mirror of
https://github.com/ruby/ruby.git
synced 2022-11-09 12:17:21 -05:00
90 lines
1.8 KiB
C
90 lines
1.8 KiB
C
#include "config.h"
|
|
|
|
#if defined(HAVE_LOCKF)
|
|
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
|
|
/* Emulate flock() with lockf() or fcntl(). This is just to increase
|
|
portability of scripts. The calls might not be completely
|
|
interchangeable. What's really needed is a good file
|
|
locking module.
|
|
*/
|
|
|
|
# ifndef F_ULOCK
|
|
# define F_ULOCK 0 /* Unlock a previously locked region */
|
|
# endif
|
|
# ifndef F_LOCK
|
|
# define F_LOCK 1 /* Lock a region for exclusive use */
|
|
# endif
|
|
# ifndef F_TLOCK
|
|
# define F_TLOCK 2 /* Test and lock a region for exclusive use */
|
|
# endif
|
|
# ifndef F_TEST
|
|
# define F_TEST 3 /* Test a region for other processes locks */
|
|
# endif
|
|
|
|
/* These are the flock() constants. Since this sytems doesn't have
|
|
flock(), the values of the constants are probably not available.
|
|
*/
|
|
# ifndef LOCK_SH
|
|
# define LOCK_SH 1
|
|
# endif
|
|
# ifndef LOCK_EX
|
|
# define LOCK_EX 2
|
|
# endif
|
|
# ifndef LOCK_NB
|
|
# define LOCK_NB 4
|
|
# endif
|
|
# ifndef LOCK_UN
|
|
# define LOCK_UN 8
|
|
# endif
|
|
|
|
int
|
|
flock(fd, operation)
|
|
int fd;
|
|
int operation;
|
|
{
|
|
int i;
|
|
switch (operation) {
|
|
|
|
/* LOCK_SH - get a shared lock */
|
|
case LOCK_SH:
|
|
/* LOCK_EX - get an exclusive lock */
|
|
case LOCK_EX:
|
|
i = lockf (fd, F_LOCK, 0);
|
|
break;
|
|
|
|
/* LOCK_SH|LOCK_NB - get a non-blocking shared lock */
|
|
case LOCK_SH|LOCK_NB:
|
|
/* LOCK_EX|LOCK_NB - get a non-blocking exclusive lock */
|
|
case LOCK_EX|LOCK_NB:
|
|
i = lockf (fd, F_TLOCK, 0);
|
|
if (i == -1)
|
|
if ((errno == EAGAIN) || (errno == EACCES))
|
|
errno = EWOULDBLOCK;
|
|
break;
|
|
|
|
/* LOCK_UN - unlock */
|
|
case LOCK_UN:
|
|
i = lockf (fd, F_ULOCK, 0);
|
|
break;
|
|
|
|
/* Default - can't decipher operation */
|
|
default:
|
|
i = -1;
|
|
errno = EINVAL;
|
|
break;
|
|
}
|
|
return i;
|
|
}
|
|
#else
|
|
int
|
|
flock(fd, operation)
|
|
int fd;
|
|
int operation;
|
|
{
|
|
rb_notimplement();
|
|
return -1;
|
|
}
|
|
#endif
|