content/renderer/scheduler/renderer_scheduler.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_RENDERER_SCHEDULER_H_
   6 #define CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
   7
   8 #include "content/renderer/scheduler/single_thread_idle_task_runner.h"
   9 #include "content/renderer/scheduler/task_queue_manager.h"
  10 #include "third_party/WebKit/public/web/WebInputEvent.h"
  11
  12 namespace cc {
  13 struct BeginFrameArgs;
  14 }
  15
  16 namespace content {
  17
  18 class CONTENT_EXPORT RendererScheduler {
  19  public:
  20   virtual ~RendererScheduler();
  21   static scoped_ptr<RendererScheduler> Create();
  22
  23   // Returns the default task runner.
  24   virtual scoped_refptr<base::SingleThreadTaskRunner> DefaultTaskRunner() = 0;
  25
  26   // Returns the compositor task runner.
  27   virtual scoped_refptr<base::SingleThreadTaskRunner>
  28   CompositorTaskRunner() = 0;
  29
  30   // Returns the idle task runner. Tasks posted to this runner may be reordered
  31   // relative to other task types and may be starved for an arbitrarily long
  32   // time if no idle time is available.
  33   virtual scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner() = 0;
  34
  35   // Returns the loading task runner.  This queue is intended for tasks related
  36   // to resource dispatch, foreground HTML parsing, etc...
  37   virtual scoped_refptr<base::SingleThreadTaskRunner> LoadingTaskRunner() = 0;
  38
  39   // Called to notify about the start of an extended period where no frames
  40   // need to be drawn. Must be called from the main thread.
  41   virtual void BeginFrameNotExpectedSoon() = 0;
  42
  43   // Called to notify about the start of a new frame.  Must be called from the
  44   // main thread.
  45   virtual void WillBeginFrame(const cc::BeginFrameArgs& args) = 0;
  46
  47   // Called to notify that a previously begun frame was committed. Must be
  48   // called from the main thread.
  49   virtual void DidCommitFrameToCompositor() = 0;
  50
  51   // Tells the scheduler that the system received an input event. Called by the
  52   // compositor (impl) thread.
  53   virtual void DidReceiveInputEventOnCompositorThread(
  54       const blink::WebInputEvent& web_input_event) = 0;
  55
  56   // Tells the scheduler that the system is displaying an input animation (e.g.
  57   // a fling). Called by the compositor (impl) thread.
  58   virtual void DidAnimateForInputOnCompositorThread() = 0;
  59
  60   // Returns true if the scheduler has reason to believe that high priority work
  61   // may soon arrive on the main thread, e.g., if gesture events were observed
  62   // recently.
  63   // Must be called from the main thread.
  64   virtual bool IsHighPriorityWorkAnticipated() = 0;
  65
  66   // Returns true if there is high priority work pending on the main thread
  67   // and the caller should yield to let the scheduler service that work. Note
  68   // that this is a stricter condition than |IsHighPriorityWorkAnticipated|,
  69   // restricted to the case where real work is pending.
  70   // Must be called from the main thread.
  71   virtual bool ShouldYieldForHighPriorityWork() = 0;
  72
  73   // Returns true if a currently running idle task could exceed its deadline
  74   // without impacting user experience too much. This should only be used if
  75   // there is a task which cannot be pre-empted and is likely to take longer
  76   // than the largest expected idle task deadline. It should NOT be polled to
  77   // check whether more work can be performed on the current idle task after
  78   // its deadline has expired - post a new idle task for the continuation of the
  79   // work in this case.
  80   // Must be called from the main thread.
  81   virtual bool CanExceedIdleDeadlineIfRequired() const = 0;
  82
  83   // Adds or removes a task observer from the scheduler. The observer will be
  84   // notified before and after every executed task. These functions can only be
  85   // called on the main thread.
  86   virtual void AddTaskObserver(
  87       base::MessageLoop::TaskObserver* task_observer) = 0;
  88   virtual void RemoveTaskObserver(
  89       base::MessageLoop::TaskObserver* task_observer) = 0;
  90
  91   // Shuts down the scheduler by dropping any remaining pending work in the work
  92   // queues. After this call any work posted to the task runners will be
  93   // silently dropped.
  94   virtual void Shutdown() = 0;
  95
  96  protected:
  97   RendererScheduler();
  98   DISALLOW_COPY_AND_ASSIGN(RendererScheduler);
  99 };
 100
 101 }  // namespace content
 102
 103 #endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_