1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
#define UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
#include <map>
#include <QuartzCore/CVDisplayLink.h>
#include "base/lazy_instance.h"
#include "base/mac/scoped_typeref.h"
#include "base/memory/ref_counted.h"
#include "base/synchronization/lock.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "ui/accelerated_widget_mac/accelerated_widget_mac_export.h"
namespace ui {
class ACCELERATED_WIDGET_MAC_EXPORT DisplayLinkMac :
public base::RefCounted<DisplayLinkMac> {
public:
static scoped_refptr<DisplayLinkMac> GetForDisplay(
CGDirectDisplayID display_id);
// Get vsync scheduling parameters.
bool GetVSyncParameters(
base::TimeTicks* timebase,
base::TimeDelta* interval);
// The vsync parameters are cached, because re-computing them is expensive.
// The parameters also skew over time (astonishingly quickly -- 0.1 msec per
// second), so, use this method to tell the display link the current time.
// If too much time has elapsed since the last time the vsync parameters were
// calculated, re-calculate them.
void NotifyCurrentTime(const base::TimeTicks& now);
private:
friend class base::RefCounted<DisplayLinkMac>;
DisplayLinkMac(
CGDirectDisplayID display_id,
base::ScopedTypeRef<CVDisplayLinkRef> display_link);
virtual ~DisplayLinkMac();
void StartOrContinueDisplayLink();
void StopDisplayLink();
void Tick(const CVTimeStamp& time);
// Called by the system on the display link thread, and posts a call to Tick
// to the UI thread.
static CVReturn DisplayLinkCallback(
CVDisplayLinkRef display_link,
const CVTimeStamp* now,
const CVTimeStamp* output_time,
CVOptionFlags flags_in,
CVOptionFlags* flags_out,
void* context);
// This is called whenever the display is reconfigured, and marks that the
// vsync parameters must be recalculated.
static void DisplayReconfigurationCallBack(
CGDirectDisplayID display,
CGDisplayChangeSummaryFlags flags,
void* user_info);
// The task runner to post tasks to from the display link thread.
scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
// The display that this display link is attached to.
CGDirectDisplayID display_id_;
// CVDisplayLink for querying VSync timing info.
base::ScopedTypeRef<CVDisplayLinkRef> display_link_;
// VSync parameters computed during Tick.
bool timebase_and_interval_valid_;
base::TimeTicks timebase_;
base::TimeDelta interval_;
// The time after which we should re-start the display link to get fresh
// parameters.
base::TimeTicks recalculate_time_;
// Each display link instance consumes a non-negligible number of cycles, so
// make all display links on the same screen share the same object.
typedef std::map<CGDirectDisplayID, DisplayLinkMac*> DisplayMap;
static base::LazyInstance<DisplayMap> display_map_;
};
} // ui
#endif // UI_ACCELERATED_WIDGET_MAC_DISPLAY_LINK_MAC_H_
|
