Add tests for Request-Reply pattern sockets.

* See http://rfc.zeromq.org/spec:28/REQREP
* Not all testable statements are covered.
* At this point, there are several failures:
  - test_spec_req: The REQ socket does not correctly discard messages
    from peers that are not currently being talked to.
  - test_spec_dealer/router: On disconnect, the queues seem to not be
    emptied. The DEALER can still receive a message the disconnected
    peer sent, the ROUTER can still send to the identity of the dis-
    connected peer.

tests/Makefile.am

@@ -24,7 +24,11 @@ noinst_PROGRAMS = test_pair_inproc \
                   test_ctx_options \
                   test_security \
                   test_security_curve \
-                  test_iov
+                  test_iov \
+                  test_spec_req \
+                  test_spec_rep \
+                  test_spec_dealer \
+                  test_spec_router
 
 if !ON_MINGW
 noinst_PROGRAMS += test_shutdown_stress \
@@ -55,6 +59,10 @@ test_ctx_options_SOURCES = test_ctx_options.cpp
 test_iov_SOURCES = test_iov.cpp
 test_security_SOURCES = test_security.cpp
 test_security_curve_SOURCES = test_security_curve.cpp
+test_spec_req_SOURCES = test_spec_req.cpp
+test_spec_rep_SOURCES = test_spec_rep.cpp
+test_spec_dealer_SOURCES = test_spec_dealer.cpp
+test_spec_router_SOURCES = test_spec_router.cpp
 if !ON_MINGW
 test_shutdown_stress_SOURCES = test_shutdown_stress.cpp
 test_pair_ipc_SOURCES = test_pair_ipc.cpp testutil.hpp
@@ -67,4 +75,4 @@ noinst_PROGRAMS += test_raw_sock
 test_raw_sock_SOURCES = test_raw_sock.cpp
 
