AudioTrackShared.cpp revision 9c64f34be9e56c70eb1aa22ea8e7ce28fe1a2970
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#define LOG_TAG "AudioTrackShared" 18//#define LOG_NDEBUG 0 19 20#include <private/media/AudioTrackShared.h> 21#include <utils/Log.h> 22 23#include <linux/futex.h> 24#include <sys/syscall.h> 25 26namespace android { 27 28// used to clamp a value to size_t. TODO: move to another file. 29template <typename T> 30size_t clampToSize(T x) { 31 return sizeof(T) > sizeof(size_t) && x > (T) SIZE_MAX ? SIZE_MAX : x < 0 ? 0 : (size_t) x; 32} 33 34// incrementSequence is used to determine the next sequence value 35// for the loop and position sequence counters. It should return 36// a value between "other" + 1 and "other" + INT32_MAX, the choice of 37// which needs to be the "least recently used" sequence value for "self". 38// In general, this means (new_self) returned is max(self, other) + 1. 39 40static uint32_t incrementSequence(uint32_t self, uint32_t other) { 41 int32_t diff = (int32_t) self - (int32_t) other; 42 if (diff >= 0 && diff < INT32_MAX) { 43 return self + 1; // we're already ahead of other. 44 } 45 return other + 1; // we're behind, so move just ahead of other. 46} 47 48audio_track_cblk_t::audio_track_cblk_t() 49 : mServer(0), mFutex(0), mMinimum(0) 50 , mVolumeLR(GAIN_MINIFLOAT_PACKED_UNITY), mSampleRate(0), mSendLevel(0) 51 , mBufferSizeInFrames(0) 52 , mFlags(0) 53{ 54 memset(&u, 0, sizeof(u)); 55} 56 57// --------------------------------------------------------------------------- 58 59Proxy::Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 60 bool isOut, bool clientInServer) 61 : mCblk(cblk), mBuffers(buffers), mFrameCount(frameCount), mFrameSize(frameSize), 62 mFrameCountP2(roundup(frameCount)), mIsOut(isOut), mClientInServer(clientInServer), 63 mIsShutdown(false), mUnreleased(0) 64{ 65} 66 67// --------------------------------------------------------------------------- 68 69ClientProxy::ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 70 size_t frameSize, bool isOut, bool clientInServer) 71 : Proxy(cblk, buffers, frameCount, frameSize, isOut, clientInServer) 72 , mEpoch(0) 73 , mTimestampObserver(&cblk->mExtendedTimestampQueue) 74{ 75 setBufferSizeInFrames(frameCount); 76} 77 78const struct timespec ClientProxy::kForever = {INT_MAX /*tv_sec*/, 0 /*tv_nsec*/}; 79const struct timespec ClientProxy::kNonBlocking = {0 /*tv_sec*/, 0 /*tv_nsec*/}; 80 81#define MEASURE_NS 10000000 // attempt to provide accurate timeouts if requested >= MEASURE_NS 82 83// To facilitate quicker recovery from server failure, this value limits the timeout per each futex 84// wait. However it does not protect infinite timeouts. If defined to be zero, there is no limit. 85// FIXME May not be compatible with audio tunneling requirements where timeout should be in the 86// order of minutes. 87#define MAX_SEC 5 88 89uint32_t ClientProxy::setBufferSizeInFrames(uint32_t size) 90{ 91 // The minimum should be greater than zero and less than the size 92 // at which underruns will occur. 93 const uint32_t minimum = 16; // based on AudioMixer::BLOCKSIZE 94 const uint32_t maximum = frameCount(); 95 uint32_t clippedSize = size; 96 if (maximum < minimum) { 97 clippedSize = maximum; 98 } else if (clippedSize < minimum) { 99 clippedSize = minimum; 100 } else if (clippedSize > maximum) { 101 clippedSize = maximum; 102 } 103 // for server to read 104 android_atomic_release_store(clippedSize, (int32_t *)&mCblk->mBufferSizeInFrames); 105 // for client to read 106 mBufferSizeInFrames = clippedSize; 107 return clippedSize; 108} 109 110__attribute__((no_sanitize("integer"))) 111status_t ClientProxy::obtainBuffer(Buffer* buffer, const struct timespec *requested, 112 struct timespec *elapsed) 113{ 114 LOG_ALWAYS_FATAL_IF(buffer == NULL || buffer->mFrameCount == 0, 115 "%s: null or zero frame buffer, buffer:%p", __func__, buffer); 116 struct timespec total; // total elapsed time spent waiting 117 total.tv_sec = 0; 118 total.tv_nsec = 0; 119 bool measure = elapsed != NULL; // whether to measure total elapsed time spent waiting 120 121 status_t status; 122 enum { 123 TIMEOUT_ZERO, // requested == NULL || *requested == 0 124 TIMEOUT_INFINITE, // *requested == infinity 125 TIMEOUT_FINITE, // 0 < *requested < infinity 126 TIMEOUT_CONTINUE, // additional chances after TIMEOUT_FINITE 127 } timeout; 128 if (requested == NULL) { 129 timeout = TIMEOUT_ZERO; 130 } else if (requested->tv_sec == 0 && requested->tv_nsec == 0) { 131 timeout = TIMEOUT_ZERO; 132 } else if (requested->tv_sec == INT_MAX) { 133 timeout = TIMEOUT_INFINITE; 134 } else { 135 timeout = TIMEOUT_FINITE; 136 if (requested->tv_sec > 0 || requested->tv_nsec >= MEASURE_NS) { 137 measure = true; 138 } 139 } 140 struct timespec before; 141 bool beforeIsValid = false; 142 audio_track_cblk_t* cblk = mCblk; 143 bool ignoreInitialPendingInterrupt = true; 144 // check