/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//
// Design rules for threadLoop() are given in the comments at section "Fast mixer thread" of
// StateQueue.h. In particular, avoid library and system calls except at well-known points.
// The design rules are only for threadLoop(), and don't apply to FastMixerDumpState methods.
//
#define LOG_TAG "FastMixer"
//#define LOG_NDEBUG 0
#define ATRACE_TAG ATRACE_TAG_AUDIO
#include "Configuration.h"
#include
#include
#include
#include
#ifdef FAST_MIXER_STATISTICS
#include
#ifdef CPU_FREQUENCY_STATISTICS
#include
#endif
#endif
#include "AudioMixer.h"
#include "FastMixer.h"
#define FAST_HOT_IDLE_NS 1000000L // 1 ms: time to sleep while hot idling
#define FAST_DEFAULT_NS 999999999L // ~1 sec: default time to sleep
#define MIN_WARMUP_CYCLES 2 // minimum number of loop cycles to wait for warmup
#define MAX_WARMUP_CYCLES 10 // maximum number of loop cycles to wait for warmup
#define FCC_2 2 // fixed channel count assumption
namespace android {
// Fast mixer thread
bool FastMixer::threadLoop()
{
static const FastMixerState initial;
const FastMixerState *previous = &initial, *current = &initial;
FastMixerState preIdle; // copy of state before we went into idle
struct timespec oldTs = {0, 0};
bool oldTsValid = false;
long slopNs = 0; // accumulated time we've woken up too early (> 0) or too late (< 0)
long sleepNs = -1; // -1: busy wait, 0: sched_yield, > 0: nanosleep
int fastTrackNames[FastMixerState::kMaxFastTracks]; // handles used by mixer to identify tracks
int generations[FastMixerState::kMaxFastTracks]; // last observed mFastTracks[i].mGeneration
unsigned i;
for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) {
fastTrackNames[i] = -1;
generations[i] = 0;
}
NBAIO_Sink *outputSink = NULL;
int outputSinkGen = 0;
AudioMixer* mixer = NULL;
short *mixBuffer = NULL;
enum {UNDEFINED, MIXED, ZEROED} mixBufferState = UNDEFINED;
NBAIO_Format format = Format_Invalid;
unsigned sampleRate = 0;
int fastTracksGen = 0;
long periodNs = 0; // expected period; the time required to render one mix buffer
long underrunNs = 0; // underrun likely when write cycle is greater than this value
long overrunNs = 0; // overrun likely when write cycle is less than this value
long forceNs = 0; // if overrun detected, force the write cycle to take this much time
long warmupNs = 0; // warmup complete when write cycle is greater than to this value
FastMixerDumpState dummyDumpState, *dumpState = &dummyDumpState;
bool ignoreNextOverrun = true; // used to ignore initial overrun and first after an underrun
#ifdef FAST_MIXER_STATISTICS
struct timespec oldLoad = {0, 0}; // previous value of clock_gettime(CLOCK_THREAD_CPUTIME_ID)
bool oldLoadValid = false; // whether oldLoad is valid
uint32_t bounds = 0;
bool full = false; // whether we have collected at least mSamplingN samples
#ifdef CPU_FREQUENCY_STATISTICS
ThreadCpuUsage tcu; // for reading the current CPU clock frequency in kHz
#endif
#endif
unsigned coldGen = 0; // last observed mColdGen
bool isWarm = false; // true means ready to mix, false means wait for warmup before mixing
struct timespec measuredWarmupTs = {0, 0}; // how long did it take for warmup to complete
uint32_t warmupCycles = 0; // counter of number of loop cycles required to warmup
NBAIO_Sink* teeSink = NULL; // if non-NULL, then duplicate write() to this non-blocking sink
NBLog::Writer dummyLogWriter, *logWriter = &dummyLogWriter;
uint32_t totalNativeFramesWritten = 0; // copied to dumpState->mFramesWritten
// next 2 fields are valid only when timestampStatus == NO_ERROR
AudioTimestamp timestamp;
uint32_t nativeFramesWrittenButNotPresented = 0; // the = 0 is to silence the compiler
status_t timestampStatus = INVALID_OPERATION;
for (;;) {
// either nanosleep, sched_yield, or busy wait
if (sleepNs >= 0) {
if (sleepNs > 0) {
ALOG_ASSERT(sleepNs < 1000000000);
const struct timespec req = {0, sleepNs};
nanosleep(&req, NULL);
} else {
sched_yield();
}
}
// default to long sleep for next cycle
sleepNs = FAST_DEFAULT_NS;
// poll for state change
const FastMixerState *next = mSQ.poll();
if (next == NULL) {
// continue to use the default initial state until a real state is available
ALOG_ASSERT(current == &initial && previous == &initial);
next = current;
}
FastMixerState::Command command = next->mCommand;
if (next != current) {
// As soon as possible of learning of a new dump area, start using it
dumpState = next->mDumpState != NULL ? next->mDumpState : &dummyDumpState;
teeSink = next->mTeeSink;
logWriter = next->mNBLogWriter != NULL ? next->mNBLogWriter : &dummyLogWriter;
if (mixer != NULL) {
mixer->setLog(logWriter);
}
// We want to always have a valid reference to the previous (non-idle) state.
