1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include "mapping.h"
static int _map_file(const char* filename, void **addr, size_t *size, int writable)
{
struct stat info;
int error = 0;
int fd;
int flags = writable ? MAP_SHARED : MAP_PRIVATE;
error = stat(filename, &info);
if (!error) {
*size = info.st_size;
if (info.st_size > 0) {
fd = open(filename, O_RDWR);
if (fd >= 0) {
*addr = mmap(NULL, *size,
PROT_READ | PROT_WRITE,
flags,
fd, 0);
if (*addr == MAP_FAILED)
error = -1;
else {
/* tell kernel to start getting the pages */
error = madvise(*addr, *size, MADV_SEQUENTIAL | MADV_WILLNEED);
if (error) {
perror("madvise");
}
}
close(fd);
} else
error = fd;
} else
*addr = NULL;
}
return error;
}
int map_file(const char* filename, void **addr, size_t *size)
{
return _map_file(filename, addr, size, 0);
}
int map_file_rw(const char* filename, void **addr, size_t *size)
{
return _map_file(filename, addr, size, 1);
}
|