for shared memory corruption 145 if (mIsShutdown) { 146 status = NO_INIT; 147 goto end; 148 } 149 for (;;) { 150 int32_t flags = android_atomic_and(~CBLK_INTERRUPT, &cblk->mFlags); 151 // check for track invalidation by server, or server death detection 152 if (flags & CBLK_INVALID) { 153 ALOGV("Track invalidated"); 154 status = DEAD_OBJECT; 155 goto end; 156 } 157 if (flags & CBLK_DISABLED) { 158 ALOGV("Track disabled"); 159 status = NOT_ENOUGH_DATA; 160 goto end; 161 } 162 // check for obtainBuffer interrupted by client 163 if (!ignoreInitialPendingInterrupt && (flags & CBLK_INTERRUPT)) { 164 ALOGV("obtainBuffer() interrupted by client"); 165 status = -EINTR; 166 goto end; 167 } 168 ignoreInitialPendingInterrupt = false; 169 // compute number of frames available to write (AudioTrack) or read (AudioRecord) 170 int32_t front; 171 int32_t rear; 172 if (mIsOut) { 173 // The barrier following the read of mFront is probably redundant. 174 // We're about to perform a conditional branch based on 'filled', 175 // which will force the processor to observe the read of mFront 176 // prior to allowing data writes starting at mRaw. 177 // However, the processor may support speculative execution, 178 // and be unable to undo speculative writes into shared memory. 179 // The barrier will prevent such speculative execution. 180 front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); 181 rear = cblk->u.mStreaming.mRear; 182 } else { 183 // On the other hand, this barrier is required. 184 rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 185 front = cblk->u.mStreaming.mFront; 186 } 187 // write to rear, read from front 188 ssize_t filled = rear - front; 189 // pipe should not be overfull 190 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 191 if (mIsOut) { 192 ALOGE("Shared memory control block is corrupt (filled=%zd, mFrameCount=%zu); " 193 "shutting down", filled, mFrameCount); 194 mIsShutdown = true; 195 status = NO_INIT; 196 goto end; 197 } 198 // for input, sync up on overrun 199 filled = 0; 200 cblk->u.mStreaming.mFront = rear; 201 (void) android_atomic_or(CBLK_OVERRUN, &cblk->mFlags); 202 } 203 // Don't allow filling pipe beyond the user settable size. 204 // The calculation for avail can go negative if the buffer size 205 // is suddenly dropped below the amount already in the buffer. 206 // So use a signed calculation to prevent a numeric overflow abort. 207 ssize_t adjustableSize = (ssize_t) getBufferSizeInFrames(); 208 ssize_t avail = (mIsOut) ? adjustableSize - filled : filled; 209 if (avail < 0) { 210 avail = 0; 211 } else if (avail > 0) { 212 // 'avail' may be non-contiguous, so return only the first contiguous chunk 213 size_t part1; 214 if (mIsOut) { 215 rear &= mFrameCountP2 - 1; 216 part1 = mFrameCountP2 - rear; 217 } else { 218 front &= mFrameCountP2 - 1; 219 part1 = mFrameCountP2 - front; 220 } 221 if (part1 > (size_t)avail) { 222 part1 = avail; 223 } 224 if (part1 > buffer->mFrameCount) { 225 part1 = buffer->mFrameCount; 226 } 227 buffer->mFrameCount = part1; 228 buffer->mRaw = part1 > 0 ? 229 &((char *) mBuffers)[(mIsOut ? rear : front) * mFrameSize] : NULL; 230 buffer->mNonContig = avail - part1; 231 mUnreleased = part1; 232 status = NO_ERROR; 233 break; 234 } 235 struct timespec remaining; 236 const struct timespec *ts; 237 switch (timeout) { 238 case TIMEOUT_ZERO: 239 status = WOULD_BLOCK; 240 goto end; 241 case TIMEOUT_INFINITE: 242 ts = NULL; 243 break; 244 case TIMEOUT_FINITE: 245 timeout = TIMEOUT_CONTINUE; 246 if (MAX_SEC == 0) { 247 ts = requested; 248 break; 249 } 250 // fall through 251 case TIMEOUT_CONTINUE: 252 // FIXME we do not retry if requested < 10ms? needs documentation on this state machine 253 if (!measure || requested->tv_sec < total.tv_sec || 254 (requested->tv_sec == total.tv_sec && requested->tv_nsec <= total.tv_nsec)) { 255 status = TIMED_OUT; 256 goto end; 257 } 258 remaining.tv_sec = requested->tv_sec - total.tv_sec; 259 if ((remaining.tv_nsec = requested->tv_nsec - total.tv_nsec) < 0) { 260 remaining.tv_nsec += 1000000000; 261 remaining.tv_sec++; 262 } 263 if (0 < MAX_SEC && MAX_SEC < remaining.tv_sec) { 264 remaining.tv_sec = MAX_SEC; 265 remaining.tv_nsec = 0; 266 } 267 ts = &remaining; 268 break; 269 default: 270 LOG_ALWAYS_FATAL("obtainBuffer() timeout=%d", timeout); 271 ts = NULL; 272 break; 273 } 274 int32_t old = android_atomic_and(~CBLK_FUTEX_WAKE, &cblk->mFutex); 275 if (!