| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ |
| #define BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ |
| |
| #include <stddef.h> |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "base/base_export.h" |
| #include "base/callback.h" |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/synchronization/atomic_flag.h" |
| #include "base/task_scheduler/scheduler_worker_pool_impl.h" |
| #include "base/task_scheduler/sequence.h" |
| #include "base/task_scheduler/task_scheduler.h" |
| #include "base/task_scheduler/task_traits.h" |
| #include "base/threading/thread.h" |
| |
| namespace base { |
| |
| class HistogramBase; |
| class SchedulerWorkerPoolParams; |
| |
| namespace internal { |
| |
| class DelayedTaskManager; |
| class TaskTracker; |
| |
| // Default TaskScheduler implementation. This class is thread-safe. |
| class BASE_EXPORT TaskSchedulerImpl : public TaskScheduler { |
| public: |
| // Creates and returns an initialized TaskSchedulerImpl. CHECKs on failure. |
| // |worker_pool_params_vector| describes the worker pools to create. |
| // |worker_pool_index_for_traits_callback| returns the index in |worker_pools| |
| // of the worker pool in which a task with given traits should run. |
| static std::unique_ptr<TaskSchedulerImpl> Create( |
| const std::vector<SchedulerWorkerPoolParams>& worker_pool_params_vector, |
| const WorkerPoolIndexForTraitsCallback& |
| worker_pool_index_for_traits_callback); |
| |
| // Destroying a TaskSchedulerImpl is not allowed in production; it is always |
| // leaked. In tests, it can only be destroyed after JoinForTesting() has |
| // returned. |
| ~TaskSchedulerImpl() override; |
| |
| // TaskScheduler: |
| void PostTaskWithTraits(const tracked_objects::Location& from_here, |
| const TaskTraits& traits, |
| const Closure& task) override; |
| scoped_refptr<TaskRunner> CreateTaskRunnerWithTraits( |
| const TaskTraits& traits) override; |
| scoped_refptr<SequencedTaskRunner> CreateSequencedTaskRunnerWithTraits( |
| const TaskTraits& traits) override; |
| scoped_refptr<SingleThreadTaskRunner> CreateSingleThreadTaskRunnerWithTraits( |
| const TaskTraits& traits) override; |
| std::vector<const HistogramBase*> GetHistograms() const override; |
| void Shutdown() override; |
| void FlushForTesting() override; |
| |
| // Joins all threads of this scheduler. Tasks that are already running are |
| // allowed to complete their execution. This can only be called once. |
| void JoinForTesting(); |
| |
| private: |
| explicit TaskSchedulerImpl(const WorkerPoolIndexForTraitsCallback& |
| worker_pool_index_for_traits_callback); |
| |
| void Initialize( |
| const std::vector<SchedulerWorkerPoolParams>& worker_pool_params_vector); |
| |
| // Returns the worker pool that runs Tasks with |traits|. |
| SchedulerWorkerPool* GetWorkerPoolForTraits(const TaskTraits& traits); |
| |
| // Callback invoked when a non-single-thread |sequence| isn't empty after a |
| // worker pops a Task from it. |
| void ReEnqueueSequenceCallback(scoped_refptr<Sequence> sequence); |
| |
| Thread service_thread_; |
| std::unique_ptr<TaskTracker> task_tracker_; |
| std::unique_ptr<DelayedTaskManager> delayed_task_manager_; |
| const WorkerPoolIndexForTraitsCallback worker_pool_index_for_traits_callback_; |
| std::vector<std::unique_ptr<SchedulerWorkerPoolImpl>> worker_pools_; |
| |
| #if DCHECK_IS_ON() |
| // Set once JoinForTesting() has returned. |
| AtomicFlag join_for_testing_returned_; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(TaskSchedulerImpl); |
| }; |
| |
| } // namespace internal |
| } // namespace base |
| |
| #endif // BASE_TASK_SCHEDULER_TASK_SCHEDULER_IMPL_H_ |