libzmq/tests/test_issue_566.cpp

/* SPDX-License-Identifier: MPL-2.0 */

#include "testutil.hpp"
#include "testutil_unity.hpp"

SETUP_TEARDOWN_TESTCONTEXT

//  Issue 566 describes a problem in libzmq v4.0.0 where a dealer to router
//  connection would fail randomly. The test works when the two sockets are
//  on the same context, and failed when they were on separate contexts.
//  Fixed by https://github.com/zeromq/libzmq/commit/be25cf.
void test_issue_566 ()
{
    char my_endpoint[MAX_SOCKET_STRING];
    void *ctx1 = zmq_ctx_new ();
    TEST_ASSERT_NOT_NULL (ctx1);

    void *ctx2 = zmq_ctx_new ();
    TEST_ASSERT_NOT_NULL (ctx2);

    void *router = zmq_socket (ctx1, ZMQ_ROUTER);
    int on = 1;
    TEST_ASSERT_SUCCESS_ERRNO (
      zmq_setsockopt (router, ZMQ_ROUTER_MANDATORY, &on, sizeof (on)));
    bind_loopback_ipv4 (router, my_endpoint, sizeof (my_endpoint));

    //  Repeat often enough to be sure this works as it should
    for (int cycle = 0; cycle < 100; cycle++) {
        //  Create dealer with unique explicit routing id
        //  We assume the router learns this out-of-band
        void *dealer = zmq_socket (ctx2, ZMQ_DEALER);
        //  Leave space for NULL char from sprintf, gcc warning
        char routing_id[11];
        snprintf (routing_id, 11 * sizeof (char), "%09d", cycle);
        TEST_ASSERT_SUCCESS_ERRNO (
          zmq_setsockopt (dealer, ZMQ_ROUTING_ID, routing_id, 10));
        int rcvtimeo = 1000;
        TEST_ASSERT_SUCCESS_ERRNO (
          zmq_setsockopt (dealer, ZMQ_RCVTIMEO, &rcvtimeo, sizeof (int)));
        TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (dealer, my_endpoint));

        //  Router will try to send to dealer, at short intervals.
        //  It typically takes 2-5 msec for the connection to establish
        //  on a loopback interface, but we'll allow up to one second
        //  before failing the test (e.g. for running on a debugger or
        //  a very slow system).
        for (int attempt = 0; attempt < 500; attempt++) {
            zmq_poll (NULL, 0, 2);
            int rc = zmq_send (router, routing_id, 10, ZMQ_SNDMORE);
            if (rc == -1 && errno == EHOSTUNREACH)
                continue;
            TEST_ASSERT_EQUAL (10, rc);
            send_string_expect_success (router, "HELLO", 0);
            break;
        }
        recv_string_expect_success (dealer, "HELLO", 0);
        close_zero_linger (dealer);
    }
    zmq_close (router);
    zmq_ctx_destroy (ctx1);
    zmq_ctx_destroy (ctx2);
}

int main ()
{
    setup_test_environment ();

    UNITY_BEGIN ();
    RUN_TEST (test_issue_566);
    return UNITY_END ();
}