xref: /freebsd/contrib/tcsh/tc.sig.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
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 }
152