1/*
2 * Copyright (C) 2014 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#import "config.h"
27#import "WebMemoryPressureHandlerIOS.h"
28
29#if PLATFORM(IOS)
30
31#import "ViewSnapshotStore.h"
32#import <dispatch/private.h>
33
34namespace WebKit {
35
36WebMemoryPressureHandler& WebMemoryPressureHandler::shared()
37{
38    static NeverDestroyed<WebMemoryPressureHandler> memoryPressureHandler;
39    return memoryPressureHandler;
40}
41
42WebMemoryPressureHandler::WebMemoryPressureHandler()
43{
44    // FIXME: This should be able to share code with WebCore's MemoryPressureHandler (and be platform independent).
45    // Right now it cannot because WebKit1 and WebKit2 need to be able to coexist in the UI process,
46    // and you can only have one WebCore::MemoryPressureHandler.
47
48    dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_MEMORYSTATUS, 0, DISPATCH_MEMORYSTATUS_PRESSURE_WARN, dispatch_get_main_queue());
49    dispatch_set_context(source, this);
50    dispatch_source_set_event_handler(source, ^{
51        ViewSnapshotStore::shared().discardSnapshotImages();
52    });
53    dispatch_resume(source);
54}
55
56} // namespace WebKit
57
58#endif
59