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 "base/message_loop/message_loop.h"
   9 #include "content/child/scheduler/single_thread_idle_task_runner.h"
  10 #include "content/common/content_export.h"
  11 #include "third_party/WebKit/public/web/WebInputEvent.h"
  12
  13 namespace cc {
  14 struct BeginFrameArgs;
  15 }
  16
  17 namespace content {
  18
  19 class CONTENT_EXPORT RendererScheduler {
  20  public:
  21   virtual ~RendererScheduler();
  22   static scoped_ptr<RendererScheduler> Create();
  23
  24   // Returns the default task runner.
  25   virtual scoped_refptr<base::SingleThreadTaskRunner> DefaultTaskRunner() = 0;
  26
  27   // Returns the compositor task runner.
  28   virtual scoped_refptr<base::SingleThreadTaskRunner>
  29   CompositorTaskRunner() = 0;
  30
  31   // Returns the idle task runner. Tasks posted to this runner may be reordered
  32   // relative to other task types and may be starved for an arbitrarily long
  33   // time if no idle time is available.
  34   virtual scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner() = 0;
  35
  36   // Returns the loading task runner.  This queue is intended for tasks related
  37   // to resource dispatch, foreground HTML parsing, etc...
  38   virtual scoped_refptr<base::SingleThreadTaskRunner> LoadingTaskRunner() = 0;
  39
  40   // Called to notify about the start of an extended period where no frames
  41   // need to be drawn. Must be called from the main thread.
  42   virtual void BeginFrameNotExpectedSoon() = 0;
  43
  44   // Called to notify about the start of a new frame.  Must be called from the
  45   // main thread.
  46   virtual void WillBeginFrame(const cc::BeginFrameArgs& args) = 0;
  47
  48   // Called to notify that a previously begun frame was committed. Must be
  49   // called from the main thread.
  50   virtual void DidCommitFrameToCompositor() = 0;
  51
  52   // Tells the scheduler that the system received an input event. Called by the
  53   // compositor (impl) thread.
  54   virtual void DidReceiveInputEventOnCompositorThread(
  55       const blink::WebInputEvent& web_input_event) = 0;
  56
  57   // Tells the scheduler that the system is displaying an input animation (e.g.
  58   // a fling). Called by the compositor (impl) thread.
  59   virtual void DidAnimateForInputOnCompositorThread() = 0;
  60
  61   // Tells the scheduler that all render widgets managed by this renderer
  62   // process have been hidden. The renderer is assumed to be visible when the
  63   // scheduler is constructed. Must be called on the main thread.
  64   virtual void OnRendererHidden() = 0;
  65
  66   // Tells the scheduler that at least one render widget managed by this
  67   // renderer process has become visible and the renderer is no longer hidden.
  68   // The renderer is assumed to be visible when the scheduler is constructed.
  69   // Must be called on the main thread.
  70   virtual void OnRendererVisible() = 0;
  71
  72   // Returns true if the scheduler has reason to believe that high priority work
  73   // may soon arrive on the main thread, e.g., if gesture events were observed
  74   // recently.
  75   // Must be called from the main thread.
  76   virtual bool IsHighPriorityWorkAnticipated() = 0;
  77
  78   // Returns true if there is high priority work pending on the main thread
  79   // and the caller should yield to let the scheduler service that work. Note
  80   // that this is a stricter condition than |IsHighPriorityWorkAnticipated|,
  81   // restricted to the case where real work is pending.
  82   // Must be called from the main thread.
  83   virtual bool ShouldYieldForHighPriorityWork() = 0;
  84
  85   // Returns true if a currently running idle task could exceed its deadline
  86   // without impacting user experience too much. This should only be used if
  87   // there is a task which cannot be pre-empted and is likely to take longer
  88   // than the largest expected idle task deadline. It should NOT be polled to
  89   // check whether more work can be performed on the current idle task after
  90   // its deadline has expired - post a new idle task for the continuation of the
  91   // work in this case.
  92   // Must be called from the main thread.
  93   virtual bool CanExceedIdleDeadlineIfRequired() const = 0;
  94
  95   // Adds or removes a task observer from the scheduler. The observer will be
  96   // notified before and after every executed task. These functions can only be
  97   // called on the main thread.
  98   virtual void AddTaskObserver(
  99       base::MessageLoop::TaskObserver* task_observer) = 0;
 100   virtual void RemoveTaskObserver(
 101       base::MessageLoop::TaskObserver* task_observer) = 0;
 102
 103   // Shuts down the scheduler by dropping any remaining pending work in the work
 104   // queues. After this call any work posted to the task runners will be
 105   // silently dropped.
 106   virtual void Shutdown() = 0;
 107
 108  protected:
 109   RendererScheduler();
 110   DISALLOW_COPY_AND_ASSIGN(RendererScheduler);
 111 };
 112
 113 }  // namespace content
 114
 115 #endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_