1/*
2 * Copyright (C) 2010 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#ifndef PageBlock_h
27#define PageBlock_h
28
29namespace WTF {
30
31// avoid false positive detection by apple
32// by putting the function inside an inline namespace
33// to obtain different name mangling
34inline namespace hidden {
35WTF_EXPORT_PRIVATE size_t pageSize();
36WTF_EXPORT_PRIVATE size_t pageMask();
37}
38inline bool isPageAligned(void* address) { return !(reinterpret_cast<intptr_t>(address) & (pageSize() - 1)); }
39inline bool isPageAligned(size_t size) { return !(size & (pageSize() - 1)); }
40inline bool isPowerOfTwo(size_t size) { return !(size & (size - 1)); }
41
42class PageBlock {
43public:
44 PageBlock();
45 PageBlock(void*, size_t, bool hasGuardPages);
46
47 void* realBase() const { return m_realBase; }
48 void* base() const { return m_base; }
49 size_t size() const
50 {
51 return m_size - 2 * (static_cast<char *>(m_base) - static_cast<char *>(m_realBase));
52 }
53 size_t realSize() const { return m_size; }
54
55 operator bool() const { return !!m_realBase; }
56
57 bool contains(void* containedBase, size_t containedSize)
58 {
59 return containedBase >= m_base
60 && (static_cast<char*>(containedBase) + containedSize) <= (static_cast<char*>(m_base) + m_size);
61 }
62
63private:
64 void* m_realBase;
65 void* m_base;
66 size_t m_size;
67};
68
69inline PageBlock::PageBlock()
70 : m_realBase(0)
71 , m_base(0)
72 , m_size(0)
73{
74}
75
76inline PageBlock::PageBlock(void* base, size_t size, bool hasGuardPages)
77 : m_realBase(base)
78 , m_base(static_cast<char*>(base) + ((base && hasGuardPages) ? pageSize() : 0))
79 , m_size(size)
80{
81}
82
83} // namespace WTF
84
85using WTF::pageSize;
86using WTF::isPageAligned;
87using WTF::isPageAligned;
88using WTF::isPowerOfTwo;
89
90#endif // PageBlock_h
91

source code of qtdeclarative/src/3rdparty/masm/wtf/PageBlock.h