 #  Run the test cases
-TESTS = $(noinst_PROGRAMS)
\ No newline at end of file
+TESTS = $(noinst_PROGRAMS)

tests/test_spec_dealer.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 <stdlib.h>
+#include "testutil.hpp"
+
+void test_round_robin_out (void *ctx)
+{
+    void *dealer = zmq_socket (ctx, ZMQ_DEALER);
+    assert (dealer);
+
+    int rc = zmq_bind (dealer, "inproc://b");
+    assert (rc == 0);
+
+    const size_t N = 5;
+    void *rep[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        rep[i] = zmq_socket (ctx, ZMQ_REP);
+        assert (rep[i]);
+
+        int timeout = 100;
+        rc = zmq_setsockopt (rep[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
+        assert (rc == 0);
+
+        rc = zmq_connect (rep[i], "inproc://b");
+        assert (rc == 0);
+    }
+
+    // Send N requests
+    for (size_t i = 0; i < N; ++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 i = 0; i < N; ++i)
+    {
+        s_recv_seq (rep[i], "ABC", SEQ_END);
+    }
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_close (dealer);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (rep[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_fair_queue_in (void *ctx)
+{
+    void *receiver = zmq_socket (ctx, ZMQ_DEALER);
+    assert (receiver);
+
+    int timeout = 100;
+    int rc = zmq_setsockopt (receiver, ZMQ_RCVTIMEO, &timeout, sizeof(int));
+    assert (rc == 0);
+
+    rc = zmq_bind (receiver, "inproc://a");
+    assert (rc == 0);
+
+    const size_t N = 5;
+    void *senders[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        senders[i] = zmq_socket (ctx, ZMQ_DEALER);
+        assert (senders[i]);
+
+        rc = zmq_setsockopt (senders[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
+        assert (rc == 0);
+
+        rc = zmq_connect (senders[i], "inproc://a");
+        assert (rc == 0);
+    }
+
+    zmq_msg_t msg;
+    rc = zmq_msg_init (&msg);
+    assert (rc == 0);
+
+    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 N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        char *str = strdup("A");
+        str[0] += i;
+        s_send_seq (senders[i], str, SEQ_END);
+        free (str);
+    }
+
+    // handle N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        char *str = strdup("A");
+        str[0] += i;
+        s_recv_seq (receiver, str, SEQ_END);
+        free (str);
+    }
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_close (receiver);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (senders[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_destroy_queue_on_disconnect (void *ctx)
+{
+    void *A = zmq_socket (ctx, ZMQ_DEALER);
+    assert (A);
+
+    int rc = zmq_bind (A, "inproc://d");
+    assert (rc == 0);
+
+    void *B = zmq_socket (ctx, ZMQ_DEALER);
+    assert (B);
+
+    rc = zmq_connect (B, "inproc://d");
+    assert (rc == 0);
+
+    // Send a message in both directions
+    s_send_seq (A, "ABC", SEQ_END);
+    s_send_seq (B, "DEF", SEQ_END);
+
+    rc = zmq_disconnect (B, "inproc://d");
+    assert (rc == 0);
+
+    // Disconnect may take time and need command processing.
+    zmq_pollitem_t poller[2] = { { A, 0, 0, 0 }, { B, 0, 0, 0 } };
+    rc = zmq_poll (poller, 2, 100);
+    assert (rc == 0);
+
+    // No messages should be available, sending should fail.
+    zmq_msg_t msg;
+    zmq_msg_init (&msg);
+
+    rc = zmq_send (A, 0, 0, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    // After a reconnect of B, the messages should still be gone
+    rc = zmq_connect (B, "inproc://d");
+    assert (rc == 0);
+
+    rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_msg_recv (&msg, B, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_close (A);
+    assert (rc == 0);
+
+    rc = zmq_close (B);
+    assert (rc == 0);
+}
+
+void test_block_on_send_no_peers (void *ctx)
+{
+    void *sc = zmq_socket (ctx, ZMQ_DEALER);
+    assert (sc);
+
+    int timeout = 100;
+    int rc = zmq_setsockopt (sc, ZMQ_SNDTIMEO, &timeout, sizeof(timeout));
+    assert (rc == 0);
+
+    rc = zmq_send (sc, 0, 0, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_send (sc, 0, 0, 0);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+}
+
+int main ()
+{
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+
+    // SHALL route outgoing messages to available peers using a round-robin
+    // strategy.
+    test_round_robin_out (ctx);
+
+    // SHALL receive incoming messages from its peers using a fair-queuing
+    // strategy.
+    test_fair_queue_in (ctx);
+
+    // SHALL block on sending, or return a suitable error, when it has no connected peers.
+    test_block_on_send_no_peers (ctx);
+
+    // 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.
+    test_destroy_queue_on_disconnect (ctx);
+
+    int rc = zmq_ctx_term (ctx);
+    assert (rc == 0);
+
+    return 0 ;
+}

