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/* this tests whether we can use a shared writeable mmap on a file -
as needed for the mmap variant of FAST_SHARE_MODES */
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define DATA "conftest.mmap"
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
int main(void)
{
int *buf;
int i;
int fd = open(DATA,O_RDWR|O_CREAT|O_TRUNC,0666);
int count=7;
if (fd == -1) exit(1);
for (i=0;i<10000;i++) {
write(fd,&i,sizeof(i));
}
close(fd);
if (fork() == 0) {
fd = open(DATA,O_RDWR);
if (fd == -1) exit(1);
buf = (int *)mmap(NULL, 10000*sizeof(int),
(PROT_READ | PROT_WRITE),
MAP_FILE | MAP_SHARED,
fd, 0);
if (buf == (int *)-1) exit(1);
while (count-- && buf[9124] != 55732) sleep(1);
if (count <= 0) exit(1);
buf[1763] = 7268;
exit(0);
}
fd = open(DATA,O_RDWR);
if (fd == -1) exit(1);
buf = (int *)mmap(NULL, 10000*sizeof(int),
(PROT_READ | PROT_WRITE),
MAP_FILE | MAP_SHARED,
fd, 0);
if (buf == (int *)-1) exit(1);
buf[9124] = 55732;
while (count-- && buf[1763] != 7268) sleep(1);
unlink(DATA);
if (count > 0) exit(0);
exit(1);
}
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