1b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Use of this source code is governed by a BSD-style license that can be 3b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// found in the LICENSE file. 4b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/metrics/field_trial.h" 6b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 7b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include <algorithm> 8b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 9b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/build_time.h" 10b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/logging.h" 11b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/rand_util.h" 1294ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez#include "base/strings/string_number_conversions.h" 13b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/strings/string_util.h" 14b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/strings/stringprintf.h" 15b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include "base/strings/utf_string_conversions.h" 16b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 17b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace base { 18b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 19b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace { 20b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 210d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// Define a separator character to use when creating a persistent form of an 220d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// instance. This is intended for use as a command line argument, passed to a 230d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// second process to mimic our state (i.e., provide the same group name). 240d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkoconst char kPersistentStringSeparator = '/'; // Currently a slash. 250d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 260d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// Define a marker character to be used as a prefix to a trial name on the 270d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// command line which forces its activation. 280d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkoconst char kActivationMarker = '*'; 290d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 30b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Created a time value based on |year|, |month| and |day_of_month| parameters. 31b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratTime CreateTimeFromParams(int year, int month, int day_of_month) { 32b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GT(year, 1970); 33b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GT(month, 0); 34b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_LT(month, 13); 35b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GT(day_of_month, 0); 36b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_LT(day_of_month, 32); 37b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 38b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Time::Exploded exploded; 39b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.year = year; 40b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.month = month; 41b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.day_of_week = 0; // Should be unused. 42b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.day_of_month = day_of_month; 43b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.hour = 0; 44b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.minute = 0; 45b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.second = 0; 46b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat exploded.millisecond = 0; 470c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez Time out_time; 480c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez if (!Time::FromLocalExploded(exploded, &out_time)) { 490c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez // TODO(maksims): implement failure handling. 500c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez // We might just return |out_time|, which is Time(0). 510c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez NOTIMPLEMENTED(); 520c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez } 53b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 540c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez return out_time; 55b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 56b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 57b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Returns the boundary value for comparing against the FieldTrial's added 58b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// groups for a given |divisor| (total probability) and |entropy_value|. 59b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial::Probability GetGroupBoundaryValue( 60b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::Probability divisor, 61b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat double entropy_value) { 62b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Add a tiny epsilon value to get consistent results when converting floating 63b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // points to int. Without it, boundary values have inconsistent results, e.g.: 64b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // 65b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // static_cast<FieldTrial::Probability>(100 * 0.56) == 56 66b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // static_cast<FieldTrial::Probability>(100 * 0.57) == 56 67b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // static_cast<FieldTrial::Probability>(100 * 0.58) == 57 68b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // static_cast<FieldTrial::Probability>(100 * 0.59) == 59 69b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const double kEpsilon = 1e-8; 70b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const FieldTrial::Probability result = 71b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat static_cast<FieldTrial::Probability>(divisor * entropy_value + kEpsilon); 72b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Ensure that adding the epsilon still results in a value < |divisor|. 73b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return std::min(result, divisor - 1); 74b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 75b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 760d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// Parses the --force-fieldtrials string |trials_string| into |entries|. 770d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// Returns true if the string was parsed correctly. On failure, the |entries| 780d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// array may end up being partially filled. 790d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkobool ParseFieldTrialsString(const std::string& trials_string, 800d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko std::vector<FieldTrial::State>* entries) { 810d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko const StringPiece trials_string_piece(trials_string); 820d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 830d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko size_t next_item = 0; 840d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko while (next_item < trials_string.length()) { 850d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko size_t name_end = trials_string.find(kPersistentStringSeparator, next_item); 860d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (name_end == trials_string.npos || next_item == name_end) 870d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return false; 880d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko size_t group_name_end = 890d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko trials_string.find(kPersistentStringSeparator, name_end + 1); 900d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (name_end + 1 == group_name_end) 910d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return false; 920d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (group_name_end == trials_string.npos) 930d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko group_name_end = trials_string.length(); 940d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 950d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial::State entry; 960d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko // Verify if the trial should be activated or not. 970d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (trials_string[next_item] == kActivationMarker) { 980d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko // Name cannot be only the indicator. 