scheduler: Move the Blink scheduler into Blink

components/scheduler/base/work_queue.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_BASE_WORK_QUEUE_H_
-#define CONTENT_RENDERER_SCHEDULER_BASE_WORK_QUEUE_H_
-
-#include <stddef.h>
-
-#include <set>
-
-#include "base/trace_event/trace_event.h"
-#include "base/trace_event/trace_event_argument.h"
-#include "components/scheduler/base/enqueue_order.h"
-#include "components/scheduler/base/task_queue_impl.h"
-#include "components/scheduler/scheduler_export.h"
-
-namespace scheduler {
-namespace internal {
-class WorkQueueSets;
-
-class SCHEDULER_EXPORT WorkQueue {
- public:
-  WorkQueue(TaskQueueImpl* task_queue, const char* name);
-  ~WorkQueue();
-
-  // Associates this work queue with the given work queue sets. This must be
-  // called before any tasks can be inserted into this work queue.
-  void AssignToWorkQueueSets(WorkQueueSets* work_queue_sets);
-
-  // Assigns the current set index.
-  void AssignSetIndex(size_t work_queue_set_index);
-
-  void AsValueInto(base::trace_event::TracedValue* state) const;
-
-  // Clears the |work_queue_|.
-  void Clear();
-
-  // returns true if the |work_queue_| is empty.
-  bool Empty() const { return work_queue_.empty(); }
-
-  // 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 GetFrontTaskEnqueueOrder(EnqueueOrder* enqueue_order) const;
-
-  // Returns the first task in this queue or null if the queue is empty.
-  const TaskQueueImpl::Task* GetFrontTask() const;
-
-  // Pushes the task onto the |work_queue_| and informs the WorkQueueSets if
-  // the head changed.
-  void Push(TaskQueueImpl::Task task);
-
-  // Pushes the task onto the |work_queue_|, sets the |enqueue_order| and
-  // informs the WorkQueueSets if the head changed.
-  void PushAndSetEnqueueOrder(TaskQueueImpl::Task task,
-                              EnqueueOrder enqueue_order);
-
-  // Swap the |work_queue_| with |incoming_queue| and informs the
-  // WorkQueueSets if the head changed. Assumes |task_queue_->any_thread_lock_|
-  // is locked.
-  void SwapLocked(std::queue<TaskQueueImpl::Task>& incoming_queue);
-
-  size_t Size() const { return work_queue_.size(); }
-
-  // Pulls a task off the |work_queue_| and informs the WorkQueueSets.
-  TaskQueueImpl::Task TakeTaskFromWorkQueue();
-
-  const char* name() const { return name_; }
-
-  TaskQueueImpl* task_queue() const { return task_queue_; }
-
-  WorkQueueSets* work_queue_sets() const { return work_queue_sets_; }
-
-  size_t work_queue_set_index() const { return work_queue_set_index_; }
-
-  // Test support function. This should not be used in production code.
-  void PopTaskForTest();
-
-  // Returns true if the front task in this queue has an older enqueue order
-  // than the front task of |other_queue|. Both queue are assumed to be
-  // non-empty.
-  bool ShouldRunBefore(const WorkQueue* other_queue) const;
-
- private:
-  std::queue<TaskQueueImpl::Task> work_queue_;
-  WorkQueueSets* work_queue_sets_;  // NOT OWNED.
-  TaskQueueImpl* task_queue_;       // NOT OWNED.
-  size_t work_queue_set_index_;
-  const char* name_;
-
-  DISALLOW_COPY_AND_ASSIGN(WorkQueue);
-};
-
-}  // namespace internal
-}  // namespace scheduler
-
-#endif  // CONTENT_RENDERER_SCHEDULER_BASE_WORK_QUEUE_H_