mirror of
https://github.com/samba-team/samba.git
synced 2024-12-24 21:34:56 +03:00
3db52feb1f
(This used to be commit 453a822a76
)
95 lines
1.7 KiB
C
95 lines
1.7 KiB
C
/* test whether fcntl locking works on this system */
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#if defined(HAVE_UNISTD_H)
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#include <unistd.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#ifdef HAVE_FCNTL_H
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#include <fcntl.h>
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#endif
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#ifdef HAVE_SYS_FCNTL_H
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#include <sys/fcntl.h>
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#endif
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#include <errno.h>
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static int sys_waitpid(pid_t pid,int *status,int options)
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{
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#ifdef HAVE_WAITPID
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return waitpid(pid,status,options);
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#else /* USE_WAITPID */
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return wait4(pid, status, options, NULL);
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#endif /* USE_WAITPID */
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}
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#define DATA "conftest.fcntl"
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#ifndef SEEK_SET
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#define SEEK_SET 0
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#endif
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/* lock a byte range in a open file */
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int main(int argc, char *argv[])
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{
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struct flock lock;
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int fd, ret, status=1;
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pid_t pid;
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if (!(pid=fork())) {
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sleep(2);
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fd = open(DATA, O_RDONLY);
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if (fd == -1) exit(1);
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lock.l_type = F_WRLCK;
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lock.l_whence = SEEK_SET;
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lock.l_start = 0;
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lock.l_len = 4;
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lock.l_pid = getpid();
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lock.l_type = F_WRLCK;
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/* check if a lock applies */
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ret = fcntl(fd,F_GETLK,&lock);
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if ((ret == -1) ||
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(lock.l_type == F_UNLCK)) {
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exit(1);
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} else {
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exit(0);
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}
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}
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fd = open(DATA, O_RDWR|O_CREAT|O_TRUNC, 0600);
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lock.l_type = F_WRLCK;
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lock.l_whence = SEEK_SET;
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lock.l_start = 0;
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lock.l_len = 4;
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lock.l_pid = getpid();
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/* set a 4 byte write lock */
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fcntl(fd,F_SETLK,&lock);
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sys_waitpid(pid, &status, 0);
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unlink(DATA);
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#if defined(WIFEXITED) && defined(WEXITSTATUS)
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if(WIFEXITED(status)) {
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status = WEXITSTATUS(status);
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} else {
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status = 1;
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}
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#else /* defined(WIFEXITED) && defined(WEXITSTATUS) */
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status = (status == 0) ? 0 : 1;
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#endif /* defined(WIFEXITED) && defined(WEXITSTATUS) */
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exit(status);
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}
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