+++ /dev/null
-/*
- * Copyright (C) 2011 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.
- */
-
-#ifndef _CENTRAL_TENDENCY_STATISTICS_H
-#define _CENTRAL_TENDENCY_STATISTICS_H
-
-#include <math.h>
-
-// Not multithread safe
-class CentralTendencyStatistics {
-
-public:
-
- CentralTendencyStatistics() :
- mMean(NAN), mMedian(NAN), mMinimum(INFINITY), mMaximum(-INFINITY), mN(0), mM2(0),
- mVariance(NAN), mVarianceKnownForN(0), mStddev(NAN), mStddevKnownForN(0) { }
-
- ~CentralTendencyStatistics() { }
-
- // add x to the set of samples
- void sample(double x);
-
- // return the arithmetic mean of all samples so far
- double mean() const { return mMean; }
-
- // return the minimum of all samples so far
- double minimum() const { return mMinimum; }
-
- // return the maximum of all samples so far
- double maximum() const { return mMaximum; }
-
- // return the variance of all samples so far
- double variance() const;
-
- // return the standard deviation of all samples so far
- double stddev() const;
-
- // return the number of samples added so far
- unsigned n() const { return mN; }
-
- // reset the set of samples to be empty
- void reset();
-
-private:
- double mMean;
- double mMedian;
- double mMinimum;
- double mMaximum;
- unsigned mN; // number of samples so far
- double mM2;
-
- // cached variance, and n at time of caching
- mutable double mVariance;
- mutable unsigned mVarianceKnownForN;
-
- // cached standard deviation, and n at time of caching
- mutable double mStddev;
- mutable unsigned mStddevKnownForN;
-
-};
-
-#endif // _CENTRAL_TENDENCY_STATISTICS_H
+++ /dev/null
-This is a static library of CPU usage statistics, originally written
-for audio but most are not actually specific to audio.
-
-Requirements to be here:
- * should be related to CPU usage statistics
- * should be portable to host; avoid Android OS dependencies without a conditional
+++ /dev/null
-/*
- * Copyright (C) 2011 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.
- */
-
-#ifndef _THREAD_CPU_USAGE_H
-#define _THREAD_CPU_USAGE_H
-
-#include <fcntl.h>
-#include <pthread.h>
-
-namespace android {
-
-// Track CPU usage for the current thread.
-// Units are in per-thread CPU ns, as reported by
-// clock_gettime(CLOCK_THREAD_CPUTIME_ID). Simple usage: for cyclic
-// threads where you want to measure the execution time of the whole
-// cycle, just call sampleAndEnable() at the start of each cycle.
-// For acyclic threads, or for cyclic threads where you want to measure/track
-// only part of each cycle, call enable(), disable(), and/or setEnabled()
-// to demarcate the region(s) of interest, and then call sample() periodically.
-// This class is not thread-safe for concurrent calls from multiple threads;
-// the methods of this class may only be called by the current thread
-// which constructed the object.
-
-class ThreadCpuUsage
-{
-
-public:
- ThreadCpuUsage() :
- mIsEnabled(false),
- mWasEverEnabled(false),
- mAccumulator(0),
- // mPreviousTs
- // mMonotonicTs
- mMonotonicKnown(false)
- {
- (void) pthread_once(&sOnceControl, &init);
- for (int i = 0; i < sKernelMax; ++i) {
- mCurrentkHz[i] = (uint32_t) ~0; // unknown
- }
- }
-
- ~ThreadCpuUsage() { }
-
- // Return whether currently tracking CPU usage by current thread
- bool isEnabled() const { return mIsEnabled; }
-
- // Enable tracking of CPU usage by current thread;
- // any CPU used from this point forward will be tracked.
- // Returns the previous enabled status.
- bool enable() { return setEnabled(true); }
-
- // Disable tracking of CPU usage by current thread;
- // any CPU used from this point forward will be ignored.
- // Returns the previous enabled status.
- bool disable() { return setEnabled(false); }
-
- // Set the enabled status and return the previous enabled status.
- // This method is intended to be used for safe nested enable/disabling.
- bool setEnabled(bool isEnabled);
-
- // Add a sample point, and also enable tracking if needed.
- // If tracking has never been enabled, then this call enables tracking but
- // does _not_ add a sample -- it is not possible to add a sample the
- // first time because there is no previous point to subtract from.