tests/test_spec_rep.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 <stdlib.h>
+#include "testutil.hpp"
+
+void test_fair_queue_in (void *ctx)
+{
+    void *rep = zmq_socket (ctx, ZMQ_REP);
+    assert (rep);
+
+    int timeout = 100;
+    int rc = zmq_setsockopt (rep, ZMQ_RCVTIMEO, &timeout, sizeof(int));
+    assert (rc == 0);
+
+    rc = zmq_bind (rep, "inproc://a");
+    assert (rc == 0);
+
+    const size_t N = 5;
+    void *reqs[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        reqs[i] = zmq_socket (ctx, ZMQ_REQ);
+        assert (reqs[i]);
+
+        rc = zmq_setsockopt (reqs[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
+        assert (rc == 0);
+
+        rc = zmq_connect (reqs[i], "inproc://a");
+        assert (rc == 0);
+    }
+
+    s_send_seq (reqs[0], "A", SEQ_END);
+    s_recv_seq (rep, "A", SEQ_END);
+    s_send_seq (rep, "A", SEQ_END);
+    s_recv_seq (reqs[0], "A", SEQ_END);
+
+    s_send_seq (reqs[0], "A", SEQ_END);
+    s_recv_seq (rep, "A", SEQ_END);
+    s_send_seq (rep, "A", SEQ_END);
+    s_recv_seq (reqs[0], "A", SEQ_END);
+
+    // send N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        char * str = strdup("A");
+        str[0] += i;
+        s_send_seq (reqs[i], str, SEQ_END);
+        free (str);
+    }
+
+    // handle N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        char * str = strdup("A");
+        str[0] += i;
+        s_recv_seq (rep, str, SEQ_END);
+        s_send_seq (rep, str, SEQ_END);
+        s_recv_seq (reqs[i], str, SEQ_END);
+        free (str);
+    }
+
+    rc = zmq_close (rep);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (reqs[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_envelope (void *ctx)
+{
+    void *rep = zmq_socket (ctx, ZMQ_REP);
+    assert (rep);
+
+    int rc = zmq_bind (rep, "inproc://b");
+    assert (rc == 0);
+
+    void *dealer = zmq_socket (ctx, ZMQ_DEALER);
+    assert (dealer);
+
+    rc = zmq_connect (dealer, "inproc://b");
+    assert (rc == 0);
+
+    // minimal envelope
+    s_send_seq (dealer, 0, "A", SEQ_END);
+    s_recv_seq (rep, "A", SEQ_END);
+    s_send_seq (rep, "A", SEQ_END);
+    s_recv_seq (dealer, 0, "A", SEQ_END);
+
+    // big envelope
+    s_send_seq (dealer, "X", "Y", 0, "A", SEQ_END);
+    s_recv_seq (rep, "A", SEQ_END);
+    s_send_seq (rep, "A", SEQ_END);
+    s_recv_seq (dealer, "X", "Y", 0, "A", SEQ_END);
+
+    rc = zmq_close (rep);
+    assert (rc == 0);
+
+    rc = zmq_close (dealer);
+    assert (rc == 0);
+}
+
+int main ()
+{
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+
+    // SHALL receive incoming messages from its peers using a fair-queuing
+    // strategy.
+    test_fair_queue_in (ctx);
+
+    // For an incoming message:
+    // SHALL remove and store the address envelope, including the delimiter.
+    // SHALL pass the remaining data frames to its calling application.
+    // SHALL wait for a single reply message from its calling application.
+    // SHALL prepend the address envelope and delimiter.
+    // SHALL deliver this message back to the originating peer.
+    test_envelope (ctx);
+
+    int rc = zmq_ctx_term (ctx);
+    assert (rc == 0);
+
+    return 0 ;
+}

