AudioTrackShared.h revision 0d09a9bec07b3bec78bd473ff0bfcf0a261f3f25
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 48struct AudioTrackSharedStreaming { 49 // similar to NBAIO MonoPipe 50 // in continuously incrementing frame units, take modulo buffer size, which must be a power of 2 51 volatile int32_t mFront; // read by server 52 volatile int32_t mRear; // write by client 53 volatile int32_t mFlush; // incremented by client to indicate a request to flush; 54 // server notices and discards all data between mFront and mRear 55 volatile uint32_t mUnderrunFrames; // server increments for each unavailable but desired frame 56}; 57 58typedef SingleStateQueue<StaticAudioTrackState> StaticAudioTrackSingleStateQueue; 59 60struct AudioTrackSharedStatic { 61 StaticAudioTrackSingleStateQueue::Shared 62 mSingleStateQueue; 63 size_t mBufferPosition; // updated asynchronously by server, 64 // "for entertainment purposes only" 65}; 66 67// ---------------------------------------------------------------------------- 68 69// Important: do not add any virtual methods, including ~ 70struct audio_track_cblk_t 71{ 72 // Since the control block is always located in shared memory, this constructor 73 // is only used for placement new(). It is never used for regular new() or stack. 74 audio_track_cblk_t(); 75 /*virtual*/ ~audio_track_cblk_t() { } 76 77 friend class Proxy; 78 friend class ClientProxy; 79 friend class AudioTrackClientProxy; 80 friend class AudioRecordClientProxy; 81 friend class ServerProxy; 82 friend class AudioTrackServerProxy; 83 friend class AudioRecordServerProxy; 84 85 // The data members are grouped so that members accessed frequently and in the same context 86 // are in the same line of data cache. 87 88 volatile uint32_t server; // updated asynchronously by server, 89 // "for entertainment purposes only" 90 91 size_t frameCount_; // used during creation to pass actual track buffer size 92 // from AudioFlinger to client, and not referenced again 93 // FIXME remove here and replace by createTrack() in/out 94 // parameter 95 // renamed to "_" to detect incorrect use 96 97 volatile int32_t mFutex; // event flag: down (P) by client, 98 // up (V) by server or binderDied() or interrupt() 99#define CBLK_FUTEX_WAKE 1 // if event flag bit is set, then a deferred wake is pending 100 101private: 102 103 size_t mMinimum; // server wakes up client if available >= mMinimum 104 105 // Channel volumes are fixed point U4.12, so 0x1000 means 1.0. 106 // Left channel is in [0:15], right channel is in [16:31]. 107 // Always read and write the combined pair atomically. 108 // For AudioTrack only, not used by AudioRecord. 109 uint32_t mVolumeLR; 110 111 uint32_t mSampleRate; // AudioTrack only: client's requested sample rate in Hz 112 // or 0 == default. Write-only client, read-only server. 113 114 // client write-only, server read-only 115 uint16_t mSendLevel; // Fixed point U4.12 so 0x1000 means 1.0 116 117 uint8_t mPad2; // unused 118 119public: 120 // read-only for client, server writes once at initialization and is then read-only 121 uint8_t mName; // normal tracks: track name, fast tracks: track index 122 123 volatile int32_t flags; 124 125 // Cache line boundary (32 bytes) 126 127public: 128 union { 129 AudioTrackSharedStreaming mStreaming; 130 AudioTrackSharedStatic mStatic; 131 int mAlign[8]; 132 } u; 133 134 // Cache line boundary (32 bytes) 135}; 136 137// ---------------------------------------------------------------------------- 138 139// Proxy for shared memory control block, to isolate callers from needing to know the details. 140// There is exactly one ClientProxy and one ServerProxy per shared memory control block. 141// The proxies are located in normal memory, and are not multi-thread safe within a given side. 142class Proxy : public RefBase { 143protected: 144 Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, bool isOut, 145 bool clientInServer); 146 virtual ~Proxy() { } 147 148public: 149 struct Buffer { 150 size_t mFrameCount; // number of frames available in this buffer 151 void* mRaw; // pointer to first frame 152 size_t mNonContig; // number of additional non-contiguous frames available 153 }; 154 155protected: 156 // These refer to shared memory, and are virtual addresses with respect to the current process. 