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kc3-lang/libevent/test/bench_cascade.c

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  • Author : Niels Provos
    Date : 2007-11-30 02:21:33
    Hash : 876c3af7
    Message : add another benchmark that tests cascading events svn:r566

  • test/bench_cascade.c
  • /*
     * Copyright 2007 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.
     * 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>
    #include <sys/stat.h>
    #include <sys/time.h>
    #ifdef WIN32
    #include <windows.h>
    #else
    #include <sys/socket.h>
    #include <sys/signal.h>
    #include <sys/resource.h>
    #endif
    #include <fcntl.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <unistd.h>
    #include <errno.h>
    
    #include <event.h>
    #include <evutil.h>
    
    /*
     * This benchmark tests how quickly we can propagate a write down a chain
     * of socket pairs.  We start by writing to the first socket pair and all
     * events will fire subsequently until the last socket pair has been reached
     * and the benchmark terminates.
     */
    
    static int fired;
    static int *pipes;
    static struct event *events;
    
    static void
    read_cb(int fd, short which, void *arg)
    {
    	char ch;
    	int idx = (int) arg;
    
    	read(fd, &ch, sizeof(ch));
    	if (idx >= 0)
    		write(idx, "e", 1);
    	fired++;
    }
    
    static struct timeval *
    run_once(int num_pipes)
    {
    	int *cp, i;
    	static struct timeval ts, te;
    
    	events = calloc(num_pipes, sizeof(struct event));
    	pipes = calloc(num_pipes * 2, sizeof(int));
    
    	if (events == NULL || pipes == NULL) {
    		perror("malloc");
    		exit(1);
    	}
    
    	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
    		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {
    			perror("socketpair");
    			exit(1);
    		}
    	}
    
    	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
    		int fd = i < num_pipes - 1 ? cp[3] : -1;
    		event_set(&events[i], cp[0], EV_READ, read_cb, (void *) fd);
    		event_add(&events[i], NULL);
    	}
    
    	fired = 0;
    
    	/* kick everything off with a single write */
    	write(pipes[1], "e", 1);
    
    	gettimeofday(&ts, NULL);
    	event_dispatch();
    
    	gettimeofday(&te, NULL);
    	evutil_timersub(&te, &ts, &te);
    
    	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {
    		event_del(&events[i]);
    		close(cp[0]);
    		close(cp[1]);
    	}
    
    	free(pipes);
    	free(events);
    
    	return (&te);
    }
    
    int
    main (int argc, char **argv)
    {
    #ifndef WIN32
    	struct rlimit rl;
    #endif
    	int i, c;
    	struct timeval *tv;
    
    	int num_pipes = 100;
    	while ((c = getopt(argc, argv, "n:")) != -1) {
    		switch (c) {
    		case 'n':
    			num_pipes = atoi(optarg);
    			break;
    		default:
    			fprintf(stderr, "Illegal argument \"%c\"\n", c);
    			exit(1);
    		}
    	}
    
    #ifndef WIN32
    	rl.rlim_cur = rl.rlim_max = num_pipes * 2 + 50;
    	if (setrlimit(RLIMIT_NOFILE, &rl) == -1) {
    		perror("setrlimit");
    		exit(1);
    	}
    #endif
    
    	event_init();
    
    	for (i = 0; i < 25; i++) {
    		tv = run_once(num_pipes);
    		if (tv == NULL)
    			exit(1);
    		fprintf(stdout, "%ld\n",
    			tv->tv_sec * 1000000L + tv->tv_usec);
    	}
    
    	exit(0);
    }