libzmq/tests/test_req_send_resets.cpp

/*
    Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file

    This file is part of 0MQ.

    0MQ is free software; you can redistribute it and/or modify it under
    the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    0MQ is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <unistd.h>
#include <time.h>
#include "testutil.hpp"

int main (void)
{
    void *ctx = zmq_ctx_new ();
    assert (ctx);

    void *req = zmq_socket (ctx, ZMQ_REQ);
    assert (req);

    int enabled = 1;
    int rc = zmq_setsockopt (req, ZMQ_REQ_SEND_RESETS, &enabled, sizeof (int));
    assert (rc == 0);

    rc = zmq_setsockopt (req, ZMQ_REQ_REQUEST_IDS, &enabled, sizeof (int));
    assert (rc == 0);

    rc = zmq_bind (req, "tcp://*:5555");
    assert (rc == 0);

    const size_t services = 5;
    void *rep [services];
    for (size_t peer = 0; peer < services; peer++) {
        rep [peer] = zmq_socket (ctx, ZMQ_REP);
        assert (rep [peer]);

        int timeout = 100;
        rc = zmq_setsockopt (rep [peer], ZMQ_RCVTIMEO, &timeout, sizeof (int));
        assert (rc == 0);

        rc = zmq_connect (rep [peer], "tcp://localhost:5555");
        assert (rc == 0);
    }
    //  We have to give the connects time to finish otherwise the requests
    //  will not properly round-robin. We could alternatively connect the
    //  REQ sockets to the REP sockets.
    struct timespec t = { 0, 250 * 1000000 };
    nanosleep (&t, NULL);


    //  Case 1: Second send() before a reply arrives in a pipe.

    //  Send a request, ensure it arrives, don't send a reply
    s_send_seq (req, "A", "B", SEQ_END);
    s_recv_seq (rep [0], "A", "B", SEQ_END);

    //  Send another request on the REQ socket
    s_send_seq (req, "C", "D", SEQ_END);
    s_recv_seq (rep [1], "C", "D", SEQ_END);

    //  Send a reply to the first request - that should be discarded by the REQ
    s_send_seq (rep [0], "WRONG", SEQ_END);

    //  Send the expected reply
    s_send_seq (rep [1], "OK", SEQ_END);
    s_recv_seq (req, "OK", SEQ_END);


    //  Another standard req-rep cycle, just to check
    s_send_seq (req, "E", SEQ_END);
    s_recv_seq (rep [2], "E", SEQ_END);
    s_send_seq (rep [2], "F", "G", SEQ_END);
    s_recv_seq (req, "F", "G", SEQ_END);


    //  Case 2: Second send() after a reply is already in a pipe on the REQ.

    //  Send a request, ensure it arrives, send a reply
    s_send_seq (req, "H", SEQ_END);
    s_recv_seq (rep [3], "H", SEQ_END);
    s_send_seq (rep [3], "BAD", SEQ_END);

    // Wait for message to be there.
    rc = zmq_poll (0, 0, 100);
    assert (rc == 0);

    //  Without receiving that reply, send another request on the REQ socket
    s_send_seq (req, "I", SEQ_END);
    s_recv_seq (rep [4], "I", SEQ_END);

    //  Send the expected reply
    s_send_seq (rep [4], "GOOD", SEQ_END);
    s_recv_seq (req, "GOOD", SEQ_END);


    close_zero_linger (req);
    for (size_t peer = 0; peer < services; peer++)
        close_zero_linger (rep [peer]);

    // Wait for disconnects.
    rc = zmq_poll (0, 0, 100);
    assert (rc == 0);

    rc = zmq_ctx_term (ctx);
    assert (rc == 0);

    return 0 ;
}