FastMixer.cpp revision eb15716b59020f342df62bce5b293f0603b94861
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#define LOG_TAG "FastMixer"
18//#define LOG_NDEBUG 0
19
20#include <sys/atomics.h>
21#include <time.h>
22#include <utils/Log.h>
23#include <utils/Trace.h>
24#include <system/audio.h>
25#ifdef FAST_MIXER_STATISTICS
26#include <cpustats/CentralTendencyStatistics.h>
27#ifdef CPU_FREQUENCY_STATISTICS
28#include <cpustats/ThreadCpuUsage.h>
29#endif
30#endif
31#include "AudioMixer.h"
32#include "FastMixer.h"
33
34#define FAST_HOT_IDLE_NS     1000000L   // 1 ms: time to sleep while hot idling
35#define FAST_DEFAULT_NS    999999999L   // ~1 sec: default time to sleep
36#define MIN_WARMUP_CYCLES          2    // minimum number of loop cycles to wait for warmup
37#define MAX_WARMUP_CYCLES         10    // maximum number of loop cycles to wait for warmup
38
39namespace android {
40
41// Fast mixer thread
42bool FastMixer::threadLoop()
43{
44    static const FastMixerState initial;
45    const FastMixerState *previous = &initial, *current = &initial;
46    FastMixerState preIdle; // copy of state before we went into idle
47    struct timespec oldTs = {0, 0};
48    bool oldTsValid = false;
49    long slopNs = 0;    // accumulated time we've woken up too early (> 0) or too late (< 0)
50    long sleepNs = -1;  // -1: busy wait, 0: sched_yield, > 0: nanosleep
51    int fastTrackNames[FastMixerState::kMaxFastTracks]; // handles used by mixer to identify tracks
52    int generations[FastMixerState::kMaxFastTracks];    // last observed mFastTracks[i].mGeneration
53    unsigned i;
54    for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) {
55        fastTrackNames[i] = -1;
56        generations[i] = 0;
57    }
58    NBAIO_Sink *outputSink = NULL;
59    int outputSinkGen = 0;
60    AudioMixer* mixer = NULL;
61    short *mixBuffer = NULL;
62    enum {UNDEFINED, MIXED, ZEROED} mixBufferState = UNDEFINED;
63    NBAIO_Format format = Format_Invalid;
64    unsigned sampleRate = 0;
65    int fastTracksGen = 0;
66    long periodNs = 0;      // expected period; the time required to render one mix buffer
67    long underrunNs = 0;    // underrun likely when write cycle is greater than this value
68    long overrunNs = 0;     // overrun likely when write cycle is less than this value
69    long forceNs = 0;       // if overrun detected, force the write cycle to take this much time
70    long warmupNs = 0;      // warmup complete when write cycle is greater than to this value
71    FastMixerDumpState dummyDumpState, *dumpState = &dummyDumpState;
72    bool ignoreNextOverrun = true;  // used to ignore initial overrun and first after an underrun
73#ifdef FAST_MIXER_STATISTICS
74    struct timespec oldLoad = {0, 0};    // previous value of clock_gettime(CLOCK_THREAD_CPUTIME_ID)
75    bool oldLoadValid = false;  // whether oldLoad is valid
76    uint32_t bounds = 0;
77    bool full = false;      // whether we have collected at least kSamplingN samples
78#ifdef CPU_FREQUENCY_STATISTICS
79    ThreadCpuUsage tcu;     // for reading the current CPU clock frequency in kHz
80#endif
81#endif
82    unsigned coldGen = 0;   // last observed mColdGen
83    bool isWarm = false;    // true means ready to mix, false means wait for warmup before mixing
84    struct timespec measuredWarmupTs = {0, 0};  // how long did it take for warmup to complete
85    uint32_t warmupCycles = 0;  // counter of number of loop cycles required to warmup
86    NBAIO_Sink* teeSink = NULL; // if non-NULL, then duplicate write() to this non-blocking sink
87
88    for (;;) {
89
90        // either nanosleep, sched_yield, or busy wait
91        if (sleepNs >= 0) {
92            if (sleepNs > 0) {
93                ALOG_ASSERT(sleepNs < 1000000000);
94                const struct timespec req = {0, sleepNs};
95                nanosleep(&req, NULL);
96            } else {
97                sched_yield();
98            }
99        }
100        // default to long sleep for next cycle
101        sleepNs = FAST_DEFAULT_NS;
102
103        // poll for state change
104        const FastMixerState *next = mSQ.poll();
105        if (next == NULL) {
106            // continue to use the default initial state until a real state is available
107            ALOG_ASSERT(current == &initial && previous == &initial);
108            next = current;
109        }
110
111        FastMixerState::Command command = next->mCommand;
112        if (next != current) {
113
114            // As soon as possible of learning of a new dump area, start using it
115            dumpState = next->mDumpState != NULL ? next->mDumpState : &dummyDumpState;
116            teeSink = next->mTeeSink;
117
118            // We want to always have a valid reference to the previous (non-idle) state.
