Fcntl locking has different semantics than flock. Prefer flock.

diff --git a/src/misc.c b/src/misc.c
index 106f10e50399f2d2cd79209e5dc160460c8cd1c7..40fc58cb0b38a8be5d500fa06f9b1602cdd71d63 100644 (file)
--- a/src/misc.c
+++ b/src/misc.c
@@ -75,7 +75,9 @@ static int LogFD = ERR;
 static int syslog_open = FALSE;
 #endif
 
-#if defined(HAVE_FCNTL) && defined(F_SETLK)
+#if defined(HAVE_FLOCK)
+# define trylock_file(fd)      flock((fd), LOCK_EX|LOCK_NB)
+#elif defined(HAVE_FCNTL) && defined(F_SETLK)
 static int trylock_file(int fd) {
        struct flock fl;
 
@@ -89,8 +91,6 @@ static int trylock_file(int fd) {
 }
 #elif defined(HAVE_LOCKF)
 # define trylock_file(fd)      lockf((fd), F_TLOCK, 0)
-#elif defined(HAVE_FLOCK)
-# define trylock_file(fd)      flock((fd), LOCK_EX|LOCK_NB)
 #endif
 
 /*
@@ -345,6 +345,13 @@ void acquire_daemonlock(int closeflag) {
                (void) fchmod(fd, 0644);
                (void) fcntl(fd, F_SETFD, 1);
        }
+#if !defined(HAVE_FLOCK)
+       else {
+               /* Racy but better than nothing, just hope the parent exits */
+               sleep(0);
+               trylock_file(fd);       
+       }
+#endif
 
        sprintf(buf, "%ld\n", (long) pid);
        (void) lseek(fd, (off_t) 0, SEEK_SET);