AudioTrackShared.cpp revision f1063e2659cad01ec334a265c31734c63c319cc4
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 = self - 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), mFlags(0) 51{ 52 memset(&u, 0, sizeof(u)); 53} 54 55// --------------------------------------------------------------------------- 56 57Proxy::Proxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, size_t frameSize, 58 bool isOut, bool clientInServer) 59 : mCblk(cblk), mBuffers(buffers), mFrameCount(frameCount), mFrameSize(frameSize), 60 mFrameCountP2(roundup(frameCount)), mIsOut(isOut), mClientInServer(clientInServer), 61 mIsShutdown(false), mUnreleased(0) 62{ 63} 64 65// --------------------------------------------------------------------------- 66 67ClientProxy::ClientProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 68 size_t frameSize, bool isOut, bool clientInServer) 69 : Proxy(cblk, buffers, frameCount, frameSize, isOut, clientInServer), mEpoch(0) 70{ 71} 72 73const struct timespec ClientProxy::kForever = {INT_MAX /*tv_sec*/, 0 /*tv_nsec*/}; 74const struct timespec ClientProxy::kNonBlocking = {0 /*tv_sec*/, 0 /*tv_nsec*/}; 75 76#define MEASURE_NS 10000000 // attempt to provide accurate timeouts if requested >= MEASURE_NS 77 78// To facilitate quicker recovery from server failure, this value limits the timeout per each futex 79// wait. However it does not protect infinite timeouts. If defined to be zero, there is no limit. 80// FIXME May not be compatible with audio tunneling requirements where timeout should be in the 81// order of minutes. 82#define MAX_SEC 5 83 84status_t ClientProxy::obtainBuffer(Buffer* buffer, const struct timespec *requested, 85 struct timespec *elapsed) 86{ 87 LOG_ALWAYS_FATAL_IF(buffer == NULL || buffer->mFrameCount == 0); 88 struct timespec total; // total elapsed time spent waiting 89 total.tv_sec = 0; 90 total.tv_nsec = 0; 91 bool measure = elapsed != NULL; // whether to measure total elapsed time spent waiting 92 93 status_t status; 94 enum { 95 TIMEOUT_ZERO, // requested == NULL || *requested == 0 96 TIMEOUT_INFINITE, // *requested == infinity 97 TIMEOUT_FINITE, // 0 < *requested < infinity 98 TIMEOUT_CONTINUE, // additional chances after TIMEOUT_FINITE 99 } timeout; 100 if (requested == NULL) { 101 timeout = TIMEOUT_ZERO; 102 } else if (requested->tv_sec == 0 && requested->tv_nsec == 0) { 103 timeout = TIMEOUT_ZERO; 104 } else if (requested->tv_sec == INT_MAX) { 105 timeout = TIMEOUT_INFINITE; 106 } else { 107 timeout = TIMEOUT_FINITE; 108 if (requested->tv_sec > 0 || requested->tv_nsec >= MEASURE_NS) { 109 measure = true; 110 } 111 } 112 struct timespec before; 113 bool beforeIsValid = false; 114 audio_track_cblk_t* cblk = mCblk; 115 bool ignoreInitialPendingInterrupt = true; 116 // check for shared memory corruption 117 if (mIsShutdown) { 118 status = NO_INIT; 119 goto end; 120 } 121 for (;;) { 122 int32_t flags = android_atomic_and(~CBLK_INTERRUPT, &cblk->mFlags); 123 // check for track invalidation by server, or server death detection 124 if (flags & CBLK_INVALID) { 125 ALOGV("Track invalidated"); 126 status = DEAD_OBJECT; 127 goto end; 128 } 129 // check for obtainBuffer interrupted by client 130 if (!ignoreInitialPendingInterrupt && (flags & CBLK_INTERRUPT)) { 131 ALOGV("obtainBuffer() interrupted by client"); 132 status = -EINTR; 133 goto end; 134 } 135 ignoreInitialPendingInterrupt = false; 136 // compute number of frames available to write (AudioTrack) or read (AudioRecord) 137 int32_t front; 138 int32_t rear; 139 if (mIsOut) { 140 // The barrier following the read of mFront is probably redundant. 141 // We're about to perform a conditional branch based on 'filled', 142 // which will force the processor to observe the read of mFront 143 // prior to allowing data writes starting at mRaw. 144 // However, the processor may support speculative execution, 145 // and be unable to undo speculative writes into shared memory. 146 // The barrier will prevent such speculative execution. 147 front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); 148 rear = cblk->u.mStreaming.mRear; 149 } else { 150 // On the other hand, this barrier is required. 