119            // However, the state queue only guarantees access to current and previous states.
120            // So when there is a transition from a non-idle state into an idle state, we make a
121            // copy of the last known non-idle state so it is still available on return from idle.
122            // The possible transitions are:
123            //  non-idle -> non-idle    update previous from current in-place
124            //  non-idle -> idle        update previous from copy of current
125            //  idle     -> idle        don't update previous
126            //  idle     -> non-idle    don't update previous
127            if (!(current->mCommand & FastMixerState::IDLE)) {
128                if (command & FastMixerState::IDLE) {
129                    preIdle = *current;
130                    current = &preIdle;
131                    oldTsValid = false;
132                    oldLoadValid = false;
133                    ignoreNextOverrun = true;
134                }
135                previous = current;
136            }
137            current = next;
138        }
139#if !LOG_NDEBUG
140        next = NULL;    // not referenced again
141#endif
142
143        dumpState->mCommand = command;
144
145        switch (command) {
146        case FastMixerState::INITIAL:
147        case FastMixerState::HOT_IDLE:
148            sleepNs = FAST_HOT_IDLE_NS;
149            continue;
150        case FastMixerState::COLD_IDLE:
151            // only perform a cold idle command once
152            // FIXME consider checking previous state and only perform if previous != COLD_IDLE
153            if (current->mColdGen != coldGen) {
154                int32_t *coldFutexAddr = current->mColdFutexAddr;
155                ALOG_ASSERT(coldFutexAddr != NULL);
156                int32_t old = android_atomic_dec(coldFutexAddr);
157                if (old <= 0) {
158                    __futex_syscall4(coldFutexAddr, FUTEX_WAIT_PRIVATE, old - 1, NULL);
159                }
160                // This may be overly conservative; there could be times that the normal mixer
161                // requests such a brief cold idle that it doesn't require resetting this flag.
162                isWarm = false;
163                measuredWarmupTs.tv_sec = 0;
164                measuredWarmupTs.tv_nsec = 0;
165                warmupCycles = 0;
166                sleepNs = -1;
167                coldGen = current->mColdGen;
168                bounds = 0;
169                full = false;
170                oldTsValid = !clock_gettime(CLOCK_MONOTONIC, &oldTs);
171            } else {
172                sleepNs = FAST_HOT_IDLE_NS;
173            }
174            continue;
175        case FastMixerState::EXIT:
176            delete mixer;
177            delete[] mixBuffer;
178            return false;
179        case FastMixerState::MIX:
180        case FastMixerState::WRITE:
181        case FastMixerState::MIX_WRITE:
182            break;
183        default:
184            LOG_FATAL("bad command %d", command);
185        }
186
187        // there is a non-idle state available to us; did the state change?
