File: features.cc

package info (click to toggle)
chromium 138.0.7204.183-1
  • links: PTS, VCS
  • area: main
  • in suites: trixie
  • size: 6,071,908 kB
  • sloc: cpp: 34,937,088; ansic: 7,176,967; javascript: 4,110,704; python: 1,419,953; asm: 946,768; xml: 739,971; pascal: 187,324; sh: 89,623; perl: 88,663; objc: 79,944; sql: 50,304; cs: 41,786; fortran: 24,137; makefile: 21,806; php: 13,980; tcl: 13,166; yacc: 8,925; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (166 lines) | stat: -rw-r--r-- 5,818 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/features.h"

#include "base/files/file_path.h"
#include "base/task/sequence_manager/sequence_manager_impl.h"
#include "base/threading/platform_thread.h"
#include "build/blink_buildflags.h"
#include "build/buildflag.h"

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
#include "base/message_loop/message_pump_epoll.h"
#endif

#if BUILDFLAG(IS_APPLE)
#include "base/files/file.h"
#include "base/message_loop/message_pump_apple.h"
#include "base/synchronization/condition_variable.h"

#if !BUILDFLAG(IS_IOS) || !BUILDFLAG(USE_BLINK)
#include "base/message_loop/message_pump_kqueue.h"
#endif

#endif

#if BUILDFLAG(IS_ANDROID)
#include "base/android/input_hint_checker.h"
#endif

#if BUILDFLAG(IS_WIN)
#include "base/task/sequence_manager/thread_controller_power_monitor.h"
#endif

namespace base::features {

// Alphabetical:

// Controls caching within BASE_FEATURE_PARAM(). This is feature-controlled
// so that ScopedFeatureList can disable it to turn off caching.
BASE_FEATURE(kFeatureParamWithCache,
             "FeatureParamWithCache",
             FEATURE_ENABLED_BY_DEFAULT);

// Whether a fast implementation of FilePath::IsParent is used. This feature
// exists to ensure that the fast implementation can be disabled quickly if
// issues are found with it.
BASE_FEATURE(kFastFilePathIsParent,
             "FastFilePathIsParent",
             FEATURE_ENABLED_BY_DEFAULT);

// Use non default low memory device threshold.
// Value should be given via |LowMemoryDeviceThresholdMB|.
#if BUILDFLAG(IS_ANDROID)
// LINT.IfChange
#define LOW_MEMORY_DEVICE_THRESHOLD_MB 1024
// LINT.ThenChange(//base/android/java/src/org/chromium/base/SysUtils.java)
#elif BUILDFLAG(IS_IOS)
// For M99, 45% of devices have 2GB of RAM, and 55% have more.
#define LOW_MEMORY_DEVICE_THRESHOLD_MB 1024
#else
// Updated Desktop default threshold to match the Android 2021 definition.
#define LOW_MEMORY_DEVICE_THRESHOLD_MB 2048
#endif
BASE_FEATURE(kLowEndMemoryExperiment,
             "LowEndMemoryExperiment",
             FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE_PARAM(size_t,
                   kLowMemoryDeviceThresholdMB,
                   &kLowEndMemoryExperiment,
                   "LowMemoryDeviceThresholdMB",
                   LOW_MEMORY_DEVICE_THRESHOLD_MB);

#if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_CHROMEOS)
// Force to enable LowEndDeviceMode partially on Android 3Gb devices.
// (see PartialLowEndModeOnMidRangeDevices below)
BASE_FEATURE(kPartialLowEndModeOn3GbDevices,
             "PartialLowEndModeOn3GbDevices",
             FEATURE_DISABLED_BY_DEFAULT);

// Used to enable LowEndDeviceMode partially on Android and ChromeOS mid-range
// devices. Such devices aren't considered low-end, but we'd like experiment
// with a subset of low-end features to see if we get a good memory vs.
// performance tradeoff.
//
// TODO(crbug.com/40264947): |#if| out 32-bit before launching or going to
// high Stable %, because we will enable the feature only for <8GB 64-bit
// devices, where we didn't ship yet. However, we first need a larger
// population to collect data.
BASE_FEATURE(kPartialLowEndModeOnMidRangeDevices,
             "PartialLowEndModeOnMidRangeDevices",
#if BUILDFLAG(IS_ANDROID)
             FEATURE_ENABLED_BY_DEFAULT);
#elif BUILDFLAG(IS_CHROMEOS)
             FEATURE_DISABLED_BY_DEFAULT);
#endif

#endif  // BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_CHROMEOS)

#if BUILDFLAG(IS_ANDROID)
// Enable not perceptible binding without cpu priority boosting.
BASE_FEATURE(kBackgroundNotPerceptibleBinding,
             "BackgroundNotPerceptibleBinding",
             FEATURE_DISABLED_BY_DEFAULT);

// Whether to report frame metrics to the Android.FrameTimeline.* histograms.
BASE_FEATURE(kCollectAndroidFrameTimelineMetrics,
             "CollectAndroidFrameTimelineMetrics",
             FEATURE_DISABLED_BY_DEFAULT);

// If enabled, post registering PowerMonitor broadcast receiver to a background
// thread,
BASE_FEATURE(kPostPowerMonitorBroadcastReceiverInitToBackground,
             "PostPowerMonitorBroadcastReceiverInitToBackground",
             FEATURE_ENABLED_BY_DEFAULT);
// If enabled, getMyMemoryState IPC will be posted to background.
BASE_FEATURE(kPostGetMyMemoryStateToBackground,
             "PostGetMyMemoryStateToBackground",
             FEATURE_ENABLED_BY_DEFAULT);

// Use shared service connection to rebind a service binding to update the LRU
// in the ProcessList of OomAdjuster.
BASE_FEATURE(kUseSharedRebindServiceConnection,
             "UseSharedRebindServiceConnection",
             FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_ANDROID)

void Init(EmitThreadControllerProfilerMetadata
              emit_thread_controller_profiler_metadata) {
  sequence_manager::internal::SequenceManagerImpl::InitializeFeatures();
  sequence_manager::internal::ThreadController::InitializeFeatures(
      emit_thread_controller_profiler_metadata);

  FilePath::InitializeFeatures();

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
  MessagePumpEpoll::InitializeFeatures();
#endif

#if BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_CHROMEOS)
  PlatformThread::InitializeFeatures();
#endif

#if BUILDFLAG(IS_APPLE)
  File::InitializeFeatures();
  MessagePumpCFRunLoopBase::InitializeFeatures();

// Kqueue is not used for ios blink.
#if !BUILDFLAG(IS_IOS) || !BUILDFLAG(USE_BLINK)
  MessagePumpKqueue::InitializeFeatures();
#endif

#endif

#if BUILDFLAG(IS_ANDROID)
  android::InputHintChecker::InitializeFeatures();
#endif

#if BUILDFLAG(IS_WIN)
  sequence_manager::internal::ThreadControllerPowerMonitor::
      InitializeFeatures();
#endif
}

}  // namespace base::features