- // Otherwise, if tracking is enabled,
- // then adds a sample for tracked CPU ns since the previous
- // sample, or since the first call to sampleAndEnable(), enable(), or
- // setEnabled(true). If there was a previous sample but tracking is
- // now disabled, then adds a sample for the tracked CPU ns accumulated
- // up until the most recent disable(), resets this accumulator, and then
- // enables tracking. Calling this method rather than enable() followed
- // by sample() avoids a race condition for the first sample.
- // Returns true if the sample 'ns' is valid, or false if invalid.
- // Note that 'ns' is an output parameter passed by reference.
- // The caller does not need to initialize this variable.
- // The units are CPU nanoseconds consumed by current thread.
- bool sampleAndEnable(double& ns);
-
- // Add a sample point, but do not
- // change the tracking enabled status. If tracking has either never been
- // enabled, or has never been enabled since the last sample, then log a warning
- // and don't add sample. Otherwise, adds a sample for tracked CPU ns since
- // the previous sample or since the first call to sampleAndEnable(),
- // enable(), or setEnabled(true) if no previous sample.
- // Returns true if the sample is valid, or false if invalid.
- // Note that 'ns' is an output parameter passed by reference.
- // The caller does not need to initialize this variable.
- // The units are CPU nanoseconds consumed by current thread.
- bool sample(double& ns);
-
- // Return the elapsed delta wall clock ns since initial enable or reset,
- // as reported by clock_gettime(CLOCK_MONOTONIC).
- long long elapsed() const;
-
- // Reset elapsed wall clock. Has no effect on tracking or accumulator.
- void resetElapsed();
-
- // Return current clock frequency for specified CPU, in kHz.
- // You can get your CPU number using sched_getcpu(2). Note that, unless CPU affinity
- // has been configured appropriately, the CPU number can change.
- // Also note that, unless the CPU governor has been configured appropriately,
- // the CPU frequency can change. And even if the CPU frequency is locked down
- // to a particular value, that the frequency might still be adjusted
- // to prevent thermal overload. Therefore you should poll for your thread's
- // current CPU number and clock frequency periodically.
- uint32_t getCpukHz(int cpuNum);
-
-private:
- bool mIsEnabled; // whether tracking is currently enabled
- bool mWasEverEnabled; // whether tracking was ever enabled
- long long mAccumulator; // accumulated thread CPU time since last sample, in ns
- struct timespec mPreviousTs; // most recent thread CPU time, valid only if mIsEnabled is true
- struct timespec mMonotonicTs; // most recent monotonic time
- bool mMonotonicKnown; // whether mMonotonicTs has been set
-
- static const int MAX_CPU = 8;
- static int sScalingFds[MAX_CPU];// file descriptor per CPU for reading scaling_cur_freq
- uint32_t mCurrentkHz[MAX_CPU]; // current CPU frequency in kHz, not static to avoid a race
- static pthread_once_t sOnceControl;
- static int sKernelMax; // like MAX_CPU, but determined at runtime == cpu/kernel_max + 1
- static void init(); // called once at first ThreadCpuUsage construction
- static pthread_mutex_t sMutex; // protects sScalingFds[] after initialization
-};
-
-} // namespace android
-
-#endif // _THREAD_CPU_USAGE_H
+++ /dev/null
-LOCAL_PATH:= $(call my-dir)
-
-include $(CLEAR_VARS)
-
-LOCAL_SRC_FILES := \
- CentralTendencyStatistics.cpp \
- ThreadCpuUsage.cpp
-
-LOCAL_MODULE := libcpustats
-
-include $(BUILD_STATIC_LIBRARY)
+++ /dev/null
-/*
- * Copyright (C) 2011 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.
- */
-
-#include <stdlib.h>
-
-#include <cpustats/CentralTendencyStatistics.h>
-
-void CentralTendencyStatistics::sample(double x)
-{
- // update min and max
- if (x < mMinimum)
- mMinimum = x;
- if (x > mMaximum)
- mMaximum = x;
- // Knuth
- if (mN == 0) {
- mMean = 0;
- }
- ++mN;
- double delta = x - mMean;
- mMean += delta / mN;
- mM2 += delta * (x - mMean);
-}
-
-void CentralTendencyStatistics::reset()
-{
- mMean = NAN;
- mMedian = NAN;
- mMinimum = INFINITY;
- mMaximum = -INFINITY;
- mN = 0;
- mM2 = 0;
- mVariance = NAN;
- mVarianceKnownForN = 0;
- mStddev = NAN;
- mStddevKnownForN = 0;
-}
-
-double CentralTendencyStatistics::variance() const
-{
- double variance;
- if (mVarianceKnownForN != mN) {
- if (mN > 1) {
- // double variance_n = M2/n;
- variance = mM2 / (mN - 1);
- } else {
- variance = NAN;
- }
- mVariance = variance;
- mVarianceKnownForN = mN;
- } else {
- variance = mVariance;
- }
- return variance;
-}
-
-double CentralTendencyStatistics::stddev() const
-{
- double stddev;
- if (mStddevKnownForN != mN) {
- stddev = sqrt(variance());
- mStddev = stddev;
- mStddevKnownForN = mN;
- } else {
- stddev = mStddev;
- }
- return stddev;
-}
+++ /dev/null
-/*
- * Copyright (C) 2011 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.