188        size_t frameCount = current->mFrameCount;
189        if (current != previous) {
190
191            // handle state change here, but since we want to diff the state,
192            // we're prepared for previous == &initial the first time through
193            unsigned previousTrackMask;
194
195            // check for change in output HAL configuration
196            NBAIO_Format previousFormat = format;
197            if (current->mOutputSinkGen != outputSinkGen) {
198                outputSink = current->mOutputSink;
199                outputSinkGen = current->mOutputSinkGen;
200                if (outputSink == NULL) {
201                    format = Format_Invalid;
202                    sampleRate = 0;
203                } else {
204                    format = outputSink->format();
205                    sampleRate = Format_sampleRate(format);
206                    ALOG_ASSERT(Format_channelCount(format) == 2);
207                }
208                dumpState->mSampleRate = sampleRate;
209            }
210
211            if ((format != previousFormat) || (frameCount != previous->mFrameCount)) {
212                // FIXME to avoid priority inversion, don't delete here
213                delete mixer;
214                mixer = NULL;
215                delete[] mixBuffer;
216                mixBuffer = NULL;
217                if (frameCount > 0 && sampleRate > 0) {
218                    // FIXME new may block for unbounded time at internal mutex of the heap
219                    //       implementation; it would be better to have normal mixer allocate for us
220                    //       to avoid blocking here and to prevent possible priority inversion
221                    mixer = new AudioMixer(frameCount, sampleRate, FastMixerState::kMaxFastTracks);
222                    mixBuffer = new short[frameCount * 2];
223                    periodNs = (frameCount * 1000000000LL) / sampleRate;    // 1.00
224                    underrunNs = (frameCount * 1750000000LL) / sampleRate;  // 1.75
225                    overrunNs = (frameCount * 250000000LL) / sampleRate;    // 0.25
226                    forceNs = (frameCount * 750000000LL) / sampleRate;      // 0.75
227                    warmupNs = (frameCount * 500000000LL) / sampleRate;     // 0.50
228                } else {
229                    periodNs = 0;
230                    underrunNs = 0;
231                    overrunNs = 0;
232                    forceNs = 0;
233                    warmupNs = 0;
234                }
235                mixBufferState = UNDEFINED;
236#if !LOG_NDEBUG
237                for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) {
238                    fastTrackNames[i] = -1;
239                }
240#endif
241                // we need to reconfigure all active tracks
242                previousTrackMask = 0;
243                fastTracksGen = current->mFastTracksGen - 1;
244                dumpState->mFrameCount = frameCount;
245            } else {
246                previousTrackMask = previous->mTrackMask;
247            }
248
249            // check for change in active track set
250            unsigned currentTrackMask = current->mTrackMask;
251            dumpState->mTrackMask = currentTrackMask;
252            if (current->mFastTracksGen != fastTracksGen) {
253                ALOG_ASSERT(mixBuffer != NULL);
254                int name;
255
256                // process removed tracks first to avoid running out of track names
257                unsigned removedTracks = previousTrackMask & ~currentTrackMask;
258                while (removedTracks != 0) {
259                    i = __builtin_ctz(removedTracks);
260                    removedTracks &= ~(1 << i);
261                    const FastTrack* fastTrack = &current->mFastTracks[i];
262                    ALOG_ASSERT(fastTrack->mBufferProvider == NULL);
263                    if (mixer != NULL) {
264                        name = fastTrackNames[i];
265                        ALOG_ASSERT(name >= 0);
266                        mixer->deleteTrackName(name);
267                    }
268#if !LOG_NDEBUG
269                    fastTrackNames[i] = -1;
270#endif
271                    // don't reset track dump state, since other side is ignoring it
272                    generations[i] = fastTrack->mGeneration;
273                }
274
275                // now process added tracks
276                unsigned addedTracks = currentTrackMask & ~previousTrackMask;
277                while (addedTracks != 0) {
278                    i = __builtin_ctz(addedTracks);
279                    addedTracks &= ~(1 << i);
280                    const FastTrack* fastTrack = &current->mFastTracks[i];
281                    AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider;
282                    ALOG_ASSERT(bufferProvider != NULL && fastTrackNames[i] == -1);
283                    if (mixer != NULL) {
284                        // calling getTrackName with default channel mask
