content: Add task queue manager

content/renderer/scheduler/task_queue_manager.h

+// Copyright 2014 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_MANAGER_H_
+#define CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_MANAGER_H_
+
+#include "base/atomic_sequence_num.h"
+#include "base/debug/task_annotator.h"
+#include "base/macros.h"
+#include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
+#include "base/pending_task.h"
+#include "base/single_thread_task_runner.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/thread_checker.h"
+
+namespace content {
+class TaskQueueScheduler;
+
+class TaskQueueManager {
+ public:
+  enum QueueId {

[alexclarke, 2014/10/13 10:06:23]

Needs a comment explaining it should be kept in sync with the enum in the
scheduler

[Sami, 2014/10/13 18:16:21]

Right, I think I'll move this to RendererBlinkPlatformImpl and keep this class
agnostic about the meaning of each queue.

+    kDefaultTaskQueue,
+    kCompositorTaskQueue,
+    // Must be the last entry.
+    kTaskQueueCount,
+  };
+
+  explicit TaskQueueManager(
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner);
+  ~TaskQueueManager();
+
+  scoped_refptr<base::SingleThreadTaskRunner> TaskRunnerForQueue(QueueId queue);
+
+  void SetScheduler(scoped_ptr<TaskQueueScheduler> scheduler);
+
+ private:
+  class TaskRunner : public base::SingleThreadTaskRunner {
+   public:
+    TaskRunner(TaskQueueManager* task_queue_manager, QueueId queue);
+
+    // base::SingleThreadTaskRunner implementation.
+    virtual bool RunsTasksOnCurrentThread() const override;
+    virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                                 const base::Closure& task,
+                                 base::TimeDelta delay) override;
+    virtual bool PostNonNestableDelayedTask(
+        const tracked_objects::Location& from_here,
+        const base::Closure& task,
+        base::TimeDelta delay) override;
+
+   private:
+    virtual ~TaskRunner();
+
+    TaskQueueManager* task_queue_manager_;
+    const QueueId queue_;
+  };
+  friend class TaskRunner;
+
+  void ScheduleWork();
+  void DoWork();
+  bool ReloadWorkQueues();
+  bool ReloadWorkQueue(QueueId queue);
+  void RunTaskFromWorkQueue(QueueId queue);
+
+  bool RunsTasksOnCurrentThread() const;
+  bool PostDelayedTask(QueueId queue,
+                       const tracked_objects::Location& from_here,
+                       const base::Closure& task,
+                       base::TimeDelta delay);
+  bool PostNonNestableDelayedTask(QueueId queue,
+                                  const tracked_objects::Location& from_here,
+                                  const base::Closure& task,
+                                  base::TimeDelta delay);
+
+  void EnqueueTask(QueueId queue, base::PendingTask pending_task);
+
+  struct TaskQueue {
+    TaskQueue(QueueId id);
+    ~TaskQueue();
+
+    const QueueId id;
+    scoped_refptr<TaskRunner> task_runner;
+
+    base::Lock incoming_queue_lock;
+    base::TaskQueue incoming_queue;
+
+    base::TaskQueue work_queue;
+  };
+
+  ScopedVector<TaskQueue> queues_;
+  base::AtomicSequenceNumber task_sequence_num_;
+  base::debug::TaskAnnotator task_annotator_;
+
+  base::ThreadChecker main_thread_checker_;
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  scoped_ptr<TaskQueueScheduler> scheduler_;
+
+  base::WeakPtrFactory<TaskQueueManager> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(TaskQueueManager);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_MANAGER_H_