xref: /titanic_41/usr/src/lib/libc/port/gen/ssignal.c (revision 80e2ca8596e3435bc3b76f3c597833ea0a87f85e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  *	ssignal, gsignal: software signals
34  */
35 
36 #include "lint.h"
37 #include <sys/types.h>
38 #include <signal.h>
39 
40 /* Highest allowable user signal number */
41 #define	MAXSIGNUM	17
42 
43 /* Lowest allowable signal number (lowest user number is always 1) */
44 #define	MINSIG	(-4)
45 
46 /* Table of signal values */
47 static int (*sigs[MAXSIGNUM-MINSIG+1])(int);
48 
49 int (*
50 ssignal(int sig, int (*action)(int)))(int)
51 {
52 	int (*savefn)(int);
53 
54 	if (sig >= MINSIG && sig <= MAXSIGNUM) {
55 		savefn = sigs[sig-MINSIG];
56 		sigs[sig-MINSIG] = action;
57 	} else
58 		savefn = (int(*)(int))SIG_DFL;
59 
60 	return (savefn);
61 }
62 
63 int
64 gsignal(int sig)
65 {
66 	int (*sigfn)(int);
67 
68 	if (sig < MINSIG || sig > MAXSIGNUM ||
69 	    (sigfn = sigs[sig-MINSIG]) == (int(*)(int))SIG_DFL)
70 		return (0);
71 	else if (sigfn == (int(*)(int))SIG_IGN)
72 		return (1);
73 	else {
74 		sigs[sig-MINSIG] = (int(*)(int))SIG_DFL;
75 		return ((*sigfn)(sig));
76 	}
77 }
78