285                        name = mixer->getTrackName(AUDIO_CHANNEL_OUT_STEREO);
286                        ALOG_ASSERT(name >= 0);
287                        fastTrackNames[i] = name;
288                        mixer->setBufferProvider(name, bufferProvider);
289                        mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::MAIN_BUFFER,
290                                (void *) mixBuffer);
291                        // newly allocated track names default to full scale volume
292                        if (fastTrack->mSampleRate != 0 && fastTrack->mSampleRate != sampleRate) {
293                            mixer->setParameter(name, AudioMixer::RESAMPLE,
294                                    AudioMixer::SAMPLE_RATE, (void*) fastTrack->mSampleRate);
295                        }
296                        mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK,
297                                (void *) fastTrack->mChannelMask);
298                        mixer->enable(name);
299                    }
300                    generations[i] = fastTrack->mGeneration;
301                }
302
303                // finally process modified tracks; these use the same slot
304                // but may have a different buffer provider or volume provider
305                unsigned modifiedTracks = currentTrackMask & previousTrackMask;
306                while (modifiedTracks != 0) {
307                    i = __builtin_ctz(modifiedTracks);
308                    modifiedTracks &= ~(1 << i);
309                    const FastTrack* fastTrack = &current->mFastTracks[i];
310                    if (fastTrack->mGeneration != generations[i]) {
311                        AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider;
312                        ALOG_ASSERT(bufferProvider != NULL);
313                        if (mixer != NULL) {
314                            name = fastTrackNames[i];
315                            ALOG_ASSERT(name >= 0);
316                            mixer->setBufferProvider(name, bufferProvider);
317                            if (fastTrack->mVolumeProvider == NULL) {
318                                mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0,
319                                        (void *)0x1000);
320                                mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1,
321                                        (void *)0x1000);
322                            }
323                            if (fastTrack->mSampleRate != 0 &&
324                                    fastTrack->mSampleRate != sampleRate) {
325                                mixer->setParameter(name, AudioMixer::RESAMPLE,
326                                        AudioMixer::SAMPLE_RATE, (void*) fastTrack->mSampleRate);
327                            } else {
328                                mixer->setParameter(name, AudioMixer::RESAMPLE,
329                                        AudioMixer::REMOVE, NULL);
330                            }
331                            mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK,
332                                    (void *) fastTrack->mChannelMask);
333                            // already enabled
334                        }
335                        generations[i] = fastTrack->mGeneration;
336                    }
337                }
338
339                fastTracksGen = current->mFastTracksGen;
340
341                dumpState->mNumTracks = popcount(currentTrackMask);
342            }
343
344#if 1   // FIXME shouldn't need this
345            // only process state change once
346            previous = current;
347#endif
348        }
349
350        // do work using current state here
351        if ((command & FastMixerState::MIX) && (mixer != NULL) && isWarm) {
352            ALOG_ASSERT(mixBuffer != NULL);
353            // for each track, update volume and check for underrun
354            unsigned currentTrackMask = current->mTrackMask;
355            while (currentTrackMask != 0) {
356                i = __builtin_ctz(currentTrackMask);
357                currentTrackMask &= ~(1 << i);
358                const FastTrack* fastTrack = &current->mFastTracks[i];
359                int name = fastTrackNames[i];
360                ALOG_ASSERT(name >= 0);
361                if (fastTrack->mVolumeProvider != NULL) {
362                    uint32_t vlr = fastTrack->mVolumeProvider->getVolumeLR();
363                    mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0,
364                            (void *)(vlr & 0xFFFF));
365                    mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1,
366                            (void *)(vlr >> 16));
367                }
368                // FIXME The current implementation of framesReady() for fast tracks
369                // takes a tryLock, which can block
370                // up to 1 ms.  If enough active tracks all blocked in sequence, this would result
371                // in the overall fast mix cycle being delayed.  Should use a non-blocking FIFO.