(old & CBLK_FUTEX_WAKE)) { 276 if (measure && !beforeIsValid) { 277 clock_gettime(CLOCK_MONOTONIC, &before); 278 beforeIsValid = true; 279 } 280 errno = 0; 281 (void) syscall(__NR_futex, &cblk->mFutex, 282 mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts); 283 status_t error = errno; // clock_gettime can affect errno 284 // update total elapsed time spent waiting 285 if (measure) { 286 struct timespec after; 287 clock_gettime(CLOCK_MONOTONIC, &after); 288 total.tv_sec += after.tv_sec - before.tv_sec; 289 long deltaNs = after.tv_nsec - before.tv_nsec; 290 if (deltaNs < 0) { 291 deltaNs += 1000000000; 292 total.tv_sec--; 293 } 294 if ((total.tv_nsec += deltaNs) >= 1000000000) { 295 total.tv_nsec -= 1000000000; 296 total.tv_sec++; 297 } 298 before = after; 299 beforeIsValid = true; 300 } 301 switch (error) { 302 case 0: // normal wakeup by server, or by binderDied() 303 case EWOULDBLOCK: // benign race condition with server 304 case EINTR: // wait was interrupted by signal or other spurious wakeup 305 case ETIMEDOUT: // time-out expired 306 // FIXME these error/non-0 status are being dropped 307 break; 308 default: 309 status = error; 310 ALOGE("%s unexpected error %s", __func__, strerror(status)); 311 goto end; 312 } 313 } 314 } 315 316end: 317 if (status != NO_ERROR) { 318 buffer->mFrameCount = 0; 319 buffer->mRaw = NULL; 320 buffer->mNonContig = 0; 321 mUnreleased = 0; 322 } 323 if (elapsed != NULL) { 324 *elapsed = total; 325 } 326 if (requested == NULL) { 327 requested = &kNonBlocking; 328 } 329 if (measure) { 330 ALOGV("requested %ld.%03ld elapsed %ld.%03ld", 331 requested->tv_sec, requested->tv_nsec / 1000000, 332 total.tv_sec, total.tv_nsec / 1000000); 333 } 334 return status; 335} 336 337__attribute__((no_sanitize("integer"))) 338void ClientProxy::releaseBuffer(Buffer* buffer) 339{ 340 LOG_ALWAYS_FATAL_IF(buffer == NULL); 341 size_t stepCount = buffer->mFrameCount; 342 if (stepCount == 0 || mIsShutdown) { 343 // prevent accidental re-use of buffer 344 buffer->mFrameCount = 0; 345 buffer->mRaw = NULL; 346 buffer->mNonContig = 0; 347 return; 348 } 349 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased && mUnreleased <= mFrameCount), 350 "%s: mUnreleased out of range, " 351 "!(stepCount:%zu <= mUnreleased:%zu <= mFrameCount:%zu), BufferSizeInFrames:%u", 352 __func__, stepCount, mUnreleased, mFrameCount, getBufferSizeInFrames()); 353 mUnreleased -= stepCount; 354 audio_track_cblk_t* cblk = mCblk; 355 // Both of these barriers are required 356 if (mIsOut) { 357 int32_t rear = cblk->u.mStreaming.mRear; 358 android_atomic_release_store(stepCount + rear, &cblk->u.mStreaming.mRear); 359 } else { 360 int32_t front = cblk->u.mStreaming.mFront; 361 android_atomic_release_store(stepCount + front, &cblk->u.mStreaming.mFront); 362 } 363} 364 365void ClientProxy::binderDied() 366{ 367 audio_track_cblk_t* cblk = mCblk; 368 if (!(android_atomic_or(CBLK_INVALID, &cblk->mFlags) & CBLK_INVALID)) { 369 android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 370 // it seems that a FUTEX_WAKE_PRIVATE will not wake a FUTEX_WAIT, even within same process 371 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 372 1); 373 } 374} 375 376void ClientProxy::interrupt() 377{ 378 audio_track_cblk_t* cblk = mCblk; 379 if (!(android_atomic_or(CBLK_INTERRUPT, &cblk->mFlags) & CBLK_INTERRUPT)) { 380 android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 381 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 382 1); 383 } 384} 385 386__attribute__((no_sanitize("integer"))) 387size_t ClientProxy::getMisalignment() 388{ 389 audio_track_cblk_t* cblk = mCblk; 390 return (mFrameCountP2 - (mIsOut ? cblk->u.mStreaming.mRear : cblk->u.mStreaming.mFront)) & 391 (mFrameCountP2 - 1); 392} 393 394// --------------------------------------------------------------------------- 395 396void AudioTrackClientProxy::flush() 397{ 398 // This works for mFrameCountP2 <= 2^30 399 size_t increment = mFrameCountP2 << 1; 400 size_t mask = increment - 1; 401 audio_track_cblk_t* cblk = mCblk; 402 // mFlush is 32 bits concatenated as [ flush_counter ] [ newfront_offset ] 403 // Should newFlush = cblk->u.mStreaming.mRear? Only problem is 404 // if you want to flush twice to the same rear location after a 32 bit wrap. 405 int32_t newFlush = (cblk->u.mStreaming.mRear & mask) | 406 ((cblk->u.mStreaming.mFlush & ~mask) + increment); 407 android_atomic_release_store(newFlush, &cblk->u.mStreaming.mFlush); 408} 409 410bool AudioTrackClientProxy::clearStreamEndDone() { 411 return (android_atomic_and(~CBLK_STREAM_END_DONE, &mCblk->mFlags) & CBLK_STREAM_END_DONE) != 0; 412} 413 414bool AudioTrackClientProxy::getStreamEndDone() const { 415 return (mCblk->mFlags & CBLK_STREAM_END_DONE) != 0; 416} 417 418status_t AudioTrackClientProxy::waitStreamEndDone(const struct timespec *requested) 419{ 420 struct timespec total; // total elapsed time spent waiting 421 total.tv_sec = 0; 422 total.tv_nsec = 0; 423 audio_track_cblk_t* cblk = mCblk; 424 status_t status; 425 enum { 426 TIMEOUT_ZERO, // requested == NULL || *requested == 0 427 TIMEOUT_INFINITE, // *requested == infinity 428 TIMEOUT_FINITE, // 0 < *requested < infinity 429 TIMEOUT_CONTINUE, // additional chances after TIMEOUT_FINITE 430 } timeout; 431 if (requested == NULL) { 432 timeout = TIMEOUT_ZERO; 433 } else if (requested->tv_sec == 0 && requested->tv_nsec == 