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#pragma once
27
28#if ENABLE(ASYNC_SCROLLING)
29
30#include <functional>
31#include <wtf/Condition.h>
32#include <wtf/Forward.h>
33#include <wtf/Function.h>
34#include <wtf/Lock.h>
35#include <wtf/Noncopyable.h>
36#include <wtf/Threading.h>
37#include <wtf/Vector.h>
38
39#if PLATFORM(COCOA)
40#include <wtf/RetainPtr.h>
41#else
42#include <wtf/RunLoop.h>
43#endif
44
45namespace WebCore {
46
47class ScrollingThread {
48 WTF_MAKE_NONCOPYABLE(ScrollingThread);
49
50public:
51 static bool isCurrentThread();
52 WEBCORE_EXPORT static void dispatch(Function<void ()>&&);
53
54 // Will dispatch the given function on the main thread once all pending functions
55 // on the scrolling thread have finished executing. Used for synchronization purposes.
56 WEBCORE_EXPORT static void dispatchBarrier(Function<void ()>&&);
57
58private:
59 friend NeverDestroyed<ScrollingThread>;
60
61 ScrollingThread();
62
63 static ScrollingThread& singleton();
64
65 void createThreadIfNeeded();
66 void dispatchFunctionsFromScrollingThread();
67
68 void initializeRunLoop();
69 void wakeUpRunLoop();
70
71#if PLATFORM(COCOA)
72 static void threadRunLoopSourceCallback(void* scrollingThread);
73 void threadRunLoopSourceCallback();
74#endif
75
76 RefPtr<Thread> m_thread;
77
78 Condition m_initializeRunLoopConditionVariable;
79 Lock m_initializeRunLoopMutex;
80
81 Lock m_functionsMutex;
82 Vector<Function<void ()>> m_functions;
83
84#if PLATFORM(COCOA)
85 // FIXME: We should use WebCore::RunLoop here.
86 RetainPtr<CFRunLoopRef> m_threadRunLoop;
87 RetainPtr<CFRunLoopSourceRef> m_threadRunLoopSource;
88#else
89 RunLoop* m_runLoop { nullptr };
90#endif
91};
92
93} // namespace WebCore
94
95#endif // ENABLE(ASYNC_SCROLLING)
96