1  #include "common.h"
 2  #include <windows.h>
 3  
 4  static inline size_t xsize_t(off_t len)
 5  {
 6          if (len > (size_t) len)
 7                  die("Cannot handle files this big");
 8          return (size_t)len;
 9  }
10  
11  void *win32_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
12  {
13  	HANDLE hmap;
14  	void *temp;
15  	off_t len;
16  	struct stat st;
17  	uint64_t o = offset;
18  	uint32_t l = o & 0xFFFFFFFF;
19  	uint32_t h = (o >> 32) & 0xFFFFFFFF;
20  
21  	if (!fstat(fd, &st))
22  		len = st.st_size;
23  	else
24  		printf("mmap: could not determine filesize");
25  
26  	if ((length + offset) > len)
27  		length = xsize_t(len - offset);
28  
29  	if (!(flags & MAP_PRIVATE))
30  		printf("Invalid usage of mmap when built with USE_WIN32_MMAP");
31  
32  	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
33  		0, 0, 0);
34  
35  	if (!hmap)
36  		return MAP_FAILED;
37  
38  	temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
39  
40  	if (!CloseHandle(hmap))
41  		printf("unable to close file mapping handle");
42  
43  	return temp ? temp : MAP_FAILED;
44  }
45  
46  int win32_munmap(void *start, size_t length)
47  {
48  	return !UnmapViewOfFile(start);
49  }