157 // They may have different virtual addresses within the other process. 158 audio_track_cblk_t* const mCblk; // the control block 159 void* const mBuffers; // starting address of buffers 160 161 const size_t mFrameCount; // not necessarily a power of 2 162 const size_t mFrameSize; // in bytes 163 const size_t mFrameCountP2; // mFrameCount rounded to power of 2, streaming mode 164 const bool mIsOut; // true for AudioTrack, false for AudioRecord 165 const bool mClientInServer; // true for OutputTrack, false for AudioTrack & AudioRecord 166 bool mIsShutdown; // latch set to true when shared memory corruption detected 167}; 168 169// ---------------------------------------------------------------------------- 170 171// Proxy seen by AudioTrack client and AudioRecord client 172class ClientProxy : public Proxy { 173protected: 174 ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 175 bool isOut, bool clientInServer); 176 virtual ~ClientProxy() { } 177 178public: 179 static const struct timespec kForever; 180 static const struct timespec kNonBlocking; 181 182 // Obtain a buffer with filled frames (reading) or empty frames (writing). 183 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 184 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 185 // sets or extends the unreleased frame count. 186 // On entry: 187 // buffer->mFrameCount should be initialized to maximum number of desired frames, 188 // which must be > 0. 189 // buffer->mNonContig is unused. 190 // buffer->mRaw is unused. 191 // requested is the requested timeout in local monotonic delta time units: 192 // NULL or &kNonBlocking means non-blocking (zero timeout). 193 // &kForever means block forever (infinite timeout). 194 // Other values mean a specific timeout in local monotonic delta time units. 195 // elapsed is a pointer to a location that will hold the total local monotonic time that 196 // elapsed while blocked, or NULL if not needed. 197 // On exit: 198 // buffer->mFrameCount has the actual number of contiguous available frames, 199 // which is always 0 when the return status != NO_ERROR. 200 // buffer->mNonContig is the number of additional non-contiguous available frames. 201 // buffer->mRaw is a pointer to the first available frame, 202 // or NULL when buffer->mFrameCount == 0. 203 // The return status is one of: 204 // NO_ERROR Success, buffer->mFrameCount > 0. 205 // WOULD_BLOCK Non-blocking mode and no frames are available. 206 // TIMED_OUT Timeout occurred before any frames became available. 207 // This can happen even for infinite timeout, due to a spurious wakeup. 208 // In this case, the caller should investigate and then re-try as appropriate. 209 // DEAD_OBJECT Server has died or invalidated, caller should destroy this proxy and re-create. 210 // -EINTR Call has been interrupted. Look around to see why, and then perhaps try again. 211 // NO_INIT Shared memory is corrupt. 212 // BAD_VALUE On entry buffer == NULL or buffer->mFrameCount == 0. 213 status_t obtainBuffer(Buffer* buffer, const struct timespec *requested = NULL, 214 struct timespec *elapsed = NULL); 215 216 // Release (some of) the frames last obtained. 