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   static CVReturn DisplayLinkCallback(
  43       CVDisplayLinkRef display_link,
  44       const CVTimeStamp* now,
  45       const CVTimeStamp* output_time,
  46       CVOptionFlags flags_in,
  47       CVOptionFlags* flags_out,
  48       void* context);
  49
  50   // The display that this display link is attached to.
  51   CGDirectDisplayID display_id_;
  52
  53   // CVDisplayLink for querying VSync timing info.
  54   base::ScopedTypeRef<CVDisplayLinkRef> display_link_;
  55
  56   // Timer for stopping the display link if it has not been queried in
  57   // the last second.
  58   base::DelayTimer<DisplayLinkMac> stop_timer_;
  59
  60   // VSync parameters computed during Tick.
  61   bool timebase_and_interval_valid_;
  62   base::TimeTicks timebase_;
  63   base::TimeDelta interval_;
  64
  65   // Lock for sharing data between UI thread and display-link thread.
  66   base::Lock lock_;
  67
  68   // Each display link instance consumes a non-negligible number of cycles, so
  69   // make all display links on the same screen share the same object.
  70   typedef std::map<CGDirectDisplayID, DisplayLinkMac*> DisplayMap;
  71   static base::LazyInstance<DisplayMap> display_map_;
  72 };
  73
  74 }  // content
  75
  76 #endif  // CONTENT_BROWSER_RENDERER_HOST_DISPLAY_LINK_MAC_H_