151 rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 152 front = cblk->u.mStreaming.mFront; 153 } 154 ssize_t filled = rear - front; 155 // pipe should not be overfull 156 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 157 if (mIsOut) { 158 ALOGE("Shared memory control block is corrupt (filled=%zd, mFrameCount=%zu); " 159 "shutting down", filled, mFrameCount); 160 mIsShutdown = true; 161 status = NO_INIT; 162 goto end; 163 } 164 // for input, sync up on overrun 165 filled = 0; 166 cblk->u.mStreaming.mFront = rear; 167 (void) android_atomic_or(CBLK_OVERRUN, &cblk->mFlags); 168 } 169 // don't allow filling pipe beyond the nominal size 170 size_t avail = mIsOut ? mFrameCount - filled : filled; 171 if (avail > 0) { 172 // 'avail' may be non-contiguous, so return only the first contiguous chunk 173 size_t part1; 174 if (mIsOut) { 175 rear &= mFrameCountP2 - 1; 176 part1 = mFrameCountP2 - rear; 177 } else { 178 front &= mFrameCountP2 - 1; 179 part1 = mFrameCountP2 - front; 180 } 181 if (part1 > avail) { 182 part1 = avail; 183 } 184 if (part1 > buffer->mFrameCount) { 185 part1 = buffer->mFrameCount; 186 } 187 buffer->mFrameCount = part1; 188 buffer->mRaw = part1 > 0 ? 189 &((char *) mBuffers)[(mIsOut ? rear : front) * mFrameSize] : NULL; 190 buffer->mNonContig = avail - part1; 191 mUnreleased = part1; 192 status = NO_ERROR; 193 break; 194 } 195 struct timespec remaining; 196 const struct timespec *ts; 197 switch (timeout) { 198 case TIMEOUT_ZERO: 199 status = WOULD_BLOCK; 200 goto end; 201 case TIMEOUT_INFINITE: 202 ts = NULL; 203 break; 204 case TIMEOUT_FINITE: 205 timeout = TIMEOUT_CONTINUE; 206 if (MAX_SEC == 0) { 207 ts = requested; 208 break; 209 } 210 // fall through 211 case TIMEOUT_CONTINUE: 212 // FIXME we do not retry if requested < 10ms? needs documentation on this state machine 213 if (!measure || requested->tv_sec < total.tv_sec || 214 (requested->tv_sec == total.tv_sec && requested->tv_nsec <= total.tv_nsec)) { 215 status = TIMED_OUT; 216 goto end; 217 } 218 remaining.tv_sec = requested->tv_sec - total.tv_sec; 219 if ((remaining.tv_nsec = requested->tv_nsec - total.tv_nsec) < 0) { 220 remaining.tv_nsec += 1000000000; 221 remaining.tv_sec++; 222 } 223 if (0 < MAX_SEC && MAX_SEC < remaining.tv_sec) { 224 remaining.tv_sec = MAX_SEC; 225 remaining.tv_nsec = 0; 226 } 227 ts = &remaining; 228 break; 229 default: 230 LOG_ALWAYS_FATAL("obtainBuffer() timeout=%d", timeout); 231 ts = NULL; 232 break; 233 } 234 int32_t old = android_atomic_and(~CBLK_FUTEX_WAKE, &cblk->mFutex); 235 if (!(old & CBLK_FUTEX_WAKE)) { 236 if (measure && !beforeIsValid) { 237 clock_gettime(CLOCK_MONOTONIC, &before); 238 beforeIsValid = true; 239 } 240 errno = 0; 241 (void) syscall(__NR_futex, &cblk->mFutex, 242 mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts); 243 // update total elapsed time spent waiting 244 if (measure) { 245 struct timespec after; 246 clock_gettime(CLOCK_MONOTONIC, &after); 247 total.tv_sec += after.tv_sec - before.tv_sec; 248 long deltaNs = after.tv_nsec - before.tv_nsec; 249 if (deltaNs < 0) { 250 deltaNs += 1000000000; 251 total.tv_sec--; 252 } 253 if ((total.tv_nsec += deltaNs) >= 1000000000) { 254 total.tv_nsec -= 1000000000; 255 total.tv_sec++; 256 } 257 before = after; 258 beforeIsValid = true; 259 } 260 switch (errno) { 261 case 0: // normal wakeup by server, or by binderDied() 262 case EWOULDBLOCK: // benign race condition with server 263 case EINTR: // wait was interrupted by signal or other spurious wakeup 264 case ETIMEDOUT: // time-out expired 265 // FIXME these error/non-0 status are being dropped 266 break; 267 default: 268 status = errno; 269 ALOGE("%s unexpected error %s", __func__, strerror(status)); 270 goto end; 271 } 272 } 273 } 274 275end: 276 if (status != NO_ERROR) { 277 buffer->mFrameCount = 0; 278 buffer->mRaw = NULL; 279 buffer->mNonContig = 0; 280 mUnreleased = 0; 281 } 282 if (elapsed != NULL) { 283 *elapsed = total; 284 } 285 if (requested == NULL) { 286 requested = &kNonBlocking; 287 } 288 if (measure) { 289 ALOGV("requested %ld.%03ld elapsed %ld.