tests/test_spec_req.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 "testutil.hpp"
+
+void test_round_robin_out (void *ctx)
+{
+    void *req = zmq_socket (ctx, ZMQ_REQ);
+    assert (req);
+
+    int rc = zmq_bind (req, "inproc://b");
+    assert (rc == 0);
+
+    const size_t N = 5;
+    void *rep[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        rep[i] = zmq_socket (ctx, ZMQ_REP);
+        assert (rep[i]);
+
+        int timeout = 100;
+        rc = zmq_setsockopt (rep[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
+        assert (rc == 0);
+
+        rc = zmq_connect (rep[i], "inproc://b");
+        assert (rc == 0);
+    }
+
+    // Send N request-replies, and expect every REP it used once in order
+    for (size_t i = 0; i < N; ++i)
+    {
+        s_send_seq (req, "ABC", SEQ_END);
+        s_recv_seq (rep[i], "ABC", SEQ_END);
+        s_send_seq (rep[i], "DEF", SEQ_END);
+        s_recv_seq (req, "DEF", SEQ_END);
+    }
+
+    rc = zmq_close (req);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (rep[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_req_only_listens_to_current_peer (void *ctx)
+{
+    void *req = zmq_socket (ctx, ZMQ_REQ);
+    assert (req);
+
+    int rc = zmq_setsockopt(req, ZMQ_IDENTITY, "A", 2);
+    assert (rc == 0);
+
+    rc = zmq_bind (req, "inproc://c");
+    assert (rc == 0);
+
+    const size_t N = 3;
+    void *router[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        router[i] = zmq_socket (ctx, ZMQ_ROUTER);
+        assert (router[i]);
+
+        int timeout = 100;
+        rc = zmq_setsockopt (router[i], ZMQ_RCVTIMEO, &timeout, sizeof(timeout));
+        assert (rc == 0);
+
+        int enabled = 1;
+        rc = zmq_setsockopt (router[i], ZMQ_ROUTER_MANDATORY, &enabled, sizeof(enabled));
+        assert (rc == 0);
+
+        rc = zmq_connect (router[i], "inproc://c");
+        assert (rc == 0);
+    }
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        s_send_seq (req, "ABC", SEQ_END);
+
+        // Receive on router i
+        s_recv_seq (router[i], "A", 0, "ABC", SEQ_END);
+
+        // Send back replies on all routers
+        for (size_t j = 0; j < N; ++j)
+        {
+            const char *replies[] = { "WRONG", "GOOD" };
+            const char *reply = replies[i == j ? 1 : 0];
+            s_send_seq (router[j], "A", 0, reply, SEQ_END);
+        }
+
+        // Recieve only the good relpy
+        s_recv_seq (req, "GOOD", SEQ_END);
+    }
+
+    rc = zmq_close (req);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (router[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_req_message_format (void *ctx)
+{
+    void *req = zmq_socket (ctx, ZMQ_REQ);
+    assert (req);
+
+    void *router = zmq_socket (ctx, ZMQ_ROUTER);
+    assert (router);
+
+    int rc = zmq_bind (req, "inproc://a");
+    assert (rc == 0);
+
+    rc = zmq_connect (router, "inproc://a");
+    assert (rc == 0);
+
+    // Send a multi-part request.
+    s_send_seq (req, "ABC", "DEF", SEQ_END);
+
+    zmq_msg_t msg;
+    zmq_msg_init (&msg);
+
+    // Receive peer identity
+    rc = zmq_msg_recv (&msg, router, 0);
+    assert (rc != -1);
+    assert (zmq_msg_size (&msg) > 0);
+    zmq_msg_t peer_id_msg;
+    zmq_msg_init (&peer_id_msg);
+    zmq_msg_copy (&peer_id_msg, &msg);
+
+    int more = 0;
+    size_t more_size = sizeof(more);
+    rc = zmq_getsockopt (router, ZMQ_RCVMORE, &more, &more_size);
+    assert (rc == 0);
+    assert (more);
+
+    // Receive the rest.
+    s_recv_seq (router, 0, "ABC", "DEF", SEQ_END);
+
+    // Send back a single-part reply.
+    rc = zmq_msg_send (&peer_id_msg, router, ZMQ_SNDMORE);
+    assert (rc != -1);
+    s_send_seq (router, 0, "GHI", SEQ_END);
+
+    // Receive reply.
+    s_recv_seq (req, "GHI", SEQ_END);
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_msg_close (&peer_id_msg);
+    assert (rc == 0);
+
+    rc = zmq_close (req);
+    assert (rc == 0);
+
+    rc = zmq_close (router);
+    assert (rc == 0);
+}
+
+void test_block_on_send_no_peers (void *ctx)
+{
+    void *sc = zmq_socket (ctx, ZMQ_REQ);
+    assert (sc);
+
+    int timeout = 100;
+    int rc = zmq_setsockopt (sc, ZMQ_SNDTIMEO, &timeout, sizeof(timeout));
+    assert (rc == 0);
+
+    rc = zmq_send (sc, 0, 0, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_send (sc, 0, 0, 0);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+}
+
+int main ()
+{
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+
+    // SHALL route outgoing messages to connected peers using a round-robin
+    // strategy.
+    test_round_robin_out (ctx);
+
+    // The request and reply messages SHALL have this format on the wire:
+    // * A delimiter, consisting of an empty frame, added by the REQ socket.
+    // * One or more data frames, comprising the message visible to the
+    //   application.
+    test_req_message_format (ctx);
+
+    // SHALL block on sending, or return a suitable error, when it has no connected peers.
+    test_block_on_send_no_peers (ctx);
+
+    // SHALL accept an incoming message only from the last peer that it sent a
+    // request to.
+    // SHALL discard silently any messages received from other peers.
+    test_req_only_listens_to_current_peer (ctx);
+
+    int rc = zmq_ctx_term (ctx);
+    assert (rc == 0);
+
+    return 0 ;
+}

