1 /*
2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #ifndef Timer_h
27 #define Timer_h
28
29 #include "platform/PlatformExport.h"
30 #include "wtf/Noncopyable.h"
31 #include "wtf/Threading.h"
32 #include "wtf/Vector.h"
33
34 namespace WebCore {
35
36 // Time intervals are all in seconds.
37
38 class TimerHeapElement;
39
40 class PLATFORM_EXPORT TimerBase {
41 WTF_MAKE_NONCOPYABLE(TimerBase); WTF_MAKE_FAST_ALLOCATED;
42 public:
43 TimerBase();
44 virtual ~TimerBase();
45
46 void start(double nextFireInterval, double repeatInterval);
47
startRepeating(double repeatInterval)48 void startRepeating(double repeatInterval) { start(repeatInterval, repeatInterval); }
startOneShot(double interval)49 void startOneShot(double interval) { start(interval, 0); }
50
51 void stop();
52 bool isActive() const;
53
54 double nextFireInterval() const;
55 double nextUnalignedFireInterval() const;
repeatInterval()56 double repeatInterval() const { return m_repeatInterval; }
57
augmentRepeatInterval(double delta)58 void augmentRepeatInterval(double delta) {
59 setNextFireTime(m_nextFireTime + delta);
60 m_repeatInterval += delta;
61 }
62
63 void didChangeAlignmentInterval();
64
65 static void fireTimersInNestedEventLoop();
66
67 private:
68 virtual void fired() = 0;
69
alignedFireTime(double fireTime)70 virtual double alignedFireTime(double fireTime) const { return fireTime; }
71
72 void checkConsistency() const;
73 void checkHeapIndex() const;
74
75 void setNextFireTime(double);
76
inHeap()77 bool inHeap() const { return m_heapIndex != -1; }
78
79 bool hasValidHeapPosition() const;
80 void updateHeapIfNeeded(double oldTime);
81
82 void heapDecreaseKey();
83 void heapDelete();
84 void heapDeleteMin();
85 void heapIncreaseKey();
86 void heapInsert();
87 void heapPop();
88 void heapPopMin();
89
timerHeap()90 Vector<TimerBase*>& timerHeap() const { ASSERT(m_cachedThreadGlobalTimerHeap); return *m_cachedThreadGlobalTimerHeap; }
91
92 double m_nextFireTime; // 0 if inactive
93 double m_unalignedNextFireTime; // m_nextFireTime not considering alignment interval
94 double m_repeatInterval; // 0 if not repeating
95 int m_heapIndex; // -1 if not in heap
96 unsigned m_heapInsertionOrder; // Used to keep order among equal-fire-time timers
97 Vector<TimerBase*>* m_cachedThreadGlobalTimerHeap;
98
99 #ifndef NDEBUG
100 ThreadIdentifier m_thread;
101 #endif
102
103 friend class ThreadTimers;
104 friend class TimerHeapLessThanFunction;
105 friend class TimerHeapReference;
106 };
107
108 template <typename TimerFiredClass>
109 class Timer : public TimerBase {
110 public:
111 typedef void (TimerFiredClass::*TimerFiredFunction)(Timer*);
112
Timer(TimerFiredClass * o,TimerFiredFunction f)113 Timer(TimerFiredClass* o, TimerFiredFunction f)
114 : m_object(o), m_function(f) { }
115
116 private:
fired()117 virtual void fired() { (m_object->*m_function)(this); }
118
119 TimerFiredClass* m_object;
120 TimerFiredFunction m_function;
121 };
122
isActive()123 inline bool TimerBase::isActive() const
124 {
125 ASSERT(m_thread == currentThread());
126 return m_nextFireTime;
127 }
128
129 template <typename TimerFiredClass>
130 class DeferrableOneShotTimer : private TimerBase {
131 public:
132 typedef void (TimerFiredClass::*TimerFiredFunction)(DeferrableOneShotTimer*);
133
DeferrableOneShotTimer(TimerFiredClass * o,TimerFiredFunction f,double delay)134 DeferrableOneShotTimer(TimerFiredClass* o, TimerFiredFunction f, double delay)
135 : m_object(o)
136 , m_function(f)
137 , m_delay(delay)
138 , m_shouldRestartWhenTimerFires(false)
139 {
140 }
141
restart()142 void restart()
143 {
144 // Setting this boolean is much more efficient than calling startOneShot
145 // again, which might result in rescheduling the system timer which
146 // can be quite expensive.
147
148 if (isActive()) {
149 m_shouldRestartWhenTimerFires = true;
150 return;
151 }
152 startOneShot(m_delay);
153 }
154
155 using TimerBase::stop;
156 using TimerBase::isActive;
157
158 private:
fired()159 virtual void fired()
160 {
161 if (m_shouldRestartWhenTimerFires) {
162 m_shouldRestartWhenTimerFires = false;
163 startOneShot(m_delay);
164 return;
165 }
166
167 (m_object->*m_function)(this);
168 }
169
170 TimerFiredClass* m_object;
171 TimerFiredFunction m_function;
172
173 double m_delay;
174 bool m_shouldRestartWhenTimerFires;
175 };
176
177 }
178
179 #endif
180