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kc3-lang/libevent/signal.c

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  • Author : Niels Provos
    Date : 2003-10-04 23:27:26
    Hash : c3f496c7
    Message : minor corrections; change license to 3-clause BSD license svn:r84

  • signal.c
  • /*	$OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $	*/
    
    /*
     * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
     * 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.
     * 3. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 "config.h"
    
    #include <sys/types.h>
    #ifdef HAVE_SYS_TIME_H
    #include <sys/time.h>
    #else
    #include <sys/_time.h>
    #endif
    #include <sys/queue.h>
    #include <signal.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>
    #include <errno.h>
    #include <err.h>
    
    #ifdef USE_LOG
    #include "log.h"
    #else
    #define LOG_DBG(x)
    #define log_error(x)	perror(x)
    #endif
    
    #include "event.h"
    #include "evsignal.h"
    
    extern struct event_list signalqueue;
    
    static short evsigcaught[NSIG];
    static int needrecalc;
    volatile sig_atomic_t evsignal_caught = 0;
    
    void evsignal_process(void);
    int evsignal_recalc(sigset_t *);
    int evsignal_deliver(sigset_t *);
    
    void
    evsignal_init(sigset_t *evsigmask)
    {
    	sigemptyset(evsigmask);
    }
    
    int
    evsignal_add(sigset_t *evsigmask, struct event *ev)
    {
    	int evsignal;
    	
    	if (ev->ev_events & (EV_READ|EV_WRITE))
    		errx(1, "%s: EV_SIGNAL incompatible use", __func__);
    	evsignal = EVENT_SIGNAL(ev);
    	sigaddset(evsigmask, evsignal);
    	
    	return (0);
    }
    
    /*
     * Nothing to be done here.
     */
    
    int
    evsignal_del(sigset_t *evsigmask, struct event *ev)
    {
    	int evsignal;
    
    	evsignal = EVENT_SIGNAL(ev);
    	sigdelset(evsigmask, evsignal);
    	needrecalc = 1;
    
    	return (sigaction(EVENT_SIGNAL(ev),(struct sigaction *)SIG_DFL, NULL));
    }
    
    static void
    evsignal_handler(int sig)
    {
    	evsigcaught[sig]++;
    	evsignal_caught = 1;
    }
    
    int
    evsignal_recalc(sigset_t *evsigmask)
    {
    	struct sigaction sa;
    	struct event *ev;
    
    	if (TAILQ_FIRST(&signalqueue) == NULL && !needrecalc)
    		return (0);
    	needrecalc = 0;
    
    	if (sigprocmask(SIG_BLOCK, evsigmask, NULL) == -1)
    		return (-1);
    	
    	/* Reinstall our signal handler. */
    	memset(&sa, 0, sizeof(sa));
    	sa.sa_handler = evsignal_handler;
    	sa.sa_mask = *evsigmask;
    	sa.sa_flags |= SA_RESTART;
    	
    	TAILQ_FOREACH(ev, &signalqueue, ev_signal_next) {
    		if (sigaction(EVENT_SIGNAL(ev), &sa, NULL) == -1)
    			return (-1);
    	}
    	return (0);
    }
    
    int
    evsignal_deliver(sigset_t *evsigmask)
    {
    	if (TAILQ_FIRST(&signalqueue) == NULL)
    		return (0);
    
    	return (sigprocmask(SIG_UNBLOCK, evsigmask, NULL));
    	/* XXX - pending signals handled here */
    }
    
    void
    evsignal_process(void)
    {
    	struct event *ev;
    	short ncalls;
    
    	TAILQ_FOREACH(ev, &signalqueue, ev_signal_next) {
    		ncalls = evsigcaught[EVENT_SIGNAL(ev)];
    		if (ncalls) {
    			if (!(ev->ev_events & EV_PERSIST))
    				event_del(ev);
    			event_active(ev, EV_SIGNAL, ncalls);
    		}
    	}
    
    	memset(evsigcaught, 0, sizeof(evsigcaught));
    	evsignal_caught = 0;
    }