// However, the state queue only guarantees access to current and previous states.
// So when there is a transition from a non-idle state into an idle state, we make a
// copy of the last known non-idle state so it is still available on return from idle.
// The possible transitions are:
// non-idle -> non-idle update previous from current in-place
// non-idle -> idle update previous from copy of current
// idle -> idle don't update previous
// idle -> non-idle don't update previous
if (!(current->mCommand & FastMixerState::IDLE)) {
if (command & FastMixerState::IDLE) {
preIdle = *current;
current = &preIdle;
oldTsValid = false;
#ifdef FAST_MIXER_STATISTICS
oldLoadValid = false;
#endif
ignoreNextOverrun = true;
}
previous = current;
}
current = next;
}
#if !LOG_NDEBUG
next = NULL; // not referenced again
#endif
dumpState->mCommand = command;
switch (command) {
case FastMixerState::INITIAL:
case FastMixerState::HOT_IDLE:
sleepNs = FAST_HOT_IDLE_NS;
continue;
case FastMixerState::COLD_IDLE:
// only perform a cold idle command once
// FIXME consider checking previous state and only perform if previous != COLD_IDLE
if (current->mColdGen != coldGen) {
int32_t *coldFutexAddr = current->mColdFutexAddr;
ALOG_ASSERT(coldFutexAddr != NULL);
int32_t old = android_atomic_dec(coldFutexAddr);
if (old <= 0) {
(void) syscall(__NR_futex, coldFutexAddr, FUTEX_WAIT_PRIVATE, old - 1, NULL);
}
int policy = sched_getscheduler(0);
if (!(policy == SCHED_FIFO || policy == SCHED_RR)) {
ALOGE("did not receive expected priority boost");
}
// This may be overly conservative; there could be times that the normal mixer
// requests such a brief cold idle that it doesn't require resetting this flag.
isWarm = false;
measuredWarmupTs.tv_sec = 0;
measuredWarmupTs.tv_nsec = 0;
warmupCycles = 0;
sleepNs = -1;
coldGen = current->mColdGen;
#ifdef FAST_MIXER_STATISTICS
bounds = 0;
full = false;
#endif
oldTsValid = !clock_gettime(CLOCK_MONOTONIC, &oldTs);
timestampStatus = INVALID_OPERATION;
} else {
sleepNs = FAST_HOT_IDLE_NS;
}
continue;
case FastMixerState::EXIT:
delete mixer;
delete[] mixBuffer;
return false;
case FastMixerState::MIX:
case FastMixerState::WRITE:
case FastMixerState::MIX_WRITE:
break;
default:
LOG_FATAL("bad command %d", command);
}
// there is a non-idle state available to us; did the state change?
