ZeroMQ TIPC load-balancing example

cli.c

/*
 * cli.c: TIPC reqrep client example
 *
 * Copyright (c) 2013 Ericsson AB
 *
 * 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. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
 */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <zmq.h>
#include <zmq_utils.h>
#include <assert.h>

int main (int argc, char **argv)
{
	void *ctx;
	void *client;
	int rc;
	char buff[255];
	char c;
	char *servname = NULL;
	char hostname[128];

	while ((c = getopt(argc, argv, "c:")) != -1)
	{
		switch (c) {
		case 'c':
			servname = optarg;
			break;
		default:
bail:
			printf("usage: %s -s tipc://{type, instance}\n"\
				"example: %s -s tipc://{1000,42}", argv[0], argv[0]);
			return -1;
		}
	}
	if (!servname)
		goto bail;

	gethostname(hostname, sizeof(hostname));
	printf("%s sending message to: %s\n", hostname, servname);
	ctx = zmq_init (1);
	assert (ctx);

	client = zmq_socket(ctx, ZMQ_REQ);
	assert (client);
	rc = zmq_connect(client, servname);
	assert (rc == 0);
	sleep(1); /* Yield, let it connect..*/
	memset(buff,0, sizeof(buff));
	sprintf(buff, "hello world from %s", hostname);
	rc = zmq_send(client, buff, strlen(buff), 0);
	assert (rc >= 0);
	printf ("client sent message '%s', rc=%d\n", buff, rc);
	rc = zmq_recv(client, buff, sizeof(buff), 0);
	assert (rc >= 0);
	printf("%s\n", buff);
	rc = zmq_close (client);
	assert (rc == 0);

	rc = zmq_term (ctx);
	assert (rc == 0);
	return 0 ;
}

Makefile

all: srv.c
	g++ srv.c /home/eerihug/dev/BakkaLinux/root/usr/local/lib/libzmq.a -lpthread -lrt -o srv
	g++ cli.c /home/eerihug/dev/BakkaLinux/root/usr/local/lib/libzmq.a -lpthread -lrt -o cli

clean:
	rm cli
	rm srv

srv.c

/*
 * srv.c: TIPC reqrep server example
 *
 * Copyright (c) 2013 Ericsson AB
 *
 * 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. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
 */


#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <zmq.h>
#include <zmq_utils.h>
#include <assert.h>

int main (int argc, char **argv)
{
	void *ctx;
	void *server;
	int rc;
	char buff[255];
	char c;
	char *servname = NULL;
	char hostname[128];

	while ((c = getopt(argc, argv, "s:")) != -1)
	{
		switch (c) {
		case 's':
			servname = optarg;
			break;
		default:
bail:
			printf("usage: %s -s tipc://{type, lower, upper}\n"\
				"example: %s -s tipc://{1000,0,10}", argv[0], argv[0]);
			return -1;
		}
	}
	if (!servname)
		goto bail;

	gethostname(hostname, sizeof(hostname));
	printf("server %s listening on %s\n", hostname, servname);
	ctx = zmq_init (1);
	assert (ctx);
	server = zmq_socket (ctx, ZMQ_REP);
	rc = zmq_bind (server, servname);
	assert (rc == 0);
again:
	rc = zmq_recv(server, buff, sizeof(buff), 0);
	assert (rc >= 0);
	printf ("server %s received message:'%s'\n", hostname, buff);
	sprintf(buff, "Your request have been served by %s\n", hostname);
	rc = zmq_send(server, buff, sizeof(buff), 0);
	assert (rc >= 0);
goto again; /* None shall pass */
	rc = zmq_close (server);
	assert (rc == 0);
	rc = zmq_term (ctx);
	assert (rc == 0);
	return 0 ;
}