0) { 434 timeout = TIMEOUT_ZERO; 435 } else if (requested->tv_sec == INT_MAX) { 436 timeout = TIMEOUT_INFINITE; 437 } else { 438 timeout = TIMEOUT_FINITE; 439 } 440 for (;;) { 441 int32_t flags = android_atomic_and(~(CBLK_INTERRUPT|CBLK_STREAM_END_DONE), &cblk->mFlags); 442 // check for track invalidation by server, or server death detection 443 if (flags & CBLK_INVALID) { 444 ALOGV("Track invalidated"); 445 status = DEAD_OBJECT; 446 goto end; 447 } 448 // a track is not supposed to underrun at this stage but consider it done 449 if (flags & (CBLK_STREAM_END_DONE | CBLK_DISABLED)) { 450 ALOGV("stream end received"); 451 status = NO_ERROR; 452 goto end; 453 } 454 // check for obtainBuffer interrupted by client 455 if (flags & CBLK_INTERRUPT) { 456 ALOGV("waitStreamEndDone() interrupted by client"); 457 status = -EINTR; 458 goto end; 459 } 460 struct timespec remaining; 461 const struct timespec *ts; 462 switch (timeout) { 463 case TIMEOUT_ZERO: 464 status = WOULD_BLOCK; 465 goto end; 466 case TIMEOUT_INFINITE: 467 ts = NULL; 468 break; 469 case TIMEOUT_FINITE: 470 timeout = TIMEOUT_CONTINUE; 471 if (MAX_SEC == 0) { 472 ts = requested; 473 break; 474 } 475 // fall through 476 case TIMEOUT_CONTINUE: 477 // FIXME we do not retry if requested < 10ms? needs documentation on this state machine 478 if (requested->tv_sec < total.tv_sec || 479 (requested->tv_sec == total.tv_sec && requested->tv_nsec <= total.tv_nsec)) { 480 status = TIMED_OUT; 481 goto end; 482 } 483 remaining.tv_sec = requested->tv_sec - total.tv_sec; 484 if ((remaining.tv_nsec = requested->tv_nsec - total.tv_nsec) < 0) { 485 remaining.tv_nsec += 1000000000; 486 remaining.tv_sec++; 487 } 488 if (0 < MAX_SEC && MAX_SEC < remaining.tv_sec) { 489 remaining.tv_sec = MAX_SEC; 490 remaining.tv_nsec = 0; 491 } 492 ts = &remaining; 493 break; 494 default: 495 LOG_ALWAYS_FATAL("waitStreamEndDone() timeout=%d", timeout); 496 ts = NULL; 497 break; 498 } 499 int32_t old = android_atomic_and(~CBLK_FUTEX_WAKE, &cblk->mFutex); 500 if (!(old & CBLK_FUTEX_WAKE)) { 501 errno = 0; 502 (void) syscall(__NR_futex, &cblk->mFutex, 503 mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts); 504 switch (errno) { 505 case 0: // normal wakeup by server, or by binderDied() 506 case EWOULDBLOCK: // benign race condition with server 507 case EINTR: // wait was interrupted by signal or other spurious wakeup 508 case ETIMEDOUT: // time-out expired 509 break; 510 default: 511 status = errno; 512 ALOGE("%s unexpected error %s", __func__, strerror(status)); 513 goto end; 514 } 515 } 516 } 517 518end: 519 if (requested == NULL) { 520 requested = &kNonBlocking; 521 } 522 return status; 523} 524 525// --------------------------------------------------------------------------- 526 527StaticAudioTrackClientProxy::StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, 528 size_t frameCount, size_t frameSize) 529 : AudioTrackClientProxy(cblk, buffers, frameCount, frameSize), 530 mMutator(&cblk->u.mStatic.mSingleStateQueue), 531 mPosLoopObserver(&cblk->u.mStatic.mPosLoopQueue) 532{ 533 memset(&mState, 0, sizeof(mState)); 534 memset(&mPosLoop, 0, sizeof(mPosLoop)); 535} 536 537void StaticAudioTrackClientProxy::flush() 538{ 539 LOG_ALWAYS_FATAL("static flush"); 540} 541 542void StaticAudioTrackClientProxy::setLoop(size_t loopStart, size_t loopEnd, int loopCount) 543{ 544 // This can only happen on a 64-bit client 545 if (loopStart > UINT32_MAX || loopEnd > UINT32_MAX) { 546 // FIXME Should return an error status 547 return; 548 } 549 mState.mLoopStart = (uint32_t) loopStart; 550 mState.mLoopEnd = (uint32_t) loopEnd; 551 mState.mLoopCount = loopCount; 552 mState.mLoopSequence = incrementSequence(mState.mLoopSequence, mState.mPositionSequence); 553 // set patch-up variables until the mState is acknowledged by the ServerProxy. 554 // observed buffer position and loop count will freeze until then to give the 555 // illusion of a synchronous change. 556 getBufferPositionAndLoopCount(NULL, NULL); 557 // preserve behavior to restart at mState.mLoopStart if position exceeds mState.mLoopEnd. 558 if (mState.mLoopCount != 0 && mPosLoop.mBufferPosition >= mState.mLoopEnd) { 559 mPosLoop.mBufferPosition = mState.mLoopStart; 560 } 561 mPosLoop.mLoopCount = mState.mLoopCount; 562 (void) mMutator.push(mState); 563} 564 565void StaticAudioTrackClientProxy::setBufferPosition(size_t position) 566{ 567 // This can only happen on a 64-bit client 568 if (position > UINT32_MAX) { 569 // FIXME Should return an error status 570 return; 571 } 572 mState.mPosition = (uint32_t) position; 573 mState.mPositionSequence = incrementSequence(mState.mPositionSequence, mState.mLoopSequence); 574 // set patch-up variables until the mState is acknowledged by the ServerProxy. 575 // observed buffer position and loop count will freeze until then to give the 576 // illusion of a synchronous change. 