FastMixer.cpp revision 3d1982595cb9cb0856841f1f57fbdb4581189e99
1/* 2 * Copyright (C) 2012 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// <IMPORTANT_WARNING> 18// Design rules for threadLoop() are given in the comments at section "Fast mixer thread" of 19// StateQueue.h. In particular, avoid library and system calls except at well-known points. 20// The design rules are only for threadLoop(), and don't apply to FastMixerDumpState methods. 21// </IMPORTANT_WARNING> 22 23#define LOG_TAG "FastMixer" 24//#define LOG_NDEBUG 0 25 26#define ATRACE_TAG ATRACE_TAG_AUDIO 27 28#include <sys/atomics.h> 29#include <time.h> 30#include <utils/Log.h> 31#include <utils/Trace.h> 32#include <system/audio.h> 33#ifdef FAST_MIXER_STATISTICS 34#include <cpustats/CentralTendencyStatistics.h> 35#ifdef CPU_FREQUENCY_STATISTICS 36#include <cpustats/ThreadCpuUsage.h> 37#endif 38#endif 39#include "AudioMixer.h" 40#include "FastMixer.h" 41 42#define FAST_HOT_IDLE_NS 1000000L // 1 ms: time to sleep while hot idling 43#define FAST_DEFAULT_NS 999999999L // ~1 sec: default time to sleep 44#define MIN_WARMUP_CYCLES 2 // minimum number of loop cycles to wait for warmup 45#define MAX_WARMUP_CYCLES 10 // maximum number of loop cycles to wait for warmup 46 47namespace android { 48 49// Fast mixer thread 50bool FastMixer::threadLoop() 51{ 52 static const FastMixerState initial; 53 const FastMixerState *previous = &initial, *current = &initial; 54 FastMixerState preIdle; // copy of state before we went into idle 55 struct timespec oldTs = {0, 0}; 56 bool oldTsValid = false; 57 long slopNs = 0; // accumulated time we've woken up too early (> 0) or too late (< 0) 58 long sleepNs = -1; // -1: busy wait, 0: sched_yield, > 0: nanosleep 59 int fastTrackNames[FastMixerState::kMaxFastTracks]; // handles used by mixer to identify tracks 60 int generations[FastMixerState::kMaxFastTracks]; // last observed mFastTracks[i].mGeneration 61 unsigned i; 62 for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) { 63 fastTrackNames[i] = -1; 64 generations[i] = 0; 65 } 66 NBAIO_Sink *outputSink = NULL; 67 int outputSinkGen = 0; 68 AudioMixer* mixer = NULL; 69 short *mixBuffer = NULL; 70 enum {UNDEFINED, MIXED, ZEROED} mixBufferState = UNDEFINED; 71 NBAIO_Format format = Format_Invalid; 72 unsigned sampleRate = 0; 73 int fastTracksGen = 0; 74 long periodNs = 0; // expected period; the time required to render one mix buffer 75 long underrunNs = 0; // underrun likely when write cycle is greater than this value 76 long overrunNs = 0; // overrun likely when write cycle is less than this value 77 long forceNs = 0; // if overrun detected, force the write cycle to take this much time 78 long warmupNs = 0; // warmup complete when write cycle is greater than to this value 79 FastMixerDumpState dummyDumpState, *dumpState = &dummyDumpState; 80 bool ignoreNextOverrun = true; // used to ignore initial overrun and first after an underrun 81#ifdef FAST_MIXER_STATISTICS 82 struct timespec oldLoad = {0, 0}; // previous value of clock_gettime(CLOCK_THREAD_CPUTIME_ID) 83 bool oldLoadValid = false; // whether oldLoad is valid 84 uint32_t bounds = 0; 85 bool full = false; // whether we have collected at least kSamplingN samples 86#ifdef CPU_FREQUENCY_STATISTICS 87 ThreadCpuUsage tcu; // for reading the current CPU clock frequency in kHz 88#endif 89#endif 90 unsigned coldGen = 0; // last observed mColdGen 91 bool isWarm = false; // true means ready to mix, false means wait for warmup before mixing 92 struct timespec measuredWarmupTs = {0, 0}; // how long did it take for warmup to complete 93 uint32_t warmupCycles = 0; // counter of number of loop cycles required to warmup 94 NBAIO_Sink* teeSink = NULL; // if non-NULL, then duplicate write() to this non-blocking sink 95 NBLog::Writer dummyLogWriter, *logWriter = &dummyLogWriter; 96 97 for (;;) { 98 99 // either nanosleep, sched_yield, or busy wait 100 if (sleepNs >= 0) { 101 if (sleepNs > 0) { 102 ALOG_ASSERT(sleepNs < 1000000000); 103 const struct timespec req = {0, sleepNs}; 104 nanosleep(&req, NULL); 105 } else { 106 sched_yield(); 107 } 108 } 109 // default to long sleep for next cycle 110 sleepNs = FAST_DEFAULT_NS; 111 112 // poll for state change 113 const FastMixerState *next = mSQ.poll(); 114 if (next == NULL) { 115 // continue to use the default initial state until a real state is available 116 ALOG_ASSERT(current == &initial && previous == &initial); 117 next = current; 118 } 119 120 FastMixerState::Command command = next->mCommand; 121 if (next != current) { 122 123 // As soon as possible of learning of a new dump area, start using it 124 dumpState = next->mDumpState != NULL ? next->mDumpState : &dummyDumpState; 125 teeSink = next->mTeeSink; 126 logWriter = next->mNBLogWriter != NULL ? next->mNBLogWriter : &dummyLogWriter; 127 if (mixer != NULL) { 128 mixer->setLog(logWriter); 129 } 130 131 // We want to always have a valid reference to the previous (non-idle) state. 132 // However, the state queue only guarantees access to current and previous states. 133 // So when there is a transition from a non-idle state into an idle state, we make a 134 // copy of the last known non-idle state so it is still available on return from idle. 135 // The possible transitions are: 136 // non-idle -> non-idle update previous from current in-place 137 // non-idle -> idle update previous from copy of current 138 // idle -> idle don't update previous 139 // idle -> non-idle don't update previous 140 if (!(current->mCommand & FastMixerState::IDLE)) { 141 if (command & FastMixerState::IDLE) { 142 preIdle = *current; 143 current = &preIdle; 144 oldTsValid = false; 145 oldLoadValid = false; 146 ignoreNextOverrun = true; 147 } 148 previous = current; 149 } 150 current = next; 151 } 152#if !LOG_NDEBUG 153 next = NULL; // not referenced again 154#endif 155 156 dumpState->mCommand = command; 157 158 switch (command) { 159 case FastMixerState::INITIAL: 160 case FastMixerState::HOT_IDLE: 161 sleepNs = FAST_HOT_IDLE_NS; 162 continue; 163 case FastMixerState::COLD_IDLE: 164 // only perform a cold idle command once 165 // FIXME consider checking previous state and only perform if previous != COLD_IDLE 166 if (current->mColdGen != coldGen) { 167 int32_t *coldFutexAddr = current->mColdFutexAddr; 168 ALOG_ASSERT(coldFutexAddr != NULL); 169 int32_t old = android_atomic_dec(coldFutexAddr); 170 if (old <= 0) { 171 __futex_syscall4(coldFutexAddr, FUTEX_WAIT_PRIVATE, old - 1, NULL); 172 } 173 int policy = sched_getscheduler(0); 174 if (!(policy == SCHED_FIFO || policy == SCHED_RR)) { 175 ALOGE("did not receive expected priority boost"); 176 } 177 // This may be overly conservative; there could be times that the normal mixer 178 // requests such a brief cold idle that it doesn't require resetting this flag. 179 isWarm = false; 180 measuredWarmupTs.tv_sec = 0; 181 measuredWarmupTs.tv_nsec = 0; 182 warmupCycles = 0; 183 sleepNs = -1; 184 coldGen = current->mColdGen; 185 bounds = 0; 186 full = false; 187 oldTsValid = !clock_gettime(CLOCK_MONOTONIC, &oldTs); 188 } else { 189 sleepNs = FAST_HOT_IDLE_NS; 190 } 191 continue; 192 case FastMixerState::EXIT: 193 delete mixer; 194 delete[] mixBuffer; 195 return false; 196 case FastMixerState::MIX: 197 case FastMixerState::WRITE: 198 case FastMixerState::MIX_WRITE: 199 break; 200 default: 201 LOG_FATAL("bad command %d", command); 202 } 203 204 // there is a non-idle state available to us; did the state change? 