xref: /titanic_41/usr/src/lib/libbc/libc/gen/common/ssignal.c (revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1987 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*      Copyright (c) 1984 AT&T */
28 /*        All Rights Reserved   */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"  /* from S5R2 1.2 */
31 
32 /*LINTLIBRARY*/
33 /*
34  *	ssignal, gsignal: software signals
35  */
36 #include <signal.h>
37 
38 /* Highest allowable user signal number */
39 #define	MAXSIG NSIG
40 
41 /* Lowest allowable signal number (lowest user number is always 1) */
42 #define	MINSIG (-4)
43 
44 /* Table of signal values */
45 typedef int (*sigfunc)();
46 sigfunc *ssigp;
47 
48 
49 sigfunc *
50 _ssig()
51 {
52 	if (ssigp == 0)
53 		ssigp = (sigfunc *)calloc(MAXSIG-MINSIG+1, sizeof (sigfunc));
54 	return (ssigp);
55 }
56 
57 int
58 (*ssignal(sig, fn))()
59 register int sig, (*fn)();
60 {
61 	register int (*savefn)();
62 	register sigfunc *sp = _ssig();
63 
64 	if (sp == 0)
65 		return ((int (*)())SIG_DFL);
66 	if (sig >= MINSIG && sig <= MAXSIG) {
67 		savefn = sp[sig-MINSIG];
68 		sp[sig-MINSIG] = fn;
69 	} else
70 		savefn = (int (*)())SIG_DFL;
71 
72 	return (savefn);
73 }
74 
75 int
76 gsignal(sig)
77 register int sig;
78 {
79 	register int (*sigfn)();
80 	register sigfunc *sp = _ssig();
81 
82 	if (sp == 0)
83 		return (0);
84 	if (sig < MINSIG || sig > MAXSIG ||
85 				(sigfn = sp[sig-MINSIG]) == (int (*)())SIG_DFL)
86 		return (0);
87 	else if (sigfn == (int (*)())SIG_IGN)
88 		return (1);
89 	else {
90 		sp[sig-MINSIG] = (int (*)())SIG_DFL;
91 		return ((*sigfn)(sig));
92 	}
93 }
94