--- /dev/null
+(* whenjobs
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+(** Handle the locking that ensures only one instance of the
+ daemon can run per user. *)
+
+val create_lock : string -> unit
+(** [create_lock jobsdir] creates the lock file (called [daemon_pid])
+ in the [jobsdir] directory. The lock is automatically released
+ when the process exits. *)
+
+val update_pid : unit -> unit
+(** Call this if the PID of the program changes, ie. after fork. *)
+
+val test_locked : string -> bool
+(** Test if there is a lock file and the lock is held by another process. *)
+
+val kill_daemon : string -> unit
+(** If there is a daemon holding the lock, kill it. *)