205 size_t frameCount = current->mFrameCount; 206 if (current != previous) { 207 208 // handle state change here, but since we want to diff the state, 209 // we're prepared for previous == &initial the first time through 210 unsigned previousTrackMask; 211 212 // check for change in output HAL configuration 213 NBAIO_Format previousFormat = format; 214 if (current->mOutputSinkGen != outputSinkGen) { 215 outputSink = current->mOutputSink; 216 outputSinkGen = current->mOutputSinkGen; 217 if (outputSink == NULL) { 218 format = Format_Invalid; 219 sampleRate = 0; 220 } else { 221 format = outputSink->format(); 222 sampleRate = Format_sampleRate(format); 223 ALOG_ASSERT(Format_channelCount(format) == 2); 224 } 225 dumpState->mSampleRate = sampleRate; 226 } 227 228 if ((format != previousFormat) || (frameCount != previous->mFrameCount)) { 229 // FIXME to avoid priority inversion, don't delete here 230 delete mixer; 231 mixer = NULL; 232 delete[] mixBuffer; 233 mixBuffer = NULL; 234 if (frameCount > 0 && sampleRate > 0) { 235 // FIXME new may block for unbounded time at internal mutex of the heap 236 // implementation; it would be better to have normal mixer allocate for us 237 // to avoid blocking here and to prevent possible priority inversion 238 mixer = new AudioMixer(frameCount, sampleRate, FastMixerState::kMaxFastTracks); 239 mixBuffer = new short[frameCount * 2]; 240 periodNs = (frameCount * 1000000000LL) / sampleRate; // 1.00 241 underrunNs = (frameCount * 1750000000LL) / sampleRate; // 1.75 242 overrunNs = (frameCount * 500000000LL) / sampleRate; // 0.50 243 forceNs = (frameCount * 950000000LL) / sampleRate; // 0.95 244 warmupNs = (frameCount * 500000000LL) / sampleRate; // 0.50 245 } else { 246 periodNs = 0; 247 underrunNs = 0; 248 overrunNs = 0; 249 forceNs = 0; 250 warmupNs = 0; 251 } 252 mixBufferState = UNDEFINED; 253#if !LOG_NDEBUG 254 for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) { 255 fastTrackNames[i] = -1; 256 } 257#endif 258 // we need to reconfigure all active tracks 259 previousTrackMask = 0; 260 fastTracksGen = current->mFastTracksGen - 1; 261 dumpState->mFrameCount = frameCount; 262 } else { 263 previousTrackMask = previous->mTrackMask; 264 } 265 266 // check for change in active track set 267 unsigned currentTrackMask = current->mTrackMask; 268 dumpState->mTrackMask = currentTrackMask; 269 if (current->mFastTracksGen != fastTracksGen) { 270 ALOG_ASSERT(mixBuffer != NULL); 271 int name; 272 273 // process removed tracks first to avoid running out of track names 274 unsigned removedTracks = previousTrackMask & ~currentTrackMask; 275 while (removedTracks != 0) { 276 i = __builtin_ctz(removedTracks); 277 removedTracks &= ~(1 << i); 278 const FastTrack* fastTrack = ¤t->mFastTracks[i]; 279 ALOG_ASSERT(fastTrack->mBufferProvider == NULL); 280 if (mixer != NULL) { 281 name = fastTrackNames[i]; 282 ALOG_ASSERT(name >= 0); 283 mixer->deleteTrackName(name); 284 } 285#if !LOG_NDEBUG 286 fastTrackNames[i] = -1; 287#endif 288 // don't reset track dump state, since other side is ignoring it 289 generations[i] = fastTrack->mGeneration; 290 } 291 292 // now process added tracks 293 unsigned addedTracks = currentTrackMask & ~previousTrackMask; 294 while (addedTracks != 0) { 295 i = __builtin_ctz(addedTracks); 296 addedTracks &= ~(1 << i); 297 const FastTrack* fastTrack = ¤t->mFastTracks[i]; 298 AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider; 299 ALOG_ASSERT(bufferProvider != NULL && fastTrackNames[i] == -1); 300 if (mixer != NULL) { 301 // calling getTrackName with default channel mask and a random invalid 302 // sessionId (no effects here) 303 name = mixer->getTrackName(AUDIO_CHANNEL_OUT_STEREO, -555); 304 ALOG_ASSERT(name >= 0); 305 fastTrackNames[i] = name; 306 mixer->setBufferProvider(name, bufferProvider); 307 mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::MAIN_BUFFER, 308 (void *) mixBuffer); 309 // newly allocated track names default to full scale volume 310 if (fastTrack->mSampleRate != 0 && fastTrack->mSampleRate != sampleRate) { 311 mixer->setParameter(name, AudioMixer::RESAMPLE, 312 AudioMixer::SAMPLE_RATE, (void*) fastTrack->mSampleRate); 313 } 314 mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK, 315 (void *) fastTrack->mChannelMask); 316 mixer->enable(name); 317 } 318 generations[i] = fastTrack->mGeneration; 319 } 320 321 // finally process (potentially) modified tracks; these use the same slot 322 // but may have a different buffer provider or volume provider 323 unsigned modifiedTracks = currentTrackMask & previousTrackMask; 324 while (modifiedTracks != 0) { 325 i = __builtin_ctz(modifiedTracks); 326 modifiedTracks &= ~(1 << i); 327 const FastTrack* fastTrack = ¤t->mFastTracks[i]; 328 if (fastTrack->mGeneration != generations[i]) { 329 // this track was actually modified 330 AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider; 331 ALOG_ASSERT(bufferProvider != NULL); 332 if (mixer != NULL) { 333 name = fastTrackNames[i]; 334 ALOG_ASSERT(name >= 0); 335 mixer->setBufferProvider(name, bufferProvider); 336 if (fastTrack->mVolumeProvider == NULL) { 337 mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0, 338 (void *)0x1000); 339 mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1, 340 (void *)0x1000); 341 } 342 if (fastTrack->mSampleRate != 0 && 343 fastTrack->mSampleRate != sampleRate) { 344 mixer->setParameter(name, AudioMixer::RESAMPLE, 345 AudioMixer::SAMPLE_RATE, (void*) fastTrack->mSampleRate); 346 } else { 347 mixer->setParameter(name, AudioMixer::RESAMPLE, 348 AudioMixer::REMOVE, NULL); 349 } 350 mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK, 351 (void *) fastTrack->mChannelMask); 352 // already enabled 353 } 354 generations[i] = fastTrack->mGeneration; 355 } 356 } 357 358 fastTracksGen = current->mFastTracksGen; 359 360 dumpState->mNumTracks = popcount(currentTrackMask); 361 } 362 363#if 1 // FIXME shouldn't need this 364 // only process state change once 365 previous = current; 366#endif 367 } 368 369 // do work using current state here 370 if ((command & FastMixerState::MIX) && (mixer != NULL) && isWarm) { 371 ALOG_ASSERT(mixBuffer != NULL); 372 // for each track, update volume and check for underrun 373 unsigned currentTrackMask = current->mTrackMask; 374 while (currentTrackMask != 0) { 375 i = __builtin_ctz(currentTrackMask); 376 currentTrackMask &= ~(1 << i); 377 const FastTrack* fastTrack = ¤t->mFastTracks[i]; 378 int name = fastTrackNames[i]; 379 ALOG_ASSERT(name >= 0); 380 if (fastTrack->mVolumeProvider != NULL) { 381 uint32_t vlr = fastTrack->mVolumeProvider->getVolumeLR(); 382 mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0, 383 (void *)(vlr & 0xFFFF)); 384 mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1, 385 (void *)(vlr >> 16)); 386 } 387 // FIXME The current implementation of framesReady() for fast tracks 388 // takes a tryLock, which can block 389 // up to 1 ms. If enough active tracks all blocked in sequence, this would result 390 // in the overall fast mix cycle being delayed. Should use a non-blocking FIFO. 391 size_t framesReady = fastTrack->mBufferProvider->framesReady(); 392 if (ATRACE_ENABLED()) { 393 // I wish we had formatted trace names 394 char traceName[16]; 395 strcpy(traceName, "fRdy"); 396 traceName[4] = i + (i < 10 ? '0' : 'A' - 10); 397 traceName[5] = '\0'; 398 