From 921832327619f7852b16f73a19504702c5a28a31 Mon Sep 17 00:00:00 2001 From: Glenn Kasten Date: Tue, 18 Jun 2013 09:39:15 -0700 Subject: mv libcpustats from frameworks/native to frameworks/av OK to lose history Change-Id: Ieca78edc5dfe479dd7ea48fe7e0f3c164356cee3 --- include/cpustats/CentralTendencyStatistics.h | 75 +++++++ include/cpustats/README.txt | 6 + include/cpustats/ThreadCpuUsage.h | 140 +++++++++++++ media/libcpustats/Android.mk | 11 + media/libcpustats/CentralTendencyStatistics.cpp | 81 ++++++++ media/libcpustats/ThreadCpuUsage.cpp | 255 ++++++++++++++++++++++++ 6 files changed, 568 insertions(+) create mode 100644 include/cpustats/CentralTendencyStatistics.h create mode 100644 include/cpustats/README.txt create mode 100644 include/cpustats/ThreadCpuUsage.h create mode 100644 media/libcpustats/Android.mk create mode 100644 media/libcpustats/CentralTendencyStatistics.cpp create mode 100644 media/libcpustats/ThreadCpuUsage.cpp diff --git a/include/cpustats/CentralTendencyStatistics.h b/include/cpustats/CentralTendencyStatistics.h new file mode 100644 index 0000000..21b6981 --- /dev/null +++ b/include/cpustats/CentralTendencyStatistics.h @@ -0,0 +1,75 @@ +/* + * 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 + +// 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 diff --git a/include/cpustats/README.txt b/include/cpustats/README.txt new file mode 100644 index 0000000..14439f0 --- /dev/null +++ b/include/cpustats/README.txt @@ -0,0 +1,6 @@ +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 diff --git a/include/cpustats/ThreadCpuUsage.h b/include/cpustats/ThreadCpuUsage.h new file mode 100644 index 0000000..9756844 --- /dev/null +++ b/include/cpustats/ThreadCpuUsage.h @@ -0,0 +1,140 @@ +/* + * 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 +#include + +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 diff --git a/media/libcpustats/Android.mk b/media/libcpustats/Android.mk new file mode 100644 index 0000000..b506353 --- /dev/null +++ b/media/libcpustats/Android.mk @@ -0,0 +1,11 @@ +LOCAL_PATH:= $(call my-dir) + +include $(CLEAR_VARS) + +LOCAL_SRC_FILES := \ + CentralTendencyStatistics.cpp \ + ThreadCpuUsage.cpp + +LOCAL_MODULE := libcpustats + +include $(BUILD_STATIC_LIBRARY) diff --git a/media/libcpustats/CentralTendencyStatistics.cpp b/media/libcpustats/CentralTendencyStatistics.cpp new file mode 100644 index 0000000..42ab62b --- /dev/null +++ b/media/libcpustats/CentralTendencyStatistics.cpp @@ -0,0 +1,81 @@ +/* + * 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 + +#include + +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; +} diff --git a/media/libcpustats/ThreadCpuUsage.cpp b/media/libcpustats/ThreadCpuUsage.cpp new file mode 100644 index 0000000..637402a --- /dev/null +++ b/media/libcpustats/ThreadCpuUsage.cpp @@ -0,0 +1,255 @@ +/* + * 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 +#include +#include + +#include +#include + +#include + +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 -- cgit v1.1