| // 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_THREAD_POOL_THREAD_POOL_IMPL_H_ |
| #define BASE_TASK_THREAD_POOL_THREAD_POOL_IMPL_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/ptr_util.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/optional.h" |
| #include "base/sequence_checker.h" |
| #include "base/strings/string_piece.h" |
| #include "base/synchronization/atomic_flag.h" |
| #include "base/task/single_thread_task_runner_thread_mode.h" |
| #include "base/task/task_executor.h" |
| #include "base/task/task_traits.h" |
| #include "base/task/thread_pool/delayed_task_manager.h" |
| #include "base/task/thread_pool/environment_config.h" |
| #include "base/task/thread_pool/pooled_single_thread_task_runner_manager.h" |
| #include "base/task/thread_pool/pooled_task_runner_delegate.h" |
| #include "base/task/thread_pool/task_source.h" |
| #include "base/task/thread_pool/task_tracker.h" |
| #include "base/task/thread_pool/thread_group.h" |
| #include "base/task/thread_pool/thread_group_impl.h" |
| #include "base/task/thread_pool/thread_pool_instance.h" |
| #include "base/updateable_sequenced_task_runner.h" |
| #include "build/build_config.h" |
| |
| #if defined(OS_POSIX) && !defined(OS_NACL_SFI) |
| #include "base/task/thread_pool/task_tracker_posix.h" |
| #endif |
| |
| #if defined(OS_WIN) |
| #include "base/win/com_init_check_hook.h" |
| #endif |
| |
| namespace base { |
| |
| class Thread; |
| |
| namespace internal { |
| |
| // Default ThreadPoolInstance implementation. This class is thread-safe. |
| class BASE_EXPORT ThreadPoolImpl : public ThreadPoolInstance, |
| public TaskExecutor, |
| public ThreadGroup::Delegate, |
| public PooledTaskRunnerDelegate { |
| public: |
| using TaskTrackerImpl = |
| #if defined(OS_POSIX) && !defined(OS_NACL_SFI) |
| TaskTrackerPosix; |
| #else |
| TaskTracker; |
| #endif |
| |
| // Creates a ThreadPoolImpl with a production TaskTracker. |histogram_label| |
| // is used to label histograms. No histograms are recorded if it is empty. |
| explicit ThreadPoolImpl(StringPiece histogram_label); |
| |
| // For testing only. Creates a ThreadPoolImpl with a custom TaskTracker. |
| ThreadPoolImpl(StringPiece histogram_label, |
| std::unique_ptr<TaskTrackerImpl> task_tracker); |
| |
| ~ThreadPoolImpl() override; |
| |
| // ThreadPoolInstance: |
| void Start(const ThreadPoolInstance::InitParams& init_params, |
| WorkerThreadObserver* worker_thread_observer) override; |
| int GetMaxConcurrentNonBlockedTasksWithTraitsDeprecated( |
| const TaskTraits& traits) const override; |
| void Shutdown() override; |
| void FlushForTesting() override; |
| void FlushAsyncForTesting(OnceClosure flush_callback) override; |
| void JoinForTesting() override; |
| void BeginFence() override; |
| void EndFence() override; |
| void BeginBestEffortFence() override; |
| void EndBestEffortFence() override; |
| |
| // TaskExecutor: |
| bool PostDelayedTask(const Location& from_here, |
| const TaskTraits& traits, |
| OnceClosure task, |
| TimeDelta delay) override; |
| scoped_refptr<TaskRunner> CreateTaskRunner(const TaskTraits& traits) override; |
| scoped_refptr<SequencedTaskRunner> CreateSequencedTaskRunner( |
| const TaskTraits& traits) override; |
| scoped_refptr<SingleThreadTaskRunner> CreateSingleThreadTaskRunner( |
| const TaskTraits& traits, |
| SingleThreadTaskRunnerThreadMode thread_mode) override; |
| #if defined(OS_WIN) |
| scoped_refptr<SingleThreadTaskRunner> CreateCOMSTATaskRunner( |
| const TaskTraits& traits, |
| SingleThreadTaskRunnerThreadMode thread_mode) override; |
| #endif // defined(OS_WIN) |
| const scoped_refptr<SequencedTaskRunner>& GetContinuationTaskRunner() |
| override; |
| scoped_refptr<UpdateableSequencedTaskRunner> |
| CreateUpdateableSequencedTaskRunner(const TaskTraits& traits); |
| |
| // PooledTaskRunnerDelegate: |
| bool EnqueueJobTaskSource(scoped_refptr<JobTaskSource> task_source) override; |
