1/*
2 * Copyright (C) 2010, 2012 Apple 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 INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "ResponsivenessTimer.h"
28
29namespace WebKit {
30
31static const Seconds responsivenessTimeout { 3_s };
32
33ResponsivenessTimer::ResponsivenessTimer(ResponsivenessTimer::Client& client)
34 : m_client(client)
35 , m_timer(RunLoop::main(), this, &ResponsivenessTimer::timerFired)
36{
37}
38
39ResponsivenessTimer::~ResponsivenessTimer() = default;
40
41void ResponsivenessTimer::invalidate()
42{
43 m_timer.stop();
44 m_restartFireTime = MonotonicTime();
45 m_waitingForTimer = false;
46 m_useLazyStop = false;
47}
48
49void ResponsivenessTimer::timerFired()
50{
51 if (!m_waitingForTimer)
52 return;
53
54 if (m_restartFireTime) {
55 MonotonicTime now = MonotonicTime::now();
56 MonotonicTime restartFireTime = m_restartFireTime;
57 m_restartFireTime = MonotonicTime();
58
59 if (restartFireTime > now) {
60 m_timer.startOneShot(now - restartFireTime);
61 return;
62 }
63 }
64
65 m_waitingForTimer = false;
66 m_useLazyStop = false;
67
68 if (!m_isResponsive)
69 return;
70
71 if (!m_client.mayBecomeUnresponsive()) {
72 m_waitingForTimer = true;
73 m_timer.startOneShot(responsivenessTimeout);
74 return;
75 }
76
77 m_client.willChangeIsResponsive();
78 m_isResponsive = false;
79 m_client.didChangeIsResponsive();
80
81 m_client.didBecomeUnresponsive();
82}
83
84void ResponsivenessTimer::start()
85{
86 if (m_waitingForTimer)
87 return;
88
89 m_waitingForTimer = true;
90 m_useLazyStop = false;
91
92 if (m_timer.isActive()) {
93 // The timer is still active from a lazy stop.
94 // Instead of restarting the timer, we schedule a new delay after this one finishes.
95 //
96 // In most cases, stop is called before we get to schedule the second timer, saving us
97 // the scheduling of the timer entirely.
98 m_restartFireTime = MonotonicTime::now() + responsivenessTimeout;
99 } else {
100 m_restartFireTime = MonotonicTime();
101 m_timer.startOneShot(responsivenessTimeout);
102 }
103}
104
105void ResponsivenessTimer::startWithLazyStop()
106{
107 if (!m_waitingForTimer) {
108 start();
109 m_useLazyStop = true;
110 }
111}
112
113void ResponsivenessTimer::stop()
114{
115 if (!m_isResponsive) {
116 // We got a life sign from the web process.
117 m_client.willChangeIsResponsive();
118 m_isResponsive = true;
119 m_client.didChangeIsResponsive();
120
121 m_client.didBecomeResponsive();
122 }
123
124 m_waitingForTimer = false;
125
126 if (m_useLazyStop)
127 m_useLazyStop = false;
128 else
129 m_timer.stop();
130}
131
132void ResponsivenessTimer::processTerminated()
133{
134 invalidate();
135}
136
137} // namespace WebKit
138