/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 1997 - 1999, 2001 Brian Somers <brian@Awfulhak.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <signal.h>
#include "log.h"
#include "sig.h"
static int caused[NSIG]; /* An array of pending signals */
static int necessary; /* Anything set ? */
static sig_type handler[NSIG]; /* all start at SIG_DFL */
/*
* Record a signal in the "caused" array
*
* This function is the only thing actually called in signal context. It
* records that a signal has been caused and that sig_Handle() should be
* called (in non-signal context) as soon as possible to process that
* signal.
*/
static void
signal_recorder(int sig)
{
caused[sig - 1]++;
necessary = 1;
}
/*
* Set up signal_recorder to handle the given sig and record ``fn'' as
* the function to ultimately call in sig_Handle(). ``fn'' will not be
* called in signal context (as sig_Handle() is not called in signal
* context).
*/
sig_type
sig_signal(int sig, sig_type fn)
{
sig_type Result;
if (sig <= 0 || sig > NSIG) {
/* Oops - we must be a bit out of date (too many sigs ?) */
log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n",
__FILE__, __LINE__);
return signal(sig, fn);
}
Result = handler[sig - 1];
if (fn == SIG_DFL || fn == SIG_IGN) {
signal(sig, fn);
handler[sig - 1] = (sig_type) 0;
} else {
handler[sig - 1] = fn;
signal(sig, signal_recorder);
}
caused[sig - 1] = 0;
return Result;
}
/*
* Call the handlers for any pending signals
*
* This function is called from a non-signal context - in fact, it's
* called every time select() in DoLoop() returns - just in case
* select() returned due to a signal being recorded by signal_recorder().
*/
int
sig_Handle(void)
{
int sig;
int got;
int result;
result = 0;
if (necessary) {
/* We've *probably* got something in `caused' set */
necessary = 0;
/* `necessary' might go back to 1 while we're in here.... */
do {
got = 0;
for (sig = 0; sig < NSIG; sig++)
if (caused[sig]) {
caused[sig]--;
got++;
result++;
(*handler[sig])(sig + 1);
}
} while (got);
}
return result;
}
plain