add another benchmark that tests cascading events

svn:r566

test/Makefile.am

@@ -4,7 +4,8 @@ CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/compat
 
 EXTRA_DIST = regress.rpc
 
-noinst_PROGRAMS = test-init test-eof test-weof test-time regress bench
+noinst_PROGRAMS = test-init test-eof test-weof test-time regress \
+	bench bench_cascade
 
 BUILT_SOURCES = regress.gen.c regress.gen.h
 test_init_SOURCES = test-init.c
@@ -21,6 +22,8 @@ regress_SOURCES = regress.c regress.h regress_http.c regress_dns.c \
 regress_LDADD = ../libevent.la
 bench_SOURCES = bench.c
 bench_LDADD = ../libevent.la
+bench_cascade_SOURCES = bench_cascade.c
+bench_cascade_LDADD = ../libevent.la
 
 regress.gen.c regress.gen.h: regress.rpc
 	$(top_srcdir)/event_rpcgen.py $(srcdir)/regress.rpc || echo "No Python installed"

test/bench_cascade.c

@@ -0,0 +1,166 @@
+/*
+ * 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);
+}