henrike@webrtc.org | f7795df | 2014-05-13 18:00:26 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2013 The WebRTC Project Authors. All rights reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
| 11 | #include "webrtc/base/profiler.h" |
| 12 | |
| 13 | #include <math.h> |
| 14 | |
| 15 | #include "webrtc/base/timeutils.h" |
| 16 | |
| 17 | namespace { |
| 18 | |
| 19 | // When written to an ostream, FormattedTime chooses an appropriate scale and |
| 20 | // suffix for a time value given in seconds. |
| 21 | class FormattedTime { |
| 22 | public: |
| 23 | explicit FormattedTime(double t) : time_(t) {} |
| 24 | double time() const { return time_; } |
| 25 | private: |
| 26 | double time_; |
| 27 | }; |
| 28 | |
| 29 | std::ostream& operator<<(std::ostream& stream, const FormattedTime& time) { |
| 30 | if (time.time() < 1.0) { |
| 31 | stream << (time.time() * 1000.0) << "ms"; |
| 32 | } else { |
| 33 | stream << time.time() << 's'; |
| 34 | } |
| 35 | return stream; |
| 36 | } |
| 37 | |
| 38 | } // namespace |
| 39 | |
| 40 | namespace rtc { |
| 41 | |
| 42 | ProfilerEvent::ProfilerEvent() |
| 43 | : total_time_(0.0), |
| 44 | mean_(0.0), |
| 45 | sum_of_squared_differences_(0.0), |
| 46 | start_count_(0), |
| 47 | event_count_(0) { |
| 48 | } |
| 49 | |
| 50 | void ProfilerEvent::Start() { |
| 51 | if (start_count_ == 0) { |
| 52 | current_start_time_ = TimeNanos(); |
| 53 | } |
| 54 | ++start_count_; |
| 55 | } |
| 56 | |
| 57 | void ProfilerEvent::Stop(uint64 stop_time) { |
| 58 | --start_count_; |
| 59 | ASSERT(start_count_ >= 0); |
| 60 | if (start_count_ == 0) { |
| 61 | double elapsed = static_cast<double>(stop_time - current_start_time_) / |
| 62 | kNumNanosecsPerSec; |
| 63 | total_time_ += elapsed; |
| 64 | if (event_count_ == 0) { |
| 65 | minimum_ = maximum_ = elapsed; |
| 66 | } else { |
| 67 | minimum_ = _min(minimum_, elapsed); |
| 68 | maximum_ = _max(maximum_, elapsed); |
| 69 | } |
| 70 | // Online variance and mean algorithm: http://en.wikipedia.org/wiki/ |
| 71 | // Algorithms_for_calculating_variance#Online_algorithm |
| 72 | ++event_count_; |
| 73 | double delta = elapsed - mean_; |
| 74 | mean_ = mean_ + delta / event_count_; |
| 75 | sum_of_squared_differences_ += delta * (elapsed - mean_); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | void ProfilerEvent::Stop() { |
| 80 | Stop(TimeNanos()); |
| 81 | } |
| 82 | |
| 83 | double ProfilerEvent::standard_deviation() const { |
| 84 | if (event_count_ <= 1) return 0.0; |
| 85 | return sqrt(sum_of_squared_differences_ / (event_count_ - 1.0)); |
| 86 | } |
| 87 | |
| 88 | Profiler* Profiler::Instance() { |
| 89 | LIBJINGLE_DEFINE_STATIC_LOCAL(Profiler, instance, ()); |
| 90 | return &instance; |
| 91 | } |
| 92 | |
| 93 | void Profiler::StartEvent(const std::string& event_name) { |
| 94 | lock_.LockShared(); |
| 95 | EventMap::iterator it = events_.find(event_name); |
| 96 | bool needs_insert = (it == events_.end()); |
| 97 | lock_.UnlockShared(); |
| 98 | |
| 99 | if (needs_insert) { |
| 100 | // Need an exclusive lock to modify the map. |
| 101 | ExclusiveScope scope(&lock_); |
