1 | /* |
2 | * Copyright (C) 2012, 2015 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 "ScrollingThread.h" |
28 | |
29 | #if ENABLE(ASYNC_SCROLLING) |
30 | |
31 | #include <mutex> |
32 | #include <wtf/MainThread.h> |
33 | #include <wtf/NeverDestroyed.h> |
34 | |
35 | namespace WebCore { |
36 | |
37 | ScrollingThread::ScrollingThread() |
38 | { |
39 | } |
40 | |
41 | bool ScrollingThread::isCurrentThread() |
42 | { |
43 | return ScrollingThread::singleton().m_thread == &Thread::current(); |
44 | } |
45 | |
46 | void ScrollingThread::dispatch(Function<void ()>&& function) |
47 | { |
48 | auto& scrollingThread = ScrollingThread::singleton(); |
49 | scrollingThread.createThreadIfNeeded(); |
50 | |
51 | { |
52 | std::lock_guard<Lock> lock(scrollingThread.m_functionsMutex); |
53 | scrollingThread.m_functions.append(WTFMove(function)); |
54 | } |
55 | |
56 | scrollingThread.wakeUpRunLoop(); |
57 | } |
58 | |
59 | void ScrollingThread::dispatchBarrier(Function<void ()>&& function) |
60 | { |
61 | dispatch([function = WTFMove(function)]() mutable { |
62 | callOnMainThread(WTFMove(function)); |
63 | }); |
64 | } |
65 | |
66 | ScrollingThread& ScrollingThread::singleton() |
67 | { |
68 | static NeverDestroyed<ScrollingThread> scrollingThread; |
69 | |
70 | return scrollingThread; |
71 | } |
72 | |
73 | void ScrollingThread::createThreadIfNeeded() |
74 | { |
75 | // Wait for the thread to initialize the run loop. |
76 | std::unique_lock<Lock> lock(m_initializeRunLoopMutex); |
77 | |
78 | if (!m_thread) { |
79 | m_thread = Thread::create("WebCore: Scrolling" , [this] { |
80 | WTF::Thread::setCurrentThreadIsUserInteractive(); |
81 | initializeRunLoop(); |
82 | }); |
83 | } |
84 | |
85 | #if PLATFORM(COCOA) |
86 | m_initializeRunLoopConditionVariable.wait(lock, [this]{ return m_threadRunLoop; }); |
87 | #else |
88 | m_initializeRunLoopConditionVariable.wait(lock, [this]{ return m_runLoop; }); |
89 | #endif |
90 | } |
91 | |
92 | void ScrollingThread::dispatchFunctionsFromScrollingThread() |
93 | { |
94 | ASSERT(isCurrentThread()); |
95 | |
96 | Vector<Function<void ()>> functions; |
97 | |
98 | { |
99 | std::lock_guard<Lock> lock(m_functionsMutex); |
100 | functions = WTFMove(m_functions); |
101 | } |
102 | |
103 | for (auto& function : functions) |
104 | function(); |
105 | } |
106 | |
107 | #if PLATFORM(IOS_FAMILY) |
108 | NO_RETURN_DUE_TO_ASSERT void ScrollingThread::initializeRunLoop() |
109 | { |
110 | ASSERT_NOT_REACHED(); |
111 | } |
112 | |
113 | void ScrollingThread::wakeUpRunLoop() |
114 | { |
115 | } |
116 | |
117 | void ScrollingThread::threadRunLoopSourceCallback(void*) |
118 | { |
119 | } |
120 | |
121 | void ScrollingThread::threadRunLoopSourceCallback() |
122 | { |
123 | } |
124 | #endif // PLATFORM(IOS_FAMILY) |
125 | |
126 | } // namespace WebCore |
127 | |
128 | #endif // ENABLE(ASYNC_SCROLLING) |
129 | |