2 * CDE - Common Desktop Environment
4 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
6 * These libraries and programs are free software; you can
7 * redistribute them and/or modify them under the terms of the GNU
8 * Lesser General Public License as published by the Free Software
9 * Foundation; either version 2 of the License, or (at your option)
12 * These libraries and programs are distributed in the hope that
13 * they will be useful, but WITHOUT ANY WARRANTY; without even the
14 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * PURPOSE. See the GNU Lesser General Public License for more
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with these libraries and programs; if not, write
20 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
21 * Floor, Boston, MA 02110-1301 USA
24 * File: lock.c $XConsortium: lock.c /main/4 1995/10/26 15:33:05 rswiston $
27 * (C) Copyright 1989, Hewlett-Packard, all rights reserved.
29 * (c) Copyright 1993, 1994 Hewlett-Packard Company *
30 * (c) Copyright 1993, 1994 International Business Machines Corp. *
31 * (c) Copyright 1993, 1994 Sun Microsystems, Inc. *
32 * (c) Copyright 1993, 1994 Novell, Inc. *
38 /******** Public Function Declarations ********/
40 extern int _DtGetLock( Display *display, char *lock_name) ;
41 extern void _DtReleaseLock( Display *display, char *lock_name) ;
42 extern int _DtTestLock( Display *display, char *lock_name) ;
44 /******** End Public Function Declarations ********/
53 Window selection_owner;
56 /* Do as much processing as possible before grabbing the server. */
57 lock_atom = XInternAtom (display, lock_name, False);
58 root_window = DefaultRootWindow (display);
60 /* Do an atomic test-and-set of the lock. To make this atomic we
61 must grab the server. */
62 XGrabServer (display);
63 if ((selection_owner = XGetSelectionOwner (display, lock_atom)) == None)
64 XSetSelectionOwner (display, lock_atom, root_window, CurrentTime);
65 XUngrabServer (display);
68 /* If the lock was clear then it was successfully acquired. */
69 if (selection_owner == None)
82 lock_atom = XInternAtom (display, lock_name, False);
83 XSetSelectionOwner (display, lock_atom, None, CurrentTime);
84 XFlush (display); /* added to release lock NOW */
94 lock_atom = XInternAtom (display, lock_name, False);
96 if (XGetSelectionOwner (display, lock_atom) == None)