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kc3-lang/libevent/poll.c

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  • Author : Niels Provos
    Date : 2003-03-08 06:37:56
    Hash : cde7a352
    Message : fix signal usage svn:r45

  • poll.c
  • /*	$OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey Exp $	*/
    
    /*
     * Copyright 2000-2003 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Niels Provos.
     * 4. 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
    
    #include <sys/types.h>
    #ifdef HAVE_SYS_TIME_H
    #include <sys/time.h>
    #else
    #include <sys/_time.h>
    #endif
    #include <sys/queue.h>
    #include <poll.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 eventqueue;
    
    extern volatile sig_atomic_t evsignal_caught;
    
    struct pollop {
    	int event_count;		/* Highest number alloc */
    	struct pollfd *event_set;
    	struct event **event_back;
    	sigset_t evsigmask;
    } pop;
    
    void *poll_init	(void);
    int poll_add		(void *, struct event *);
    int poll_del		(void *, struct event *);
    int poll_recalc	(void *, int);
    int poll_dispatch	(void *, struct timeval *);
    
    struct eventop pollops = {
    	"poll",
    	poll_init,
    	poll_add,
    	poll_del,
    	poll_recalc,
    	poll_dispatch
    };
    
    void *
    poll_init(void)
    {
    	/* Disable kqueue when this environment variable is set */
    	if (getenv("EVENT_NOPOLL"))
    		return (NULL);
    
    	memset(&pop, 0, sizeof(pop));
    
    	evsignal_init(&pop.evsigmask);
    
    	return (&pop);
    }
    
    /*
     * Called with the highest fd that we know about.  If it is 0, completely
     * recalculate everything.
     */
    
    int
    poll_recalc(void *arg, int max)
    {
    	struct pollop *pop = arg;
    
    	return (evsignal_recalc(&pop->evsigmask));
    }
    
    int
    poll_dispatch(void *arg, struct timeval *tv)
    {
    	int res, i, count, sec, nfds;
    	struct event *ev;
    	struct pollop *pop = arg;
    
    	count = pop->event_count;
    	nfds = 0;
    	TAILQ_FOREACH(ev, &eventqueue, ev_next) {
    		if (nfds + 1 >= count) {
    			if (count < 32)
    				count = 32;
    			else
    				count *= 2;
    
    			/* We need more file descriptors */
    			pop->event_set = realloc(pop->event_set,
    			    count * sizeof(struct pollfd));
    			if (pop->event_set == NULL) {
    				log_error("realloc");
    				return (-1);
    			}
    			pop->event_back = realloc(pop->event_back,
    			    count * sizeof(struct event *));
    			if (pop->event_back == NULL) {
    				log_error("realloc");
    				return (-1);
    			}
    			pop->event_count = count;
    		}
    		if (ev->ev_events & EV_WRITE) {
    			struct pollfd *pfd = &pop->event_set[nfds];
    			pfd->fd = ev->ev_fd;
    			pfd->events = POLLOUT;
    			pfd->revents = 0;
    
    			pop->event_back[nfds] = ev;
    
    			nfds++;
    		}
    		if (ev->ev_events & EV_READ) {
    			struct pollfd *pfd = &pop->event_set[nfds];
    
    			pfd->fd = ev->ev_fd;
    			pfd->events = POLLIN;
    			pfd->revents = 0;
    
    			pop->event_back[nfds] = ev;
    
    			nfds++;
    		}
    	}
    
    	if (evsignal_deliver(&pop->evsigmask) == -1)
    		return (-1);
    
    	sec = tv->tv_sec * 1000 + tv->tv_usec / 1000;
    	res = poll(pop->event_set, nfds, sec);
    
    	if (evsignal_recalc(&pop->evsigmask) == -1)
    		return (-1);
    
    	if (res == -1) {
    		if (errno != EINTR) {
    			log_error("poll");
    			return (-1);
    		}
    
    		evsignal_process();
    		return (0);
    	} else if (evsignal_caught)
    		evsignal_process();
    
    	LOG_DBG((LOG_MISC, 80, "%s: poll reports %d", __func__, res));
    
    	if (res == 0)
    		return (0);
    
    	for (i = 0; i < nfds; i++) {
    		res = 0;
    		if (pop->event_set[i].revents & POLLIN)
    			res = EV_READ;
    		else if (pop->event_set[i].revents & POLLOUT)
    			res = EV_WRITE;
    		if (res == 0)
    			continue;
    
    		ev = pop->event_back[i];
    		res &= ev->ev_events;
    
    		if (res) {
    			if (!(ev->ev_events & EV_PERSIST))
    				event_del(ev);
    			event_active(ev, res, 1);
    		}	
    	}
    
    	return (0);
    }
    
    int
    poll_add(void *arg, struct event *ev)
    {
    	struct pollop *pop = arg;
    
    	if (ev->ev_events & EV_SIGNAL)
    		return (evsignal_add(&pop->evsigmask, ev));
    
    	return (0);
    }
    
    /*
     * Nothing to be done here.
     */
    
    int
    poll_del(void *arg, struct event *ev)
    {
    	struct pollop *pop = arg;
    
    	if (!(ev->ev_events & EV_SIGNAL))
    		return (0);
    
    	return (evsignal_del(&pop->evsigmask, ev));
    }