372                size_t framesReady = fastTrack->mBufferProvider->framesReady();
373#if defined(ATRACE_TAG) && (ATRACE_TAG != ATRACE_TAG_NEVER)
374                // I wish we had formatted trace names
375                char traceName[16];
376                strcpy(traceName, "framesReady");
377                traceName[11] = i + (i < 10 ? '0' : 'A' - 10);
378                traceName[12] = '\0';
379                ATRACE_INT(traceName, framesReady);
380#endif
381                FastTrackDump *ftDump = &dumpState->mTracks[i];
382                FastTrackUnderruns underruns = ftDump->mUnderruns;
383                if (framesReady < frameCount) {
384                    if (framesReady == 0) {
385                        underruns.mBitFields.mEmpty++;
386                        underruns.mBitFields.mMostRecent = UNDERRUN_EMPTY;
387                        mixer->disable(name);
388                    } else {
389                        // allow mixing partial buffer
390                        underruns.mBitFields.mPartial++;
391                        underruns.mBitFields.mMostRecent = UNDERRUN_PARTIAL;
392                        mixer->enable(name);
393                    }
394                } else {
395                    underruns.mBitFields.mFull++;
396                    underruns.mBitFields.mMostRecent = UNDERRUN_FULL;
397                    mixer->enable(name);
398                }
399                ftDump->mUnderruns = underruns;
400                ftDump->mFramesReady = framesReady;
401            }
402            // process() is CPU-bound
403            mixer->process(AudioBufferProvider::kInvalidPTS);
404            mixBufferState = MIXED;
405        } else if (mixBufferState == MIXED) {
406            mixBufferState = UNDEFINED;
407        }
408        bool attemptedWrite = false;
409        //bool didFullWrite = false;    // dumpsys could display a count of partial writes
410        if ((command & FastMixerState::WRITE) && (outputSink != NULL) && (mixBuffer != NULL)) {
411            if (mixBufferState == UNDEFINED) {
412                memset(mixBuffer, 0, frameCount * 2 * sizeof(short));
413                mixBufferState = ZEROED;
414            }
415            if (teeSink != NULL) {
416                (void) teeSink->write(mixBuffer, frameCount);
417            }
418            // FIXME write() is non-blocking and lock-free for a properly implemented NBAIO sink,
419            //       but this code should be modified to handle both non-blocking and blocking sinks
420            dumpState->mWriteSequence++;
421#if defined(ATRACE_TAG) && (ATRACE_TAG != ATRACE_TAG_NEVER)
422            Tracer::traceBegin(ATRACE_TAG, "write");
423#endif
424            ssize_t framesWritten = outputSink->write(mixBuffer, frameCount);
425#if defined(ATRACE_TAG) && (ATRACE_TAG != ATRACE_TAG_NEVER)
426            Tracer::traceEnd(ATRACE_TAG);
427#endif
428            dumpState->mWriteSequence++;
429            if (framesWritten >= 0) {
430                ALOG_ASSERT(framesWritten <= frameCount);
431                dumpState->mFramesWritten += framesWritten;
432                //if ((size_t) framesWritten == frameCount) {
433                //    didFullWrite = true;
434                //}
435            } else {
436                dumpState->mWriteErrors++;
437            }
438            attemptedWrite = true;
439            // FIXME count # of writes blocked excessively, CPU usage, etc. for dump
440        }
441
442        // To be exactly periodic, compute the next sleep time based on current time.
443        // This code doesn't have long-term stability when the sink is non-blocking.
444        // FIXME To avoid drift, use the local audio clock or watch the sink's fill status.
445        struct timespec newTs;
446        int rc = clock_gettime(CLOCK_MONOTONIC, &newTs);
447        if (rc == 0) {
448            if (oldTsValid) {
449                time_t sec = newTs.tv_sec - oldTs.tv_sec;
450                long nsec = newTs.tv_nsec - oldTs.tv_nsec;
451                if (nsec < 0) {
452                    --sec;
453                    nsec += 1000000000;
454                }
455                // To avoid an initial underrun on fast tracks after exiting standby,
456                // do not start pulling data from tracks and mixing until warmup is complete.
457                // Warmup is considered complete after the earlier of:
458                //      MIN_WARMUP_CYCLES write() attempts and last one blocks for at least warmupNs
459                //      MAX_WARMUP_CYCLES write() attempts.
460                // This is overly conservative, but to get better accuracy requires a new HAL API.
461                if (!isWarm && attemptedWrite) {
462                    measuredWarmupTs.tv_sec += sec;
463                    measuredWarmupTs.tv_nsec += nsec;
464                    if (measuredWarmupTs.tv_nsec >= 1000000000) {
465                        measuredWarmupTs.tv_sec++;
466                        measuredWarmupTs.tv_nsec -= 1000000000;
467                    }
468                    ++warmupCycles;
469                    if ((nsec > warmupNs && warmupCycles >= MIN_WARMUP_CYCLES) ||
470                            (warmupCycles >= MAX_WARMUP_CYCLES)) {
471                        isWarm = true;
472                        dumpState->mMeasuredWarmupTs = measuredWarmupTs;
473                        dumpState->mWarmupCycles = warmupCycles;
474                    }
475                }
476                sleepNs = -1;
477              if (isWarm) {
478                if (sec > 0 || nsec > underrunNs) {
479#if defined(ATRACE_TAG) && (ATRACE_TAG != ATRACE_TAG_NEVER)
480                    ScopedTrace st(ATRACE_TAG, "underrun");
481#endif
482                    // FIXME only log occasionally
483                    ALOGV("underrun: time since last cycle %d.%03ld sec",
484                            (int) sec, nsec / 1000000L);
485                    dumpState->mUnderruns++;
486                    ignoreNextOverrun = true;
487                } else if (nsec < overrunNs) {
488                    if (ignoreNextOverrun) {
489                        ignoreNextOverrun = false;
490                    } else {
491                        // FIXME only log occasionally
492                        ALOGV("overrun: time since last cycle %d.%03ld sec",
493                                (int) sec, nsec / 1000000L);
494                        dumpState->mOverruns++;
495                    }
496                    // This forces a minimum cycle time. It:
497                    //   - compensates for an audio HAL with jitter due to sample rate conversion
498                    //   - works with a variable buffer depth audio HAL that never pulls at a rate
499                    //     < than overrunNs per buffer.