577 if (mState.mLoopCount > 0) { // only check if loop count is changing 578 getBufferPositionAndLoopCount(NULL, NULL); // get last position 579 } 580 mPosLoop.mBufferPosition = position; 581 if (position >= mState.mLoopEnd) { 582 // no ongoing loop is possible if position is greater than loopEnd. 583 mPosLoop.mLoopCount = 0; 584 } 585 (void) mMutator.push(mState); 586} 587 588void StaticAudioTrackClientProxy::setBufferPositionAndLoop(size_t position, size_t loopStart, 589 size_t loopEnd, int loopCount) 590{ 591 setLoop(loopStart, loopEnd, loopCount); 592 setBufferPosition(position); 593} 594 595size_t StaticAudioTrackClientProxy::getBufferPosition() 596{ 597 getBufferPositionAndLoopCount(NULL, NULL); 598 return mPosLoop.mBufferPosition; 599} 600 601void StaticAudioTrackClientProxy::getBufferPositionAndLoopCount( 602 size_t *position, int *loopCount) 603{ 604 if (mMutator.ack() == StaticAudioTrackSingleStateQueue::SSQ_DONE) { 605 if (mPosLoopObserver.poll(mPosLoop)) { 606 ; // a valid mPosLoop should be available if ackDone is true. 607 } 608 } 609 if (position != NULL) { 610 *position = mPosLoop.mBufferPosition; 611 } 612 if (loopCount != NULL) { 613 *loopCount = mPosLoop.mLoopCount; 614 } 615} 616 617// --------------------------------------------------------------------------- 618 619ServerProxy::ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 620 size_t frameSize, bool isOut, bool clientInServer) 621 : Proxy(cblk, buffers, frameCount, frameSize, isOut, clientInServer), 622 mAvailToClient(0), mFlush(0), mReleased(0), mFlushed(0) 623 , mTimestampMutator(&cblk->mExtendedTimestampQueue) 624{ 625 cblk->mBufferSizeInFrames = frameCount; 626} 627 628__attribute__((no_sanitize("integer"))) 629void ServerProxy::flushBufferIfNeeded() 630{ 631 audio_track_cblk_t* cblk = mCblk; 632 // The acquire_load is not really required. But since the write is a release_store in the 633 // client, using acquire_load here makes it easier for people to maintain the code, 634 // and the logic for communicating ipc variables seems somewhat standard, 635 // and there really isn't much penalty for 4 or 8 byte atomics. 636 int32_t flush = android_atomic_acquire_load(&cblk->u.mStreaming.mFlush); 637 if (flush != mFlush) { 638 ALOGV("ServerProxy::flushBufferIfNeeded() mStreaming.mFlush = 0x%x, mFlush = 0x%0x", 639 flush, mFlush); 640 int32_t rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 641 int32_t front = cblk->u.mStreaming.mFront; 642 643 // effectively obtain then release whatever is in the buffer 644 const size_t overflowBit = mFrameCountP2 << 1; 645 const size_t mask = overflowBit - 1; 646 int32_t newFront = (front & ~mask) | (flush & mask); 647 ssize_t filled = rear - newFront; 648 if (filled >= (ssize_t)overflowBit) { 649 // front and rear offsets span the overflow bit of the p2 mask 650 // so rebasing newFront on the front offset is off by the overflow bit. 651 // adjust newFront to match rear offset. 652 ALOGV("flush wrap: filled %zx >= overflowBit %zx", filled, overflowBit); 653 newFront += overflowBit; 654 filled -= overflowBit; 655 } 656 // Rather than shutting down on a corrupt flush, just treat it as a full flush 657 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 658 ALOGE("mFlush %#x -> %#x, front %#x, rear %#x, mask %#x, newFront %#x, " 659 "filled %zd=%#x", 660 mFlush, flush, front, rear, 661 (unsigned)mask, newFront, filled, (unsigned)filled); 662 newFront = rear; 663 } 664 mFlush = flush; 665 android_atomic_release_store(newFront, &cblk->u.mStreaming.mFront); 666 // There is no danger from a false positive, so err on the side of caution 667 if (true /*front != newFront*/) { 668 int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 669 if (!(old & CBLK_FUTEX_WAKE)) { 670 (void) syscall(__NR_futex, &cblk->mFutex, 671 mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); 672 } 673 } 674 mFlushed += (newFront - front) & mask; 675 } 676} 677 678__attribute__((no_sanitize("integer"))) 679status_t ServerProxy::obtainBuffer(Buffer* buffer, bool ackFlush) 680{ 681 LOG_ALWAYS_FATAL_IF(buffer == NULL || buffer->mFrameCount == 0, 682 "%s: null or zero frame buffer, buffer:%p", __func__, buffer); 683 if (mIsShutdown) { 684 goto no_init; 685 } 686 { 687 audio_track_cblk_t* cblk = mCblk; 688 // compute number of frames available to write (AudioTrack) or read (AudioRecord), 689 // or use previous cached value from framesReady(), with added barrier if it omits. 