990d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (name_end - next_item == 1) 1000d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return false; 1010d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko next_item++; 1020d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko entry.activated = true; 1030d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko } 1040d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko entry.trial_name = 1050d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko trials_string_piece.substr(next_item, name_end - next_item); 1060d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko entry.group_name = 1070d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko trials_string_piece.substr(name_end + 1, group_name_end - name_end - 1); 1080d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko next_item = group_name_end + 1; 1090d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 1100d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko entries->push_back(entry); 1110d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko } 1120d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return true; 1130d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko} 1140d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 115b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace 116b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 117b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// statics 118b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratconst int FieldTrial::kNotFinalized = -1; 119b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratconst int FieldTrial::kDefaultGroupNumber = 0; 120b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratbool FieldTrial::enable_benchmarking_ = false; 121b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 122b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratint FieldTrialList::kNoExpirationYear = 0; 123b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 124b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat//------------------------------------------------------------------------------ 125b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// FieldTrial methods and members. 126b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 127b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial::EntropyProvider::~EntropyProvider() { 128b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 129b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 1300d205d712abd16eeed2f5d5b1052a367d23a223fAlex VakulenkoFieldTrial::State::State() : activated(false) {} 1310d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 13245779228f8c9e40851cfd23f727e2bd8ffdd4714Alex VakulenkoFieldTrial::State::State(const State& other) = default; 13345779228f8c9e40851cfd23f727e2bd8ffdd4714Alex Vakulenko 1340d205d712abd16eeed2f5d5b1052a367d23a223fAlex VakulenkoFieldTrial::State::~State() {} 1350d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 136b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::Disable() { 137b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!group_reported_); 138b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat enable_field_trial_ = false; 139b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 140b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // In case we are disabled after initialization, we need to switch 141b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // the trial to the default group. 142b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (group_ != kNotFinalized) { 143b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Only reset when not already the default group, because in case we were 144b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // forced to the default group, the group number may not be 145b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // kDefaultGroupNumber, so we should keep it as is. 146b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (group_name_ != default_group_name_) 147b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat SetGroupChoice(default_group_name_, kDefaultGroupNumber); 148b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 149b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 150b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 151b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratint FieldTrial::AppendGroup(const std::string& name, 152b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Probability group_probability) { 153b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // When the group choice was previously forced, we only need to return the 154b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // the id of the chosen group, and anything can be returned for the others. 155b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (forced_) { 156b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!group_name_.empty()); 157b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (name == group_name_) { 158b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Note that while |group_| may be equal to |kDefaultGroupNumber| on the 159b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // forced trial, it will not have the same value as the default group 160b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // number returned from the non-forced |FactoryGetFieldTrial()| call, 161b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // which takes care to ensure that this does not happen. 162b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return group_; 163b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 164b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_NE(next_group_number_, group_); 165b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // We still return different numbers each time, in case some caller need 166b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // them to be different. 167b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return next_group_number_++; 168b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 169b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 170b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_LE(group_probability, divisor_); 171b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GE(group_probability, 0); 172b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 173b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (enable_benchmarking_ || !enable_field_trial_) 174b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group_probability = 0; 175b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 176b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat accumulated_group_probability_ += group_probability; 177b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 178b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_LE(accumulated_group_probability_, divisor_); 179b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (group_ == kNotFinalized && accumulated_group_probability_ > random_) { 180b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // This is the group that crossed the random line, so we do the assignment. 181b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat SetGroupChoice(name, next_group_number_); 182b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 183b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return next_group_number_++; 184b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 185b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 186b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratint FieldTrial::group() { 187b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FinalizeGroupChoice(); 188b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (trial_registered_) 189b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrialList::NotifyFieldTrialGroupSelection(this); 190b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return group_; 191b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 192b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 193b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratconst std::string& FieldTrial::group_name() { 194b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Call |group()| to ensure group gets assigned and observers are notified. 195b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group(); 196b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!group_name_.empty()); 197b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return group_name_; 198b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 199b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 2000d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkoconst std::string& FieldTrial::GetGroupNameWithoutActivation() { 2010d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FinalizeGroupChoice(); 2020d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return group_name_; 2030d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko} 2040d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 205b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::SetForced() { 206b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // We might have been forced before (e.g., by CreateFieldTrial) and it's 207b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // first come first served, e.g., command line switch has precedence. 208b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (forced_) 209b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 210b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 211b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // And we must finalize the group choice before we mark ourselves as forced. 