ATRACE_INT(traceName, framesReady); 399 } 400 FastTrackDump *ftDump = &dumpState->mTracks[i]; 401 FastTrackUnderruns underruns = ftDump->mUnderruns; 402 if (framesReady < frameCount) { 403 if (framesReady == 0) { 404 underruns.mBitFields.mEmpty++; 405 underruns.mBitFields.mMostRecent = UNDERRUN_EMPTY; 406 mixer->disable(name); 407 } else { 408 // allow mixing partial buffer 409 underruns.mBitFields.mPartial++; 410 underruns.mBitFields.mMostRecent = UNDERRUN_PARTIAL; 411 mixer->enable(name); 412 } 413 } else { 414 underruns.mBitFields.mFull++; 415 underruns.mBitFields.mMostRecent = UNDERRUN_FULL; 416 mixer->enable(name); 417 } 418 ftDump->mUnderruns = underruns; 419 ftDump->mFramesReady = framesReady; 420 } 421 422 int64_t pts; 423 if (outputSink == NULL || (OK != outputSink->getNextWriteTimestamp(&pts))) 424 pts = AudioBufferProvider::kInvalidPTS; 425 426 // process() is CPU-bound 427 mixer->process(pts); 428 mixBufferState = MIXED; 429 } else if (mixBufferState == MIXED) { 430 mixBufferState = UNDEFINED; 431 } 432 bool attemptedWrite = false; 433 //bool didFullWrite = false; // dumpsys could display a count of partial writes 434 if ((command & FastMixerState::WRITE) && (outputSink != NULL) && (mixBuffer != NULL)) { 435 if (mixBufferState == UNDEFINED) { 436 memset(mixBuffer, 0, frameCount * 2 * sizeof(short)); 437 mixBufferState = ZEROED; 438 } 439 if (teeSink != NULL) { 440 (void) teeSink->write(mixBuffer, frameCount); 441 } 442 // FIXME write() is non-blocking and lock-free for a properly implemented NBAIO sink, 443 // but this code should be modified to handle both non-blocking and blocking sinks 444 dumpState->mWriteSequence++; 445 ATRACE_BEGIN("write"); 446 ssize_t framesWritten = outputSink->write(mixBuffer, frameCount); 447 ATRACE_END(); 448 dumpState->mWriteSequence++; 449 if (framesWritten >= 0) { 450 ALOG_ASSERT((size_t) framesWritten <= frameCount); 451 dumpState->mFramesWritten += framesWritten; 452 //if ((size_t) framesWritten == frameCount) { 453 // didFullWrite = true; 454 //} 455 } else { 456 dumpState->mWriteErrors++; 457 } 458 attemptedWrite = true; 459 // FIXME count # of writes blocked excessively, CPU usage, etc. for dump 460 } 461 462 // To be exactly periodic, compute the next sleep time based on current time. 463 // This code doesn't have long-term stability when the sink is non-blocking. 464 // FIXME To avoid drift, use the local audio clock or watch the sink's fill status. 465 struct timespec newTs; 466 int rc = clock_gettime(CLOCK_MONOTONIC, &newTs); 467 if (rc == 0) { 468 //logWriter->logTimestamp(newTs); 469 if (oldTsValid) { 470 time_t sec = newTs.tv_sec - oldTs.tv_sec; 471 long nsec = newTs.tv_nsec - oldTs.tv_nsec; 472 ALOGE_IF(sec < 0 || (sec == 0 && nsec < 0), 473 "clock_gettime(CLOCK_MONOTONIC) failed: was %ld.%09ld but now %ld.%09ld", 474 oldTs.tv_sec, oldTs.tv_nsec, newTs.tv_sec, newTs.tv_nsec); 475 if (nsec < 0) { 476 --sec; 477 nsec += 1000000000; 478 } 479 // To avoid an initial underrun on fast tracks after exiting standby, 480 // do not start pulling data from tracks and mixing until warmup is complete. 481 // Warmup is considered complete after the earlier of: 482 // MIN_WARMUP_CYCLES write() attempts and last one blocks for at least warmupNs 483 // MAX_WARMUP_CYCLES write() attempts. 484 // This is overly conservative, but to get better accuracy requires a new HAL API. 485 if (!isWarm && attemptedWrite) { 486 measuredWarmupTs.tv_sec += sec; 487 measuredWarmupTs.tv_nsec += nsec; 488 if (measuredWarmupTs.tv_nsec >= 1000000000) { 489 measuredWarmupTs.tv_sec++; 490 measuredWarmupTs.tv_nsec -= 1000000000; 491 } 492 ++warmupCycles; 493 if ((nsec > warmupNs && warmupCycles >= MIN_WARMUP_CYCLES) || 494 (warmupCycles >= MAX_WARMUP_CYCLES)) { 495 isWarm = true; 496 dumpState->mMeasuredWarmupTs = measuredWarmupTs; 497 dumpState->mWarmupCycles = warmupCycles; 498 } 499 } 500 sleepNs = -1; 501 if (isWarm) { 502 if (sec > 0 || nsec > underrunNs) { 503 ATRACE_NAME("underrun"); 504 // FIXME only log occasionally 505 ALOGV("underrun: time since last cycle %d.