libzmq/tests/test_spec_dealer.cpp

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

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

SETUP_TEARDOWN_TESTCONTEXT

// SHALL route outgoing messages to available peers using a round-robin
// strategy.
void test_round_robin_out (const char *bind_address_)
{
    void *dealer = test_context_socket (ZMQ_DEALER);

    char connect_address[MAX_SOCKET_STRING];
    test_bind (dealer, bind_address_, connect_address,
               sizeof (connect_address));

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

        TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (rep[peer], connect_address));
    }

    // Wait for connections.
    msleep (SETTLE_TIME);

    // Send all requests
    for (size_t i = 0; i < services; ++i)
        s_send_seq (dealer, 0, "ABC", SEQ_END);

    // Expect every REP got one message
    zmq_msg_t msg;
    zmq_msg_init (&msg);

    for (size_t peer = 0; peer < services; ++peer)
        s_recv_seq (rep[peer], "ABC", SEQ_END);

    TEST_ASSERT_SUCCESS_ERRNO (zmq_msg_close (&msg));

    test_context_socket_close_zero_linger (dealer);

    for (size_t peer = 0; peer < services; ++peer)
        test_context_socket_close_zero_linger (rep[peer]);
}

// SHALL receive incoming messages from its peers using a fair-queuing
// strategy.
void test_fair_queue_in (const char *bind_address_)
{
    void *receiver = test_context_socket (ZMQ_DEALER);

    char connect_address[MAX_SOCKET_STRING];
    test_bind (receiver, bind_address_, connect_address,
               sizeof (connect_address));

    const size_t services = 5;
    void *senders[services];
    for (size_t peer = 0; peer < services; ++peer) {
        senders[peer] = test_context_socket (ZMQ_DEALER);

        TEST_ASSERT_SUCCESS_ERRNO (
          zmq_connect (senders[peer], connect_address));
    }

    zmq_msg_t msg;
    TEST_ASSERT_SUCCESS_ERRNO (zmq_msg_init (&msg));

    s_send_seq (senders[0], "A", SEQ_END);
    s_recv_seq (receiver, "A", SEQ_END);

    s_send_seq (senders[0], "A", SEQ_END);
    s_recv_seq (receiver, "A", SEQ_END);

    // send our requests
    for (size_t peer = 0; peer < services; ++peer)
        s_send_seq (senders[peer], "B", SEQ_END);

    // Wait for data.
    msleep (SETTLE_TIME);

    // handle the requests
    for (size_t peer = 0; peer < services; ++peer)
        s_recv_seq (receiver, "B", SEQ_END);

    TEST_ASSERT_SUCCESS_ERRNO (zmq_msg_close (&msg));

    test_context_socket_close_zero_linger (receiver);

    for (size_t peer = 0; peer < services; ++peer)
        test_context_socket_close_zero_linger (senders[peer]);
}

// SHALL create a double queue when a peer connects to it. If this peer
// disconnects, the DEALER socket SHALL destroy its double queue and SHALL
// discard any messages it contains.
void test_destroy_queue_on_disconnect (const char *bind_address_)
{
    void *a = test_context_socket (ZMQ_DEALER);

    char connect_address[MAX_SOCKET_STRING];
    test_bind (a, bind_address_, connect_address, sizeof (connect_address));

    void *b = test_context_socket (ZMQ_DEALER);

    TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (b, connect_address));

    // Send a message in both directions
    s_send_seq (a, "ABC", SEQ_END);
    s_send_seq (b, "DEF", SEQ_END);

    TEST_ASSERT_SUCCESS_ERRNO (zmq_disconnect (b, connect_address));

    // Disconnect may take time and need command processing.
    zmq_pollitem_t poller[2] = {{a, 0, 0, 0}, {b, 0, 0, 0}};
    TEST_ASSERT_SUCCESS_ERRNO (zmq_poll (poller, 2, 100));
    TEST_ASSERT_SUCCESS_ERRNO (zmq_poll (poller, 2, 100));

    // No messages should be available, sending should fail.
    zmq_msg_t msg;
    zmq_msg_init (&msg);

    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_send (a, 0, 0, ZMQ_DONTWAIT));

    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_msg_recv (&msg, a, ZMQ_DONTWAIT));

    // After a reconnect of B, the messages should still be gone
    TEST_ASSERT_SUCCESS_ERRNO (zmq_connect (b, connect_address));

    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_msg_recv (&msg, a, ZMQ_DONTWAIT));

    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_msg_recv (&msg, b, ZMQ_DONTWAIT));

    TEST_ASSERT_SUCCESS_ERRNO (zmq_msg_close (&msg));

    test_context_socket_close_zero_linger (a);
    test_context_socket_close_zero_linger (b);
}

// SHALL block on sending, or return a suitable error, when it has no connected peers.
void test_block_on_send_no_peers (const char *bind_address_)
{
    void *sc = test_context_socket (ZMQ_DEALER);

    int timeout = 250;
    TEST_ASSERT_SUCCESS_ERRNO (
      zmq_setsockopt (sc, ZMQ_SNDTIMEO, &timeout, sizeof (timeout)));

    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_send (sc, 0, 0, ZMQ_DONTWAIT));
    TEST_ASSERT_FAILURE_ERRNO (EAGAIN, zmq_send (sc, 0, 0, 0));

    test_context_socket_close (sc);
}

#define TEST_CASES(name, bind_address)                                         \
    void test_round_robin_out_##name ()                                        \
    {                                                                          \
        test_round_robin_out (bind_address);                                   \
    }                                                                          \
    void test_fair_queue_in_##name ()                                          \
    {                                                                          \
        test_fair_queue_in (bind_address);                                     \
    }                                                                          \
    void test_block_on_send_no_peers_##name ()                                 \
    {                                                                          \
        test_block_on_send_no_peers (bind_address);                            \
    }

TEST_CASES (inproc, "inproc://a")
TEST_CASES (tcp, "tcp://127.0.0.1:*")

int main (void)
{
    setup_test_environment ();

    UNITY_BEGIN ();

    RUN_TEST (test_round_robin_out_inproc);
    RUN_TEST (test_fair_queue_in_inproc);
    RUN_TEST (test_block_on_send_no_peers_inproc);

    RUN_TEST (test_round_robin_out_tcp);
    RUN_TEST (test_fair_queue_in_tcp);
    RUN_TEST (test_block_on_send_no_peers_tcp);

    // TODO *** Test disabled until libzmq does this properly ***
    // test_destroy_queue_on_disconnect (ctx);

    return UNITY_END ();
}