Revert of [chromeos/about:power] Collect cpuidle and cpufreq stats

chrome/browser/chromeos/power/cpu_data_collector.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <vector>
-
-#include "base/bind.h"
-#include "base/file_util.h"
-#include "base/logging.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_split.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "chrome/browser/chromeos/power/cpu_data_collector.h"
-#include "chrome/browser/chromeos/power/power_data_collector.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace chromeos {
-
-namespace {
-// The sampling of CPU idle or CPU freq data should not take more than this
-// limit.
-const int kSamplingDurationLimitMs = 500;
-
-// The CPU data is sampled every |kCpuDataSamplePeriodSec| seconds.
-const int kCpuDataSamplePeriodSec = 30;
-
-// The value in the file /sys/devices/system/cpu/cpu<n>/online which indicates
-// that CPU-n is online.
-const int kCpuOnlineStatus = 1;
-
-// The base of the path to the files and directories which contain CPU data in
-// the sysfs.
-const char kCpuDataPathBase[] = "/sys/devices/system/cpu";
-
-// Suffix of the path to the file listing the range of possible CPUs on the
-// system.
-const char kPossibleCpuPathSuffix[] = "/possible";
-
-// Format of the suffix of the path to the file which contains information
-// about a particular CPU being online or offline.
-const char kCpuOnlinePathSuffixFormat[] = "/cpu%d/online";
-
-// Format of the suffix of the path to the file which contains freq state
-// information of a CPU.
-const char kCpuFreqTimeInStatePathSuffixFormat[] =
-    "/cpu%d/cpufreq/stats/time_in_state";
-
-// Format of the suffix of the path to the directory which contains information
-// about an idle state of a CPU on the system.
-const char kCpuIdleStateDirPathSuffixFormat[] = "/cpu%d/cpuidle/state%d";
-
-// Format of the suffix of the path to the file which contains the name of an
-// idle state of a CPU.
-const char kCpuIdleStateNamePathSuffixFormat[] = "/cpu%d/cpuidle/state%d/name";
-
-// Format of the suffix of the path which contains information about time spent
-// in an idle state on a CPU.
-const char kCpuIdleStateTimePathSuffixFormat[] = "/cpu%d/cpuidle/state%d/time";
-
-// Returns the index at which |str| is in |vector|. If |str| is not present in
-// |vector|, then it is added to it before its index is returned.
-size_t IndexInVector(const std::string& str,
-                  std::vector<std::string>* vector) {
-  for (size_t i = 0; i < vector->size(); ++i) {
-    if (str == (*vector)[i])
-      return i;
-  }
-
-  // If this is reached, then it means |str| is not present in vector.  Add it.
-  vector->push_back(str);
-  return vector->size() - 1;
-}
-
-// Returns true if the |i|-th CPU is online; false otherwise.
-bool CpuIsOnline(const int i) {
-  const std::string online_file_format = base::StringPrintf(
-      "%s%s", kCpuDataPathBase, kCpuOnlinePathSuffixFormat);
-  const std::string cpu_online_file = base::StringPrintf(
-      online_file_format.c_str(), i);
-  if (!base::PathExists(base::FilePath(cpu_online_file))) {
-    // If the 'online' status file is missing, then it means that the CPU is
-    // not hot-pluggable and hence is always online.
-    return true;
-  }
-
-  int online;
-  std::string cpu_online_string;
-  if (base::ReadFileToString(base::FilePath(cpu_online_file),
-                             &cpu_online_string)) {
-    base::TrimWhitespace(cpu_online_string, base::TRIM_ALL, &cpu_online_string);
-    if (base::StringToInt(cpu_online_string, &online))
-      return online == kCpuOnlineStatus;
-  }
-
-  LOG(ERROR) << "Bad format or error reading " << cpu_online_file << ". "
-             << "Assuming offline.";
-  return false;
-}
-
-// Samples the CPU idle state information from sysfs. |cpu_count| is the number
-// of possible CPUs on the system. Sample at index i in |idle_samples|
-// corresponds to the idle state information of the i-th CPU.
