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 /*

  * Copyright 2003-2007 Niels Provos <provos@citi.umich.edu>

  * Copyright 2007-2012 Niels Provos and Nick Mathewson

  *

  * 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.

  *

  *

  * Mon 03/10/2003 - Modified by Davide Libenzi <davidel@xmailserver.org>

  *

  *     Added chain event propagation to improve the sensitivity of

  *     the measure respect to the event loop efficency.

  *

  *

  */

 #include "event2/event-config.h"

 #include <sys/types.h>

 #include <sys/stat.h>

 #ifdef _EVENT_HAVE_SYS_TIME_H

 #include <sys/time.h>

 #endif

 #ifdef WIN32

 #define WIN32_LEAN_AND_MEAN

 #include <windows.h>

 #else

 #include <sys/socket.h>

 #include <signal.h>

 #include <sys/resource.h>

 #endif

 #include <fcntl.h>

 #include <stdlib.h>

 #include <stdio.h>

 #include <string.h>

 #ifdef _EVENT_HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 #include <errno.h>

 #include <event.h>

 #include <evutil.h>

 static int count, writes, fired;

 static evutil_socket_t *pipes;

 static int num_pipes, num_active, num_writes;

 static struct event *events;

 static void

 read_cb(evutil_socket_t fd, short which, void *arg)

 {

 	ev_intptr_t idx = (ev_intptr_t) arg, widx = idx + 1;

 	u_char ch;

 	count += recv(fd, (char*)&ch, sizeof(ch), 0);

 	if (writes) {

 		if (widx >= num_pipes)

 			widx -= num_pipes;

 		send(pipes[2 * widx + 1], "e", 1, 0);

 		writes--;

 		fired++;

 	}

 }

 static struct timeval *

 run_once(void)

 {

 	evutil_socket_t *cp, space;

 	long i;

 	static struct timeval ts, te;

 	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {

 		if (event_initialized(&events[i]))

 			event_del(&events[i]);

 		event_set(&events[i], cp[0], EV_READ | EV_PERSIST, read_cb, (void *)(ev_intptr_t) i);

 		event_add(&events[i], NULL);

 	}

 	event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);

 	fired = 0;

 	space = num_pipes / num_active;

 	space = space * 2;

 	for (i = 0; i < num_active; i++, fired++)

 		send(pipes[i * space + 1], "e", 1, 0);

 	count = 0;

 	writes = num_writes;

 	{ int xcount = 0;

 	evutil_gettimeofday(&ts, NULL);

 	do {

 		event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);

 		xcount++;

 	} while (count != fired);

 	evutil_gettimeofday(&te, NULL);

 	if (xcount != count) fprintf(stderr, "Xcount: %d, Rcount: %d\n", xcount, count);

 	}

 	evutil_timersub(&te, &ts, &te);

 	return (&te);

 }

 int

 main(int argc, char **argv)

 {

 #ifndef WIN32

 	struct rlimit rl;

 #endif

 	int i, c;

 	struct timeval *tv;

 	evutil_socket_t *cp;

 #ifdef WIN32

 	WSADATA WSAData;

 	WSAStartup(0x101, &WSAData);

 #endif

 	num_pipes = 100;

 	num_active = 1;

 	num_writes = num_pipes;

 	while ((c = getopt(argc, argv, "n:a:w:")) != -1) {

 		switch (c) {

 		case 'n':

 			num_pipes = atoi(optarg);

 			break;

 		case 'a':

 			num_active = atoi(optarg);

 			break;

 		case 'w':

 			num_writes = 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

 	events = calloc(num_pipes, sizeof(struct event));

 	pipes = calloc(num_pipes * 2, sizeof(evutil_socket_t));

 	if (events == NULL || pipes == NULL) {

 		perror("malloc");

 		exit(1);

 	}

 	event_init();

 	for (cp = pipes, i = 0; i < num_pipes; i++, cp += 2) {

 #ifdef USE_PIPES

 		if (pipe(cp) == -1) {

 #else

 		if (evutil_socketpair(AF_UNIX, SOCK_STREAM, 0, cp) == -1) {

 #endif

 			perror("pipe");

 			exit(1);

 		}

 	}

 	for (i = 0; i < 25; i++) {

 		tv = run_once();

 		if (tv == NULL)

 			exit(1);

 		fprintf(stdout, "%ld\n",

 			tv->tv_sec * 1000000L + tv->tv_usec);

 	}

 	exit(0);

 }