tc.sig.c revision 316958 
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
35RCSID("$tcsh: tc.sig.c,v 3.40 2012/01/25 15:34:41 christos Exp $")
36
37#include "tc.wait.h"
38
39void
40sigset_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
55static volatile sig_atomic_t alrmcatch_pending; /* = 0; */
56static volatile sig_atomic_t pchild_pending; /* = 0; */
57static volatile sig_atomic_t phup_pending; /* = 0; */
58static volatile sig_atomic_t pintr_pending; /* = 0; */
59int alrmcatch_disabled; /* = 0; */
60int phup_disabled; /* = 0; */
61int pchild_disabled; /* = 0; */
62int pintr_disabled; /* = 0; */
63int handle_interrupt; /* = 0; */
64
65int
66handle_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
97void
98queue_alrmcatch(int sig)
99{
100    USE(sig);
101    alrmcatch_pending = 1;
102}
103
104void
105queue_pchild(int sig)
106{
107    USE(sig);
108    pchild_pending = 1;
109}
110
111void
112queue_phup(int sig)
113{
114    USE(sig);
115    phup_pending = 1;
116}
117
118void
119queue_pintr(int sig)
120{
121    USE(sig);
122    pintr_pending = 1;
123}
124
125void
126disabled_cleanup(void *xdisabled)
127{
128    int *disabled;
129
130    disabled = xdisabled;
131    if (--*disabled == 0)
132	handle_pending_signals();
133}
134
135void
136pintr_disabled_restore(void *xold)
137{
138    int *old;
139
140    old = xold;
141    pintr_disabled = *old;
142}
143
144void
145pintr_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}
152