1 /* mmap() replacement for Windows
3 * Author: Mike Frysinger <vapier@gentoo.org>
4 * Placed into the public domain
8 * CreateFileMapping: http://msdn.microsoft.com/en-us/library/aa366537(VS.85).aspx
9 * CloseHandle: http://msdn.microsoft.com/en-us/library/ms724211(VS.85).aspx
10 * MapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366761(VS.85).aspx
11 * UnmapViewOfFile: http://msdn.microsoft.com/en-us/library/aa366882(VS.85).aspx
16 #include <sys/types.h>
19 #define PROT_WRITE 0x2
20 /* This flag is only available in WinXP+ */
21 #ifdef FILE_MAP_EXECUTE
25 #define FILE_MAP_EXECUTE 0
28 #define MAP_SHARED 0x01
29 #define MAP_PRIVATE 0x02
30 #define MAP_ANONYMOUS 0x20
31 #define MAP_ANON MAP_ANONYMOUS
32 #define MAP_FAILED ((void *) -1)
34 #ifdef __USE_FILE_OFFSET64
35 # define DWORD_HI(x) (x >> 32)
36 # define DWORD_LO(x) ((x) & 0xffffffff)
38 # define DWORD_HI(x) (0)
39 # define DWORD_LO(x) (x)
42 static void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
44 if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
47 if (!(flags & MAP_ANON) || offset)
49 } else if (flags & MAP_ANON)
53 if (prot & PROT_WRITE) {
55 flProtect = PAGE_EXECUTE_READWRITE;
57 flProtect = PAGE_READWRITE;
58 } else if (prot & PROT_EXEC) {
60 flProtect = PAGE_EXECUTE_READ;
61 else if (prot & PROT_EXEC)
62 flProtect = PAGE_EXECUTE;
64 flProtect = PAGE_READONLY;
66 off_t end = length + offset;
69 mmap_fd = INVALID_HANDLE_VALUE;
71 mmap_fd = (HANDLE)_get_osfhandle(fd);
72 h = CreateFileMapping(mmap_fd, NULL, flProtect, DWORD_HI(end), DWORD_LO(end), NULL);
76 DWORD dwDesiredAccess;
77 if (prot & PROT_WRITE)
78 dwDesiredAccess = FILE_MAP_WRITE;
80 dwDesiredAccess = FILE_MAP_READ;
82 dwDesiredAccess |= FILE_MAP_EXECUTE;
83 if (flags & MAP_PRIVATE)
84 dwDesiredAccess |= FILE_MAP_COPY;
85 void *ret = MapViewOfFile(h, dwDesiredAccess, DWORD_HI(offset), DWORD_LO(offset), length);
93 static void munmap(void *addr, size_t length)
95 UnmapViewOfFile(addr);
96 /* ruh-ro, we leaked handle from CreateFileMapping() ... */