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