%03ld", 290 requested->tv_sec, requested->tv_nsec / 1000000, 291 total.tv_sec, total.tv_nsec / 1000000); 292 } 293 return status; 294} 295 296void ClientProxy::releaseBuffer(Buffer* buffer) 297{ 298 LOG_ALWAYS_FATAL_IF(buffer == NULL); 299 size_t stepCount = buffer->mFrameCount; 300 if (stepCount == 0 || mIsShutdown) { 301 // prevent accidental re-use of buffer 302 buffer->mFrameCount = 0; 303 buffer->mRaw = NULL; 304 buffer->mNonContig = 0; 305 return; 306 } 307 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased && mUnreleased <= mFrameCount)); 308 mUnreleased -= stepCount; 309 audio_track_cblk_t* cblk = mCblk; 310 // Both of these barriers are required 311 if (mIsOut) { 312 int32_t rear = cblk->u.mStreaming.mRear; 313 android_atomic_release_store(stepCount + rear, &cblk->u.mStreaming.mRear); 314 } else { 315 int32_t front = cblk->u.mStreaming.mFront; 316 android_atomic_release_store(stepCount + front, &cblk->u.mStreaming.mFront); 317 } 318} 319 320void ClientProxy::binderDied() 321{ 322 audio_track_cblk_t* cblk = mCblk; 323 if (!(android_atomic_or(CBLK_INVALID, &cblk->mFlags) & CBLK_INVALID)) { 324 android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 325 // it seems that a FUTEX_WAKE_PRIVATE will not wake a FUTEX_WAIT, even within same process 326 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 327 1); 328 } 329} 330 331void ClientProxy::interrupt() 332{ 333 audio_track_cblk_t* cblk = mCblk; 334 if (!(android_atomic_or(CBLK_INTERRUPT, &cblk->mFlags) & CBLK_INTERRUPT)) { 335 android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 336 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 337 1); 338 } 339} 340 341size_t ClientProxy::getMisalignment() 342{ 343 audio_track_cblk_t* cblk = mCblk; 344 return (mFrameCountP2 - (mIsOut ? cblk->u.mStreaming.mRear : cblk->u.mStreaming.mFront)) & 345 (mFrameCountP2 - 1); 346} 347 348size_t ClientProxy::getFramesFilled() { 349 audio_track_cblk_t* cblk = mCblk; 350 int32_t front; 351 int32_t rear; 352 353 if (mIsOut) { 354 front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); 355 rear = cblk->u.mStreaming.mRear; 356 } else { 357 rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 358 front = cblk->u.mStreaming.mFront; 359 } 360 ssize_t filled = rear - front; 361 // pipe should not be overfull 362 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 363 ALOGE("Shared memory control block is corrupt (filled=%zd); shutting down", filled); 364 return 0; 365 } 366 return (size_t)filled; 367} 368 369// --------------------------------------------------------------------------- 370 371void AudioTrackClientProxy::flush() 372{ 373 // This works for mFrameCountP2 <= 2^30 374 size_t increment = mFrameCountP2 << 1; 375 size_t mask = increment - 1; 376 audio_track_cblk_t* cblk = mCblk; 377 int32_t newFlush = (cblk->u.mStreaming.mRear & mask) | 378 ((cblk->u.mStreaming.mFlush & ~mask) + increment); 379 android_atomic_release_store(newFlush, &cblk->u.mStreaming.mFlush); 380} 381 382bool AudioTrackClientProxy::clearStreamEndDone() { 383 return (android_atomic_and(~CBLK_STREAM_END_DONE, &mCblk->mFlags) & CBLK_STREAM_END_DONE) != 0; 384} 385 386bool AudioTrackClientProxy::getStreamEndDone() const { 387 return (mCblk->mFlags & CBLK_STREAM_END_DONE) != 0; 388} 389 390status_t AudioTrackClientProxy::waitStreamEndDone(const struct timespec *requested) 391{ 392 struct timespec total; // total elapsed time spent waiting 393 total.tv_sec = 0; 394 total.tv_nsec = 0; 395 audio_track_cblk_t* cblk = mCblk; 396 status_t status; 397 enum { 398 TIMEOUT_ZERO, // requested == NULL || *requested == 0 399 TIMEOUT_INFINITE, // *requested == infinity 400 TIMEOUT_FINITE, // 0 < *requested < infinity 401 TIMEOUT_CONTINUE, // additional chances after TIMEOUT_FINITE 402 } timeout; 403 if (requested == NULL) { 404 timeout = TIMEOUT_ZERO; 405 } else if (requested->tv_sec == 0 && requested->tv_nsec == 0) { 406 timeout = TIMEOUT_ZERO; 407 } else if (requested->tv_sec == INT_MAX) { 408 timeout = TIMEOUT_INFINITE; 409 } else { 410 timeout = TIMEOUT_FINITE; 411 } 412 for (;;) { 413 int32_t flags = android_atomic_and(~(CBLK_INTERRUPT|CBLK_STREAM_END_DONE), &cblk->mFlags); 414 // check for track invalidation by server, or server death detection 415 if (flags & CBLK_INVALID) { 416 ALOGV("Track invalidated"); 417 status = DEAD_OBJECT; 418 goto end; 419 } 420 if (flags & CBLK_STREAM_END_DONE) { 421 ALOGV("stream end received"); 422 status = NO_ERROR; 423 goto end; 