usr/src/lib/libbc/libc/gen/common/ssignal.c

   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 }