usr/src/lib/libbc/libc/gen/sys5/sighold.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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  23
  24 /*
  25  * Copyright (c) 1987 Sun Microsystems, Inc.
  26  */
  27
  28 #include <errno.h>
  29 #include <sys/signal.h>
  30
  31 int
  32 sighold(sig)
  33         int sig;
  34 {
  35
  36         if (sig == SIGKILL) {
  37                 errno = EINVAL;
  38                 return (-1);    /* sigblock quietly disallows SIGKILL */
  39         }
  40         (void) sigblock(sigmask(sig));
  41         return (0);             /* SVID specifies 0 return on success */
  42 }
  43
  44 int
  45 sigrelse(sig)
  46         int sig;
  47 {
  48
  49         if (sig == SIGKILL) {
  50                 errno = EINVAL;
  51                 return (-1);    /* sigsetmask quietly disallows SIGKILL */
  52         }
  53         (void) sigsetmask(sigblock(0) & ~sigmask(sig));
  54         return (0);             /* SVID specifies 0 return on success */
  55 }
  56
  57 int
  58 sigignore(sig)
  59         int sig;
  60 {
  61         struct sigvec vec;
  62
  63         if (sig == SIGKILL) {
  64                 errno = EINVAL;
  65                 return (-1);    /* sigsetmask quietly disallows SIGKILL */
  66         }
  67         if (sigvec(sig, (struct sigvec *)0, &vec) < 0)
  68                 return (-1);
  69         vec.sv_handler = SIG_IGN;
  70         if (sigvec(sig, &vec, (struct sigvec *)0) < 0)
  71                 return (-1);
  72         (void) sigsetmask(sigblock(0) & ~sigmask(sig));
  73         return (0);             /* SVID specifies 0 return on success */
  74 }
  75
  76 void (*
  77 sigset(sig, func))()
  78         int sig;
  79         void (*func)();
  80 {
  81         struct sigvec newvec;
  82         int newmask;
  83         struct sigvec oldvec;
  84         int oldmask;
  85
  86         if (sigvec(sig, (struct sigvec *)0, &oldvec) < 0)
  87                 return (SIG_ERR);
  88         oldmask = sigblock(0);
  89         newvec = oldvec;
  90         newvec.sv_flags |= SV_INTERRUPT;
  91         newvec.sv_flags &= ~SV_RESETHAND;
  92         newvec.sv_mask = 0;
  93         newmask = oldmask;
  94         if (func == SIG_HOLD) {
  95                 /*
  96                  * Signal will be held.  Set the bit for that
  97                  * signal in the signal mask.  Leave the action
  98                  * alone.
  99                  */
 100                 newmask |= sigmask(sig);
 101         } else {
 102                 /*
 103                  * Signal will not be held.  Clear the bit
 104                  * for it in the signal mask.  Set the action
 105                  * for it.
 106                  */
 107                 newmask &= ~sigmask(sig);
 108                 newvec.sv_handler = func;
 109         }
 110         if (sigvec(sig, &newvec, (struct sigvec *)0) < 0)
 111                 return (SIG_ERR);
 112         if (sigsetmask(newmask) < 0)
 113                 return (SIG_ERR);
 114         if (oldmask & sigmask(sig))
 115                 return (SIG_HOLD);      /* signal was held */
 116         else
 117                 return (oldvec.sv_handler);
 118 }