- */
-
-#define LOG_TAG "ThreadCpuUsage"
-//#define LOG_NDEBUG 0
-
-#include <errno.h>
-#include <stdlib.h>
-#include <time.h>
-
-#include <utils/Debug.h>
-#include <utils/Log.h>
-
-#include <cpustats/ThreadCpuUsage.h>
-
-namespace android {
-
-bool ThreadCpuUsage::setEnabled(bool isEnabled)
-{
- bool wasEnabled = mIsEnabled;
- // only do something if there is a change
- if (isEnabled != wasEnabled) {
- ALOGV("setEnabled(%d)", isEnabled);
- int rc;
- // enabling
- if (isEnabled) {
- rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &mPreviousTs);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_THREAD_CPUTIME_ID) errno=%d", errno);
- isEnabled = false;
- } else {
- mWasEverEnabled = true;
- // record wall clock time at first enable
- if (!mMonotonicKnown) {
- rc = clock_gettime(CLOCK_MONOTONIC, &mMonotonicTs);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_MONOTONIC) errno=%d", errno);
- } else {
- mMonotonicKnown = true;
- }
- }
- }
- // disabling
- } else {
- struct timespec ts;
- rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_THREAD_CPUTIME_ID) errno=%d", errno);
- } else {
- long long delta = (ts.tv_sec - mPreviousTs.tv_sec) * 1000000000LL +
- (ts.tv_nsec - mPreviousTs.tv_nsec);
- mAccumulator += delta;
-#if 0
- mPreviousTs = ts;
-#endif
- }
- }
- mIsEnabled = isEnabled;
- }
- return wasEnabled;
-}
-
-bool ThreadCpuUsage::sampleAndEnable(double& ns)
-{
- bool ret;
- bool wasEverEnabled = mWasEverEnabled;
- if (enable()) {
- // already enabled, so add a new sample relative to previous
- return sample(ns);
- } else if (wasEverEnabled) {
- // was disabled, but add sample for accumulated time while enabled
- ns = (double) mAccumulator;
- mAccumulator = 0;
- ALOGV("sampleAndEnable %.0f", ns);
- return true;
- } else {
- // first time called
- ns = 0.0;
- ALOGV("sampleAndEnable false");
- return false;
- }
-}
-
-bool ThreadCpuUsage::sample(double &ns)
-{
- if (mWasEverEnabled) {
- if (mIsEnabled) {
- struct timespec ts;
- int rc;
- rc = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_THREAD_CPUTIME_ID) errno=%d", errno);
- ns = 0.0;
- return false;
- } else {
- long long delta = (ts.tv_sec - mPreviousTs.tv_sec) * 1000000000LL +
- (ts.tv_nsec - mPreviousTs.tv_nsec);
- mAccumulator += delta;
- mPreviousTs = ts;
- }
- } else {
- mWasEverEnabled = false;
- }
- ns = (double) mAccumulator;
- ALOGV("sample %.0f", ns);
- mAccumulator = 0;
- return true;
- } else {
- ALOGW("Can't add sample because measurements have never been enabled");
- ns = 0.0;
- return false;
- }
-}
-
-long long ThreadCpuUsage::elapsed() const
-{
- long long elapsed;
- if (mMonotonicKnown) {
- struct timespec ts;
- int rc;
- rc = clock_gettime(CLOCK_MONOTONIC, &ts);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_MONOTONIC) errno=%d", errno);
- elapsed = 0;
- } else {
- // mMonotonicTs is updated only at first enable and resetStatistics
- elapsed = (ts.tv_sec - mMonotonicTs.tv_sec) * 1000000000LL +
- (ts.tv_nsec - mMonotonicTs.tv_nsec);