%03ld sec", 506 (int) sec, nsec / 1000000L); 507 dumpState->mUnderruns++; 508 ignoreNextOverrun = true; 509 } else if (nsec < overrunNs) { 510 if (ignoreNextOverrun) { 511 ignoreNextOverrun = false; 512 } else { 513 // FIXME only log occasionally 514 ALOGV("overrun: time since last cycle %d.%03ld sec", 515 (int) sec, nsec / 1000000L); 516 dumpState->mOverruns++; 517 } 518 // This forces a minimum cycle time. It: 519 // - compensates for an audio HAL with jitter due to sample rate conversion 520 // - works with a variable buffer depth audio HAL that never pulls at a 521 // rate < than overrunNs per buffer. 522 // - recovers from overrun immediately after underrun 523 // It doesn't work with a non-blocking audio HAL. 524 sleepNs = forceNs - nsec; 525 } else { 526 ignoreNextOverrun = false; 527 } 528 } 529#ifdef FAST_MIXER_STATISTICS 530 if (isWarm) { 531 // advance the FIFO queue bounds 532 size_t i = bounds & (FastMixerDumpState::kSamplingN - 1); 533 bounds = (bounds & 0xFFFF0000) | ((bounds + 1) & 0xFFFF); 534 if (full) { 535 bounds += 0x10000; 536 } else if (!(bounds & (FastMixerDumpState::kSamplingN - 1))) { 537 full = true; 538 } 539 // compute the delta value of clock_gettime(CLOCK_MONOTONIC) 540 uint32_t monotonicNs = nsec; 541 if (sec > 0 && sec < 4) { 542 monotonicNs += sec * 1000000000; 543 } 544 // compute raw CPU load = delta value of clock_gettime(CLOCK_THREAD_CPUTIME_ID) 545 uint32_t loadNs = 0; 546 struct timespec newLoad; 547 rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &newLoad); 548 if (rc == 0) { 549 if (oldLoadValid) { 550 sec = newLoad.tv_sec - oldLoad.tv_sec; 551 nsec = newLoad.tv_nsec - oldLoad.tv_nsec; 552 if (nsec < 0) { 553 --sec; 554 nsec += 1000000000; 555 } 556 loadNs = nsec; 557 if (sec > 0 && sec < 4) { 558 loadNs += sec * 1000000000; 559 } 560 } else { 561 // first time through the loop 562 oldLoadValid = true; 563 } 564 oldLoad = newLoad; 565 } 566#ifdef CPU_FREQUENCY_STATISTICS 567 // get the absolute value of CPU clock frequency in kHz 568 int cpuNum = sched_getcpu(); 569 uint32_t kHz = tcu.getCpukHz(cpuNum); 570 kHz = (kHz << 4) | (cpuNum & 0xF); 571#endif 572 // save values in FIFO queues for dumpsys 573 // these stores #1, #2, #3 are not atomic with respect to each other, 574 // or with respect to store #4 below 575 dumpState->mMonotonicNs[i] = monotonicNs; 576 dumpState->mLoadNs[i] = loadNs; 577#ifdef CPU_FREQUENCY_STATISTICS 578 dumpState->mCpukHz[i] = kHz; 579#endif 580 // this store #4 is not atomic with respect to stores #1, #2, #3 above, but 581 // the newest open & oldest closed halves are atomic with respect to each other 582 dumpState->mBounds = bounds; 583 ATRACE_INT("cycle_ms", monotonicNs / 1000000); 584 ATRACE_INT("load_us", loadNs / 1000); 585 } 586#endif 587 } else { 588 // first time through the loop 589 oldTsValid = true; 590 sleepNs = periodNs; 591 ignoreNextOverrun = true; 592 } 593 oldTs = newTs; 594 } else { 595 // monotonic clock is broken 596 oldTsValid = false; 597 sleepNs = periodNs; 598 } 599 600 601 } // for (;;) 602 603 // never return 'true'; Thread::_threadLoop() locks mutex which can result in priority inversion 604} 605 606FastMixerDumpState::FastMixerDumpState() : 607 mCommand(FastMixerState::INITIAL), mWriteSequence(0), mFramesWritten(0), 608 mNumTracks(0), mWriteErrors(0), mUnderruns(0), mOverruns(0), 