1/*
2 * Copyright (C) 2011 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. ``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 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#include "config.h"
27
28#include "LayerFlushScheduler.h"
29
30#include <wtf/AutodrainedPool.h>
31
32#if PLATFORM(IOS)
33#include "RuntimeApplicationChecksIOS.h"
34#include <CoreFoundation/CFBundle.h>
35#include <WebCore/WebCoreThread.h>
36#endif
37
38namespace WebCore {
39
40static const CFIndex layerFlushRunLoopOrder = (CFIndex)RunLoopObserver::WellKnownRunLoopOrders::CoreAnimationCommit - 1;
41
42static CFRunLoopRef currentRunLoop()
43{
44#if PLATFORM(IOS)
45    // A race condition during WebView deallocation can lead to a crash if the layer sync run loop
46    // observer is added to the main run loop <rdar://problem/9798550>. However, for responsiveness,
47    // we still allow this, see <rdar://problem/7403328>. Since the race condition and subsequent
48    // crash are especially troublesome for iBooks, we never allow the observer to be added to the
49    // main run loop in iBooks.
50    if (applicationIsIBooksOnIOS())
51        return WebThreadRunLoop();
52#endif
53    return CFRunLoopGetCurrent();
54}
55
56LayerFlushScheduler::LayerFlushScheduler(LayerFlushSchedulerClient* client)
57    : m_isSuspended(false)
58    , m_client(client)
59{
60    ASSERT_ARG(client, client);
61
62    m_runLoopObserver = RunLoopObserver::create(layerFlushRunLoopOrder, [this]() {
63        if (this->isSuspended())
64            return;
65        this->layerFlushCallback();
66    });
67}
68
69LayerFlushScheduler::~LayerFlushScheduler()
70{
71}
72
73void LayerFlushScheduler::layerFlushCallback()
74{
75    ASSERT(!m_isSuspended);
76
77    AutodrainedPool pool;
78    if (m_client->flushLayers())
79        invalidate();
80}
81
82void LayerFlushScheduler::schedule()
83{
84    if (m_isSuspended)
85        return;
86
87    m_runLoopObserver->schedule(currentRunLoop());
88}
89
90void LayerFlushScheduler::invalidate()
91{
92    m_runLoopObserver->invalidate();
93}
94
95} // namespace WebCore
96