tests/test_spec_router.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 <stdlib.h>
+#include "testutil.hpp"
+
+void test_fair_queue_in (void *ctx)
+{
+    void *receiver = zmq_socket (ctx, ZMQ_ROUTER);
+    assert (receiver);
+
+    int timeout = 100;
+    int rc = zmq_setsockopt (receiver, ZMQ_RCVTIMEO, &timeout, sizeof(int));
+    assert (rc == 0);
+
+    rc = zmq_bind (receiver, "inproc://a");
+    assert (rc == 0);
+
+    const size_t N = 5;
+    void *senders[N];
+    for (size_t i = 0; i < N; ++i)
+    {
+        senders[i] = zmq_socket (ctx, ZMQ_DEALER);
+        assert (senders[i]);
+
+        rc = zmq_setsockopt (senders[i], ZMQ_RCVTIMEO, &timeout, sizeof(int));
+        assert (rc == 0);
+
+        char *str = strdup("A");
+        str[0] += i;
+        rc = zmq_setsockopt (senders[i], ZMQ_IDENTITY, str, 2);
+        assert (rc == 0);
+        free (str);
+
+        rc = zmq_connect (senders[i], "inproc://a");
+        assert (rc == 0);
+    }
+
+    zmq_msg_t msg;
+    rc = zmq_msg_init (&msg);
+    assert (rc == 0);
+
+    s_send_seq (senders[0], "M", SEQ_END);
+    s_recv_seq (receiver, "A", "M", SEQ_END);
+
+    s_send_seq (senders[0], "M", SEQ_END);
+    s_recv_seq (receiver, "A", "M", SEQ_END);
+
+    // send N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        s_send_seq (senders[i], "M", SEQ_END);
+    }
+
+    // handle N requests
+    for (size_t i = 0; i < N; ++i)
+    {
+        char *str = strdup("A");
+        str[0] += i;
+        s_recv_seq (receiver, str, "M", SEQ_END);
+        free (str);
+    }
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_close (receiver);
+    assert (rc == 0);
+
+    for (size_t i = 0; i < N; ++i)
+    {
+        rc = zmq_close (senders[i]);
+        assert (rc == 0);
+    }
+}
+
+void test_destroy_queue_on_disconnect (void *ctx)
+{
+    void *A = zmq_socket (ctx, ZMQ_ROUTER);
+    assert (A);
+
+    int enabled = 1;
+    int rc = zmq_setsockopt (A, ZMQ_ROUTER_MANDATORY, &enabled, sizeof(enabled));
+    assert (rc == 0);
+
+    rc = zmq_bind (A, "inproc://d");
+    assert (rc == 0);
+
+    void *B = zmq_socket (ctx, ZMQ_DEALER);
+    assert (B);
+
+    rc = zmq_setsockopt (B, ZMQ_IDENTITY, "B", 2);
+    assert (rc == 0);
+
+    rc = zmq_connect (B, "inproc://d");
+    assert (rc == 0);
+
+    // Send a message in both directions
+    s_send_seq (A, "B", "ABC", SEQ_END);
+    s_send_seq (B, "DEF", SEQ_END);
+
+    rc = zmq_disconnect (B, "inproc://d");
+    assert (rc == 0);
+
+    // Disconnect may take time and need command processing.
+    zmq_pollitem_t poller[2] = { { A, 0, 0, 0 }, { B, 0, 0, 0 } };
+    rc = zmq_poll (poller, 2, 100);
+    assert (rc == 0);
+
+    // No messages should be available, sending should fail.
+    zmq_msg_t msg;
+    zmq_msg_init (&msg);
+
+    rc = zmq_send (A, "B", 2, ZMQ_SNDMORE | ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EHOSTUNREACH);
+
+    rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    // After a reconnect of B, the messages should still be gone
+    rc = zmq_connect (B, "inproc://d");
+    assert (rc == 0);
+
+    rc = zmq_msg_recv (&msg, A, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_msg_recv (&msg, B, ZMQ_DONTWAIT);
+    assert (rc == -1);
+    assert (errno == EAGAIN);
+
+    rc = zmq_msg_close (&msg);
+    assert (rc == 0);
+
+    rc = zmq_close (A);
+    assert (rc == 0);
+
+    rc = zmq_close (B);
+    assert (rc == 0);
+}
+
+
+int main ()
+{
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+
+    // SHALL receive incoming messages from its peers using a fair-queuing
+    // strategy.
+    test_fair_queue_in (ctx);
+
+    // SHALL create a double queue when a peer connects to it. If this peer
+    // disconnects, the ROUTER socket SHALL destroy its double queue and SHALL
+    // discard any messages it contains.
+    test_destroy_queue_on_disconnect (ctx);
+
+    int rc = zmq_ctx_term (ctx);
+    assert (rc == 0);
+
+    return 0 ;
+}