212b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FinalizeGroupChoice(); 213b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat forced_ = true; 214b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 215b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 216b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 217b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::EnableBenchmarking() { 2180c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez DCHECK_EQ(0u, FieldTrialList::GetFieldTrialCount()); 219b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat enable_benchmarking_ = true; 220b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 221b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 222b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 223b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial* FieldTrial::CreateSimulatedFieldTrial( 224b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& trial_name, 225b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Probability total_probability, 226b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& default_group_name, 227b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat double entropy_value) { 228b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return new FieldTrial(trial_name, total_probability, default_group_name, 229b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat entropy_value); 230b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 231b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 232b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial::FieldTrial(const std::string& trial_name, 233b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const Probability total_probability, 234b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& default_group_name, 235b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat double entropy_value) 236b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat : trial_name_(trial_name), 237b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat divisor_(total_probability), 238b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat default_group_name_(default_group_name), 239b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat random_(GetGroupBoundaryValue(total_probability, entropy_value)), 240b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat accumulated_group_probability_(0), 241b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat next_group_number_(kDefaultGroupNumber + 1), 242b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group_(kNotFinalized), 243b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat enable_field_trial_(true), 244b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat forced_(false), 245b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group_reported_(false), 246b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial_registered_(false) { 247b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GT(total_probability, 0); 248b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!trial_name_.empty()); 249b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!default_group_name_.empty()); 250b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 251b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 252b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial::~FieldTrial() {} 253b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 254b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::SetTrialRegistered() { 255b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(kNotFinalized, group_); 256b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!trial_registered_); 257b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial_registered_ = true; 258b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 259b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 260b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::SetGroupChoice(const std::string& group_name, int number) { 261b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group_ = number; 262b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (group_name.empty()) 263b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat StringAppendF(&group_name_, "%d", group_); 264b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat else 265b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat group_name_ = group_name; 266b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DVLOG(1) << "Field trial: " << trial_name_ << " Group choice:" << group_name_; 267b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 268b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 269b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrial::FinalizeGroupChoice() { 270b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (group_ != kNotFinalized) 271b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 272b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat accumulated_group_probability_ = divisor_; 273b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Here it's OK to use |kDefaultGroupNumber| since we can't be forced and not 274b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // finalized. 275b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!forced_); 276b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat SetGroupChoice(default_group_name_, kDefaultGroupNumber); 277b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 278b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 279b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratbool FieldTrial::GetActiveGroup(ActiveGroup* active_group) const { 280b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!group_reported_ || !enable_field_trial_) 281b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return false; 282b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_NE(group_, kNotFinalized); 283b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat active_group->trial_name = trial_name_; 284b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat active_group->group_name = group_name_; 285b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return true; 286b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 287b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 2880d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkobool FieldTrial::GetState(State* field_trial_state) { 289b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!enable_field_trial_) 290b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return false; 2910d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FinalizeGroupChoice(); 292b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial_state->trial_name = trial_name_; 2930d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko field_trial_state->group_name = group_name_; 294b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial_state->activated = group_reported_; 295b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return true; 296b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 297b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 298b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat//------------------------------------------------------------------------------ 299b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// FieldTrialList methods and members. 300b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 301b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 302b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrialList* FieldTrialList::global_ = NULL; 303b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 304b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 305b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratbool FieldTrialList::used_without_global_ = false; 306b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 307b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrialList::Observer::~Observer() { 308b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 309b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 310b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrialList::FieldTrialList( 311b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const FieldTrial::EntropyProvider* entropy_provider) 312b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat : entropy_provider_(entropy_provider), 313b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat observer_list_(new ObserverListThreadSafe<FieldTrialList::Observer>( 314b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ObserverListBase<FieldTrialList::Observer>::NOTIFY_EXISTING_ONLY)) { 3150c4f26a46430b8c503c65f5cae1d2b6876d53e30Luis Hector Chavez DCHECK(!global_); 316b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(!used_without_global_); 317b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_ = this; 318b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 319b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Time two_years_from_build_time = GetBuildTime() + TimeDelta::FromDays(730); 320b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Time::Exploded exploded; 321b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat two_years_from_build_time.LocalExplode(&exploded); 322b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat kNoExpirationYear = exploded.year; 323b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 