424 } 425 // check for obtainBuffer interrupted by client 426 if (flags & CBLK_INTERRUPT) { 427 ALOGV("waitStreamEndDone() interrupted by client"); 428 status = -EINTR; 429 goto end; 430 } 431 struct timespec remaining; 432 const struct timespec *ts; 433 switch (timeout) { 434 case TIMEOUT_ZERO: 435 status = WOULD_BLOCK; 436 goto end; 437 case TIMEOUT_INFINITE: 438 ts = NULL; 439 break; 440 case TIMEOUT_FINITE: 441 timeout = TIMEOUT_CONTINUE; 442 if (MAX_SEC == 0) { 443 ts = requested; 444 break; 445 } 446 // fall through 447 case TIMEOUT_CONTINUE: 448 // FIXME we do not retry if requested < 10ms? needs documentation on this state machine 449 if (requested->tv_sec < total.tv_sec || 450 (requested->tv_sec == total.tv_sec && requested->tv_nsec <= total.tv_nsec)) { 451 status = TIMED_OUT; 452 goto end; 453 } 454 remaining.tv_sec = requested->tv_sec - total.tv_sec; 455 if ((remaining.tv_nsec = requested->tv_nsec - total.tv_nsec) < 0) { 456 remaining.tv_nsec += 1000000000; 457 remaining.tv_sec++; 458 } 459 if (0 < MAX_SEC && MAX_SEC < remaining.tv_sec) { 460 remaining.tv_sec = MAX_SEC; 461 remaining.tv_nsec = 0; 462 } 463 ts = &remaining; 464 break; 465 default: 466 LOG_ALWAYS_FATAL("waitStreamEndDone() timeout=%d", timeout); 467 ts = NULL; 468 break; 469 } 470 int32_t old = android_atomic_and(~CBLK_FUTEX_WAKE, &cblk->mFutex); 471 if (!(old & CBLK_FUTEX_WAKE)) { 472 errno = 0; 473 (void) syscall(__NR_futex, &cblk->mFutex, 474 mClientInServer ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT, old & ~CBLK_FUTEX_WAKE, ts); 475 switch (errno) { 476 case 0: // normal wakeup by server, or by binderDied() 477 case EWOULDBLOCK: // benign race condition with server 478 case EINTR: // wait was interrupted by signal or other spurious wakeup 479 case ETIMEDOUT: // time-out expired 480 break; 481 default: 482 status = errno; 483 ALOGE("%s unexpected error %s", __func__, strerror(status)); 484 goto end; 485 } 486 } 487 } 488 489end: 490 if (requested == NULL) { 491 requested = &kNonBlocking; 492 } 493 return status; 494} 495 496// --------------------------------------------------------------------------- 497 498StaticAudioTrackClientProxy::StaticAudioTrackClientProxy(audio_track_cblk_t* cblk, void *buffers, 499 size_t frameCount, size_t frameSize) 500 : AudioTrackClientProxy(cblk, buffers, frameCount, frameSize), 501 mMutator(&cblk->u.mStatic.mSingleStateQueue), 502 mPosLoopObserver(&cblk->u.mStatic.mPosLoopQueue) 503{ 504 memset(&mState, 0, sizeof(mState)); 505 memset(&mPosLoop, 0, sizeof(mPosLoop)); 506} 507 508void StaticAudioTrackClientProxy::flush() 509{ 510 LOG_ALWAYS_FATAL("static flush"); 511} 512 513void StaticAudioTrackClientProxy::setLoop(size_t loopStart, size_t loopEnd, int loopCount) 514{ 515 // This can only happen on a 64-bit client 516 if (loopStart > UINT32_MAX || loopEnd > UINT32_MAX) { 517 // FIXME Should return an error status 518 return; 519 } 520 mState.mLoopStart = (uint32_t) loopStart; 521 mState.mLoopEnd = (uint32_t) loopEnd; 522 mState.mLoopCount = loopCount; 523 mState.mLoopSequence = incrementSequence(mState.mLoopSequence, mState.mPositionSequence); 524 // set patch-up variables until the mState is acknowledged by the ServerProxy. 525 // observed buffer position and loop count will freeze until then to give the 526 // illusion of a synchronous change. 527 getBufferPositionAndLoopCount(NULL, NULL); 528 // preserve behavior to restart at mState.mLoopStart if position exceeds mState.mLoopEnd. 529 if (mState.mLoopCount != 0 && mPosLoop.mBufferPosition >= mState.mLoopEnd) { 530 mPosLoop.mBufferPosition = mState.mLoopStart; 531 } 532 mPosLoop.mLoopCount = mState.mLoopCount; 533 (void) mMutator.push(mState); 534} 535 536void StaticAudioTrackClientProxy::setBufferPosition(size_t position) 537{ 538 // This can only happen on a 64-bit client 539 if (position > UINT32_MAX) { 540 // FIXME Should return an error status 541 return; 542 } 543 mState.mPosition = (uint32_t) position; 544 mState.mPositionSequence = incrementSequence(mState.mPositionSequence, mState.mLoopSequence); 545 // set patch-up variables until the mState is acknowledged by the ServerProxy. 546 // observed buffer position and loop count will freeze until then to give the 547 // illusion of a synchronous change. 