size_t frameCount = current->mFrameCount;
if (current != previous) {
// handle state change here, but since we want to diff the state,
// we're prepared for previous == &initial the first time through
unsigned previousTrackMask;
// check for change in output HAL configuration
NBAIO_Format previousFormat = format;
if (current->mOutputSinkGen != outputSinkGen) {
outputSink = current->mOutputSink;
outputSinkGen = current->mOutputSinkGen;
if (outputSink == NULL) {
format = Format_Invalid;
sampleRate = 0;
} else {
format = outputSink->format();
sampleRate = Format_sampleRate(format);
ALOG_ASSERT(Format_channelCount(format) == FCC_2);
}
}
if ((format != previousFormat) || (frameCount != previous->mFrameCount)) {
// FIXME to avoid priority inversion, don't delete here
delete mixer;
mixer = NULL;
delete[] mixBuffer;
mixBuffer = NULL;
if (frameCount > 0 && sampleRate > 0) {
// FIXME new may block for unbounded time at internal mutex of the heap
// implementation; it would be better to have normal mixer allocate for us
// to avoid blocking here and to prevent possible priority inversion
mixer = new AudioMixer(frameCount, sampleRate, FastMixerState::kMaxFastTracks);
mixBuffer = new short[frameCount * FCC_2];
periodNs = (frameCount * 1000000000LL) / sampleRate; // 1.00
underrunNs = (frameCount * 1750000000LL) / sampleRate; // 1.75
overrunNs = (frameCount * 500000000LL) / sampleRate; // 0.50
forceNs = (frameCount * 950000000LL) / sampleRate; // 0.95
warmupNs = (frameCount * 500000000LL) / sampleRate; // 0.50
} else {
periodNs = 0;
underrunNs = 0;
overrunNs = 0;
forceNs = 0;
warmupNs = 0;
}
mixBufferState = UNDEFINED;
#if !LOG_NDEBUG
for (i = 0; i < FastMixerState::kMaxFastTracks; ++i) {
fastTrackNames[i] = -1;
}
#endif
// we need to reconfigure all active tracks
previousTrackMask = 0;
fastTracksGen = current->mFastTracksGen - 1;
dumpState->mFrameCount = frameCount;
} else {
previousTrackMask = previous->mTrackMask;
}
// check for change in active track set
unsigned currentTrackMask = current->mTrackMask;
dumpState->mTrackMask = currentTrackMask;
if (current->mFastTracksGen != fastTracksGen) {
ALOG_ASSERT(mixBuffer != NULL);
int name;
// process removed tracks first to avoid running out of track names
unsigned removedTracks = previousTrackMask & ~currentTrackMask;
while (removedTracks != 0) {
i = __builtin_ctz(removedTracks);
removedTracks &= ~(1 << i);
const FastTrack* fastTrack = ¤t->mFastTracks[i];
ALOG_ASSERT(fastTrack->mBufferProvider == NULL);
if (mixer != NULL) {
name = fastTrackNames[i];
ALOG_ASSERT(name >= 0);
mixer->deleteTrackName(name);
}
#if !LOG_NDEBUG
fastTrackNames[i] = -1;
#endif
// don't reset track dump state, since other side is ignoring it
generations[i] = fastTrack->mGeneration;
}
// now process added tracks
unsigned addedTracks = currentTrackMask & ~previousTrackMask;
while (addedTracks != 0) {
i = __builtin_ctz(addedTracks);
addedTracks &= ~(1 << i);
const FastTrack* fastTrack = ¤t->mFastTracks[i];
AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider;
ALOG_ASSERT(bufferProvider != NULL && fastTrackNames[i] == -1);
if (mixer != NULL) {
// calling getTrackName with default channel mask and a random invalid
// sessionId (no effects here)
name = mixer->getTrackName(AUDIO_CHANNEL_OUT_STEREO, -555);
ALOG_ASSERT(name >= 0);
fastTrackNames[i] = name;
mixer->setBufferProvider(name, bufferProvider);
mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::MAIN_BUFFER,
(void *) mixBuffer);
// newly allocated track names default to full scale volume
mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK,
(void *)(uintptr_t)fastTrack->mChannelMask);
mixer->enable(name);
}
generations[i] = fastTrack->mGeneration;
}
// finally process (potentially) modified tracks; these use the same slot
// but may have a different buffer provider or volume provider