500                    //   - recovers from overrun immediately after underrun
501                    // It doesn't work with a non-blocking audio HAL.
502                    sleepNs = forceNs - nsec;
503                } else {
504                    ignoreNextOverrun = false;
505                }
506              }
507#ifdef FAST_MIXER_STATISTICS
508              if (isWarm) {
509                // advance the FIFO queue bounds
510                size_t i = bounds & (FastMixerDumpState::kSamplingN - 1);
511                bounds = (bounds & 0xFFFF0000) | ((bounds + 1) & 0xFFFF);
512                if (full) {
513                    bounds += 0x10000;
514                } else if (!(bounds & (FastMixerDumpState::kSamplingN - 1))) {
515                    full = true;
516                }
517                // compute the delta value of clock_gettime(CLOCK_MONOTONIC)
518                uint32_t monotonicNs = nsec;
519                if (sec > 0 && sec < 4) {
520                    monotonicNs += sec * 1000000000;
521                }
522                // compute the raw CPU load = delta value of clock_gettime(CLOCK_THREAD_CPUTIME_ID)
523                uint32_t loadNs = 0;
524                struct timespec newLoad;
525                rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &newLoad);
526                if (rc == 0) {
527                    if (oldLoadValid) {
528                        sec = newLoad.tv_sec - oldLoad.tv_sec;
529                        nsec = newLoad.tv_nsec - oldLoad.tv_nsec;
530                        if (nsec < 0) {
531                            --sec;
532                            nsec += 1000000000;
533                        }
534                        loadNs = nsec;
535                        if (sec > 0 && sec < 4) {
536                            loadNs += sec * 1000000000;
537                        }
538                    } else {
539                        // first time through the loop
540                        oldLoadValid = true;
541                    }
542                    oldLoad = newLoad;
543                }
544#ifdef CPU_FREQUENCY_STATISTICS
545                // get the absolute value of CPU clock frequency in kHz
546                int cpuNum = sched_getcpu();
547                uint32_t kHz = tcu.getCpukHz(cpuNum);
548                kHz = (kHz << 4) | (cpuNum & 0xF);
549#endif
550                // save values in FIFO queues for dumpsys
551                // these stores #1, #2, #3 are not atomic with respect to each other,
552                // or with respect to store #4 below
553                dumpState->mMonotonicNs[i] = monotonicNs;
554                dumpState->mLoadNs[i] = loadNs;
555#ifdef CPU_FREQUENCY_STATISTICS
556                dumpState->mCpukHz[i] = kHz;
557#endif
558                // this store #4 is not atomic with respect to stores #1, #2, #3 above, but
559                // the newest open and oldest closed halves are atomic with respect to each other
560                dumpState->mBounds = bounds;
561#if defined(ATRACE_TAG) && (ATRACE_TAG != ATRACE_TAG_NEVER)
562                ATRACE_INT("cycle_ms", monotonicNs / 1000000);
563                ATRACE_INT("load_us", loadNs / 1000);
564#endif
565              }
566#endif
567            } else {
568                // first time through the loop
569                oldTsValid = true;
570                sleepNs = periodNs;
571                ignoreNextOverrun = true;
572            }
573            oldTs = newTs;
574        } else {
575            // monotonic clock is broken
576            oldTsValid = false;
