Revert of scheduler: Add a base directory

components/scheduler/child/task_queue_impl.h

+// Copyright 2015 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 CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_IMPL_H_
+#define CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_IMPL_H_
+
+#include <set>
+
+#include "base/pending_task.h"
+#include "base/threading/thread_checker.h"
+#include "base/trace_event/trace_event.h"
+#include "base/trace_event/trace_event_argument.h"
+#include "components/scheduler/child/lazy_now.h"
+#include "components/scheduler/child/task_queue.h"
+#include "components/scheduler/scheduler_export.h"
+
+namespace scheduler {
+class TaskQueueManager;
+
+namespace internal {
+
+class SCHEDULER_EXPORT TaskQueueImpl final : public TaskQueue {
+ public:
+  TaskQueueImpl(TaskQueueManager* task_queue_manager,
+                const Spec& spec,
+                const char* disabled_by_default_tracing_category,
+                const char* disabled_by_default_verbose_tracing_category);
+
+  class SCHEDULER_EXPORT Task : public base::PendingTask {
+   public:
+    Task();
+    Task(const tracked_objects::Location& posted_from,
+         const base::Closure& task,
+         int sequence_number,
+         bool nestable);
+
+    int enqueue_order() const {
+#ifndef NDEBUG
+      DCHECK(enqueue_order_set_);
+#endif
+      return enqueue_order_;
+    }
+
+    void set_enqueue_order(int enqueue_order) {
+#ifndef NDEBUG
+      DCHECK(!enqueue_order_set_);
+      enqueue_order_set_ = true;
+#endif
+      enqueue_order_ = enqueue_order;
+    }
+
+   private:
+#ifndef NDEBUG
+    bool enqueue_order_set_;
+#endif
+    // Similar to sequence number, but the |enqueue_order| is set by
+    // EnqueueTasksLocked and is not initially defined for delayed tasks until
+    // they are enqueued on the |incoming_queue_|.
+    int enqueue_order_;
+  };
+
+  // TaskQueue implementation.
+  void UnregisterTaskQueue() override;
+  bool RunsTasksOnCurrentThread() const override;
+  bool PostDelayedTask(const tracked_objects::Location& from_here,
+                       const base::Closure& task,
+                       base::TimeDelta delay) override;
+  bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
+                                  const base::Closure& task,
+                                  base::TimeDelta delay) override;
+  bool PostDelayedTaskAt(const tracked_objects::Location& from_here,
+                         const base::Closure& task,
+                         base::TimeTicks desired_run_time) override;
+
+  bool IsQueueEnabled() const override;
+  QueueState GetQueueState() const override;
+  void SetQueuePriority(QueuePriority priority) override;
+  void PumpQueue() override;
+  void SetPumpPolicy(PumpPolicy pump_policy) override;
+  void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer) override;
+  void RemoveTaskObserver(
+      base::MessageLoop::TaskObserver* task_observer) override;
+
+  bool NextPendingDelayedTaskRunTime(
+      base::TimeTicks* next_pending_delayed_task);
+
+  void UpdateWorkQueue(LazyNow* lazy_now,
+                       bool should_trigger_wakeup,
+                       const Task* previous_task);
+  Task TakeTaskFromWorkQueue();
+
+  std::queue<Task>& work_queue() { return work_queue_; }
+
+  WakeupPolicy wakeup_policy() const {
+    DCHECK(main_thread_checker_.CalledOnValidThread());
+    return wakeup_policy_;
+  }
+
+  const char* GetName() const override;
+
+  void AsValueInto(base::trace_event::TracedValue* state) const;
+
+  size_t get_task_queue_set_index() const { return set_index_; }
+
+  void set_task_queue_set_index(size_t set_index) { set_index_ = set_index; }
+
+  // If the work queue isn't empty, |enqueue_order| gets set to the enqueue
+  // order of the front task and the function returns true.  Otherwise the
+  // function returns false.