690 int32_t front; 691 int32_t rear; 692 // See notes on barriers at ClientProxy::obtainBuffer() 693 if (mIsOut) { 694 flushBufferIfNeeded(); // might modify mFront 695 rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 696 front = cblk->u.mStreaming.mFront; 697 } else { 698 front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); 699 rear = cblk->u.mStreaming.mRear; 700 } 701 ssize_t filled = rear - front; 702 // pipe should not already be overfull 703 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 704 ALOGE("Shared memory control block is corrupt (filled=%zd, mFrameCount=%zu); shutting down", 705 filled, mFrameCount); 706 mIsShutdown = true; 707 } 708 if (mIsShutdown) { 709 goto no_init; 710 } 711 // don't allow filling pipe beyond the nominal size 712 size_t availToServer; 713 if (mIsOut) { 714 availToServer = filled; 715 mAvailToClient = mFrameCount - filled; 716 } else { 717 availToServer = mFrameCount - filled; 718 mAvailToClient = filled; 719 } 720 // 'availToServer' may be non-contiguous, so return only the first contiguous chunk 721 size_t part1; 722 if (mIsOut) { 723 front &= mFrameCountP2 - 1; 724 part1 = mFrameCountP2 - front; 725 } else { 726 rear &= mFrameCountP2 - 1; 727 part1 = mFrameCountP2 - rear; 728 } 729 if (part1 > availToServer) { 730 part1 = availToServer; 731 } 732 size_t ask = buffer->mFrameCount; 733 if (part1 > ask) { 734 part1 = ask; 735 } 736 // is assignment redundant in some cases? 737 buffer->mFrameCount = part1; 738 buffer->mRaw = part1 > 0 ? 739 &((char *) mBuffers)[(mIsOut ? front : rear) * mFrameSize] : NULL; 740 buffer->mNonContig = availToServer - part1; 741 // After flush(), allow releaseBuffer() on a previously obtained buffer; 742 // see "Acknowledge any pending flush()" in audioflinger/Tracks.cpp. 743 if (!ackFlush) { 744 mUnreleased = part1; 745 } 746 return part1 > 0 ? NO_ERROR : WOULD_BLOCK; 747 } 748no_init: 749 buffer->mFrameCount = 0; 750 buffer->mRaw = NULL; 751 buffer->mNonContig = 0; 752 mUnreleased = 0; 753 return NO_INIT; 754} 755 756__attribute__((no_sanitize("integer"))) 757void ServerProxy::releaseBuffer(Buffer* buffer) 758{ 759 LOG_ALWAYS_FATAL_IF(buffer == NULL); 760 size_t stepCount = buffer->mFrameCount; 761 if (stepCount == 0 || mIsShutdown) { 762 // prevent accidental re-use of buffer 763 buffer->mFrameCount = 0; 764 buffer->mRaw = NULL; 765 buffer->mNonContig = 0; 766 return; 767 } 768 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased && mUnreleased <= mFrameCount), 769 "%s: mUnreleased out of range, " 770 "!(stepCount:%zu <= mUnreleased:%zu <= mFrameCount:%zu)", 771 __func__, stepCount, mUnreleased, mFrameCount); 772 mUnreleased -= stepCount; 773 audio_track_cblk_t* cblk = mCblk; 774 if (mIsOut) { 775 int32_t front = cblk->u.mStreaming.mFront; 776 android_atomic_release_store(stepCount + front, &cblk->u.mStreaming.mFront); 777 } else { 778 int32_t rear = cblk->u.mStreaming.mRear; 779 android_atomic_release_store(stepCount + rear, &cblk->u.mStreaming.mRear); 780 } 781 782 cblk->mServer += stepCount; 783 mReleased += stepCount; 784 785 size_t half = mFrameCount / 2; 786 if (half == 0) { 787 half = 1; 788 } 789 size_t minimum = (size_t) cblk->mMinimum; 790 if (minimum == 0) { 791 minimum = mIsOut ? half : 1; 792 } else if (minimum > half) { 793 minimum = half; 794 } 795 // FIXME AudioRecord wakeup needs to be optimized; it currently wakes up client every time 796 if (!mIsOut || (mAvailToClient + stepCount >= minimum)) { 797 ALOGV("mAvailToClient=%zu stepCount=%zu minimum=%zu", mAvailToClient, stepCount, minimum); 798 int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 799 if (!(old & CBLK_FUTEX_WAKE)) { 800 (void) syscall(__NR_futex, &cblk->mFutex, 801 mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); 802 } 803 } 804 805 buffer->mFrameCount = 0; 806 buffer->mRaw = NULL; 807 buffer->mNonContig = 0; 808} 809 810// --------------------------------------------------------------------------- 811 812__attribute__((no_sanitize("integer"))) 813size_t AudioTrackServerProxy::framesReady() 814{ 815 LOG_ALWAYS_FATAL_IF(!mIsOut); 816 817 if (mIsShutdown) { 818 return 0; 819 } 820 audio_track_cblk_t* cblk = mCblk; 821 822 int32_t flush = cblk->u.mStreaming.mFlush; 823 if (flush != mFlush) { 824 // FIXME should return an accurate value, but over-estimate is better than under-estimate 825 return mFrameCount; 826 } 827 // the acquire might not be necessary since not doing a subsequent read 828 int32_t rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 829 ssize_t filled = rear - cblk->u.mStreaming.mFront; 830 // pipe should not already be overfull 831 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 832 ALOGE("Shared memory control block is corrupt (filled=%zd, mFrameCount=%zu); shutting down", 833 filled, mFrameCount); 834 mIsShutdown = true; 835 return 0; 836 } 837 // cache this value for later use by obtainBuffer(), with added barrier 838 // and racy if called by normal mixer thread 839 // ignores flush(), so framesReady() may report a larger mFrameCount than obtainBuffer() 840 return filled; 841} 842 843bool AudioTrackServerProxy::setStreamEndDone() { 844 audio_track_cblk_t* cblk = mCblk; 845 bool old = 846 (android_atomic_or(CBLK_STREAM_END_DONE, &cblk->mFlags) & CBLK_STREAM_END_DONE) != 0; 847 if (!old) { 848 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 849 1); 850 } 851 return old; 852} 853 854void AudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount) 855{ 856 audio_track_cblk_t* cblk = mCblk; 857 if (frameCount > 0) { 858 cblk->u.mStreaming.mUnderrunFrames += frameCount; 859 860 if (!mUnderrunning) { // start of underrun? 