548 if (mState.mLoopCount > 0) { // only check if loop count is changing 549 getBufferPositionAndLoopCount(NULL, NULL); // get last position 550 } 551 mPosLoop.mBufferPosition = position; 552 if (position >= mState.mLoopEnd) { 553 // no ongoing loop is possible if position is greater than loopEnd. 554 mPosLoop.mLoopCount = 0; 555 } 556 (void) mMutator.push(mState); 557} 558 559void StaticAudioTrackClientProxy::setBufferPositionAndLoop(size_t position, size_t loopStart, 560 size_t loopEnd, int loopCount) 561{ 562 setLoop(loopStart, loopEnd, loopCount); 563 setBufferPosition(position); 564} 565 566size_t StaticAudioTrackClientProxy::getBufferPosition() 567{ 568 getBufferPositionAndLoopCount(NULL, NULL); 569 return mPosLoop.mBufferPosition; 570} 571 572void StaticAudioTrackClientProxy::getBufferPositionAndLoopCount( 573 size_t *position, int *loopCount) 574{ 575 if (mMutator.ack() == StaticAudioTrackSingleStateQueue::SSQ_DONE) { 576 if (mPosLoopObserver.poll(mPosLoop)) { 577 ; // a valid mPosLoop should be available if ackDone is true. 578 } 579 } 580 if (position != NULL) { 581 *position = mPosLoop.mBufferPosition; 582 } 583 if (loopCount != NULL) { 584 *loopCount = mPosLoop.mLoopCount; 585 } 586} 587 588// --------------------------------------------------------------------------- 589 590ServerProxy::ServerProxy(audio_track_cblk_t* cblk, void *buffers, size_t frameCount, 591 size_t frameSize, bool isOut, bool clientInServer) 592 : Proxy(cblk, buffers, frameCount, frameSize, isOut, clientInServer), 593 mAvailToClient(0), mFlush(0) 594{ 595} 596 597status_t ServerProxy::obtainBuffer(Buffer* buffer, bool ackFlush) 598{ 599 LOG_ALWAYS_FATAL_IF(buffer == NULL || buffer->mFrameCount == 0); 600 if (mIsShutdown) { 601 goto no_init; 602 } 603 { 604 audio_track_cblk_t* cblk = mCblk; 605 // compute number of frames available to write (AudioTrack) or read (AudioRecord), 606 // or use previous cached value from framesReady(), with added barrier if it omits. 607 int32_t front; 608 int32_t rear; 609 // See notes on barriers at ClientProxy::obtainBuffer() 610 if (mIsOut) { 611 int32_t flush = cblk->u.mStreaming.mFlush; 612 rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 613 front = cblk->u.mStreaming.mFront; 614 if (flush != mFlush) { 615 // effectively obtain then release whatever is in the buffer 616 size_t mask = (mFrameCountP2 << 1) - 1; 617 int32_t newFront = (front & ~mask) | (flush & mask); 618 ssize_t filled = rear - newFront; 619 // Rather than shutting down on a corrupt flush, just treat it as a full flush 620 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 621 ALOGE("mFlush %#x -> %#x, front %#x, rear %#x, mask %#x, newFront %#x, " 622 "filled %zd=%#x", 623 mFlush, flush, front, rear, 624 (unsigned)mask, newFront, filled, (unsigned)filled); 625 newFront = rear; 626 } 627 mFlush = flush; 628 android_atomic_release_store(newFront, &cblk->u.mStreaming.mFront); 629 // There is no danger from a false positive, so err on the side of caution 630 if (true /*front != newFront*/) { 631 int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 632 if (!(old & CBLK_FUTEX_WAKE)) { 633 (void) syscall(__NR_futex, &cblk->mFutex, 634 mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); 635 } 636 } 637 front = newFront; 638 } 639 } else { 640 front = android_atomic_acquire_load(&cblk->u.mStreaming.mFront); 641 rear = cblk->u.mStreaming.mRear; 642 } 643 ssize_t filled = rear - front; 644 // pipe should not already be overfull 645 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 646 ALOGE("Shared memory control block is corrupt (filled=%zd); shutting down", filled); 647 mIsShutdown = true; 648 } 649 if (mIsShutdown) { 650 goto no_init; 651 } 652 // don't allow filling pipe beyond the nominal size 653 size_t availToServer; 654 if (mIsOut) { 655 availToServer = filled; 656 mAvailToClient = mFrameCount - filled; 657 } else { 658 availToServer = mFrameCount - filled; 659 mAvailToClient = filled; 660 } 661 // 'availToServer' may be non-contiguous, so return only the first contiguous chunk 662 size_t part1; 663 if (mIsOut) { 664 front &= mFrameCountP2 - 1; 665 part1 = mFrameCountP2 - front; 666 } else { 667 rear &= mFrameCountP2 - 1; 668 part1 = mFrameCountP2 - rear; 669 } 670 if (part1 > availToServer) { 671 part1 = availToServer; 672 } 673 size_t ask = buffer->mFrameCount; 674 if (part1 > ask) { 675 part1 = ask; 676 } 677 // is assignment redundant in some cases? 