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kc3-lang/libevent/signal.c

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  • Author : Niels Provos
    Date : 2007-11-03 23:53:49
    Hash : 2026b215
    Message : remove last vestiges of RBTREE svn:r470

  • 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.
     */
    #ifdef HAVE_CONFIG_H
    #include "config.h"
    #endif
    
    #ifdef WIN32
    #define WIN32_LEAN_AND_MEAN
    #include <windows.h>
    #include <winsock2.h>
    #undef WIN32_LEAN_AND_MEAN
    #endif
    #include <sys/types.h>
    #ifdef HAVE_SYS_TIME_H
    #include <sys/time.h>
    #else
    #include <sys/_time.h>
    #endif
    #include <sys/queue.h>
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #include <signal.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>
    #include <errno.h>
    #ifdef HAVE_FCNTL_H
    #include <fcntl.h>
    #endif
    #include <assert.h>
    
    #include "event.h"
    #include "event-internal.h"
    #include "evsignal.h"
    #include "evutil.h"
    #include "log.h"
    
    struct event_base *evsignal_base = NULL;
    
    static void evsignal_handler(int sig);
    
    /* Callback for when the signal handler write a byte to our signaling socket */
    static void
    evsignal_cb(int fd, short what, void *arg)
    {
    	static char signals[100];
    	struct event *ev = arg;
    	ssize_t n;
    
    	n = recv(fd, signals, sizeof(signals), 0);
    	if (n == -1)
    		event_err(1, "%s: read", __func__);
    	event_add(ev, NULL);
    }
    
    #ifdef HAVE_SETFD
    #define FD_CLOSEONEXEC(x) do { \
            if (fcntl(x, F_SETFD, 1) == -1) \
                    event_warn("fcntl(%d, F_SETFD)", x); \
    } while (0)
    #else
    #define FD_CLOSEONEXEC(x)
    #endif
    
    void
    evsignal_init(struct event_base *base)
    {
    	/* 
    	 * Our signal handler is going to write to one end of the socket
    	 * pair to wake up our event loop.  The event loop then scans for
    	 * signals that got delivered.
    	 */
    	if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, base->sig.ev_signal_pair) == -1)
    		event_err(1, "%s: socketpair", __func__);
    
    	FD_CLOSEONEXEC(base->sig.ev_signal_pair[0]);
    	FD_CLOSEONEXEC(base->sig.ev_signal_pair[1]);
    	base->sig.evsignal_caught = 0;
    	memset(&base->sig.evsigcaught, 0, sizeof(sig_atomic_t)*NSIG);
    
            evutil_make_socket_nonblocking(base->sig.ev_signal_pair[0]);
    
    	event_set(&base->sig.ev_signal, base->sig.ev_signal_pair[1], EV_READ,
    	    evsignal_cb, &base->sig.ev_signal);
    	base->sig.ev_signal.ev_base = base;
    	base->sig.ev_signal.ev_flags |= EVLIST_INTERNAL;
    }
    
    int
    evsignal_add(struct event *ev)
    {
    	int evsignal;
    #ifdef HAVE_SIGACTION
    	struct sigaction sa;
    #endif
    	struct event_base *base = ev->ev_base;
    
    	if (ev->ev_events & (EV_READ|EV_WRITE))
    		event_errx(1, "%s: EV_SIGNAL incompatible use", __func__);
    	evsignal = EVENT_SIGNAL(ev);
    
    #ifdef HAVE_SIGACTION
    	memset(&sa, 0, sizeof(sa));
    	sa.sa_handler = evsignal_handler;
    	sigfillset(&sa.sa_mask);
    	sa.sa_flags |= SA_RESTART;
    	/* catch signals if they happen quickly */
    	evsignal_base = base;
    
    	if (sigaction(evsignal, &sa, NULL) == -1)
    		return (-1);
    #else
    	evsignal_base = base;
    	if (signal(evsignal, evsignal_handler) == SIG_ERR)
    		return (-1);
    #endif
    
    	if (!base->sig.ev_signal_added) {
    		base->sig.ev_signal_added = 1;
    		event_add(&base->sig.ev_signal, NULL);
    	}
    
    	return (0);
    }
    
    int
    evsignal_del(struct event *ev)
    {
    #ifdef HAVE_SIGACTION
    	return (sigaction(EVENT_SIGNAL(ev),(struct sigaction *)SIG_DFL, NULL));
    #else
    	return (signal(EVENT_SIGNAL(ev),SIG_DFL))==SIG_ERR ? -1 : 0;
    #endif
    }
    
    static void
    evsignal_handler(int sig)
    {
    	int save_errno = errno;
    
    	if(evsignal_base == NULL) {
    		event_warn(
    			"%s: received signal %s, but have no base configured",
    			__func__, sig);
    		return;
    	}
    
    	evsignal_base->sig.evsigcaught[sig]++;
    	evsignal_base->sig.evsignal_caught = 1;
    
    #ifndef HAVE_SIGACTION
    	signal(sig, evsignal_handler);
    #endif
    
    	/* Wake up our notification mechanism */
    	send(evsignal_base->sig.ev_signal_pair[0], "a", 1, 0);
    	errno = save_errno;
    }
    
    void
    evsignal_process(struct event_base *base)
    {
    	struct event *ev;
    	sig_atomic_t ncalls;
    
    	base->sig.evsignal_caught = 0;
    	TAILQ_FOREACH(ev, &base->sig.signalqueue, ev_signal_next) {
    		ncalls = base->sig.evsigcaught[EVENT_SIGNAL(ev)];
    		if (ncalls) {
    			if (!(ev->ev_events & EV_PERSIST))
    				event_del(ev);
    			event_active(ev, EV_SIGNAL, ncalls);
    			base->sig.evsigcaught[EVENT_SIGNAL(ev)] = 0;
    		}
    	}
    }
    
    void
    evsignal_dealloc(struct event_base *base)
    {
    	if(base->sig.ev_signal_added) {
    		event_del(&base->sig.ev_signal);
    		base->sig.ev_signal_added = 0;
    	}
    	assert(TAILQ_EMPTY(&base->sig.signalqueue));
    
    	EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[0]);
    	base->sig.ev_signal_pair[0] = -1;
    	EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[1]);
    	base->sig.ev_signal_pair[1] = -1;
    }