unsigned modifiedTracks = currentTrackMask & previousTrackMask;
while (modifiedTracks != 0) {
i = __builtin_ctz(modifiedTracks);
modifiedTracks &= ~(1 << i);
const FastTrack* fastTrack = ¤t->mFastTracks[i];
if (fastTrack->mGeneration != generations[i]) {
// this track was actually modified
AudioBufferProvider *bufferProvider = fastTrack->mBufferProvider;
ALOG_ASSERT(bufferProvider != NULL);
if (mixer != NULL) {
name = fastTrackNames[i];
ALOG_ASSERT(name >= 0);
mixer->setBufferProvider(name, bufferProvider);
if (fastTrack->mVolumeProvider == NULL) {
mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0,
(void *)0x1000);
mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1,
(void *)0x1000);
}
mixer->setParameter(name, AudioMixer::RESAMPLE,
AudioMixer::REMOVE, NULL);
mixer->setParameter(name, AudioMixer::TRACK, AudioMixer::CHANNEL_MASK,
(void *)(uintptr_t) fastTrack->mChannelMask);
// already enabled
}
generations[i] = fastTrack->mGeneration;
}
}
fastTracksGen = current->mFastTracksGen;
dumpState->mNumTracks = popcount(currentTrackMask);
}
#if 1 // FIXME shouldn't need this
// only process state change once
previous = current;
#endif
}
// do work using current state here
if ((command & FastMixerState::MIX) && (mixer != NULL) && isWarm) {
ALOG_ASSERT(mixBuffer != NULL);
// for each track, update volume and check for underrun
unsigned currentTrackMask = current->mTrackMask;
while (currentTrackMask != 0) {
i = __builtin_ctz(currentTrackMask);
currentTrackMask &= ~(1 << i);
const FastTrack* fastTrack = ¤t->mFastTracks[i];
// Refresh the per-track timestamp
if (timestampStatus == NO_ERROR) {
uint32_t trackFramesWrittenButNotPresented =
nativeFramesWrittenButNotPresented;
uint32_t trackFramesWritten = fastTrack->mBufferProvider->framesReleased();
// Can't provide an AudioTimestamp before first frame presented,
// or during the brief 32-bit wraparound window
if (trackFramesWritten >= trackFramesWrittenButNotPresented) {
AudioTimestamp perTrackTimestamp;
perTrackTimestamp.mPosition =
trackFramesWritten - trackFramesWrittenButNotPresented;
perTrackTimestamp.mTime = timestamp.mTime;
fastTrack->mBufferProvider->onTimestamp(perTrackTimestamp);
}
}
int name = fastTrackNames[i];
ALOG_ASSERT(name >= 0);
if (fastTrack->mVolumeProvider != NULL) {
uint32_t vlr = fastTrack->mVolumeProvider->getVolumeLR();
mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME0,
(void *)(uintptr_t)(vlr & 0xFFFF));
mixer->setParameter(name, AudioMixer::VOLUME, AudioMixer::VOLUME1,
(void *)(uintptr_t)(vlr >> 16));
}
// FIXME The current implementation of framesReady() for fast tracks
// takes a tryLock, which can block
// up to 1 ms. If enough active tracks all blocked in sequence, this would result
// in the overall fast mix cycle being delayed. Should use a non-blocking FIFO.
size_t framesReady = fastTrack->mBufferProvider->framesReady();
if (ATRACE_ENABLED()) {
// I wish we had formatted trace names
char traceName[16];
strcpy(traceName, "fRdy");
traceName[4] = i + (i < 10 ? '0' : 'A' - 10);
traceName[5] = '\0';
ATRACE_INT(traceName, framesReady);
}
FastTrackDump *ftDump = &dumpState->mTracks[i];
FastTrackUnderruns underruns = ftDump->mUnderruns;
if (framesReady < frameCount) {
if (framesReady == 0) {
underruns.mBitFields.mEmpty++;
underruns.mBitFields.mMostRecent = UNDERRUN_EMPTY;
mixer->disable(name);
} else {
// allow mixing partial buffer
underruns.mBitFields.mPartial++;
underruns.mBitFields.mMostRecent = UNDERRUN_PARTIAL;
mixer->enable(name);
}
} else {
underruns.mBitFields.mFull++;
underruns.mBitFields.mMostRecent = UNDERRUN_FULL;
mixer->enable(name);
}
ftDump->mUnderruns = underruns;
ftDump->mFramesReady = framesReady;
}
int64_t pts;
if (outputSink == NULL || (OK != outputSink->getNextWriteTimestamp(&pts)))
pts = AudioBufferProvider::kInvalidPTS;
// process() is CPU-bound
mixer->process(pts);
mixBufferState = MIXED;