678 buffer->mFrameCount = part1; 679 buffer->mRaw = part1 > 0 ? 680 &((char *) mBuffers)[(mIsOut ? front : rear) * mFrameSize] : NULL; 681 buffer->mNonContig = availToServer - part1; 682 // After flush(), allow releaseBuffer() on a previously obtained buffer; 683 // see "Acknowledge any pending flush()" in audioflinger/Tracks.cpp. 684 if (!ackFlush) { 685 mUnreleased = part1; 686 } 687 return part1 > 0 ? NO_ERROR : WOULD_BLOCK; 688 } 689no_init: 690 buffer->mFrameCount = 0; 691 buffer->mRaw = NULL; 692 buffer->mNonContig = 0; 693 mUnreleased = 0; 694 return NO_INIT; 695} 696 697void ServerProxy::releaseBuffer(Buffer* buffer) 698{ 699 LOG_ALWAYS_FATAL_IF(buffer == NULL); 700 size_t stepCount = buffer->mFrameCount; 701 if (stepCount == 0 || mIsShutdown) { 702 // prevent accidental re-use of buffer 703 buffer->mFrameCount = 0; 704 buffer->mRaw = NULL; 705 buffer->mNonContig = 0; 706 return; 707 } 708 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased && mUnreleased <= mFrameCount)); 709 mUnreleased -= stepCount; 710 audio_track_cblk_t* cblk = mCblk; 711 if (mIsOut) { 712 int32_t front = cblk->u.mStreaming.mFront; 713 android_atomic_release_store(stepCount + front, &cblk->u.mStreaming.mFront); 714 } else { 715 int32_t rear = cblk->u.mStreaming.mRear; 716 android_atomic_release_store(stepCount + rear, &cblk->u.mStreaming.mRear); 717 } 718 719 cblk->mServer += stepCount; 720 721 size_t half = mFrameCount / 2; 722 if (half == 0) { 723 half = 1; 724 } 725 size_t minimum = (size_t) cblk->mMinimum; 726 if (minimum == 0) { 727 minimum = mIsOut ? half : 1; 728 } else if (minimum > half) { 729 minimum = half; 730 } 731 // FIXME AudioRecord wakeup needs to be optimized; it currently wakes up client every time 732 if (!mIsOut || (mAvailToClient + stepCount >= minimum)) { 733 ALOGV("mAvailToClient=%zu stepCount=%zu minimum=%zu", mAvailToClient, stepCount, minimum); 734 int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex); 735 if (!(old & CBLK_FUTEX_WAKE)) { 736 (void) syscall(__NR_futex, &cblk->mFutex, 737 mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1); 738 } 739 } 740 741 buffer->mFrameCount = 0; 742 buffer->mRaw = NULL; 743 buffer->mNonContig = 0; 744} 745 746// --------------------------------------------------------------------------- 747 748size_t AudioTrackServerProxy::framesReady() 749{ 750 LOG_ALWAYS_FATAL_IF(!mIsOut); 751 752 if (mIsShutdown) { 753 return 0; 754 } 755 audio_track_cblk_t* cblk = mCblk; 756 757 int32_t flush = cblk->u.mStreaming.mFlush; 758 if (flush != mFlush) { 759 // FIXME should return an accurate value, but over-estimate is better than under-estimate 760 return mFrameCount; 761 } 762 // the acquire might not be necessary since not doing a subsequent read 763 int32_t rear = android_atomic_acquire_load(&cblk->u.mStreaming.mRear); 764 ssize_t filled = rear - cblk->u.mStreaming.mFront; 765 // pipe should not already be overfull 766 if (!(0 <= filled && (size_t) filled <= mFrameCount)) { 767 ALOGE("Shared memory control block is corrupt (filled=%zd); shutting down", filled); 768 mIsShutdown = true; 769 return 0; 770 } 771 // cache this value for later use by obtainBuffer(), with added barrier 772 // and racy if called by normal mixer thread 773 // ignores flush(), so framesReady() may report a larger mFrameCount than obtainBuffer() 774 return filled; 775} 776 777bool AudioTrackServerProxy::setStreamEndDone() { 778 audio_track_cblk_t* cblk = mCblk; 779 bool old = 780 (android_atomic_or(CBLK_STREAM_END_DONE, &cblk->mFlags) & CBLK_STREAM_END_DONE) != 0; 781 if (!old) { 782 (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 783 1); 784 } 785 return old; 786} 787 788void AudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount) 789{ 790 audio_track_cblk_t* cblk = mCblk; 791 cblk->u.mStreaming.mUnderrunFrames += frameCount; 792 793 // FIXME also wake futex so that underrun is noticed more quickly 794 (void) android_atomic_or(CBLK_UNDERRUN, &cblk->mFlags); 795} 796 797void