324b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 325b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrialList::~FieldTrialList() { 326b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(lock_); 327b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat while (!registered_.empty()) { 328b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat RegistrationMap::iterator it = registered_.begin(); 329b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat it->second->Release(); 330b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat registered_.erase(it->first); 331b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 332b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(this, global_); 333b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_ = NULL; 334b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 335b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 336b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 337b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial* FieldTrialList::FactoryGetFieldTrial( 338b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& trial_name, 339b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::Probability total_probability, 340b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& default_group_name, 341b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int year, 342b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int month, 343b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int day_of_month, 344b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::RandomizationType randomization_type, 345b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat int* default_group_number) { 346b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return FactoryGetFieldTrialWithRandomizationSeed( 34794ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez trial_name, total_probability, default_group_name, year, month, 34894ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez day_of_month, randomization_type, 0, default_group_number, NULL); 349b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 350b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 351b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 352b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial* FieldTrialList::FactoryGetFieldTrialWithRandomizationSeed( 353b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& trial_name, 354b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::Probability total_probability, 355b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& default_group_name, 356b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int year, 357b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int month, 358b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int day_of_month, 359b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::RandomizationType randomization_type, 3600d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko uint32_t randomization_seed, 36194ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez int* default_group_number, 36294ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez const FieldTrial::EntropyProvider* override_entropy_provider) { 363b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (default_group_number) 364b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat *default_group_number = FieldTrial::kDefaultGroupNumber; 365b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Check if the field trial has already been created in some other way. 366b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial* existing_trial = Find(trial_name); 367b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (existing_trial) { 368b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat CHECK(existing_trial->forced_); 369b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // If the default group name differs between the existing forced trial 370b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // and this trial, then use a different value for the default group number. 371b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (default_group_number && 372b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat default_group_name != existing_trial->default_group_name()) { 373b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // If the new default group number corresponds to the group that was 374b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // chosen for the forced trial (which has been finalized when it was 375b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // forced), then set the default group number to that. 376b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (default_group_name == existing_trial->group_name_internal()) { 377b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat *default_group_number = existing_trial->group_; 378b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } else { 379b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Otherwise, use |kNonConflictingGroupNumber| (-2) for the default 380b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // group number, so that it does not conflict with the |AppendGroup()| 381b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // result for the chosen group. 382b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int kNonConflictingGroupNumber = -2; 3830d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko static_assert( 384b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat kNonConflictingGroupNumber != FieldTrial::kDefaultGroupNumber, 3850d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko "The 'non-conflicting' group number conflicts"); 3860d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko static_assert(kNonConflictingGroupNumber != FieldTrial::kNotFinalized, 3870d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko "The 'non-conflicting' group number conflicts"); 388b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat *default_group_number = kNonConflictingGroupNumber; 389b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 390b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 391b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return existing_trial; 392b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 393b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 394b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat double entropy_value; 395b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (randomization_type == FieldTrial::ONE_TIME_RANDOMIZED) { 39694ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez // If an override entropy provider is given, use it. 397b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const FieldTrial::EntropyProvider* entropy_provider = 39894ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez override_entropy_provider ? override_entropy_provider 39994ffa55491333f3dcc701befd0d2652922916d99Luis Hector Chavez : GetEntropyProviderForOneTimeRandomization(); 400b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat CHECK(entropy_provider); 401b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat entropy_value = entropy_provider->GetEntropyForTrial(trial_name, 402b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat randomization_seed); 403b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } else { 404b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(FieldTrial::SESSION_RANDOMIZED, randomization_type); 405b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(0U, randomization_seed); 406b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat entropy_value = RandDouble(); 407b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 408b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 409b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial* field_trial = new FieldTrial(trial_name, total_probability, 410b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat default_group_name, entropy_value); 411b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (GetBuildTime() > CreateTimeFromParams(year, month, day_of_month)) 412b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial->Disable(); 413b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrialList::Register(field_trial); 414b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return field_trial; 415b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 416b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 417b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 4180d205d712abd16eeed2f5d5b1052a367d23a223fAlex VakulenkoFieldTrial* FieldTrialList::Find(const std::string& trial_name) { 419b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 420b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return NULL; 421b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 4220d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return global_->PreLockedFind(trial_name); 423b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 424b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 425b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 4260d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkoint FieldTrialList::FindValue(const std::string& trial_name) { 4270d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial* field_trial = Find(trial_name); 