609 mSampleRate(0), mFrameCount(0), /* mMeasuredWarmupTs({0, 0}), */ mWarmupCycles(0), 610 mTrackMask(0) 611#ifdef FAST_MIXER_STATISTICS 612 , mBounds(0) 613#endif 614{ 615 mMeasuredWarmupTs.tv_sec = 0; 616 mMeasuredWarmupTs.tv_nsec = 0; 617 // sample arrays aren't accessed atomically with respect to the bounds, 618 // so clearing reduces chance for dumpsys to read random uninitialized samples 619 memset(&mMonotonicNs, 0, sizeof(mMonotonicNs)); 620 memset(&mLoadNs, 0, sizeof(mLoadNs)); 621#ifdef CPU_FREQUENCY_STATISTICS 622 memset(&mCpukHz, 0, sizeof(mCpukHz)); 623#endif 624} 625 626FastMixerDumpState::~FastMixerDumpState() 627{ 628} 629 630// helper function called by qsort() 631static int compare_uint32_t(const void *pa, const void *pb) 632{ 633 uint32_t a = *(const uint32_t *)pa; 634 uint32_t b = *(const uint32_t *)pb; 635 if (a < b) { 636 return -1; 637 } else if (a > b) { 638 return 1; 639 } else { 640 return 0; 641 } 642} 643 644void FastMixerDumpState::dump(int fd) 645{ 646 if (mCommand == FastMixerState::INITIAL) { 647 fdprintf(fd, "FastMixer not initialized\n"); 648 return; 649 } 650#define COMMAND_MAX 32 651 char string[COMMAND_MAX]; 652 switch (mCommand) { 653 case FastMixerState::INITIAL: 654 strcpy(string, "INITIAL"); 655 break; 656 case FastMixerState::HOT_IDLE: 657 strcpy(string, "HOT_IDLE"); 658 break; 659 case FastMixerState::COLD_IDLE: 660 strcpy(string, "COLD_IDLE"); 661 break; 662 case FastMixerState::EXIT: 663 strcpy(string, "EXIT"); 664 break; 665 case FastMixerState::MIX: 666 strcpy(string, "MIX"); 667 break; 668 case FastMixerState::WRITE: 669 strcpy(string, "WRITE"); 670 break; 671 case FastMixerState::MIX_WRITE: 672 strcpy(string, "MIX_WRITE"); 673 break; 674 default: 675 snprintf(string, COMMAND_MAX, "%d", mCommand); 676 break; 677 } 678 double measuredWarmupMs = (mMeasuredWarmupTs.tv_sec * 1000.0) + 679 (mMeasuredWarmupTs.tv_nsec / 1000000.0); 680 double mixPeriodSec = (double) mFrameCount / (double) mSampleRate; 681 fdprintf(fd, "FastMixer command=%s writeSequence=%u framesWritten=%u\n" 682 " numTracks=%u writeErrors=%u underruns=%u overruns=%u\n" 683 " sampleRate=%u frameCount=%u measuredWarmup=%.3g ms, warmupCycles=%u\n" 684 " mixPeriod=%.2f ms\n", 685 string, mWriteSequence, mFramesWritten, 686 mNumTracks, mWriteErrors, mUnderruns, mOverruns, 687 mSampleRate, mFrameCount, measuredWarmupMs, mWarmupCycles, 688 mixPeriodSec * 1e3); 689#ifdef FAST_MIXER_STATISTICS 690 // find the interval of valid samples 691 uint32_t bounds = mBounds; 692 uint32_t newestOpen = bounds & 0xFFFF; 693 uint32_t oldestClosed = bounds >> 16; 694 uint32_t n = (newestOpen - oldestClosed) & 0xFFFF; 695 if (n > kSamplingN) { 696 ALOGE("too many samples %u", n); 697 n = kSamplingN; 698 } 699 // statistics for monotonic (wall clock) time, thread raw CPU load in time, CPU clock frequency, 700 // and adjusted CPU load in MHz normalized for CPU clock frequency 701 CentralTendencyStatistics wall, loadNs; 702#ifdef CPU_FREQUENCY_STATISTICS 703 CentralTendencyStatistics kHz, loadMHz; 704 uint32_t previousCpukHz = 0; 705#endif 706 // Assuming a normal distribution for cycle times, three standard deviations on either side of 707 // the mean account for 99.73% of the population. So if we take each tail to be 1/1000 of the 708 // sample set, we get 99.8% combined, or close to three standard deviations. 