From ee162dd22f64c7b9653b65be570f0a70fc2607bd Mon Sep 17 00:00:00 2001 From: ache Date: Tue, 5 Aug 1997 12:58:02 +0000 Subject: Improve weak locking by using flock() --- lib/libutil/uucplock.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'lib/libutil') diff --git a/lib/libutil/uucplock.c b/lib/libutil/uucplock.c index 5559990..837558a 100644 --- a/lib/libutil/uucplock.c +++ b/lib/libutil/uucplock.c @@ -30,7 +30,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: uucplock.c,v 1.5 1997/04/02 04:24:39 ache Exp $ + * $Id: uucplock.c,v 1.6 1997/05/12 10:36:14 brian Exp $ * */ @@ -70,13 +70,13 @@ int uu_lock (const char *ttyname) int err; (void)snprintf(tbuf, sizeof(tbuf), _PATH_UUCPLOCK LOCKFMT, ttyname); - fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL, 0660); + fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL|O_EXLOCK, 0660); if (fd < 0) { /* * file is already locked * check to see if the process holding the lock still exists */ - fd = open(tbuf, O_RDWR, 0); + fd = open(tbuf, O_RDWR|O_SHLOCK); if (fd < 0) return UU_LOCK_OPEN_ERR; @@ -100,13 +100,17 @@ int uu_lock (const char *ttyname) errno = err; return UU_LOCK_SEEK_ERR; } + if (flock(fd, LOCK_EX|LOCK_NB) < 0) { + (void)close(fd); + return UU_LOCK_INUSE; + } /* fall out and finish the locking process */ } pid = getpid(); if (!put_pid (fd, pid)) { err = errno; - (void)close(fd); (void)unlink(tbuf); + (void)close(fd); errno = err; return UU_LOCK_WRITE_ERR; } -- cgit v1.1