| void RemoveJobTaskSource(scoped_refptr<JobTaskSource> task_source) override; |
| void UpdatePriority(scoped_refptr<TaskSource> task_source, |
| TaskPriority priority) override; |
| |
| // Returns the TimeTicks of the next task scheduled on ThreadPool (Now() if |
| // immediate, nullopt if none). This is thread-safe, i.e., it's safe if tasks |
| // are being posted in parallel with this call but such a situation obviously |
| // results in a race as to whether this call will see the new tasks in time. |
| Optional<TimeTicks> NextScheduledRunTimeForTesting() const; |
| |
| // Forces ripe delayed tasks to be posted (e.g. when time is mocked and |
| // advances faster than the real-time delay on ServiceThread). |
| void ProcessRipeDelayedTasksForTesting(); |
| |
| private: |
| // Invoked after |num_fences_| or |num_best_effort_fences_| is updated. Sets |
| // the CanRunPolicy in TaskTracker and wakes up workers as appropriate. |
| void UpdateCanRunPolicy(); |
| |
| // Returns |traits|, with priority set to TaskPriority::USER_BLOCKING if |
| // |all_tasks_user_blocking_| is set. |
| TaskTraits SetUserBlockingPriorityIfNeeded(TaskTraits traits) const; |
| |
| void ReportHeartbeatMetrics() const; |
| |
| const ThreadGroup* GetThreadGroupForTraits(const TaskTraits& traits) const; |
| |
| // ThreadGroup::Delegate: |
| ThreadGroup* GetThreadGroupForTraits(const TaskTraits& traits) override; |
| |
| // Posts |task| to be executed by the appropriate thread group as part of |
| // |sequence|. This must only be called after |task| has gone through |
| // TaskTracker::WillPostTask() and after |task|'s delayed run time. |
| bool PostTaskWithSequenceNow(Task task, scoped_refptr<Sequence> sequence); |
| |
| // PooledTaskRunnerDelegate: |
| bool PostTaskWithSequence(Task task, |
| scoped_refptr<Sequence> sequence) override; |
| bool ShouldYield(const TaskSource* task_source) const override; |
| |
| const std::unique_ptr<TaskTrackerImpl> task_tracker_; |
| std::unique_ptr<Thread> service_thread_; |
| DelayedTaskManager delayed_task_manager_; |
| PooledSingleThreadTaskRunnerManager single_thread_task_runner_manager_; |
| |
| // Indicates that all tasks are handled as if they had been posted with |
| // TaskPriority::USER_BLOCKING. Since this is set in Start(), it doesn't apply |
| // to tasks posted before Start() or to tasks posted to TaskRunners created |
| // before Start(). |
| // |
| // TODO(fdoray): Remove after experiment. https://crbug.com/757022 |
| AtomicFlag all_tasks_user_blocking_; |
| |
| std::unique_ptr<ThreadGroup> foreground_thread_group_; |
| std::unique_ptr<ThreadGroupImpl> background_thread_group_; |
| |
| // Whether this TaskScheduler was started. Access controlled by |
| // |sequence_checker_|. |
| bool started_ = false; |
| |
| // Whether the --disable-best-effort-tasks switch is preventing execution of |
| // BEST_EFFORT tasks until shutdown. |
| const bool has_disable_best_effort_switch_; |
| |
| // Number of fences preventing execution of tasks of any/BEST_EFFORT priority. |
| // Access controlled by |sequence_checker_|. |
| int num_fences_ = 0; |
| int num_best_effort_fences_ = 0; |
| |
| #if DCHECK_IS_ON() |
| // Set once JoinForTesting() has returned. |
| AtomicFlag join_for_testing_returned_; |
| #endif |
| |
| #if defined(OS_WIN) && defined(COM_INIT_CHECK_HOOK_ENABLED) |
| // Provides COM initialization verification for supported builds. |
| base::win::ComInitCheckHook com_init_check_hook_; |
| #endif |
| |
| // Asserts that operations occur in sequence with Start(). |
| SEQUENCE_CHECKER(sequence_checker_); |
| |
| TrackedRefFactory<ThreadGroup::Delegate> tracked_ref_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ThreadPoolImpl); |
| }; |
| |
| } // namespace internal |
| } // namespace base |
| |
| #endif // BASE_TASK_THREAD_POOL_THREAD_POOL_IMPL_H_ |