AudioTrackServerProxy::getPlaybackRate(float *speed, float *pitch) 798{ // do not call from multiple threads without holding lock 799 AudioTrackPlaybackRate playbackRate; 800 if (mPlaybackRateObserver.poll(playbackRate)) { 801 mPlaybackRate = playbackRate; 802 } 803 *speed = mPlaybackRate.mSpeed; 804 *pitch = mPlaybackRate.mPitch; 805} 806 807// --------------------------------------------------------------------------- 808 809StaticAudioTrackServerProxy::StaticAudioTrackServerProxy(audio_track_cblk_t* cblk, void *buffers, 810 size_t frameCount, size_t frameSize) 811 : AudioTrackServerProxy(cblk, buffers, frameCount, frameSize), 812 mObserver(&cblk->u.mStatic.mSingleStateQueue), 813 mPosLoopMutator(&cblk->u.mStatic.mPosLoopQueue), 814 mFramesReadySafe(frameCount), mFramesReady(frameCount), 815 mFramesReadyIsCalledByMultipleThreads(false) 816{ 817 memset(&mState, 0, sizeof(mState)); 818} 819 820void StaticAudioTrackServerProxy::framesReadyIsCalledByMultipleThreads() 821{ 822 mFramesReadyIsCalledByMultipleThreads = true; 823} 824 825size_t StaticAudioTrackServerProxy::framesReady() 826{ 827 // Can't call pollPosition() from multiple threads. 828 if (!mFramesReadyIsCalledByMultipleThreads) { 829 (void) pollPosition(); 830 } 831 return mFramesReadySafe; 832} 833 834status_t StaticAudioTrackServerProxy::updateStateWithLoop( 835 StaticAudioTrackState *localState, const StaticAudioTrackState &update) const 836{ 837 if (localState->mLoopSequence != update.mLoopSequence) { 838 bool valid = false; 839 const size_t loopStart = update.mLoopStart; 840 const size_t loopEnd = update.mLoopEnd; 841 size_t position = localState->mPosition; 842 if (update.mLoopCount == 0) { 843 valid = true; 844 } else if (update.mLoopCount >= -1) { 845 if (loopStart < loopEnd && loopEnd <= mFrameCount && 846 loopEnd - loopStart >= MIN_LOOP) { 847 // If the current position is greater than the end of the loop 848 // we "wrap" to the loop start. This might cause an audible pop. 849 if (position >= loopEnd) { 850 position = loopStart; 851 } 852 valid = true; 853 } 854 } 855 if (!valid || position > mFrameCount) { 856 return NO_INIT; 857 } 858 localState->mPosition = position; 859 localState->mLoopCount = update.mLoopCount; 860 localState->mLoopEnd = loopEnd; 861 localState->mLoopStart = loopStart; 862 localState->mLoopSequence = update.mLoopSequence; 863 } 864 return OK; 865} 866 867status_t StaticAudioTrackServerProxy::updateStateWithPosition( 868 StaticAudioTrackState *localState, const StaticAudioTrackState &update) const 869{ 870 if (localState->mPositionSequence != update.mPositionSequence) { 871 if (update.mPosition > mFrameCount) { 872 return NO_INIT; 873 } else if (localState->mLoopCount != 0 && update.mPosition >= localState->mLoopEnd) { 874 localState->mLoopCount = 0; // disable loop count if position is beyond loop end. 875 } 876 localState->mPosition = update.mPosition; 877 localState->mPositionSequence = update.mPositionSequence; 878 } 879 return OK; 880} 881 882ssize_t StaticAudioTrackServerProxy::pollPosition() 883{ 884 StaticAudioTrackState state; 885 if (mObserver.poll(state)) { 886 StaticAudioTrackState trystate = mState; 887 bool result; 888 const int32_t diffSeq = state.mLoopSequence - state.mPositionSequence; 889 890 if (diffSeq < 0) { 891 result = updateStateWithLoop(&trystate, state) == OK && 892 updateStateWithPosition(&trystate, state) == OK; 893 } else { 894 result = updateStateWithPosition(&trystate, state) == OK && 895 updateStateWithLoop(&trystate, state) == OK; 896 } 897 if (!result) { 898 mObserver.done(); 899 // caution: no update occurs so server state will be inconsistent with client state. 900 ALOGE("%s client pushed an invalid state, shutting down", __func__); 901 mIsShutdown = true; 902 return (ssize_t) NO_INIT; 903 } 904 mState = trystate; 905 if (mState.mLoopCount == -1) { 906 mFramesReady = INT64_MAX; 907 } else if (mState.mLoopCount == 0) { 908 mFramesReady = mFrameCount - mState.mPosition; 909 } else if (mState.mLoopCount > 0) { 910 // TODO: Later consider fixing overflow, but does not seem needed now 911 // as will not overflow if loopStart and loopEnd are Java "ints". 