ui/accelerated_widget_mac/display_link_mac.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 UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
   6 #define UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
   7
   8 #include <QuartzCore/CVDisplayLink.h>
   9 #include <map>
  10
  11 #include "base/lazy_instance.h"
  12 #include "base/mac/scoped_typeref.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/synchronization/lock.h"
  15 #include "base/time/time.h"
  16 #include "base/timer/timer.h"
  17 #include "ui/accelerated_widget_mac/accelerated_widget_mac_export.h"
  18
  19 namespace ui {
  20
  21 class ACCELERATED_WIDGET_MAC_EXPORT DisplayLinkMac :
  22     public base::RefCounted<DisplayLinkMac> {
  23  public:
  24   static scoped_refptr<DisplayLinkMac> GetForDisplay(
  25       CGDirectDisplayID display_id);
  26
  27   // Get vsync scheduling parameters.
  28   bool GetVSyncParameters(
  29       base::TimeTicks* timebase,
  30       base::TimeDelta* interval);
  31
  32  private:
  33   friend class base::RefCounted<DisplayLinkMac>;
  34
  35   DisplayLinkMac(
  36       CGDirectDisplayID display_id,
  37       base::ScopedTypeRef<CVDisplayLinkRef> display_link);
  38   virtual ~DisplayLinkMac();
  39
  40   void StartOrContinueDisplayLink();
  41   void StopDisplayLink();
  42   void Tick(const CVTimeStamp& time);
  43
  44   // Called by the system on the display link thread, and posts a call to Tick
  45   // to the UI thread.
  46   static CVReturn DisplayLinkCallback(
  47       CVDisplayLinkRef display_link,
  48       const CVTimeStamp* now,
  49       const CVTimeStamp* output_time,
  50       CVOptionFlags flags_in,
  51       CVOptionFlags* flags_out,
  52       void* context);
  53
  54   // This is called whenever the display is reconfigured, and marks that the
  55   // vsync parameters must be recalculated.
  56   static void DisplayReconfigurationCallBack(
  57       CGDirectDisplayID display,
  58       CGDisplayChangeSummaryFlags flags,
  59       void* user_info);
  60
  61   // The task runner to post tasks to from the display link thread.
  62   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
  63
  64   // The display that this display link is attached to.
  65   CGDirectDisplayID display_id_;
  66
  67   // CVDisplayLink for querying VSync timing info.
  68   base::ScopedTypeRef<CVDisplayLinkRef> display_link_;
  69
  70   // VSync parameters computed during Tick.
  71   bool timebase_and_interval_valid_;
  72   base::TimeTicks timebase_;
  73   base::TimeDelta interval_;
  74
  75   // Each display link instance consumes a non-negligible number of cycles, so
  76   // make all display links on the same screen share the same object.
  77   typedef std::map<CGDirectDisplayID, DisplayLinkMac*> DisplayMap;
  78   static base::LazyInstance<DisplayMap> display_map_;
  79 };
  80
  81 }  // ui
  82
  83 #endif  // UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_