861 mUnderrunCount++; 862 cblk->u.mStreaming.mUnderrunCount = mUnderrunCount; 863 mUnderrunning = true; 864 ALOGV("tallyUnderrunFrames(%3u) at uf = %u, bump mUnderrunCount = %u", 865 frameCount, cblk->u.mStreaming.mUnderrunFrames, mUnderrunCount); 866 } 867 868 // FIXME also wake futex so that underrun is noticed more quickly 869 (void) android_atomic_or(CBLK_UNDERRUN, &cblk->mFlags); 870 } else { 871 ALOGV_IF(mUnderrunning, 872 "tallyUnderrunFrames(%3u) at uf = %u, underrun finished", 873 frameCount, cblk->u.mStreaming.mUnderrunFrames); 874 mUnderrunning = false; // so we can detect the next edge 875 } 876} 877 878AudioPlaybackRate AudioTrackServerProxy::getPlaybackRate() 879{ // do not call from multiple threads without holding lock 880 mPlaybackRateObserver.poll(mPlaybackRate); 881 return mPlaybackRate; 882} 883 884// --------------------------------------------------------------------------- 885 886StaticAudioTrackServerProxy::StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, 887 size_t frameCount, size_t frameSize) 888 : AudioTrackServerProxy(cblk, buffers, frameCount, frameSize), 889 mObserver(&cblk->u.mStatic.mSingleStateQueue), 890 mPosLoopMutator(&cblk->u.mStatic.mPosLoopQueue), 891 mFramesReadySafe(frameCount), mFramesReady(frameCount), 892 mFramesReadyIsCalledByMultipleThreads(false) 893{ 894 memset(&mState, 0, sizeof(mState)); 895} 896 897void StaticAudioTrackServerProxy::framesReadyIsCalledByMultipleThreads() 898{ 899 mFramesReadyIsCalledByMultipleThreads = true; 900} 901 902size_t StaticAudioTrackServerProxy::framesReady() 903{ 904 // Can't call pollPosition() from multiple threads. 905 if (!mFramesReadyIsCalledByMultipleThreads) { 906 (void) pollPosition(); 907 } 908 return mFramesReadySafe; 909} 910 911status_t StaticAudioTrackServerProxy::updateStateWithLoop( 912 StaticAudioTrackState *localState, const StaticAudioTrackState &update) const 913{ 914 if (localState->mLoopSequence != update.mLoopSequence) { 915 bool valid = false; 916 const size_t loopStart = update.mLoopStart; 917 const size_t loopEnd = update.mLoopEnd; 918 size_t position = localState->mPosition; 919 if (update.mLoopCount == 0) { 920 valid = true; 921 } else if (update.mLoopCount >= -1) { 922 if (loopStart < loopEnd && loopEnd <= mFrameCount && 923 loopEnd - loopStart >= MIN_LOOP) { 924 // If the current position is greater than the end of the loop 925 // we "wrap" to the loop start. This might cause an audible pop. 926 if (position >= loopEnd) { 927 position = loopStart; 928 } 929 valid = true; 930 } 931 } 932 if (!valid || position > mFrameCount) { 933 return NO_INIT; 934 } 935 localState->mPosition = position; 936 localState->mLoopCount = update.mLoopCount; 937 localState->mLoopEnd = loopEnd; 938 localState->mLoopStart = loopStart; 939 localState->mLoopSequence = update.mLoopSequence; 940 } 941 return OK; 942} 943 944status_t StaticAudioTrackServerProxy::updateStateWithPosition( 945 StaticAudioTrackState *localState, const StaticAudioTrackState &update) const 946{ 947 if (localState->mPositionSequence != update.mPositionSequence) { 948 if (update.mPosition > mFrameCount) { 949 return NO_INIT; 950 } else if (localState->mLoopCount != 0 && update.mPosition >= localState->mLoopEnd) { 951 localState->mLoopCount = 0; // disable loop count if position is beyond loop end. 952 } 953 localState->mPosition = update.mPosition; 954 localState->mPositionSequence = update.mPositionSequence; 955 } 956 return OK; 957} 958 959ssize_t StaticAudioTrackServerProxy::pollPosition() 960{ 961 StaticAudioTrackState state; 962 if (mObserver.poll(state)) { 963 StaticAudioTrackState trystate = mState; 964 bool result; 965 const int32_t diffSeq = (int32_t) state.mLoopSequence - (int32_t) state.mPositionSequence; 966 967 if (diffSeq < 0) { 968 result = updateStateWithLoop(&trystate, state) == OK && 969 updateStateWithPosition(&trystate, state) == OK; 970 } else { 971 result = updateStateWithPosition(&trystate, state) == OK && 972 updateStateWithLoop(&trystate, state) == OK; 973 } 974 if (!result) { 975 mObserver.done(); 976 // caution: no update occurs so server state will be inconsistent with client state. 977 ALOGE("%s client pushed an invalid state, shutting down", __func__); 978 mIsShutdown = true; 979 return (ssize_t) NO_INIT; 980 } 981 mState = trystate; 982 if (mState.mLoopCount == -1) { 983 mFramesReady = INT64_MAX; 984 } else if (mState.mLoopCount == 0) { 985 mFramesReady = mFrameCount - mState.mPosition; 986 } else if (mState.mLoopCount > 0) { 987 // TODO: Later consider fixing overflow, but does not seem needed now 988 // as will not overflow if loopStart and loopEnd are Java "ints". 