577            sleepNs = periodNs;
578        }
579
580
581    }   // for (;;)
582
583    // never return 'true'; Thread::_threadLoop() locks mutex which can result in priority inversion
584}
585
586FastMixerDumpState::FastMixerDumpState() :
587    mCommand(FastMixerState::INITIAL), mWriteSequence(0), mFramesWritten(0),
588    mNumTracks(0), mWriteErrors(0), mUnderruns(0), mOverruns(0),
589    mSampleRate(0), mFrameCount(0), /* mMeasuredWarmupTs({0, 0}), */ mWarmupCycles(0),
590    mTrackMask(0)
591#ifdef FAST_MIXER_STATISTICS
592    , mBounds(0)
593#endif
594{
595    mMeasuredWarmupTs.tv_sec = 0;
596    mMeasuredWarmupTs.tv_nsec = 0;
597    // sample arrays aren't accessed atomically with respect to the bounds,
598    // so clearing reduces chance for dumpsys to read random uninitialized samples
599    memset(&mMonotonicNs, 0, sizeof(mMonotonicNs));
600    memset(&mLoadNs, 0, sizeof(mLoadNs));
601#ifdef CPU_FREQUENCY_STATISTICS
602    memset(&mCpukHz, 0, sizeof(mCpukHz));
603#endif
604}
605
606FastMixerDumpState::~FastMixerDumpState()
607{
608}
609
610void FastMixerDumpState::dump(int fd)
611{
612    if (mCommand == FastMixerState::INITIAL) {
613        fdprintf(fd, "FastMixer not initialized\n");
614        return;
615    }
616#define COMMAND_MAX 32
617    char string[COMMAND_MAX];
618    switch (mCommand) {
619    case FastMixerState::INITIAL:
620        strcpy(string, "INITIAL");
621        break;
622    case FastMixerState::HOT_IDLE:
623        strcpy(string, "HOT_IDLE");
624        break;
625    case FastMixerState::COLD_IDLE:
626        strcpy(string, "COLD_IDLE");
627        break;
628    case FastMixerState::EXIT:
629        strcpy(string, "EXIT");
630        break;
631    case FastMixerState::MIX:
632        strcpy(string, "MIX");
633        break;
634    case FastMixerState::WRITE:
635        strcpy(string, "WRITE");
636        break;
637    case FastMixerState::MIX_WRITE:
638        strcpy(string, "MIX_WRITE");
639        break;
640    default:
641        snprintf(string, COMMAND_MAX, "%d", mCommand);
642        break;
643    }
644    double measuredWarmupMs = (mMeasuredWarmupTs.tv_sec * 1000.0) +
645            (mMeasuredWarmupTs.tv_nsec / 1000000.0);
646    double mixPeriodSec = (double) mFrameCount / (double) mSampleRate;
647    fdprintf(fd, "FastMixer command=%s writeSequence=%u framesWritten=%u\n"
648                 "          numTracks=%u writeErrors=%u underruns=%u overruns=%u\n"
649                 "          sampleRate=%u frameCount=%u measuredWarmup=%.3g ms, warmupCycles=%u\n"
650                 "          mixPeriod=%.2f ms\n",
651                 string, mWriteSequence, mFramesWritten,
652                 mNumTracks, mWriteErrors, mUnderruns, mOverruns,
653                 mSampleRate, mFrameCount, measuredWarmupMs, mWarmupCycles,
654                 mixPeriodSec * 1e3);
655#ifdef FAST_MIXER_STATISTICS
656    // find the interval of valid samples
657    uint32_t bounds = mBounds;
658    uint32_t newestOpen = bounds & 0xFFFF;
659    uint32_t oldestClosed = bounds >> 16;
660    uint32_t n = (newestOpen - oldestClosed) & 0xFFFF;
661    if (n > kSamplingN) {
662        ALOGE("too many samples %u", n);
663        n = kSamplingN;
664    }
665    // statistics for monotonic (wall clock) time, thread raw CPU load in time, CPU clock frequency,
666    // and adjusted CPU load in MHz normalized for CPU clock frequency
667    CentralTendencyStatistics wall, loadNs;
668#ifdef CPU_FREQUENCY_STATISTICS
669    CentralTendencyStatistics kHz, loadMHz;
670    uint32_t previousCpukHz = 0;
671#endif
672    // loop over all the samples
673    for (; n > 0; --n) {
