| // Copyright 2018 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_TASK_TASK_FEATURES_H_ |
| #define BASE_TASK_TASK_FEATURES_H_ |
| |
| #include "base/base_export.h" |
| #include "base/feature_list.h" |
| #include "base/metrics/field_trial_params.h" |
| #include "build/build_config.h" |
| |
| namespace base { |
| |
| // Fixed amount of threads that will be used as a cap for thread pools. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kThreadPoolCap2); |
| |
| extern const BASE_EXPORT base::FeatureParam<int> kThreadPoolCapRestrictedCount; |
| |
| // Under this feature, a utility_thread_group will be created for |
| // running USER_VISIBLE tasks. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kUseUtilityThreadGroup); |
| |
| // Under this feature, worker threads are not reclaimed after a timeout. Rather, |
| // only excess workers are cleaned up immediately after finishing a task. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kNoWorkerThreadReclaim); |
| |
| // This feature controls whether ThreadPool WorkerThreads should hold off waking |
| // up to purge PartitionAlloc within the first minute of their lifetime. See |
| // base::internal::GetSleepDurationBeforePurge. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kDelayFirstWorkerWake); |
| |
| // Under this feature, a non-zero leeway is added to delayed tasks. Along with |
| // DelayPolicy, this affects the time at which a delayed task runs. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kAddTaskLeewayFeature); |
| #if BUILDFLAG(IS_WIN) |
| constexpr TimeDelta kDefaultLeeway = Milliseconds(16); |
| #else |
| constexpr TimeDelta kDefaultLeeway = Milliseconds(8); |
| #endif // #if !BUILDFLAG(IS_WIN) |
| extern const BASE_EXPORT base::FeatureParam<TimeDelta> kTaskLeewayParam; |
| |
| // We consider that delayed tasks above |kMaxPreciseDelay| never need |
| // DelayPolicy::kPrecise. The default value is slightly above 30Hz timer. |
| constexpr TimeDelta kDefaultMaxPreciseDelay = Milliseconds(36); |
| extern const BASE_EXPORT base::FeatureParam<TimeDelta> kMaxPreciseDelay; |
| |
| // Under this feature, wake ups are aligned at a 8ms boundary when allowed per |
| // DelayPolicy. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kAlignWakeUps); |
| |
| // Under this feature, slack is added on mac message pumps that support it when |
| // allowed per DelayPolicy. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kTimerSlackMac); |
| |
| // Under this feature, tasks that need high resolution timer are determined |
| // based on explicit DelayPolicy rather than based on a threshold. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kExplicitHighResolutionTimerWin); |
| |
| // Feature to run tasks by batches before pumping out messages. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kRunTasksByBatches); |
| |
| // Controls the max number of delayed tasks that can run before selecting an |
| // immediate task in sequence manager. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kMaxDelayedStarvationTasks); |
| extern const BASE_EXPORT base::FeatureParam<int> |
| kMaxDelayedStarvationTasksParam; |
| |
| // Feature to use ThreadGroupSemaphore instead of ThreadGroupImpl. |
| BASE_EXPORT BASE_DECLARE_FEATURE(kThreadGroupSemaphore); |
| extern const BASE_EXPORT base::FeatureParam<int> kMaxNumWorkersCreated; |
| |
| } // namespace base |
| |
| #endif // BASE_TASK_TASK_FEATURES_H_ |