1 // Copyright 2016 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 #ifndef BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ 6 #define BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ 7 8 #include <memory> 9 #include <vector> 10 11 #include "base/base_export.h" 12 #include "base/callback.h" 13 #include "base/logging.h" 14 #include "base/macros.h" 15 #include "base/memory/ptr_util.h" 16 #include "base/memory/ref_counted.h" 17 #include "base/strings/string_piece.h" 18 #include "base/synchronization/atomic_flag.h" 19 #include "base/task_scheduler/delayed_task_manager.h" 20 #include "base/task_scheduler/environment_config.h" 21 #include "base/task_scheduler/scheduler_single_thread_task_runner_manager.h" 22 #include "base/task_scheduler/scheduler_worker_pool_impl.h" 23 #include "base/task_scheduler/single_thread_task_runner_thread_mode.h" 24 #include "base/task_scheduler/task_scheduler.h" 25 #include "base/task_scheduler/task_tracker.h" 26 #include "base/task_scheduler/task_traits.h" 27 #include "build/build_config.h" 28 29 #if defined(OS_POSIX) && !defined(OS_NACL_SFI) 30 #include "base/task_scheduler/task_tracker_posix.h" 31 #endif 32 33 #if defined(OS_WIN) 34 #include "base/win/com_init_check_hook.h" 35 #endif 36 37 namespace base { 38 39 class HistogramBase; 40 class Thread; 41 42 namespace internal { 43 44 // Default TaskScheduler implementation. This class is thread-safe. 45 class BASE_EXPORT TaskSchedulerImpl : public TaskScheduler { 46 public: 47 using TaskTrackerImpl = 48 #if defined(OS_POSIX) && !defined(OS_NACL_SFI) 49 TaskTrackerPosix; 50 #else 51 TaskTracker; 52 #endif 53 54 // Creates a TaskSchedulerImpl with a production TaskTracker. 55 //|histogram_label| is used to label histograms, it must not be empty. 56 explicit TaskSchedulerImpl(StringPiece histogram_label); 57 58 // For testing only. Creates a TaskSchedulerImpl with a custom TaskTracker. 59 TaskSchedulerImpl(StringPiece histogram_label, 60 std::unique_ptr<TaskTrackerImpl> task_tracker); 61 62 ~TaskSchedulerImpl() override; 63 64 // TaskScheduler: 65 void Start(const TaskScheduler::InitParams& init_params, 66 SchedulerWorkerObserver* scheduler_worker_observer) override; 67 void PostDelayedTaskWithTraits(const Location& from_here, 68 const TaskTraits& traits, 69 OnceClosure task, 70 TimeDelta delay) override; 71 scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits( 72 const TaskTraits& traits) override; 73 scoped_refptr<SequencedTaskRunner> CreateSequencedTaskRunnerWithTraits( 74 const TaskTraits& traits) override; 75 scoped_refptr<SingleThreadTaskRunner> CreateSingleThreadTaskRunnerWithTraits( 76 const TaskTraits& traits, 77 SingleThreadTaskRunnerThreadMode thread_mode) override; 78 #if defined(OS_WIN) 79 scoped_refptr<SingleThreadTaskRunner> CreateCOMSTATaskRunnerWithTraits( 80 const TaskTraits& traits, 81 SingleThreadTaskRunnerThreadMode thread_mode) override; 82 #endif // defined(OS_WIN) 83 std::vector<const HistogramBase*> GetHistograms() const override; 84 int GetMaxConcurrentNonBlockedTasksWithTraitsDeprecated( 85 const TaskTraits& traits) const override; 86 void Shutdown() override; 87 void FlushForTesting() override; 88 void FlushAsyncForTesting(OnceClosure flush_callback) override; 89 void JoinForTesting() override; 90 91 private: 92 // Returns the worker pool that runs Tasks with |traits|. 93 SchedulerWorkerPoolImpl* GetWorkerPoolForTraits( 94 const TaskTraits& traits) const; 95 96 // Returns |traits|, with priority set to TaskPriority::USER_BLOCKING if 97 // |all_tasks_user_blocking_| is set. 98 TaskTraits SetUserBlockingPriorityIfNeeded(const TaskTraits& traits) const; 99 100 const std::unique_ptr<TaskTrackerImpl> task_tracker_; 101 std::unique_ptr<Thread> service_thread_; 102 DelayedTaskManager delayed_task_manager_; 103 SchedulerSingleThreadTaskRunnerManager single_thread_task_runner_manager_; 104 105 // Indicates that all tasks are handled as if they had been posted with 106 // TaskPriority::USER_BLOCKING. Since this is set in Start(), it doesn't apply 107 // to tasks posted before Start() or to tasks posted to TaskRunners created 108 // before Start(). 109 // 110 // TODO(fdoray): Remove after experiment. https://crbug.com/757022 111 AtomicFlag all_tasks_user_blocking_; 112 113 // Owns all the pools managed by this TaskScheduler. 114 std::vector<std::unique_ptr<SchedulerWorkerPoolImpl>> worker_pools_; 115 116 // Maps an environment from EnvironmentType to a pool in |worker_pools_|. 117 SchedulerWorkerPoolImpl* environment_to_worker_pool_[static_cast<int>( 118 EnvironmentType::ENVIRONMENT_COUNT)]; 119 120 #if DCHECK_IS_ON() 121 // Set once JoinForTesting() has returned. 122 AtomicFlag join_for_testing_returned_; 123 #endif 124 125 #if defined(OS_WIN) && defined(COM_INIT_CHECK_HOOK_ENABLED) 126 // Provides COM initialization verification for supported builds. 127 base::win::ComInitCheckHook com_init_check_hook_; 128 #endif 129 130 DISALLOW_COPY_AND_ASSIGN(TaskSchedulerImpl); 131 }; 132 133 } // namespace internal 134 } // namespace base 135 136 #endif // BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ 137