blob: a9229c3f0cc968de83d3ff7916721ded6e0be0e1 (
plain)
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
|
// Copyright 2011 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 CCDelayBasedTimeSource_h
#define CCDelayBasedTimeSource_h
#include "base/memory/weak_ptr.h"
#include "cc/time_source.h"
namespace cc {
// This timer implements a time source that achieves the specified interval
// in face of millisecond-precision delayed callbacks and random queueing delays.
class DelayBasedTimeSource : public TimeSource {
public:
static scoped_refptr<DelayBasedTimeSource> create(base::TimeDelta interval, Thread* thread);
virtual void setClient(TimeSourceClient* client) OVERRIDE;
// TimeSource implementation
virtual void setTimebaseAndInterval(base::TimeTicks timebase, base::TimeDelta interval) OVERRIDE;
virtual void setActive(bool) OVERRIDE;
virtual bool active() const OVERRIDE;
// Get the last and next tick times. nextTimeTime() returns null when
// inactive.
virtual base::TimeTicks lastTickTime() OVERRIDE;
virtual base::TimeTicks nextTickTime() OVERRIDE;
// Virtual for testing.
virtual base::TimeTicks now() const;
protected:
DelayBasedTimeSource(base::TimeDelta interval, Thread* thread);
virtual ~DelayBasedTimeSource();
base::TimeTicks nextTickTarget(base::TimeTicks now);
void postNextTickTask(base::TimeTicks now);
void onTimerFired();
enum State {
STATE_INACTIVE,
STATE_STARTING,
STATE_ACTIVE,
};
struct Parameters {
Parameters(base::TimeDelta interval, base::TimeTicks tickTarget)
: interval(interval), tickTarget(tickTarget)
{ }
base::TimeDelta interval;
base::TimeTicks tickTarget;
};
TimeSourceClient* m_client;
bool m_hasTickTarget;
base::TimeTicks m_lastTickTime;
// m_currentParameters should only be written by postNextTickTask.
// m_nextParameters will take effect on the next call to postNextTickTask.
// Maintaining a pending set of parameters allows nextTickTime() to always
// reflect the actual time we expect onTimerFired to be called.
Parameters m_currentParameters;
Parameters m_nextParameters;
State m_state;
Thread* m_thread;
base::WeakPtrFactory<DelayBasedTimeSource> m_weakFactory;
DISALLOW_COPY_AND_ASSIGN(DelayBasedTimeSource);
};
} // namespace cc
#endif // CCDelayBasedTimeSource_h
|