} else if (mixBufferState == MIXED) {
mixBufferState = UNDEFINED;
}
bool attemptedWrite = false;
//bool didFullWrite = false; // dumpsys could display a count of partial writes
if ((command & FastMixerState::WRITE) && (outputSink != NULL) && (mixBuffer != NULL)) {
if (mixBufferState == UNDEFINED) {
memset(mixBuffer, 0, frameCount * FCC_2 * sizeof(short));
mixBufferState = ZEROED;
}
if (teeSink != NULL) {
(void) teeSink->write(mixBuffer, frameCount);
}
// FIXME write() is non-blocking and lock-free for a properly implemented NBAIO sink,
// but this code should be modified to handle both non-blocking and blocking sinks
dumpState->mWriteSequence++;
ATRACE_BEGIN("write");
ssize_t framesWritten = outputSink->write(mixBuffer, frameCount);
ATRACE_END();
dumpState->mWriteSequence++;
if (framesWritten >= 0) {
ALOG_ASSERT((size_t) framesWritten <= frameCount);
totalNativeFramesWritten += framesWritten;
dumpState->mFramesWritten = totalNativeFramesWritten;
//if ((size_t) framesWritten == frameCount) {
// didFullWrite = true;
//}
} else {
dumpState->mWriteErrors++;
}
attemptedWrite = true;
// FIXME count # of writes blocked excessively, CPU usage, etc. for dump
timestampStatus = outputSink->getTimestamp(timestamp);
if (timestampStatus == NO_ERROR) {
uint32_t totalNativeFramesPresented = timestamp.mPosition;
if (totalNativeFramesPresented <= totalNativeFramesWritten) {
nativeFramesWrittenButNotPresented =
totalNativeFramesWritten - totalNativeFramesPresented;
} else {
// HAL reported that more frames were presented than were written
timestampStatus = INVALID_OPERATION;
}
}
}
// To be exactly periodic, compute the next sleep time based on current time.
// This code doesn't have long-term stability when the sink is non-blocking.
// FIXME To avoid drift, use the local audio clock or watch the sink's fill status.
struct timespec newTs;
int rc = clock_gettime(CLOCK_MONOTONIC, &newTs);
if (rc == 0) {
//logWriter->logTimestamp(newTs);
if (oldTsValid) {
time_t sec = newTs.tv_sec - oldTs.tv_sec;
long nsec = newTs.tv_nsec - oldTs.tv_nsec;
ALOGE_IF(sec < 0 || (sec == 0 && nsec < 0),
"clock_gettime(CLOCK_MONOTONIC) failed: was %ld.%09ld but now %ld.%09ld",
oldTs.tv_sec, oldTs.tv_nsec, newTs.tv_sec, newTs.tv_nsec);
if (nsec < 0) {
--sec;
nsec += 1000000000;
}
// To avoid an initial underrun on fast tracks after exiting standby,
// do not start pulling data from tracks and mixing until warmup is complete.
// Warmup is considered complete after the earlier of:
// MIN_WARMUP_CYCLES write() attempts and last one blocks for at least warmupNs
// MAX_WARMUP_CYCLES write() attempts.
// This is overly conservative, but to get better accuracy requires a new HAL API.
if (!isWarm && attemptedWrite) {
measuredWarmupTs.tv_sec += sec;
measuredWarmupTs.tv_nsec += nsec;
if (measuredWarmupTs.tv_nsec >= 1000000000) {
measuredWarmupTs.tv_sec++;
measuredWarmupTs.tv_nsec -= 1000000000;
}
++warmupCycles;
if ((nsec > warmupNs && warmupCycles >= MIN_WARMUP_CYCLES) ||
(warmupCycles >= MAX_WARMUP_CYCLES)) {
isWarm = true;
dumpState->mMeasuredWarmupTs = measuredWarmupTs;
dumpState->mWarmupCycles = warmupCycles;
}
}
sleepNs = -1;
if (isWarm) {
if (sec > 0 || nsec > underrunNs) {
ATRACE_NAME("underrun");
// FIXME only log occasionally
ALOGV("underrun: time since last cycle %d.%03ld sec",
(int) sec, nsec / 1000000L);
dumpState->mUnderruns++;
ignoreNextOverrun = true;
} else if (nsec < overrunNs) {
if (ignoreNextOverrun) {
ignoreNextOverrun = false;
} else {
// FIXME only log occasionally
ALOGV("overrun: time since last cycle %d.%03ld sec",
(int) sec, nsec / 1000000L);
dumpState->mOverruns++;
}
// This forces a minimum cycle time. It:
// - compensates for an audio HAL with jitter due to sample rate conversion
// - works with a variable buffer depth audio HAL that never pulls at a
// rate < than overrunNs per buffer.
