chrome/browser/stack_sampling_configuration.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/stack_sampling_configuration.h"
   6
   7 #include "base/rand_util.h"
   8 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
   9 #include "chrome/common/channel_info.h"
  10 #include "components/version_info/version_info.h"
  11
  12 namespace {
  13
  14 bool IsProfilerEnabledForCurrentChannel() {
  15   const version_info::Channel channel = chrome::GetChannel();
  16   return (channel == version_info::Channel::UNKNOWN ||
  17           channel == version_info::Channel::CANARY ||
  18           channel == version_info::Channel::DEV);
  19 }
  20
  21 }  // namespace
  22
  23 StackSamplingConfiguration::StackSamplingConfiguration()
  24     // We must do our own randomization here, rather than relying on a
  25     // traditional field trial, because the configuration is needed to start the
  26     // profiler before the metrics system is set up.
  27     : configuration_(static_cast<ProfileConfiguration>(
  28         base::RandInt(0, PROFILE_COUNT))) {
  29 }
  30
  31 base::StackSamplingProfiler::SamplingParams
  32 StackSamplingConfiguration::GetSamplingParams() const {
  33   base::StackSamplingProfiler::SamplingParams params;
  34   params.bursts = 1;
  35   const base::TimeDelta duration = base::TimeDelta::FromSeconds(30);
  36
  37   switch (configuration_) {
  38     case PROFILE_DISABLED:
  39       params.initial_delay = base::TimeDelta::FromMilliseconds(0);
  40       params.sampling_interval = base::TimeDelta::FromMilliseconds(0);
  41       params.samples_per_burst = 0;
  42       break;
  43
  44     case PROFILE_NO_SAMPLES:
  45       params.initial_delay = duration;
  46       params.sampling_interval = base::TimeDelta::FromMilliseconds(0);
  47       params.samples_per_burst = 0;
  48       break;
  49
  50     case PROFILE_5HZ:
  51       params.initial_delay = base::TimeDelta::FromMilliseconds(0);
  52       params.sampling_interval = base::TimeDelta::FromMilliseconds(200);
  53       params.samples_per_burst = duration / params.sampling_interval;
  54       break;
  55
  56     case PROFILE_10HZ:
  57       params.initial_delay = base::TimeDelta::FromMilliseconds(0);
  58       params.sampling_interval = base::TimeDelta::FromMilliseconds(100);
  59       params.samples_per_burst = duration / params.sampling_interval;
  60       break;
  61
  62     case PROFILE_100HZ:
  63       params.initial_delay = base::TimeDelta::FromMilliseconds(0);
  64       params.sampling_interval = base::TimeDelta::FromMilliseconds(10);
  65       params.samples_per_burst = duration / params.sampling_interval;
  66       break;
  67   }
  68   return params;
  69 }
  70
  71 bool StackSamplingConfiguration::IsProfilerEnabled() const {
  72   return IsProfilerEnabledForCurrentChannel() &&
  73       configuration_ != PROFILE_DISABLED;
  74 }
  75
  76 void StackSamplingConfiguration::RegisterSyntheticFieldTrial() const {
  77   if (!IsProfilerEnabledForCurrentChannel())
  78     return;
  79
  80   std::string group;
  81   switch (configuration_) {
  82     case PROFILE_DISABLED:
  83       group = "Disabled";
  84       break;
  85
  86     case PROFILE_NO_SAMPLES:
  87       group = "NoSamples";
  88       break;
  89
  90     case PROFILE_5HZ:
  91       group = "5Hz";
  92       break;
  93
  94     case PROFILE_10HZ:
  95       group = "10Hz";
  96       break;
  97
  98     case PROFILE_100HZ:
  99       group = "100Hz";
 100       break;
 101   }
 102
 103   ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
 104       "SyntheticStackProfilingConfiguration",
 105       group);
 106 }