428b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (field_trial) 429b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return field_trial->group(); 430b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return FieldTrial::kNotFinalized; 431b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 432b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 433b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 4340d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkostd::string FieldTrialList::FindFullName(const std::string& trial_name) { 4350d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial* field_trial = Find(trial_name); 436b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (field_trial) 437b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return field_trial->group_name(); 438b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return std::string(); 439b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 440b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 441b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 4420d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkobool FieldTrialList::TrialExists(const std::string& trial_name) { 4430d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return Find(trial_name) != NULL; 4440d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko} 4450d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 4460d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// static 4470d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkobool FieldTrialList::IsTrialActive(const std::string& trial_name) { 4480d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial* field_trial = Find(trial_name); 4490d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial::ActiveGroup active_group; 4500d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return field_trial && field_trial->GetActiveGroup(&active_group); 451b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 452b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 453b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 454b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::StatesToString(std::string* output) { 455b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::ActiveGroups active_groups; 456b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat GetActiveFieldTrialGroups(&active_groups); 457b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat for (FieldTrial::ActiveGroups::const_iterator it = active_groups.begin(); 458b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat it != active_groups.end(); ++it) { 459b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(std::string::npos, 460b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat it->trial_name.find(kPersistentStringSeparator)); 461b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(std::string::npos, 462b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat it->group_name.find(kPersistentStringSeparator)); 463b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(it->trial_name); 464b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(1, kPersistentStringSeparator); 465b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(it->group_name); 466b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(1, kPersistentStringSeparator); 467b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 468b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 469b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 470b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 471b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::AllStatesToString(std::string* output) { 472b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 473b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 474b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 475b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 476b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat for (const auto& registered : global_->registered_) { 4770d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial::State trial; 478b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!registered.second->GetState(&trial)) 479b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat continue; 480b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(std::string::npos, 481b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial.trial_name.find(kPersistentStringSeparator)); 482b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_EQ(std::string::npos, 483b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial.group_name.find(kPersistentStringSeparator)); 484b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (trial.activated) 485b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(1, kActivationMarker); 4860d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko trial.trial_name.AppendToString(output); 487b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(1, kPersistentStringSeparator); 4880d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko trial.group_name.AppendToString(output); 489b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat output->append(1, kPersistentStringSeparator); 490b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 491b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 492b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 493b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 494b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::GetActiveFieldTrialGroups( 495b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::ActiveGroups* active_groups) { 496b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(active_groups->empty()); 497b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 498b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 499b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 500b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 501b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat for (RegistrationMap::iterator it = global_->registered_.begin(); 502b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat it != global_->registered_.end(); ++it) { 503b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial::ActiveGroup active_group; 504b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (it->second->GetActiveGroup(&active_group)) 505b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat active_groups->push_back(active_group); 506b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 507b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 508b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 509b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 5100d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenkovoid FieldTrialList::GetActiveFieldTrialGroupsFromString( 5110d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko const std::string& trials_string, 5120d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial::ActiveGroups* active_groups) { 5130d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko std::vector<FieldTrial::State> entries; 5140d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (!ParseFieldTrialsString(trials_string, &entries)) 5150d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return; 5160d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 5170d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko for (const auto& entry : entries) { 5180d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (entry.activated) { 5190d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial::ActiveGroup group; 5200d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko group.trial_name = entry.trial_name.as_string(); 5210d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko group.group_name = entry.group_name.as_string(); 5220d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko active_groups->push_back(group); 5230d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko } 5240d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko } 5250d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko} 5260d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko 5270d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko// static 528b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratbool FieldTrialList::CreateTrialsFromString( 529b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& trials_string, 530b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::set<std::string>& ignored_trial_names) { 531b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(global_); 532b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (trials_string.empty() || !global_) 533b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return true; 534b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5350d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko std::vector<FieldTrial::State> entries; 5360d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (!ParseFieldTrialsString(trials_string, &entries)) 5370d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko return false; 538b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5390d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko for (const auto& entry : entries) { 5400d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko const std::string trial_name = entry.trial_name.as_string(); 5410d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko const std::string group_name = entry.group_name.as_string(); 542b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5430d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko if (ContainsKey(ignored_trial_names, trial_name)) 544b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat continue; 545b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5460d205d712abd16eeed2f5d5b1052a367d23a223fAlex Vakulenko FieldTrial* trial = CreateFieldTrial(trial_name, group_name); 547b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!trial) 548b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return false; 54945779228f8c9e40851cfd23f727e2bd8ffdd4714Alex Vakulenko if (entry.activated) { 550b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Call |group()| to mark the trial as "used" and notify observers, if 551b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // any. This is useful to ensure that field trials created in child 552b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // processes are properly reported in crash reports. 