// - recovers from overrun immediately after underrun
// It doesn't work with a non-blocking audio HAL.
sleepNs = forceNs - nsec;
} else {
ignoreNextOverrun = false;
}
}
#ifdef FAST_MIXER_STATISTICS
if (isWarm) {
// advance the FIFO queue bounds
size_t i = bounds & (dumpState->mSamplingN - 1);
bounds = (bounds & 0xFFFF0000) | ((bounds + 1) & 0xFFFF);
if (full) {
bounds += 0x10000;
} else if (!(bounds & (dumpState->mSamplingN - 1))) {
full = true;
}
// compute the delta value of clock_gettime(CLOCK_MONOTONIC)
uint32_t monotonicNs = nsec;
if (sec > 0 && sec < 4) {
monotonicNs += sec * 1000000000;
}
// compute raw CPU load = delta value of clock_gettime(CLOCK_THREAD_CPUTIME_ID)
uint32_t loadNs = 0;
struct timespec newLoad;
rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &newLoad);
if (rc == 0) {
if (oldLoadValid) {
sec = newLoad.tv_sec - oldLoad.tv_sec;
nsec = newLoad.tv_nsec - oldLoad.tv_nsec;
if (nsec < 0) {
--sec;
nsec += 1000000000;
}
loadNs = nsec;
if (sec > 0 && sec < 4) {
loadNs += sec * 1000000000;
}
} else {
// first time through the loop
oldLoadValid = true;
}
oldLoad = newLoad;
}
#ifdef CPU_FREQUENCY_STATISTICS
// get the absolute value of CPU clock frequency in kHz
int cpuNum = sched_getcpu();
uint32_t kHz = tcu.getCpukHz(cpuNum);
kHz = (kHz << 4) | (cpuNum & 0xF);
#endif
// save values in FIFO queues for dumpsys
// these stores #1, #2, #3 are not atomic with respect to each other,
// or with respect to store #4 below
dumpState->mMonotonicNs[i] = monotonicNs;
dumpState->mLoadNs[i] = loadNs;
#ifdef CPU_FREQUENCY_STATISTICS
dumpState->mCpukHz[i] = kHz;
#endif
// this store #4 is not atomic with respect to stores #1, #2, #3 above, but
// the newest open & oldest closed halves are atomic with respect to each other
dumpState->mBounds = bounds;
ATRACE_INT("cycle_ms", monotonicNs / 1000000);
ATRACE_INT("load_us", loadNs / 1000);
}
#endif
} else {
// first time through the loop
oldTsValid = true;
sleepNs = periodNs;
ignoreNextOverrun = true;
}
oldTs = newTs;
} else {
// monotonic clock is broken
oldTsValid = false;
sleepNs = periodNs;
}
} // for (;;)
// never return 'true'; Thread::_threadLoop() locks mutex which can result in priority inversion
}
FastMixerDumpState::FastMixerDumpState(
#ifdef FAST_MIXER_STATISTICS
uint32_t samplingN
#endif
) :
mCommand(FastMixerState::INITIAL), mWriteSequence(0), mFramesWritten(0),
mNumTracks(0), mWriteErrors(0), mUnderruns(0), mOverruns(0),
mSampleRate(0), mFrameCount(0), /* mMeasuredWarmupTs({0, 0}), */ mWarmupCycles(0),
mTrackMask(0)
#ifdef FAST_MIXER_STATISTICS
, mSamplingN(0), mBounds(0)
#endif
{
mMeasuredWarmupTs.tv_sec = 0;
mMeasuredWarmupTs.tv_nsec = 0;
#ifdef FAST_MIXER_STATISTICS
increaseSamplingN(samplingN);
#endif
}
#ifdef FAST_MIXER_STATISTICS
void FastMixerDumpState::increaseSamplingN(uint32_t samplingN)
{
if (samplingN <= mSamplingN || samplingN > kSamplingN || roundup(samplingN) != samplingN) {
return;
}
