sig.c revision 36285 
1/*-
2 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	$Id: sig.c,v 1.11.2.5 1998/05/01 19:25:56 brian Exp $
27 */
28
29#include <sys/types.h>
30
31#include <signal.h>
32
33#include "log.h"
34#include "sig.h"
35
36static int caused[NSIG];	/* An array of pending signals */
37static sig_type handler[NSIG];	/* all start at SIG_DFL */
38
39
40/* Record a signal in the "caused" array */
41
42static void
43signal_recorder(int sig)
44{
45  caused[sig - 1]++;
46}
47
48
49/*
50 * Set up signal_recorder, and record handler as the function to ultimately
51 * call in handle_signal()
52*/
53
54sig_type
55sig_signal(int sig, sig_type fn)
56{
57  sig_type Result;
58
59  if (sig <= 0 || sig > NSIG) {
60    /* Oops - we must be a bit out of date (too many sigs ?) */
61    log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n",
62	      __FILE__, __LINE__);
63    return signal(sig, fn);
64  }
65  Result = handler[sig - 1];
66  if (fn == SIG_DFL || fn == SIG_IGN) {
67    signal(sig, fn);
68    handler[sig - 1] = (sig_type) 0;
69  } else {
70    handler[sig - 1] = fn;
71    signal(sig, signal_recorder);
72  }
73  caused[sig - 1] = 0;
74  return Result;
75}
76
77
78/* Call the handlers for any pending signals */
79
80void
81sig_Handle()
82{
83  int sig;
84  int got;
85
86  do {
87    got = 0;
88    for (sig = 0; sig < NSIG; sig++)
89      if (caused[sig]) {
90	caused[sig]--;
91	got++;
92	(*handler[sig]) (sig + 1);
93      }
94  } while (got);
95}
96