[176] | 1 | // -*- C++ -*- |
---|
| 2 | |
---|
| 3 | /* |
---|
| 4 | |
---|
| 5 | Heap Layers: An Extensible Memory Allocation Infrastructure |
---|
| 6 | |
---|
| 7 | Copyright (C) 2000-2005 by Emery Berger |
---|
| 8 | http://www.cs.umass.edu/~emery |
---|
| 9 | emery@cs.umass.edu |
---|
| 10 | |
---|
| 11 | This program is free software; you can redistribute it and/or modify |
---|
| 12 | it under the terms of the GNU General Public License as published by |
---|
| 13 | the Free Software Foundation; either version 2 of the License, or |
---|
| 14 | (at your option) any later version. |
---|
| 15 | |
---|
| 16 | This program is distributed in the hope that it will be useful, |
---|
| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
| 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
| 19 | GNU General Public License for more details. |
---|
| 20 | |
---|
| 21 | You should have received a copy of the GNU General Public License |
---|
| 22 | along with this program; if not, write to the Free Software |
---|
| 23 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
---|
| 24 | |
---|
| 25 | */ |
---|
| 26 | |
---|
| 27 | #ifndef _MMAPWRAPPER_H_ |
---|
| 28 | #define _MMAPWRAPPER_H_ |
---|
| 29 | |
---|
| 30 | #if defined(_WIN32) |
---|
| 31 | #include <windows.h> |
---|
| 32 | #else |
---|
| 33 | // UNIX |
---|
| 34 | #include <sys/types.h> |
---|
| 35 | #include <sys/stat.h> |
---|
| 36 | #include <fcntl.h> |
---|
| 37 | #include <unistd.h> |
---|
| 38 | #include <sys/mman.h> |
---|
| 39 | #include <map> |
---|
| 40 | #endif |
---|
| 41 | |
---|
| 42 | #if HL_EXECUTABLE_HEAP |
---|
| 43 | #define HL_MMAP_PROTECTION_MASK (PROT_READ | PROT_WRITE | PROT_EXEC) |
---|
| 44 | #else |
---|
| 45 | #define HL_MMAP_PROTECTION_MASK (PROT_READ | PROT_WRITE) |
---|
| 46 | #endif |
---|
| 47 | |
---|
| 48 | #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) |
---|
| 49 | #define MAP_ANONYMOUS MAP_ANON |
---|
| 50 | #endif |
---|
| 51 | |
---|
| 52 | namespace HL { |
---|
| 53 | |
---|
| 54 | class MmapWrapper { |
---|
| 55 | public: |
---|
| 56 | |
---|
| 57 | #if defined(_WIN32) |
---|
| 58 | |
---|
| 59 | // Microsoft Windows has 4K pages aligned to a 64K boundary. |
---|
| 60 | enum { Size = 4 * 1024 }; |
---|
| 61 | enum { Alignment = 64 * 1024 }; |
---|
| 62 | |
---|
| 63 | static void * map (size_t sz) { |
---|
| 64 | void * ptr; |
---|
| 65 | #if HL_EXECUTABLE_HEAP |
---|
| 66 | const int permflags = PAGE_EXECUTE_READWRITE; |
---|
| 67 | #else |
---|
| 68 | const int permflags = PAGE_READWRITE; |
---|
| 69 | #endif |
---|
| 70 | ptr = VirtualAlloc (NULL, sz, MEM_RESERVE | MEM_COMMIT | MEM_TOP_DOWN, permflags); |
---|
| 71 | return ptr; |
---|
| 72 | } |
---|
| 73 | |
---|
| 74 | static void unmap (void * ptr, size_t) { |
---|
| 75 | VirtualFree (ptr, 0, MEM_RELEASE); |
---|
| 76 | } |
---|
| 77 | |
---|
| 78 | #else |
---|
| 79 | |
---|
| 80 | #if defined(__SVR4) |
---|
| 81 | // Solaris aligns 8K pages to a 64K boundary. |
---|
| 82 | enum { Size = 8 * 1024 }; |
---|
| 83 | enum { Alignment = 64 * 1024 }; |
---|
| 84 | #else |
---|
| 85 | // Linux and most other operating systems align memory to a 4K boundary. |
---|
| 86 | enum { Size = 4 * 1024 }; |
---|
| 87 | enum { Alignment = 4 * 1024 }; |
---|
| 88 | #endif |
---|
| 89 | |
---|
| 90 | static void * map (size_t sz) { |
---|
| 91 | |
---|
| 92 | if (sz == 0) { |
---|
| 93 | return NULL; |
---|
| 94 | } |
---|
| 95 | |
---|
| 96 | void * ptr; |
---|
| 97 | |
---|
| 98 | #if defined(MAP_ALIGN) && defined(MAP_ANON) |
---|
| 99 | // Request memory aligned to the Alignment value above. |
---|
| 100 | ptr = mmap ((char *) Alignment, sz, HL_MMAP_PROTECTION_MASK, MAP_PRIVATE | MAP_ALIGN | MAP_ANON, -1, 0); |
---|
| 101 | #elif !defined(MAP_ANONYMOUS) |
---|
| 102 | static int fd = ::open ("/dev/zero", O_RDWR); |
---|
| 103 | ptr = mmap (NULL, sz, HL_MMAP_PROTECTION_MASK, MAP_PRIVATE, fd, 0); |
---|
| 104 | #else |
---|
| 105 | ptr = mmap (0, sz, HL_MMAP_PROTECTION_MASK, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
---|
| 106 | #endif |
---|
| 107 | |
---|
| 108 | if (ptr == MAP_FAILED) { |
---|
| 109 | return NULL; |
---|
| 110 | } else { |
---|
| 111 | return ptr; |
---|
| 112 | } |
---|
| 113 | } |
---|
| 114 | |
---|
| 115 | static void unmap (void * ptr, size_t sz) { |
---|
| 116 | munmap (reinterpret_cast<char *>(ptr), sz); |
---|
| 117 | } |
---|
| 118 | |
---|
| 119 | #endif |
---|
| 120 | |
---|
| 121 | }; |
---|
| 122 | |
---|
| 123 | } |
---|
| 124 | |
---|
| 125 | #endif |
---|