uint32_t additional = samplingN - mSamplingN;
// sample arrays aren't accessed atomically with respect to the bounds,
// so clearing reduces chance for dumpsys to read random uninitialized samples
memset(&mMonotonicNs[mSamplingN], 0, sizeof(mMonotonicNs[0]) * additional);
memset(&mLoadNs[mSamplingN], 0, sizeof(mLoadNs[0]) * additional);
#ifdef CPU_FREQUENCY_STATISTICS
memset(&mCpukHz[mSamplingN], 0, sizeof(mCpukHz[0]) * additional);
#endif
mSamplingN = samplingN;
}
#endif
FastMixerDumpState::~FastMixerDumpState()
{
}
// helper function called by qsort()
static int compare_uint32_t(const void *pa, const void *pb)
{
uint32_t a = *(const uint32_t *)pa;
uint32_t b = *(const uint32_t *)pb;
if (a < b) {
return -1;
} else if (a > b) {
return 1;
} else {
return 0;
}
}
void FastMixerDumpState::dump(int fd) const
{
if (mCommand == FastMixerState::INITIAL) {
dprintf(fd, "FastMixer not initialized\n");
return;
}
#define COMMAND_MAX 32
char string[COMMAND_MAX];
switch (mCommand) {
case FastMixerState::INITIAL:
strcpy(string, "INITIAL");
break;
case FastMixerState::HOT_IDLE:
strcpy(string, "HOT_IDLE");
break;
case FastMixerState::COLD_IDLE:
strcpy(string, "COLD_IDLE");
break;
case FastMixerState::EXIT:
strcpy(string, "EXIT");
break;
case FastMixerState::MIX:
strcpy(string, "MIX");
break;
case FastMixerState::WRITE:
strcpy(string, "WRITE");
break;
case FastMixerState::MIX_WRITE:
strcpy(string, "MIX_WRITE");
break;
default:
snprintf(string, COMMAND_MAX, "%d", mCommand);
break;
}
double measuredWarmupMs = (mMeasuredWarmupTs.tv_sec * 1000.0) +
(mMeasuredWarmupTs.tv_nsec / 1000000.0);
double mixPeriodSec = (double) mFrameCount / (double) mSampleRate;
dprintf(fd, "FastMixer command=%s writeSequence=%u framesWritten=%u\n"
" numTracks=%u writeErrors=%u underruns=%u overruns=%u\n"
" sampleRate=%u frameCount=%zu measuredWarmup=%.3g ms, warmupCycles=%u\n"
" mixPeriod=%.2f ms\n",
string, mWriteSequence, mFramesWritten,
mNumTracks, mWriteErrors, mUnderruns, mOverruns,
mSampleRate, mFrameCount, measuredWarmupMs, mWarmupCycles,
mixPeriodSec * 1e3);
#ifdef FAST_MIXER_STATISTICS
// find the interval of valid samples
uint32_t bounds = mBounds;
uint32_t newestOpen = bounds & 0xFFFF;
uint32_t oldestClosed = bounds >> 16;
uint32_t n = (newestOpen - oldestClosed) & 0xFFFF;
if (n > mSamplingN) {
ALOGE("too many samples %u", n);
n = mSamplingN;
}
// statistics for monotonic (wall clock) time, thread raw CPU load in time, CPU clock frequency,
// and adjusted CPU load in MHz normalized for CPU clock frequency
CentralTendencyStatistics wall, loadNs;
#ifdef CPU_FREQUENCY_STATISTICS
CentralTendencyStatistics kHz, loadMHz;
uint32_t previousCpukHz = 0;
#endif
// Assuming a normal distribution for cycle times, three standard deviations on either side of
// the mean account for 99.73% of the population. So if we take each tail to be 1/1000 of the
// sample set, we get 99.8% combined, or close to three standard deviations.
