 // buffer->mRaw is NULL. 379 virtual void releaseBuffer(Buffer* buffer); 380 381protected: 382 size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() 383 int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only 384private: 385 bool mDeferWake; // whether another releaseBuffer() is expected soon 386}; 387 388// Proxy used by AudioFlinger for servicing AudioTrack 389class AudioTrackServerProxy : public ServerProxy { 390public: 391 AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 392 size_t frameSize, bool clientInServer = false) 393 : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } 394protected: 395 virtual ~AudioTrackServerProxy() { } 396 397public: 398 // return value of these methods must be validated by the caller 399 uint32_t getSampleRate() const { return mCblk->mSampleRate; } 400 uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } 401 uint32_t getVolumeLR() const { return mCblk->mVolumeLR; } 402 403 // estimated total number of filled frames available to server to read, 404 // which may include non-contiguous frames 405 virtual size_t framesReady(); 406 407 // Currently AudioFlinger will call framesReady() for a fast track from two threads: 408 // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended 409 // to be called from at most one thread of server, and one thread of client. 410 // As a temporary workaround, this method informs the proxy implementation that it 411 // should avoid doing a state queue poll from within framesReady(). 412 // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. 413 virtual void framesReadyIsCalledByMultipleThreads() { } 414 415 bool setStreamEndDone(); // and return previous value 416}; 417 418class StaticAudioTrackServerProxy : public AudioTrackServerProxy { 419public: 420 StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 421 size_t frameSize); 422protected: 423 virtual ~StaticAudioTrackServerProxy() { } 424 425public: 426 virtual size_t framesReady(); 427 virtual void framesReadyIsCalledByMultipleThreads(); 428 virtual status_t obtainBuffer(Buffer* buffer); 429 virtual void releaseBuffer(Buffer* buffer); 430 431private: 432 ssize_t pollPosition(); // poll for state queue update, and return current position 433 StaticAudioTrackSingleStateQueue::Observer mObserver; 434 size_t mPosition; // server's current play position in frames, relative to 0 435 size_t mEnd; // cached value computed from mState, safe for asynchronous read 436 bool mFramesReadyIsCalledByMultipleThreads; 437 StaticAudioTrackState mState; 438}; 439 440// Proxy used by AudioFlinger for servicing AudioRecord 441class AudioRecordServerProxy : public ServerProxy { 442public: 443 AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 444 size_t frameSize) 445 : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, 446 false /*clientInServer*/) { } 447protected: 448 virtual ~AudioRecordServerProxy() { } 449}; 450 451// ---------------------------------------------------------------------------- 452 453}; // namespace android 454 455#endif // ANDROID_AUDIO_TRACK_SHARED_H 456