content/renderer/scheduler/task_queue_selector.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_
   6 #define CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11
  12 namespace base {
  13 class TaskQueue;
  14 namespace trace_event {
  15 class TracedValue;
  16 }  // namespace trace_event
  17
  18 // TODO(ssid): remove these aliases after the tracing clients are moved to the
  19 // new trace_event namespace. See crbug.com/451032. ETA: March 2015
  20 namespace debug {
  21 using ::base::trace_event::TracedValue;
  22 }  // namespace debug
  23 }  // namespace base
  24
  25 namespace content {
  26
  27 class TaskQueueSelector {
  28  public:
  29   virtual ~TaskQueueSelector() {}
  30
  31   // Called once to register the work queues to be selected from. This function
  32   // is called on the main thread.
  33   virtual void RegisterWorkQueues(
  34       const std::vector<const base::TaskQueue*>& work_queues) = 0;
  35
  36   // Called to choose the work queue from which the next task should be taken
  37   // and run. Return true if |out_queue| indicates the queue to service or
  38   // false to avoid running any task.
  39   //
  40   // This function is called on the main thread.
  41   virtual bool SelectWorkQueueToService(size_t* out_queue_index) = 0;
  42
  43   // Serialize the selector state for tracing.
  44   virtual void AsValueInto(base::debug::TracedValue* state) const = 0;
  45 };
  46
  47 }  // namespace content
  48
  49 #endif  // CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_SELECTOR_H_