static const uint32_t kTailDenominator = 1000;
uint32_t *tail = n >= kTailDenominator ? new uint32_t[n] : NULL;
// loop over all the samples
for (uint32_t j = 0; j < n; ++j) {
size_t i = oldestClosed++ & (mSamplingN - 1);
uint32_t wallNs = mMonotonicNs[i];
if (tail != NULL) {
tail[j] = wallNs;
}
wall.sample(wallNs);
uint32_t sampleLoadNs = mLoadNs[i];
loadNs.sample(sampleLoadNs);
#ifdef CPU_FREQUENCY_STATISTICS
uint32_t sampleCpukHz = mCpukHz[i];
// skip bad kHz samples
if ((sampleCpukHz & ~0xF) != 0) {
kHz.sample(sampleCpukHz >> 4);
if (sampleCpukHz == previousCpukHz) {
double megacycles = (double) sampleLoadNs * (double) (sampleCpukHz >> 4) * 1e-12;
double adjMHz = megacycles / mixPeriodSec; // _not_ wallNs * 1e9
loadMHz.sample(adjMHz);
}
}
previousCpukHz = sampleCpukHz;
#endif
}
dprintf(fd, "Simple moving statistics over last %.1f seconds:\n", wall.n() * mixPeriodSec);
dprintf(fd, " wall clock time in ms per mix cycle:\n"
" mean=%.2f min=%.2f max=%.2f stddev=%.2f\n",
wall.mean()*1e-6, wall.minimum()*1e-6, wall.maximum()*1e-6, wall.stddev()*1e-6);
dprintf(fd, " raw CPU load in us per mix cycle:\n"
" mean=%.0f min=%.0f max=%.0f stddev=%.0f\n",
loadNs.mean()*1e-3, loadNs.minimum()*1e-3, loadNs.maximum()*1e-3,
loadNs.stddev()*1e-3);
#ifdef CPU_FREQUENCY_STATISTICS
dprintf(fd, " CPU clock frequency in MHz:\n"
" mean=%.0f min=%.0f max=%.0f stddev=%.0f\n",
kHz.mean()*1e-3, kHz.minimum()*1e-3, kHz.maximum()*1e-3, kHz.stddev()*1e-3);
dprintf(fd, " adjusted CPU load in MHz (i.e. normalized for CPU clock frequency):\n"
" mean=%.1f min=%.1f max=%.1f stddev=%.1f\n",
loadMHz.mean(), loadMHz.minimum(), loadMHz.maximum(), loadMHz.stddev());
#endif
if (tail != NULL) {
qsort(tail, n, sizeof(uint32_t), compare_uint32_t);
// assume same number of tail samples on each side, left and right
uint32_t count = n / kTailDenominator;
CentralTendencyStatistics left, right;
for (uint32_t i = 0; i < count; ++i) {
left.sample(tail[i]);
right.sample(tail[n - (i + 1)]);
}
dprintf(fd, "Distribution of mix cycle times in ms for the tails (> ~3 stddev outliers):\n"
" left tail: mean=%.2f min=%.2f max=%.2f stddev=%.2f\n"
" right tail: mean=%.2f min=%.2f max=%.2f stddev=%.2f\n",
left.mean()*1e-6, left.minimum()*1e-6, left.maximum()*1e-6, left.stddev()*1e-6,
right.mean()*1e-6, right.minimum()*1e-6, right.maximum()*1e-6,
right.stddev()*1e-6);
delete[] tail;
}
#endif
// The active track mask and track states are updated non-atomically.
// So if we relied on isActive to decide whether to display,
// then we might display an obsolete track or omit an active track.
// Instead we always display all tracks, with an indication
// of whether we think the track is active.
uint32_t trackMask = mTrackMask;
dprintf(fd, "Fast tracks: kMaxFastTracks=%u activeMask=%#x\n",
FastMixerState::kMaxFastTracks, trackMask);
dprintf(fd, "Index Active Full Partial Empty Recent Ready\n");
for (uint32_t i = 0; i < FastMixerState::kMaxFastTracks; ++i, trackMask >>= 1) {
bool isActive = trackMask & 1;
const FastTrackDump *ftDump = &mTracks[i];
const FastTrackUnderruns& underruns = ftDump->mUnderruns;
const char *mostRecent;
switch (underruns.mBitFields.mMostRecent) {
case UNDERRUN_FULL:
mostRecent = "full";
break;
case UNDERRUN_PARTIAL:
mostRecent = "partial";
break;
case UNDERRUN_EMPTY:
mostRecent = "empty";
break;
default:
mostRecent = "?";
break;
}
dprintf(fd, "%5u %6s %4u %7u %5u %7s %5zu\n", i, isActive ? "yes" : "no",
(underruns.mBitFields.mFull) & UNDERRUN_MASK,
(underruns.mBitFields.mPartial) & UNDERRUN_MASK,
(underruns.mBitFields.mEmpty) & UNDERRUN_MASK,
mostRecent, ftDump->mFramesReady);
}
}
} // namespace android