-void SampleCpuIdleData(
-    int cpu_count,
-    std::vector<std::string>* cpu_idle_state_names,
-    std::vector<CpuDataCollector::StateOccupancySample>* idle_samples) {
-  base::Time start_time = base::Time::Now();
-  for (int cpu = 0; cpu < cpu_count; ++cpu) {
-    CpuDataCollector::StateOccupancySample idle_sample;
-    idle_sample.time = base::Time::Now();
-    idle_sample.time_in_state.reserve(cpu_idle_state_names->size());
-
-    if (!CpuIsOnline(cpu)) {
-      idle_sample.cpu_online = false;
-    } else {
-      idle_sample.cpu_online = true;
-
-      const std::string idle_state_dir_format = base::StringPrintf(
-          "%s%s", kCpuDataPathBase, kCpuIdleStateDirPathSuffixFormat);
-      for (int state_count = 0; ; ++state_count) {
-        std::string idle_state_dir = base::StringPrintf(
-            idle_state_dir_format.c_str(), cpu, state_count);
-        if (!base::DirectoryExists(base::FilePath(idle_state_dir)))
-          break;
-
-        const std::string name_file_format = base::StringPrintf(
-            "%s%s", kCpuDataPathBase, kCpuIdleStateNamePathSuffixFormat);
-        const std::string name_file_path = base::StringPrintf(
-            name_file_format.c_str(), cpu, state_count);
-        DCHECK(base::PathExists(base::FilePath(name_file_path)));
-
-        const std::string time_file_format = base::StringPrintf(
-            "%s%s", kCpuDataPathBase, kCpuIdleStateTimePathSuffixFormat);
-        const std::string time_file_path = base::StringPrintf(
-            time_file_format.c_str(), cpu, state_count);
-        DCHECK(base::PathExists(base::FilePath(time_file_path)));
-
-        std::string state_name, occupancy_time_string;
-        int64 occupancy_time_usec;
-        if (!base::ReadFileToString(base::FilePath(name_file_path),
-                                    &state_name) ||
-            !base::ReadFileToString(base::FilePath(time_file_path),
-                                    &occupancy_time_string)) {
-          // If an error occurs reading/parsing single state data, drop all the
-          // samples as an incomplete sample can mislead consumers of this
-          // sample.
-          LOG(ERROR) << "Error reading idle state from "
-                     << idle_state_dir << ". Dropping sample.";
-          idle_samples->clear();
-          return;
-        }
-
-        base::TrimWhitespace(state_name, base::TRIM_ALL, &state_name);
-        base::TrimWhitespace(
-            occupancy_time_string, base::TRIM_ALL, &occupancy_time_string);
-        if (base::StringToInt64(occupancy_time_string, &occupancy_time_usec)) {
-          // idle state occupancy time in sysfs is recorded in microseconds.
-          int64 time_in_state_ms = occupancy_time_usec / 1000;
-          size_t index = IndexInVector(state_name, cpu_idle_state_names);
-          if (index >= idle_sample.time_in_state.size())
-            idle_sample.time_in_state.resize(index + 1);
-          idle_sample.time_in_state[index] = time_in_state_ms;
-        } else {
-          LOG(ERROR) << "Bad format in " << time_file_path << ". "
-                     << "Dropping sample.";
-          idle_samples->clear();
-          return;
-        }
-      }
-    }
-
-    idle_samples->push_back(idle_sample);
-  }
-
-  // If there was an interruption in sampling (like system suspended),
-  // discard the samples!
-  int64 delay =
-      base::TimeDelta(base::Time::Now() - start_time).InMilliseconds();
-  if (delay > kSamplingDurationLimitMs) {
-    idle_samples->clear();
-    LOG(WARNING) << "Dropped an idle state sample due to excessive time delay: "
-                 << delay << "milliseconds.";
-  }
-}
-
-// Samples the CPU freq state information from sysfs. |cpu_count| is the number
-// of possible CPUs on the system. Sample at index i in |freq_samples|
-// corresponds to the freq state information of the i-th CPU.
-void SampleCpuFreqData(
-    int cpu_count,
-    std::vector<std::string>* cpu_freq_state_names,
-    std::vector<CpuDataCollector::StateOccupancySample>* freq_samples) {
-  base::Time start_time = base::Time::Now();
-  for (int cpu = 0; cpu < cpu_count; ++cpu) {
-    CpuDataCollector::StateOccupancySample freq_sample;
-    freq_sample.time_in_state.reserve(cpu_freq_state_names->size());
-
-    if (!CpuIsOnline(cpu)) {
-      freq_sample.time = base::Time::Now();
-      freq_sample.cpu_online = false;
-    } else {
-      freq_sample.cpu_online = true;
-
-      const std::string time_in_state_path_format = base::StringPrintf(
-          "%s%s", kCpuDataPathBase, kCpuFreqTimeInStatePathSuffixFormat);
-      const std::string time_in_state_path = base::StringPrintf(
-          time_in_state_path_format.c_str(), cpu);
-      DCHECK(base::PathExists(base::FilePath(time_in_state_path)));
-
-      std::string time_in_state_string;
-      // Note time as close to reading the file as possible. This is not
-      // possible for idle state samples as the information for each state there
-      // is recorded in different files.