tests/testutil.hpp

@@ -24,11 +24,12 @@
 #include <string.h>
 #undef NDEBUG
 #include <assert.h>
+#include <stdarg.h>
 
 //  Bounce a message from client to server and back
 //  For REQ/REP or DEALER/DEALER pairs only
 
-static void
+void
 bounce (void *server, void *client)
 {
     const char *content = "12345678ABCDEFGH12345678abcdefgh";
@@ -108,4 +109,81 @@ s_sendmore (void *socket, const char *string) {
 #define streq(s1,s2)    (!strcmp ((s1), (s2)))
 #define strneq(s1,s2)   (strcmp ((s1), (s2)))
 
+
+const char * SEQ_END = (const char *)1;
+
+//  Sends a message composed of frames that are C strings or null frames.
+//  The list must be terminated by SEQ_END.
+//  Example: s_send_seq (req, "ABC", 0, "DEF", SEQ_END);
+void s_send_seq (void *socket, ...)
+{
+    va_list ap;
+    va_start (ap, socket);
+    const char * data = va_arg (ap, const char *);
+    while (true)
+    {
+        const char * prev = data;
+        data = va_arg (ap, const char *);
+        bool end = data == SEQ_END;
+
+        if (!prev)
+        {
+            int rc = zmq_send (socket, 0, 0, end ? 0 : ZMQ_SNDMORE);
+            assert (rc != -1);
+        }
+        else
+        {
+            int rc = zmq_send (socket, prev, strlen (prev)+1, end ? 0 : ZMQ_SNDMORE);
+            assert (rc != -1);
+        }
+        if (end)
+            break;
+    }
+    va_end (ap);
+}
+
+//  Receives message a number of frames long and checks that the frames have
+//  the given data which can be either C strings or 0 for a null frame.
+//  The list must be terminated by SEQ_END.
+//  Example: s_recv_seq (rep, "ABC", 0, "DEF", SEQ_END);
+void s_recv_seq (void *socket, ...)
+{
+    zmq_msg_t msg;
+    zmq_msg_init (&msg);
+
+    int more;
+    size_t more_size = sizeof(more);
+
+    va_list ap;
+    va_start (ap, socket);
+    const char * data = va_arg (ap, const char *);
+    while (true)
+    {
+        int rc = zmq_msg_recv (&msg, socket, 0);
+        assert (rc != -1);
+
+        if (!data)
+        {
+            assert (zmq_msg_size (&msg) == 0);
+        }
+        else
+        {
+            assert (strcmp (data, (const char *)zmq_msg_data (&msg)) == 0);
+        }
+
+        data = va_arg (ap, const char *);
+        bool end = data == SEQ_END;
+
+        rc = zmq_getsockopt (socket, ZMQ_RCVMORE, &more, &more_size);
+        assert (rc == 0);
+
+        assert (!more == end);
+        if (end)
+            break;
+    }
+    va_end (ap);
+
+    zmq_msg_close (&msg);
+}
+
 #endif