217 // On entry, buffer->mFrameCount should have the number of frames to release, 218 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 219 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 220 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 221 // On exit: 222 // buffer->mFrameCount is zero. 223 // buffer->mRaw is NULL. 224 void releaseBuffer(Buffer* buffer); 225 226 // Call after detecting server's death 227 void binderDied(); 228 229 // Call to force an obtainBuffer() to return quickly with -EINTR 230 void interrupt(); 231 232 size_t getPosition() { 233 return mEpoch + mCblk->server; 234 } 235 236 void setEpoch(size_t epoch) { 237 mEpoch = epoch; 238 } 239 240 void setMinimum(size_t minimum) { 241 mCblk->mMinimum = minimum; 242 } 243 244 // Return the number of frames that would need to be obtained and released 245 // in order for the client to be aligned at start of buffer 246 virtual size_t getMisalignment(); 247 248 size_t getEpoch() const { 249 return mEpoch; 250 } 251 252private: 253 size_t mEpoch; 254}; 255 256// ---------------------------------------------------------------------------- 257 258// Proxy used by AudioTrack client, which also includes AudioFlinger::PlaybackThread::OutputTrack 259class AudioTrackClientProxy : public ClientProxy { 260public: 261 AudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 262 size_t frameSize, bool clientInServer = false) 263 : ClientProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, 264 clientInServer) { } 265 virtual ~AudioTrackClientProxy() { } 266 267 // No barriers on the following operations, so the ordering of loads/stores 268 // with respect to other parameters is UNPREDICTABLE. That's considered safe. 269 270 // caller must limit to 0.0 <= sendLevel <= 1.0 271 void setSendLevel(float sendLevel) { 272 mCblk->mSendLevel = uint16_t(sendLevel * 0x1000); 273 } 274 275 // caller must limit to 0 <= volumeLR <= 0x10001000 276 void setVolumeLR(uint32_t volumeLR) { 277 mCblk->mVolumeLR = volumeLR; 278 } 279 280 void setSampleRate(uint32_t sampleRate) { 281 mCblk->mSampleRate = sampleRate; 282 } 283 284 virtual void flush(); 285 286 virtual uint32_t getUnderrunFrames() const { 287 return mCblk->u.mStreaming.mUnderrunFrames; 288 } 289}; 290 291class StaticAudioTrackClientProxy : public AudioTrackClientProxy { 292public: 293 StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 294 size_t frameSize); 295 virtual ~StaticAudioTrackClientProxy() { } 296 297 virtual void flush(); 298 299#define MIN_LOOP 16 // minimum length of each loop iteration in frames 300 void setLoop(size_t loopStart, size_t loopEnd, int loopCount); 301 size_t getBufferPosition(); 302 303 virtual size_t getMisalignment() { 304 return 0; 305 } 306 307 virtual uint32_t getUnderrunFrames() const { 308 return 0; 309 } 310 311private: 312 StaticAudioTrackSingleStateQueue::Mutator mMutator; 313 size_t mBufferPosition; // so that getBufferPosition() appears to be synchronous 314}; 315 316// ---------------------------------------------------------------------------- 317 318// Proxy used by AudioRecord client 319class AudioRecordClientProxy : public ClientProxy { 320public: 321 AudioRecordClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 322 size_t frameSize) 323 : ClientProxy(cblk, buffers, frameCount, frameSize, 324 false /*isOut*/, false /*clientInServer*/) { } 325 ~AudioRecordClientProxy() { } 326}; 327 328// ---------------------------------------------------------------------------- 329 330// Proxy used by AudioFlinger server 331class ServerProxy : public Proxy { 332protected: 333 ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 334 bool isOut, bool clientInServer); 335public: 336 virtual ~ServerProxy() { } 337 338 // Obtain a buffer with filled frames (writing) or empty frames (reading). 339 // It is permitted to call obtainBuffer() multiple times in succession, without any intervening 340 // calls to releaseBuffer(). In that case, the final obtainBuffer() is the one that effectively 341 // sets or extends the unreleased frame count. 342 // Always non-blocking. 343 // On entry: 344 // buffer->mFrameCount should be initialized to maximum number of desired frames, 345 // which must be > 0. 346 // buffer->mNonContig is unused. 347 // buffer->mRaw is unused. 348 // On exit: 349 // buffer->mFrameCount has the actual number of contiguous available frames, 350 // which is always 0 when the return status != NO_ERROR. 351 // buffer->mNonContig is the number of additional non-contiguous available frames. 352 // buffer->mRaw is a pointer to the first available frame, 353 // or NULL when buffer->mFrameCount == 0. 