-      base::Time now = base::Time::Now();
-      if (!base::ReadFileToString(base::FilePath(time_in_state_path),
-                                  &time_in_state_string)) {
-        LOG(ERROR) << "Error reading " << time_in_state_path << ". "
-                   << "Dropping sample.";
-        freq_samples->clear();
-        return;
-      }
-
-      freq_sample.time = now;
-
-      std::vector<std::string> lines;
-      base::SplitString(time_in_state_string, '\n', &lines);
-      // The last line could end with '\n'. Ignore the last empty string in
-      // such cases.
-      size_t state_count = lines.size();
-      if (state_count > 0 && lines.back().empty())
-        state_count -= 1;
-      for (size_t state = 0; state < state_count; ++state) {
-        std::vector<std::string> pair;
-        int freq_in_khz;
-        int64 occupancy_time_centisecond;
-
-        // Occupancy of each state is in the format "<state> <time>"
-        base::SplitString(lines[state], ' ', &pair);
-        for (size_t s = 0; s < pair.size(); ++s)
-          base::TrimWhitespace(pair[s], base::TRIM_ALL, &pair[s]);
-        if (pair.size() == 2 &&
-            base::StringToInt(pair[0], &freq_in_khz) &&
-            base::StringToInt64(pair[1], &occupancy_time_centisecond)) {
-          const std::string state_name = base::IntToString(freq_in_khz / 1000);
-          size_t index = IndexInVector(state_name, cpu_freq_state_names);
-          if (index >= freq_sample.time_in_state.size())
-            freq_sample.time_in_state.resize(index + 1);
-          // The occupancy time is in units of centiseconds.
-          freq_sample.time_in_state[index] = occupancy_time_centisecond * 10;
-        } else {
-          LOG(ERROR) << "Bad format in " << time_in_state_path << ". "
-                     << "Dropping sample.";
-          freq_samples->clear();
-          return;
-        }
-      }
-    }
-
-    freq_samples->push_back(freq_sample);
-  }
-
-  // If there was an interruption in sampling (like system suspended),
-  // discard the samples!
-  int64 delay =
-      base::TimeDelta(base::Time::Now() - start_time).InMilliseconds();
-  if (delay > kSamplingDurationLimitMs) {
-    freq_samples->clear();
-    LOG(WARNING) << "Dropped a freq state sample due to excessive time delay: "
-                 << delay << "milliseconds.";
-  }
-}
-
-}  // namespace
-
-// Set |cpu_count_| to -1 and let SampleCpuStateOnBlockingPool discover the
-// correct number of CPUs.
-CpuDataCollector::CpuDataCollector() : cpu_count_(-1), weak_ptr_factory_(this) {
-}
-
-CpuDataCollector::~CpuDataCollector() {
-}
-
-void CpuDataCollector::Start() {
-  timer_.Start(FROM_HERE,
-               base::TimeDelta::FromSeconds(kCpuDataSamplePeriodSec),
-               this,
-               &CpuDataCollector::PostSampleCpuState);
-}
-
-void CpuDataCollector::PostSampleCpuState() {
-  std::vector<std::string>* cpu_idle_state_names =
-      new std::vector<std::string>(cpu_idle_state_names_);
-  std::vector<StateOccupancySample>* idle_samples =
-      new std::vector<StateOccupancySample>;
-  std::vector<std::string>* cpu_freq_state_names =
-      new std::vector<std::string>(cpu_freq_state_names_);
-  std::vector<StateOccupancySample>* freq_samples =
-      new std::vector<StateOccupancySample>;
-  content::BrowserThread::PostBlockingPoolTaskAndReply(
-      FROM_HERE,
-      base::Bind(&CpuDataCollector::SampleCpuStateOnBlockingPool,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Unretained(cpu_idle_state_names),
-                 base::Unretained(idle_samples),
-                 base::Unretained(cpu_freq_state_names),
-                 base::Unretained(freq_samples)),
-      base::Bind(&CpuDataCollector::SaveCpuStateSamplesOnUIThread,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Owned(cpu_idle_state_names),
-                 base::Owned(idle_samples),
-                 base::Owned(cpu_freq_state_names),
-                 base::Owned(freq_samples)));
-}
-
-void CpuDataCollector::SampleCpuStateOnBlockingPool(
-    std::vector<std::string>* cpu_idle_state_names,
-    std::vector<CpuDataCollector::StateOccupancySample>* idle_samples,
-    std::vector<std::string>* cpu_freq_state_names,
-    std::vector<CpuDataCollector::StateOccupancySample>* freq_samples) {
-  DCHECK(!content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  if (cpu_count_ < 0) {
-    // Set |cpu_count_| to 1. If it is something else, it will get corrected
-    // later. A system will at least have one CPU. Hence, a value of 1 here
-    // will serve as a default value in case of errors.
