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. ``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 | #ifndef PageAllocation_h |
27 | #define PageAllocation_h |
28 | |
29 | #include <wtf/Assertions.h> |
30 | #include <wtf/OSAllocator.h> |
31 | #include <wtf/PageBlock.h> |
32 | #include <wtf/UnusedParam.h> |
33 | #include <wtf/VMTags.h> |
34 | #include <algorithm> |
35 | |
36 | #if OS(DARWIN) |
37 | #include <mach/mach_init.h> |
38 | #include <mach/vm_map.h> |
39 | #endif |
40 | |
41 | #if OS(WINDOWS) |
42 | #include <malloc.h> |
43 | #include <windows.h> |
44 | #endif |
45 | |
46 | #if HAVE(ERRNO_H) |
47 | #include <errno.h> |
48 | #endif |
49 | |
50 | #if HAVE(MMAP) |
51 | #include <sys/mman.h> |
52 | #include <unistd.h> |
53 | #endif |
54 | |
55 | namespace WTF { |
56 | |
57 | /* |
58 | PageAllocation |
59 | |
60 | The PageAllocation class provides a cross-platform memory allocation interface |
61 | with similar capabilities to posix mmap/munmap. Memory is allocated by calling |
62 | PageAllocation::allocate, and deallocated by calling deallocate on the |
63 | PageAllocation object. The PageAllocation holds the allocation's base pointer |
64 | and size. |
65 | |
66 | The allocate method is passed the size required (which must be a multiple of |
67 | the system page size, which can be accessed using PageAllocation::pageSize). |
68 | Callers may also optinally provide a flag indicating the usage (for use by |
69 | system memory usage tracking tools, where implemented), and boolean values |
70 | specifying the required protection (defaulting to writable, non-executable). |
71 | */ |
72 | |
73 | class PageAllocation : private PageBlock { |
74 | public: |
75 | PageAllocation() |
76 | { |
77 | } |
78 | |
79 | using PageBlock::size; |
80 | using PageBlock::base; |
81 | |
82 | #ifndef __clang__ |
83 | using PageBlock::operator bool; |
84 | #else |
85 | // FIXME: This is a workaround for <rdar://problem/8876150>, wherein Clang incorrectly emits an access |
86 | // control warning when a client tries to use operator bool exposed above via "using PageBlock::operator bool". |
87 | operator bool() const { return PageBlock::operator bool(); } |
88 | #endif |
89 | bool operator<(const PageAllocation &b) { return base() < b.base(); } |
90 | |
91 | static PageAllocation allocate(size_t size, |
92 | OSAllocator::Usage usage = OSAllocator::UnknownUsage, |
93 | bool writable = true, bool executable = false, |
94 | bool includesGuardPages = false) |
95 | { |
96 | ASSERT(isPageAligned(size)); |
97 | return PageAllocation(OSAllocator::reserveAndCommit(size, usage, writable, executable, |
98 | includesGuardPages), size, |
99 | includesGuardPages); |
100 | } |
101 | |
102 | void deallocate() |
103 | { |
104 | // Clear base & size before calling release; if this is *inside* allocation |
105 | // then we won't be able to clear then after deallocating the memory. |
106 | PageAllocation tmp; |
107 | std::swap(a&: tmp, b&: *this); |
108 | |
109 | ASSERT(tmp); |
110 | ASSERT(!*this); |
111 | |
112 | OSAllocator::decommitAndRelease(base: tmp.realBase(), size: tmp.realSize()); |
113 | } |
114 | |
115 | private: |
116 | PageAllocation(void* base, size_t size, bool includesGuardPages = false) |
117 | : PageBlock(base, size, includesGuardPages) |
118 | { |
119 | } |
120 | }; |
121 | |
122 | } // namespace WTF |
123 | |
124 | using WTF::PageAllocation; |
125 | |
126 | #endif // PageAllocation_h |
127 | |