354 // The return status is one of: 355 // NO_ERROR Success, buffer->mFrameCount > 0. 356 // WOULD_BLOCK No frames are available. 357 // NO_INIT Shared memory is corrupt. 358 virtual status_t obtainBuffer(Buffer* buffer); 359 360 // Release (some of) the frames last obtained. 361 // On entry, buffer->mFrameCount should have the number of frames to release, 362 // which must (cumulatively) be <= the number of frames last obtained but not yet released. 363 // It is permitted to call releaseBuffer() multiple times to release the frames in chunks. 364 // buffer->mRaw is ignored, but is normally same pointer returned by last obtainBuffer(). 365 // On exit: 366 // buffer->mFrameCount is zero. 367 // buffer->mRaw is NULL. 368 virtual void releaseBuffer(Buffer* buffer); 369 370protected: 371 size_t mUnreleased; // unreleased frames remaining from most recent obtainBuffer() 372 size_t mAvailToClient; // estimated frames available to client prior to releaseBuffer() 373private: 374 int32_t mFlush; // our copy of cblk->u.mStreaming.mFlush, for streaming output only 375 bool mDeferWake; // whether another releaseBuffer() is expected soon 376}; 377 378// Proxy used by AudioFlinger for servicing AudioTrack 379class AudioTrackServerProxy : public ServerProxy { 380public: 381 AudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 382 size_t frameSize, bool clientInServer = false) 383 : ServerProxy(cblk, buffers, frameCount, frameSize, true /*isOut*/, clientInServer) { } 384protected: 385 virtual ~AudioTrackServerProxy() { } 386 387public: 388 // return value of these methods must be validated by the caller 389 uint32_t getSampleRate() const { return mCblk->mSampleRate; } 390 uint16_t getSendLevel_U4_12() const { return mCblk->mSendLevel; } 391 uint32_t getVolumeLR() const { return mCblk->mVolumeLR; } 392 393 // estimated total number of filled frames available to server to read, 394 // which may include non-contiguous frames 395 virtual size_t framesReady(); 396 397 // Currently AudioFlinger will call framesReady() for a fast track from two threads: 398 // FastMixer thread, and normal mixer thread. This is dangerous, as the proxy is intended 399 // to be called from at most one thread of server, and one thread of client. 400 // As a temporary workaround, this method informs the proxy implementation that it 401 // should avoid doing a state queue poll from within framesReady(). 402 // FIXME Change AudioFlinger to not call framesReady() from normal mixer thread. 403 virtual void framesReadyIsCalledByMultipleThreads() { } 404}; 405 406class StaticAudioTrackServerProxy : public AudioTrackServerProxy { 407public: 408 StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 409 size_t frameSize); 410protected: 411 virtual ~StaticAudioTrackServerProxy() { } 412 413public: 414 virtual size_t framesReady(); 415 virtual void framesReadyIsCalledByMultipleThreads(); 416 virtual status_t obtainBuffer(Buffer* buffer); 417 virtual void releaseBuffer(Buffer* buffer); 418 419private: 420 ssize_t pollPosition(); // poll for state queue update, and return current position 421 StaticAudioTrackSingleStateQueue::Observer mObserver; 422 size_t mPosition; // server's current play position in frames, relative to 0 423 size_t mEnd; // cached value computed from mState, safe for asynchronous read 424 bool mFramesReadyIsCalledByMultipleThreads; 425 StaticAudioTrackState mState; 426}; 427 428// Proxy used by AudioFlinger for servicing AudioRecord 429class AudioRecordServerProxy : public ServerProxy { 430public: 431 AudioRecordServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 432 size_t frameSize) 433 : ServerProxy(cblk, buffers, frameCount, frameSize, false /*isOut*/, 434 false /*clientInServer*/) { } 435protected: 436 virtual ~AudioRecordServerProxy() { } 437}; 438 439// ---------------------------------------------------------------------------- 440 441}; // namespace android 442 443#endif // ANDROID_AUDIO_TRACK_SHARED_H 444