-    cpu_count_ = 1;
-    const std::string possible_cpu_path = base::StringPrintf(
-        "%s%s", kCpuDataPathBase, kPossibleCpuPathSuffix);
-    if (!base::PathExists(base::FilePath(possible_cpu_path))) {
-      LOG(ERROR) << "File listing possible CPUs missing. "
-                 << "Defaulting CPU count to 1.";
-    } else {
-      std::string possible_string;
-      if (base::ReadFileToString(base::FilePath(possible_cpu_path),
-                                 &possible_string)) {
-        int max_cpu;
-        // The possible CPUs are listed in the format "0-N". Hence, N is present
-        // in the substring starting at offset 2.
-        base::TrimWhitespace(possible_string, base::TRIM_ALL, &possible_string);
-        if (possible_string.find("-") != std::string::npos &&
-            possible_string.length() > 2 &&
-            base::StringToInt(possible_string.substr(2), &max_cpu)) {
-          cpu_count_ = max_cpu + 1;
-        } else {
-          LOG(ERROR) << "Unknown format in the file listing possible CPUs. "
-                     << "Defaulting CPU count to 1.";
-        }
-      } else {
-        LOG(ERROR) << "Error reading the file listing possible CPUs. "
-                   << "Defaulting CPU count to 1.";
-      }
-    }
-  }
-
-  // Initialize the deques in the data vectors.
-  SampleCpuIdleData(cpu_count_, cpu_idle_state_names, idle_samples);
-  SampleCpuFreqData(cpu_count_, cpu_freq_state_names, freq_samples);
-}
-
-void CpuDataCollector::SaveCpuStateSamplesOnUIThread(
-    const std::vector<std::string>* cpu_idle_state_names,
-    const std::vector<CpuDataCollector::StateOccupancySample>* idle_samples,
-    const std::vector<std::string>* cpu_freq_state_names,
-    const std::vector<CpuDataCollector::StateOccupancySample>* freq_samples) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  // |idle_samples| or |freq_samples| could be empty sometimes (for example, if
-  // sampling was interrupted due to system suspension). Iff they are not empty,
-  // they will have one sample each for each of the CPUs.
-
-  if (!idle_samples->empty()) {
-    // When committing the first sample, resize the data vector to the number of
-    // CPUs on the system. This number should be the same as the number of
-    // samples in |idle_samples|.
-    if (cpu_idle_state_data_.empty()) {
-      cpu_idle_state_data_.resize(idle_samples->size());
-    } else {
-      DCHECK_EQ(idle_samples->size(), cpu_idle_state_data_.size());
-    }
-    for (size_t i = 0; i < cpu_idle_state_data_.size(); ++i)
-      AddSample(&cpu_idle_state_data_[i], (*idle_samples)[i]);
-
-    cpu_idle_state_names_ = *cpu_idle_state_names;
-  }
-
-  if (!freq_samples->empty()) {
-    // As with idle samples, resize the data vector before committing the first
-    // sample.
-    if (cpu_freq_state_data_.empty()) {
-      cpu_freq_state_data_.resize(freq_samples->size());
-    } else {
-      DCHECK_EQ(freq_samples->size(), cpu_freq_state_data_.size());
-    }
-    for (size_t i = 0; i < cpu_freq_state_data_.size(); ++i)
-      AddSample(&cpu_freq_state_data_[i], (*freq_samples)[i]);
-
-    cpu_freq_state_names_ = *cpu_freq_state_names;
-  }
-}
-
-CpuDataCollector::StateOccupancySample::StateOccupancySample()
-    : cpu_online(false) {
-}
-
-CpuDataCollector::StateOccupancySample::~StateOccupancySample() {
-}
-
-}  // namespace chromeos