| 102 | it = events_.insert( |
| 103 | EventMap::value_type(event_name, ProfilerEvent())).first; |
| 104 | } |
| 105 | |
| 106 | it->second.Start(); |
| 107 | } |
| 108 | |
| 109 | void Profiler::StopEvent(const std::string& event_name) { |
| 110 | // Get the time ASAP, then wait for the lock. |
| 111 | uint64 stop_time = TimeNanos(); |
| 112 | SharedScope scope(&lock_); |
| 113 | EventMap::iterator it = events_.find(event_name); |
| 114 | if (it != events_.end()) { |
| 115 | it->second.Stop(stop_time); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | void Profiler::ReportToLog(const char* file, int line, |
| 120 | LoggingSeverity severity_to_use, |
| 121 | const std::string& event_prefix) { |
| 122 | if (!LogMessage::Loggable(severity_to_use)) { |
| 123 | return; |
| 124 | } |
| 125 | |
| 126 | SharedScope scope(&lock_); |
| 127 | |
| 128 | { // Output first line. |
| 129 | LogMessage msg(file, line, severity_to_use); |
| 130 | msg.stream() << "=== Profile report "; |
| 131 | if (event_prefix.empty()) { |
| 132 | msg.stream() << "(prefix: '" << event_prefix << "') "; |
| 133 | } |
| 134 | msg.stream() << "==="; |
| 135 | } |
| 136 | for (EventMap::const_iterator it = events_.begin(); |
| 137 | it != events_.end(); ++it) { |
| 138 | if (event_prefix.empty() || it->first.find(event_prefix) == 0) { |
| 139 | LogMessage(file, line, severity_to_use).stream() |
| 140 | << it->first << " " << it->second; |
| 141 | } |
| 142 | } |
| 143 | LogMessage(file, line, severity_to_use).stream() |
| 144 | << "=== End profile report ==="; |
| 145 | } |
| 146 | |
| 147 | void Profiler::ReportAllToLog(const char* file, int line, |
| 148 | LoggingSeverity severity_to_use) { |
| 149 | ReportToLog(file, line, severity_to_use, ""); |
| 150 | } |
| 151 | |
| 152 | const ProfilerEvent* Profiler::GetEvent(const std::string& event_name) const { |
| 153 | SharedScope scope(&lock_); |
| 154 | EventMap::const_iterator it = |
| 155 | events_.find(event_name); |
| 156 | return (it == events_.end()) ? NULL : &it->second; |
| 157 | } |
| 158 | |
| 159 | bool Profiler::Clear() { |
| 160 | ExclusiveScope scope(&lock_); |
| 161 | bool result = true; |
| 162 | // Clear all events that aren't started. |
| 163 | EventMap::iterator it = events_.begin(); |
| 164 | while (it != events_.end()) { |
| 165 | if (it->second.is_started()) { |
| 166 | ++it; // Can't clear started events. |
| 167 | result = false; |
| 168 | } else { |
| 169 | events_.erase(it++); |
| 170 | } |
| 171 | } |
| 172 | return result; |
| 173 | } |
| 174 | |
| 175 | std::ostream& operator<<(std::ostream& stream, |
| 176 | const ProfilerEvent& profiler_event) { |
| 177 | stream << "count=" << profiler_event.event_count() |
| 178 | << " total=" << FormattedTime(profiler_event.total_time()) |
| 179 | << " mean=" << FormattedTime(profiler_event.mean()) |
| 180 | << " min=" << FormattedTime(profiler_event.minimum()) |
| 181 | << " max=" << FormattedTime(profiler_event.maximum()) |
| 182 | << " sd=" << profiler_event.standard_deviation(); |
| 183 | return stream; |
| 184 | } |
| 185 | |
| 186 | } // namespace rtc |