contrib/tcsh-6/tc.sig.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/tc.sig.c,v 3.40 2012/01/25 15:34:41 christos Exp $ */
   2 /*
   3  * tc.sig.c: Signal routine emulations
   4  */
   5 /*-
   6  * Copyright (c) 1980, 1991 The Regents of the University of California.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33 #include "sh.h"
  34
  35 RCSID("$tcsh: tc.sig.c,v 3.40 2012/01/25 15:34:41 christos Exp $")
  36
  37 #include "tc.wait.h"
  38
  39 void
  40 sigset_interrupting(int sig, void (*fn) (int))
  41 {
  42     struct sigaction act;
  43
  44     act.sa_handler = fn;
  45     sigemptyset(&act.sa_mask);
  46     act.sa_flags = 0;
  47     if (sigaction(sig, &act, NULL) == 0) {
  48         sigset_t set;
  49         sigemptyset(&set);
  50         sigaddset(&set, sig);
  51         sigprocmask(SIG_UNBLOCK, &set, NULL);
  52     }
  53 }
  54
  55 static volatile sig_atomic_t alrmcatch_pending; /* = 0; */
  56 static volatile sig_atomic_t pchild_pending; /* = 0; */
  57 static volatile sig_atomic_t phup_pending; /* = 0; */
  58 static volatile sig_atomic_t pintr_pending; /* = 0; */
  59 int alrmcatch_disabled; /* = 0; */
  60 int phup_disabled; /* = 0; */
  61 int pchild_disabled; /* = 0; */
  62 int pintr_disabled; /* = 0; */
  63 int handle_interrupt; /* = 0; */
  64
  65 int
  66 handle_pending_signals(void)
  67 {
  68     int rv = 0;
  69     if (!phup_disabled && phup_pending) {
  70         phup_pending = 0;
  71         handle_interrupt++;
  72         phup();
  73         handle_interrupt--;
  74     }
  75     if (!pintr_disabled && pintr_pending) {
  76         pintr_pending = 0;
  77         handle_interrupt++;
  78         pintr();
  79         handle_interrupt--;
  80         rv = 1;
  81     }
  82     if (!pchild_disabled && pchild_pending) {
  83         pchild_pending = 0;
  84         handle_interrupt++;
  85         pchild();
  86         handle_interrupt--;
  87     }
  88     if (!alrmcatch_disabled && alrmcatch_pending) {
  89         alrmcatch_pending = 0;
  90         handle_interrupt++;
  91         alrmcatch();
  92         handle_interrupt--;
  93     }
  94     return rv;
  95 }
  96
  97 void
  98 queue_alrmcatch(int sig)
  99 {
 100     USE(sig);
 101     alrmcatch_pending = 1;
 102 }
 103
 104 void
 105 queue_pchild(int sig)
 106 {
 107     USE(sig);
 108     pchild_pending = 1;
 109 }
 110
 111 void
 112 queue_phup(int sig)
 113 {
 114     USE(sig);
 115     phup_pending = 1;
 116 }
 117
 118 void
 119 queue_pintr(int sig)
 120 {
 121     USE(sig);
 122     pintr_pending = 1;
 123 }
 124
 125 void
 126 disabled_cleanup(void *xdisabled)
 127 {
 128     int *disabled;
 129
 130     disabled = xdisabled;
 131     if (--*disabled == 0)
 132         handle_pending_signals();
 133 }
 134
 135 void
 136 pintr_disabled_restore(void *xold)
 137 {
 138     int *old;
 139
 140     old = xold;
 141     pintr_disabled = *old;
 142 }
 143
 144 void
 145 pintr_push_enable(int *saved)
 146 {
 147     *saved = pintr_disabled;
 148     pintr_disabled = 0;
 149     cleanup_push(saved, pintr_disabled_restore);
 150     handle_pending_signals();
 151 }