989 mFramesReady = int64_t(mState.mLoopCount) * (mState.mLoopEnd - mState.mLoopStart) 990 + mFrameCount - mState.mPosition; 991 } 992 mFramesReadySafe = clampToSize(mFramesReady); 993 // This may overflow, but client is not supposed to rely on it 994 StaticAudioTrackPosLoop posLoop; 995 996 posLoop.mLoopCount = (int32_t) mState.mLoopCount; 997 posLoop.mBufferPosition = (uint32_t) mState.mPosition; 998 mPosLoopMutator.push(posLoop); 999 mObserver.done(); // safe to read mStatic variables. 1000 } 1001 return (ssize_t) mState.mPosition; 1002} 1003 1004status_t StaticAudioTrackServerProxy::obtainBuffer(Buffer* buffer, bool ackFlush) 1005{ 1006 if (mIsShutdown) { 1007 buffer->mFrameCount = 0; 1008 buffer->mRaw = NULL; 1009 buffer->mNonContig = 0; 1010 mUnreleased = 0; 1011 return NO_INIT; 1012 } 1013 ssize_t positionOrStatus = pollPosition(); 1014 if (positionOrStatus < 0) { 1015 buffer->mFrameCount = 0; 1016 buffer->mRaw = NULL; 1017 buffer->mNonContig = 0; 1018 mUnreleased = 0; 1019 return (status_t) positionOrStatus; 1020 } 1021 size_t position = (size_t) positionOrStatus; 1022 size_t end = mState.mLoopCount != 0 ? mState.mLoopEnd : mFrameCount; 1023 size_t avail; 1024 if (position < end) { 1025 avail = end - position; 1026 size_t wanted = buffer->mFrameCount; 1027 if (avail < wanted) { 1028 buffer->mFrameCount = avail; 1029 } else { 1030 avail = wanted; 1031 } 1032 buffer->mRaw = &((char *) mBuffers)[position * mFrameSize]; 1033 } else { 1034 avail = 0; 1035 buffer->mFrameCount = 0; 1036 buffer->mRaw = NULL; 1037 } 1038 // As mFramesReady is the total remaining frames in the static audio track, 1039 // it is always larger or equal to avail. 1040 LOG_ALWAYS_FATAL_IF(mFramesReady < (int64_t) avail, 1041 "%s: mFramesReady out of range, mFramesReady:%lld < avail:%zu", 1042 __func__, (long long)mFramesReady, avail); 1043 buffer->mNonContig = mFramesReady == INT64_MAX ? SIZE_MAX : clampToSize(mFramesReady - avail); 1044 if (!ackFlush) { 1045 mUnreleased = avail; 1046 } 1047 return NO_ERROR; 1048} 1049 1050void StaticAudioTrackServerProxy::releaseBuffer(Buffer* buffer) 1051{ 1052 size_t stepCount = buffer->mFrameCount; 1053 LOG_ALWAYS_FATAL_IF(!((int64_t) stepCount <= mFramesReady), 1054 "%s: stepCount out of range, " 1055 "!(stepCount:%zu <= mFramesReady:%lld)", 1056 __func__, stepCount, (long long)mFramesReady); 1057 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased), 1058 "%s: stepCount out of range, " 1059 "!(stepCount:%zu <= mUnreleased:%zu)", 1060 __func__, stepCount, mUnreleased); 1061 if (stepCount == 0) { 1062 // prevent accidental re-use of buffer 1063 buffer->mRaw = NULL; 1064 buffer->mNonContig = 0; 1065 return; 1066 } 1067 mUnreleased -= stepCount; 1068 audio_track_cblk_t* cblk = mCblk; 1069 size_t position = mState.mPosition; 1070 size_t newPosition = position + stepCount; 1071 int32_t setFlags = 0; 1072 if (!(position <= newPosition && newPosition <= mFrameCount)) { 1073 ALOGW("%s newPosition %zu outside [%zu, %zu]", __func__, newPosition, position, 1074 mFrameCount); 1075 newPosition = mFrameCount; 1076 } else if (mState.mLoopCount != 0 && newPosition == mState.mLoopEnd) { 1077 newPosition = mState.mLoopStart; 1078 if (mState.mLoopCount == -1 || --mState.mLoopCount != 0) { 1079 setFlags = CBLK_LOOP_CYCLE; 1080 } else { 1081 setFlags = CBLK_LOOP_FINAL; 1082 } 1083 } 1084 if (newPosition == mFrameCount) { 1085 setFlags |= CBLK_BUFFER_END; 1086 } 1087 mState.mPosition = newPosition; 1088 if (mFramesReady != INT64_MAX) { 1089 mFramesReady -= stepCount; 1090 } 1091 mFramesReadySafe = clampToSize(mFramesReady); 1092 1093 cblk->mServer += stepCount; 1094 mReleased += stepCount; 1095 1096 // This may overflow, but client is not supposed to rely on it 1097 StaticAudioTrackPosLoop posLoop; 1098 posLoop.mBufferPosition = mState.mPosition; 1099 posLoop.mLoopCount = mState.mLoopCount; 1100 mPosLoopMutator.push(posLoop); 1101 if (setFlags != 0) { 1102 (void) android_atomic_or(setFlags, &cblk->mFlags); 1103 // this would be a good place to wake a futex 1104 } 1105 1106 buffer->mFrameCount = 0; 1107 buffer->mRaw = NULL; 1108 buffer->mNonContig = 0; 1109} 1110 1111void StaticAudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount) 1112{ 1113 // Unlike AudioTrackServerProxy::tallyUnderrunFrames() used for streaming tracks, 1114 // we don't have a location to count underrun frames. The underrun frame counter 1115 // only exists in AudioTrackSharedStreaming. Fortunately, underruns are not 1116 // possible for static buffer tracks other than at end of buffer, so this is not a loss. 1117 1118 // FIXME also wake futex so that underrun is noticed more quickly 1119 if (frameCount > 0) { 1120 (void) android_atomic_or(CBLK_UNDERRUN, &mCblk->mFlags); 1121 } 1122} 1123 1124// --------------------------------------------------------------------------- 1125 1126} // namespace android 1127