709 static const uint32_t kTailDenominator = 1000; 710 uint32_t *tail = n >= kTailDenominator ? new uint32_t[n] : NULL; 711 // loop over all the samples 712 for (uint32_t j = 0; j < n; ++j) { 713 size_t i = oldestClosed++ & (kSamplingN - 1); 714 uint32_t wallNs = mMonotonicNs[i]; 715 if (tail != NULL) { 716 tail[j] = wallNs; 717 } 718 wall.sample(wallNs); 719 uint32_t sampleLoadNs = mLoadNs[i]; 720 loadNs.sample(sampleLoadNs); 721#ifdef CPU_FREQUENCY_STATISTICS 722 uint32_t sampleCpukHz = mCpukHz[i]; 723 // skip bad kHz samples 724 if ((sampleCpukHz & ~0xF) != 0) { 725 kHz.sample(sampleCpukHz >> 4); 726 if (sampleCpukHz == previousCpukHz) { 727 double megacycles = (double) sampleLoadNs * (double) (sampleCpukHz >> 4) * 1e-12; 728 double adjMHz = megacycles / mixPeriodSec; // _not_ wallNs * 1e9 729 loadMHz.sample(adjMHz); 730 } 731 } 732 previousCpukHz = sampleCpukHz; 733#endif 734 } 735 fdprintf(fd, "Simple moving statistics over last %.1f seconds:\n", wall.n() * mixPeriodSec); 736 fdprintf(fd, " wall clock time in ms per mix cycle:\n" 737 " mean=%.2f min=%.2f max=%.2f stddev=%.2f\n", 738 wall.mean()*1e-6, wall.minimum()*1e-6, wall.maximum()*1e-6, wall.stddev()*1e-6); 739 fdprintf(fd, " raw CPU load in us per mix cycle:\n" 740 " mean=%.0f min=%.0f max=%.0f stddev=%.0f\n", 741 loadNs.mean()*1e-3, loadNs.minimum()*1e-3, loadNs.maximum()*1e-3, 742 loadNs.stddev()*1e-3); 743#ifdef CPU_FREQUENCY_STATISTICS 744 fdprintf(fd, " CPU clock frequency in MHz:\n" 745 " mean=%.0f min=%.0f max=%.0f stddev=%.0f\n", 746 kHz.mean()*1e-3, kHz.minimum()*1e-3, kHz.maximum()*1e-3, kHz.stddev()*1e-3); 747 fdprintf(fd, " adjusted CPU load in MHz (i.e. normalized for CPU clock frequency):\n" 748 " mean=%.1f min=%.1f max=%.1f stddev=%.1f\n", 749 loadMHz.mean(), loadMHz.minimum(), loadMHz.maximum(), loadMHz.stddev()); 750#endif 751 if (tail != NULL) { 752 qsort(tail, n, sizeof(uint32_t), compare_uint32_t); 753 // assume same number of tail samples on each side, left and right 754 uint32_t count = n / kTailDenominator; 755 CentralTendencyStatistics left, right; 756 for (uint32_t i = 0; i < count; ++i) { 757 left.sample(tail[i]); 758 right.sample(tail[n - (i + 1)]); 759 } 760 fdprintf(fd, "Distribution of mix cycle times in ms for the tails (> ~3 stddev outliers):\n" 761 " left tail: mean=%.2f min=%.2f max=%.2f stddev=%.2f\n" 762 " right tail: mean=%.2f min=%.2f max=%.2f stddev=%.2f\n", 763 left.mean()*1e-6, left.minimum()*1e-6, left.maximum()*1e-6, left.stddev()*1e-6, 764 right.mean()*1e-6, right.minimum()*1e-6, right.maximum()*1e-6, 765 right.stddev()*1e-6); 766 delete[] tail; 767 } 768#endif 769 // The active track mask and track states are updated non-atomically. 770 // So if we relied on isActive to decide whether to display, 771 // then we might display an obsolete track or omit an active track. 772 // Instead we always display all tracks, with an indication 773 // of whether we think the track is active. 774 uint32_t trackMask = mTrackMask; 775 fdprintf(fd, "Fast tracks: kMaxFastTracks=%u activeMask=%#x\n", 776 FastMixerState::kMaxFastTracks, trackMask); 777 fdprintf(fd, "Index Active Full Partial Empty Recent Ready\n"); 778 for (uint32_t i = 0; i < FastMixerState::kMaxFastTracks; ++i, trackMask >>= 1) { 779 bool isActive = trackMask & 1; 780 const FastTrackDump *ftDump = &mTracks[i]; 781 const FastTrackUnderruns& underruns = ftDump->mUnderruns; 782 const char *mostRecent; 783 switch (underruns.mBitFields.mMostRecent) { 784 case UNDERRUN_FULL: 785 mostRecent = "full"; 786 break; 787 case UNDERRUN_PARTIAL: 788 mostRecent = "partial"; 789 break; 790 case UNDERRUN_EMPTY: 791 mostRecent = "empty"; 792 break; 793 default: 794 mostRecent = "?"; 795 break; 796 } 797 fdprintf(fd, "%5u %6s %4u %7u %5u %7s %5u\n", i, isActive ? "yes" : "no", 798 (underruns.mBitFields.mFull) & UNDERRUN_MASK, 799 (underruns.mBitFields.mPartial) & UNDERRUN_MASK, 800 (underruns.mBitFields.mEmpty) & UNDERRUN_MASK, 801 mostRecent, ftDump->mFramesReady); 802 } 803} 804 805} // namespace android 806