674        size_t i = oldestClosed++ & (kSamplingN - 1);
675        uint32_t wallNs = mMonotonicNs[i];
676        wall.sample(wallNs);
677        uint32_t sampleLoadNs = mLoadNs[i];
678        loadNs.sample(sampleLoadNs);
679#ifdef CPU_FREQUENCY_STATISTICS
680        uint32_t sampleCpukHz = mCpukHz[i];
681        // skip bad kHz samples
682        if ((sampleCpukHz & ~0xF) != 0) {
683            kHz.sample(sampleCpukHz >> 4);
684            if (sampleCpukHz == previousCpukHz) {
685                double megacycles = (double) sampleLoadNs * (double) (sampleCpukHz >> 4) * 1e-12;
686                double adjMHz = megacycles / mixPeriodSec;  // _not_ wallNs * 1e9
687                loadMHz.sample(adjMHz);
688            }
689        }
690        previousCpukHz = sampleCpukHz;
691#endif
692    }
693    fdprintf(fd, "Simple moving statistics over last %.1f seconds:\n", wall.n() * mixPeriodSec);
694    fdprintf(fd, "  wall clock time in ms per mix cycle:\n"
695                 "    mean=%.2f min=%.2f max=%.2f stddev=%.2f\n",
696                 wall.mean()*1e-6, wall.minimum()*1e-6, wall.maximum()*1e-6, wall.stddev()*1e-6);
697    fdprintf(fd, "  raw CPU load in us per mix cycle:\n"
698                 "    mean=%.0f min=%.0f max=%.0f stddev=%.0f\n",
699                 loadNs.mean()*1e-3, loadNs.minimum()*1e-3, loadNs.maximum()*1e-3,
700                 loadNs.stddev()*1e-3);
701#ifdef CPU_FREQUENCY_STATISTICS
702    fdprintf(fd, "  CPU clock frequency in MHz:\n"
703                 "    mean=%.0f min=%.0f max=%.0f stddev=%.0f\n",
704                 kHz.mean()*1e-3, kHz.minimum()*1e-3, kHz.maximum()*1e-3, kHz.stddev()*1e-3);
705    fdprintf(fd, "  adjusted CPU load in MHz (i.e. normalized for CPU clock frequency):\n"
706                 "    mean=%.1f min=%.1f max=%.1f stddev=%.1f\n",
707                 loadMHz.mean(), loadMHz.minimum(), loadMHz.maximum(), loadMHz.stddev());
708#endif
709#endif
710    // The active track mask and track states are updated non-atomically.
711    // So if we relied on isActive to decide whether to display,
712    // then we might display an obsolete track or omit an active track.
713    // Instead we always display all tracks, with an indication
714    // of whether we think the track is active.
715    uint32_t trackMask = mTrackMask;
716    fdprintf(fd, "Fast tracks: kMaxFastTracks=%u activeMask=%#x\n",
717            FastMixerState::kMaxFastTracks, trackMask);
718    fdprintf(fd, "Index Active Full Partial Empty  Recent Ready\n");
719    for (uint32_t i = 0; i < FastMixerState::kMaxFastTracks; ++i, trackMask >>= 1) {
720        bool isActive = trackMask & 1;
721        const FastTrackDump *ftDump = &mTracks[i];
722        const FastTrackUnderruns& underruns = ftDump->mUnderruns;
723        const char *mostRecent;
724        switch (underruns.mBitFields.mMostRecent) {
725        case UNDERRUN_FULL:
726            mostRecent = "full";
727            break;
728        case UNDERRUN_PARTIAL:
729            mostRecent = "partial";
730            break;
731        case UNDERRUN_EMPTY:
732            mostRecent = "empty";
733            break;
734        default:
735            mostRecent = "?";
736            break;
737        }
738        fdprintf(fd, "%5u %6s %4u %7u %5u %7s %5u\n", i, isActive ? "yes" : "no",
739                (underruns.mBitFields.mFull) & UNDERRUN_MASK,
740                (underruns.mBitFields.mPartial) & UNDERRUN_MASK,
741                (underruns.mBitFields.mEmpty) & UNDERRUN_MASK,
742                mostRecent, ftDump->mFramesReady);
743    }
744}
745
746}   // namespace android
747