553b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial->group(); 554b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 555b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 556b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return true; 557b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 558b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 559b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 560b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial* FieldTrialList::CreateFieldTrial( 561b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& name, 562b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const std::string& group_name) { 563b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK(global_); 564b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GE(name.size(), 0u); 565b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat DCHECK_GE(group_name.size(), 0u); 566b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (name.empty() || group_name.empty() || !global_) 567b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return NULL; 568b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 569b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrial* field_trial = FieldTrialList::Find(name); 570b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (field_trial) { 571b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // In single process mode, or when we force them from the command line, 572b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // we may have already created the field trial. 573b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (field_trial->group_name_internal() != group_name) 574b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return NULL; 575b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return field_trial; 576b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 577b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat const int kTotalProbability = 100; 578b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial = new FieldTrial(name, kTotalProbability, group_name, 0); 579b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrialList::Register(field_trial); 580b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Force the trial, which will also finalize the group choice. 581b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial->SetForced(); 582b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return field_trial; 583b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 584b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 585b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 586b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::AddObserver(Observer* observer) { 587b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 588b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 589b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_->observer_list_->AddObserver(observer); 590b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 591b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 592b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 593b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::RemoveObserver(Observer* observer) { 594b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 595b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 596b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_->observer_list_->RemoveObserver(observer); 597b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 598b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 599b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 600b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::NotifyFieldTrialGroupSelection(FieldTrial* field_trial) { 601b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 602b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 603b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 604b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat { 605b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 606b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (field_trial->group_reported_) 607b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 608b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial->group_reported_ = true; 609b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 610b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 611b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!field_trial->enable_field_trial_) 612b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 613b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 614b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_->observer_list_->Notify( 615b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FROM_HERE, &FieldTrialList::Observer::OnFieldTrialGroupFinalized, 616b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat field_trial->trial_name(), field_trial->group_name_internal()); 617b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 618b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 619b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 620b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratsize_t FieldTrialList::GetFieldTrialCount() { 621b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) 622b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return 0; 623b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 624b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return global_->registered_.size(); 625b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 626b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 627b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 628b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratconst FieldTrial::EntropyProvider* 629b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat FieldTrialList::GetEntropyProviderForOneTimeRandomization() { 630b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) { 631b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat used_without_global_ = true; 632b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return NULL; 633b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 634b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 635b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return global_->entropy_provider_.get(); 636b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 637b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 638b8cf94937c52feb53b55c39e3f82094d27de464cDaniel EratFieldTrial* FieldTrialList::PreLockedFind(const std::string& name) { 639b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat RegistrationMap::iterator it = registered_.find(name); 640b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (registered_.end() == it) 641b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return NULL; 642b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return it->second; 643b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 644b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 645b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// static 646b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratvoid FieldTrialList::Register(FieldTrial* trial) { 647b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat if (!global_) { 648b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat used_without_global_ = true; 649b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return; 650b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat } 651b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat AutoLock auto_lock(global_->lock_); 65245779228f8c9e40851cfd23f727e2bd8ffdd4714Alex Vakulenko CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name(); 653b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial->AddRef(); 654b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat trial->SetTrialRegistered(); 655b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat global_->registered_[trial->trial_name()] = trial; 656b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 657b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 658b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace base 659