1/*
2 * Copyright (C) 2016 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 "ResourceUsageThread.h"
28
29#if ENABLE(RESOURCE_USAGE)
30
31#include "CommonVM.h"
32#include "JSDOMWindow.h"
33#include <thread>
34#include <wtf/MainThread.h>
35#include <wtf/Vector.h>
36
37namespace WebCore {
38
39ResourceUsageThread::ResourceUsageThread()
40{
41}
42
43ResourceUsageThread& ResourceUsageThread::singleton()
44{
45 static NeverDestroyed<ResourceUsageThread> resourceUsageThread;
46 return resourceUsageThread;
47}
48
49void ResourceUsageThread::addObserver(void* key, ResourceUsageCollectionMode mode, std::function<void (const ResourceUsageData&)> function)
50{
51 auto& resourceUsageThread = ResourceUsageThread::singleton();
52 resourceUsageThread.createThreadIfNeeded();
53
54 {
55 LockHolder locker(resourceUsageThread.m_lock);
56 bool wasEmpty = resourceUsageThread.m_observers.isEmpty();
57 resourceUsageThread.m_observers.set(key, std::make_pair(mode, function));
58
59 resourceUsageThread.recomputeCollectionMode();
60
61 if (wasEmpty) {
62 resourceUsageThread.platformSaveStateBeforeStarting();
63 resourceUsageThread.m_condition.notifyAll();
64 }
65 }
66}
67
68void ResourceUsageThread::removeObserver(void* key)
69{
70 auto& resourceUsageThread = ResourceUsageThread::singleton();
71
72 {
73 LockHolder locker(resourceUsageThread.m_lock);
74 resourceUsageThread.m_observers.remove(key);
75
76 resourceUsageThread.recomputeCollectionMode();
77 }
78}
79
80void ResourceUsageThread::waitUntilObservers()
81{
82 LockHolder locker(m_lock);
83 while (m_observers.isEmpty()) {
84 m_condition.wait(m_lock);
85
86 // Wait a bit after waking up for the first time.
87 WTF::sleep(10_ms);
88 }
89}
90
91void ResourceUsageThread::notifyObservers(ResourceUsageData&& data)
92{
93 callOnMainThread([data = WTFMove(data)]() mutable {
94 Vector<std::pair<ResourceUsageCollectionMode, std::function<void (const ResourceUsageData&)>>> pairs;
95
96 {
97 auto& resourceUsageThread = ResourceUsageThread::singleton();
98 LockHolder locker(resourceUsageThread.m_lock);
99 pairs = copyToVector(resourceUsageThread.m_observers.values());
100 }
101
102 for (auto& pair : pairs)
103 pair.second(data);
104 });
105}
106
107void ResourceUsageThread::recomputeCollectionMode()
108{
109 m_collectionMode = None;
110
111 for (auto& pair : m_observers.values())
112 m_collectionMode = static_cast<ResourceUsageCollectionMode>(m_collectionMode | pair.first);
113}
114
115void ResourceUsageThread::createThreadIfNeeded()
116{
117 if (m_thread)
118 return;
119
120 m_vm = &commonVM();
121 m_thread = Thread::create("WebCore: ResourceUsage", [this] {
122 threadBody();
123 });
124}
125
126NO_RETURN void ResourceUsageThread::threadBody()
127{
128 // Wait a bit after waking up for the first time.
129 WTF::sleep(10_ms);
130
131 while (true) {
132 // Only do work if we have observers.
133 waitUntilObservers();
134
135 auto start = WallTime::now();
136
137 ResourceUsageData data;
138 ResourceUsageCollectionMode mode = m_collectionMode;
139 if (mode & CPU)
140 platformCollectCPUData(m_vm, data);
141 if (mode & Memory)
142 platformCollectMemoryData(m_vm, data);
143
144 notifyObservers(WTFMove(data));
145
146 // NOTE: Web Inspector expects this interval to be 500ms (CPU / Memory timelines),
147 // so if this interval changes Web Inspector may need to change.
148 auto duration = WallTime::now() - start;
149 auto difference = 500_ms - duration;
150 WTF::sleep(difference);
151 }
152}
153
154} // namespace WebCore
155
156#endif // ENABLE(RESOURCE_USAGE)
157