1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 
24 #include <ast.h>
25 
26 #if _lib_sigunblock
27 
28 NoN(sigunblock)
29 
30 #else
31 
32 #include <sig.h>
33 
34 #ifndef SIG_UNBLOCK
35 #undef	_lib_sigprocmask
36 #endif
37 
38 int
39 sigunblock(int s)
40 {
41 #if _lib_sigprocmask
42 	int		op;
43 	sigset_t	mask;
44 
45 	sigemptyset(&mask);
46 	if (s)
47 	{
48 		sigaddset(&mask, s);
49 		op = SIG_UNBLOCK;
50 	}
51 	else op = SIG_SETMASK;
52 	return(sigprocmask(op, &mask, NiL));
53 #else
54 #if _lib_sigsetmask
55 	return(sigsetmask(s ? (sigsetmask(0L) & ~sigmask(s)) : 0L));
56 #else
57 	NoP(s);
58 	return(0);
59 #endif
60 #endif
61 }
62 
63 #endif
64