+  bool GetWorkQueueFrontTaskEnqueueOrder(int* enqueue_order) const;
+
+  bool GetQuiescenceMonitored() const { return should_monitor_quiescence_; }
+  bool GetShouldNotifyObservers() const { return should_notify_observers_; }
+
+  void NotifyWillProcessTask(const base::PendingTask& pending_task);
+  void NotifyDidProcessTask(const base::PendingTask& pending_task);
+
+  // Delayed task posted to the underlying run loop, which locks |lock_| and
+  // calls MoveReadyDelayedTasksToIncomingQueueLocked to process dealyed tasks
+  // that need to be run now.  Thread safe, but in practice it's always called
+  // from the main thread.
+  void MoveReadyDelayedTasksToIncomingQueue(LazyNow* lazy_now);
+
+  // Test support functions.  These should not be used in production code.
+  void PushTaskOntoWorkQueueForTest(const Task& task);
+  void PopTaskFromWorkQueueForTest();
+  size_t WorkQueueSizeForTest() const { return work_queue_.size(); }
+
+  // Can be called on any thread.
+  static const char* PumpPolicyToString(TaskQueue::PumpPolicy pump_policy);
+
+  // Can be called on any thread.
+  static const char* WakeupPolicyToString(
+      TaskQueue::WakeupPolicy wakeup_policy);
+
+  // Can be called on any thread.
+  static const char* PriorityToString(TaskQueue::QueuePriority priority);
+
+ private:
+  enum class TaskType {
+    NORMAL,
+    NON_NESTABLE,
+  };
+
+  ~TaskQueueImpl() override;
+
+  bool PostDelayedTaskImpl(const tracked_objects::Location& from_here,
+                           const base::Closure& task,
+                           base::TimeDelta delay,
+                           TaskType task_type);
+  bool PostDelayedTaskLocked(LazyNow* lazy_now,
+                             const tracked_objects::Location& from_here,
+                             const base::Closure& task,
+                             base::TimeTicks desired_run_time,
+                             TaskType task_type);
+
+  // Enqueues any delayed tasks which should be run now on the incoming_queue_
+  // and calls ScheduleDelayedWorkLocked to ensure future tasks are scheduled.
+  // Must be called with |lock_| locked.
+  void MoveReadyDelayedTasksToIncomingQueueLocked(LazyNow* lazy_now);
+
+  void PumpQueueLocked();
+  bool TaskIsOlderThanQueuedTasks(const Task* task);
+  bool ShouldAutoPumpQueueLocked(bool should_trigger_wakeup,
+                                 const Task* previous_task);
+
+  // Push the task onto the |incoming_queue_| and for auto pumped queues it
+  // calls MaybePostDoWorkOnMainRunner if the incomming queue was empty.
+  void EnqueueTaskLocked(const Task& pending_task);
+
+  // Push the task onto the |incoming_queue_| and allocates an
+  // enqueue_order for it based on |enqueue_order_policy|.  Does not call
+  // MaybePostDoWorkOnMainRunner!
+  void EnqueueDelayedTaskLocked(const Task& pending_task);
+
+  void TraceQueueSize(bool is_locked) const;
+  static void QueueAsValueInto(const std::queue<Task>& queue,
+                               base::trace_event::TracedValue* state);
+  static void QueueAsValueInto(const std::priority_queue<Task>& queue,
+                               base::trace_event::TracedValue* state);
+  static void TaskAsValueInto(const Task& task,
+                              base::trace_event::TracedValue* state);
+
+  // This lock protects all members in the contigious block below.
+  // TODO(alexclarke): Group all the members protected by the lock into a struct
+  mutable base::Lock lock_;
+  base::PlatformThreadId thread_id_;
+  TaskQueueManager* task_queue_manager_;
+  std::queue<Task> incoming_queue_;
+  PumpPolicy pump_policy_;
+  std::priority_queue<Task> delayed_task_queue_;
+
+  const char* name_;
+  const char* disabled_by_default_tracing_category_;
+  const char* disabled_by_default_verbose_tracing_category_;
+
+  base::ThreadChecker main_thread_checker_;
+  std::queue<Task> work_queue_;
+  base::ObserverList<base::MessageLoop::TaskObserver> task_observers_;
+  WakeupPolicy wakeup_policy_;
+  size_t set_index_;
+  bool should_monitor_quiescence_;
+  bool should_notify_observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskQueueImpl);
+};
+
+}  // namespace internal
+}  // namespace scheduler
+
+#endif  // CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_IMPL_H_