- }
- } else {
- ALOGW("Can't compute elapsed time because measurements have never been enabled");
- elapsed = 0;
- }
- ALOGV("elapsed %lld", elapsed);
- return elapsed;
-}
-
-void ThreadCpuUsage::resetElapsed()
-{
- ALOGV("resetElapsed");
- if (mMonotonicKnown) {
- int rc;
- rc = clock_gettime(CLOCK_MONOTONIC, &mMonotonicTs);
- if (rc) {
- ALOGE("clock_gettime(CLOCK_MONOTONIC) errno=%d", errno);
- mMonotonicKnown = false;
- }
- }
-}
-
-/*static*/
-int ThreadCpuUsage::sScalingFds[ThreadCpuUsage::MAX_CPU];
-pthread_once_t ThreadCpuUsage::sOnceControl = PTHREAD_ONCE_INIT;
-int ThreadCpuUsage::sKernelMax;
-pthread_mutex_t ThreadCpuUsage::sMutex = PTHREAD_MUTEX_INITIALIZER;
-
-/*static*/
-void ThreadCpuUsage::init()
-{
- // read the number of CPUs
- sKernelMax = 1;
- int fd = open("/sys/devices/system/cpu/kernel_max", O_RDONLY);
- if (fd >= 0) {
-#define KERNEL_MAX_SIZE 12
- char kernelMax[KERNEL_MAX_SIZE];
- ssize_t actual = read(fd, kernelMax, sizeof(kernelMax));
- if (actual >= 2 && kernelMax[actual-1] == '\n') {
- sKernelMax = atoi(kernelMax);
- if (sKernelMax >= MAX_CPU - 1) {
- ALOGW("kernel_max %d but MAX_CPU %d", sKernelMax, MAX_CPU);
- sKernelMax = MAX_CPU;
- } else if (sKernelMax < 0) {
- ALOGW("kernel_max invalid %d", sKernelMax);
- sKernelMax = 1;
- } else {
- ++sKernelMax;
- ALOGV("number of CPUs %d", sKernelMax);
- }
- } else {
- ALOGW("Can't read number of CPUs");
- }
- (void) close(fd);
- } else {
- ALOGW("Can't open number of CPUs");
- }
- int i;
- for (i = 0; i < MAX_CPU; ++i) {
- sScalingFds[i] = -1;
- }
-}
-
-uint32_t ThreadCpuUsage::getCpukHz(int cpuNum)
-{
- if (cpuNum < 0 || cpuNum >= MAX_CPU) {
- ALOGW("getCpukHz called with invalid CPU %d", cpuNum);
- return 0;
- }
- // double-checked locking idiom is not broken for atomic values such as fd
- int fd = sScalingFds[cpuNum];
- if (fd < 0) {
- // some kernels can't open a scaling file until hot plug complete
- pthread_mutex_lock(&sMutex);
- fd = sScalingFds[cpuNum];
- if (fd < 0) {
-#define FREQ_SIZE 64
- char freq_path[FREQ_SIZE];
-#define FREQ_DIGIT 27
- COMPILE_TIME_ASSERT_FUNCTION_SCOPE(MAX_CPU <= 10);
-#define FREQ_PATH "/sys/devices/system/cpu/cpu?/cpufreq/scaling_cur_freq"
- strlcpy(freq_path, FREQ_PATH, sizeof(freq_path));
- freq_path[FREQ_DIGIT] = cpuNum + '0';
- fd = open(freq_path, O_RDONLY | O_CLOEXEC);
- // keep this fd until process exit or exec
- sScalingFds[cpuNum] = fd;
- }
- pthread_mutex_unlock(&sMutex);
- if (fd < 0) {
- ALOGW("getCpukHz can't open CPU %d", cpuNum);
- return 0;
- }
- }
-#define KHZ_SIZE 12
- char kHz[KHZ_SIZE]; // kHz base 10
- ssize_t actual = pread(fd, kHz, sizeof(kHz), (off_t) 0);
- uint32_t ret;
- if (actual >= 2 && kHz[actual-1] == '\n') {
- ret = atoi(kHz);
- } else {
- ret = 0;
- }
- if (ret != mCurrentkHz[cpuNum]) {
- if (ret > 0) {
- ALOGV("CPU %d frequency %u kHz", cpuNum, ret);
- } else {
- ALOGW("Can't read CPU %d frequency", cpuNum);
- }
- mCurrentkHz[cpuNum] = ret;
- }
- return ret;
-}
-
-} // namespace android