912 mFramesReady = int64_t(mState.mLoopCount) * (mState.mLoopEnd - mState.mLoopStart) 913 + mFrameCount - mState.mPosition; 914 } 915 mFramesReadySafe = clampToSize(mFramesReady); 916 // This may overflow, but client is not supposed to rely on it 917 StaticAudioTrackPosLoop posLoop; 918 919 posLoop.mLoopCount = (int32_t) mState.mLoopCount; 920 posLoop.mBufferPosition = (uint32_t) mState.mPosition; 921 mPosLoopMutator.push(posLoop); 922 mObserver.done(); // safe to read mStatic variables. 923 } 924 return (ssize_t) mState.mPosition; 925} 926 927status_t StaticAudioTrackServerProxy::obtainBuffer(Buffer* buffer, bool ackFlush __unused) 928{ 929 if (mIsShutdown) { 930 buffer->mFrameCount = 0; 931 buffer->mRaw = NULL; 932 buffer->mNonContig = 0; 933 mUnreleased = 0; 934 return NO_INIT; 935 } 936 ssize_t positionOrStatus = pollPosition(); 937 if (positionOrStatus < 0) { 938 buffer->mFrameCount = 0; 939 buffer->mRaw = NULL; 940 buffer->mNonContig = 0; 941 mUnreleased = 0; 942 return (status_t) positionOrStatus; 943 } 944 size_t position = (size_t) positionOrStatus; 945 size_t end = mState.mLoopCount != 0 ? mState.mLoopEnd : mFrameCount; 946 size_t avail; 947 if (position < end) { 948 avail = end - position; 949 size_t wanted = buffer->mFrameCount; 950 if (avail < wanted) { 951 buffer->mFrameCount = avail; 952 } else { 953 avail = wanted; 954 } 955 buffer->mRaw = &((char *) mBuffers)[position * mFrameSize]; 956 } else { 957 avail = 0; 958 buffer->mFrameCount = 0; 959 buffer->mRaw = NULL; 960 } 961 // As mFramesReady is the total remaining frames in the static audio track, 962 // it is always larger or equal to avail. 963 LOG_ALWAYS_FATAL_IF(mFramesReady < (int64_t) avail); 964 buffer->mNonContig = mFramesReady == INT64_MAX ? SIZE_MAX : clampToSize(mFramesReady - avail); 965 mUnreleased = avail; 966 return NO_ERROR; 967} 968 969void StaticAudioTrackServerProxy::releaseBuffer(Buffer* buffer) 970{ 971 size_t stepCount = buffer->mFrameCount; 972 LOG_ALWAYS_FATAL_IF(!((int64_t) stepCount <= mFramesReady)); 973 LOG_ALWAYS_FATAL_IF(!(stepCount <= mUnreleased)); 974 if (stepCount == 0) { 975 // prevent accidental re-use of buffer 976 buffer->mRaw = NULL; 977 buffer->mNonContig = 0; 978 return; 979 } 980 mUnreleased -= stepCount; 981 audio_track_cblk_t* cblk = mCblk; 982 size_t position = mState.mPosition; 983 size_t newPosition = position + stepCount; 984 int32_t setFlags = 0; 985 if (!(position <= newPosition && newPosition <= mFrameCount)) { 986 ALOGW("%s newPosition %zu outside [%zu, %zu]", __func__, newPosition, position, 987 mFrameCount); 988 newPosition = mFrameCount; 989 } else if (mState.mLoopCount != 0 && newPosition == mState.mLoopEnd) { 990 newPosition = mState.mLoopStart; 991 if (mState.mLoopCount == -1 || --mState.mLoopCount != 0) { 992 setFlags = CBLK_LOOP_CYCLE; 993 } else { 994 setFlags = CBLK_LOOP_FINAL; 995 } 996 } 997 if (newPosition == mFrameCount) { 998 setFlags |= CBLK_BUFFER_END; 999 } 1000 mState.mPosition = newPosition; 1001 if (mFramesReady != INT64_MAX) { 1002 mFramesReady -= stepCount; 1003 } 1004 mFramesReadySafe = clampToSize(mFramesReady); 1005 1006 cblk->mServer += stepCount; 1007 // This may overflow, but client is not supposed to rely on it 1008 StaticAudioTrackPosLoop posLoop; 1009 posLoop.mBufferPosition = mState.mPosition; 1010 posLoop.mLoopCount = mState.mLoopCount; 1011 mPosLoopMutator.push(posLoop); 1012 if (setFlags != 0) { 1013 (void) android_atomic_or(setFlags, &cblk->mFlags); 1014 // this would be a good place to wake a futex 1015 } 1016 1017 buffer->mFrameCount = 0; 1018 buffer->mRaw = NULL; 1019 buffer->mNonContig = 0; 1020} 1021 1022void StaticAudioTrackServerProxy::tallyUnderrunFrames(uint32_t frameCount __unused) 1023{ 1024 // Unlike AudioTrackServerProxy::tallyUnderrunFrames() used for streaming tracks, 1025 // we don't have a location to count underrun frames. The underrun frame counter 1026 // only exists in AudioTrackSharedStreaming. Fortunately, underruns are not 1027 // possible for static buffer tracks other than at end of buffer, so this is not a loss. 1028 1029 // FIXME also wake futex so that underrun is noticed more quickly 1030 (void) android_atomic_or(CBLK_UNDERRUN, &mCblk->mFlags); 1031} 1032 1033// --------------------------------------------------------------------------- 1034 1035} // namespace android 1036