Added test case for issue 566

* Tests dealer-to-router connection 100 times
* This was failing in ZMQ v4.0.0 RC1

.gitignore

@@ -22,6 +22,7 @@ autom4te.cache
 .*~
 tools/curve_keygen.o
 tools/curve_keygen
+tests/test_issue_566
 tests/test_ctx_destroy
 tests/test_term_endpoint
 tests/test_system

src/stream_engine.cpp

@@ -739,7 +739,7 @@ int zmq::stream_engine_t::write (const void *data_, size_t size_)
     //  we'll get an error (this may happen during the speculative write).
     if (nbytes == SOCKET_ERROR && WSAGetLastError () == WSAEWOULDBLOCK)
         return 0;
-		
+        
     //  Signalise peer failure.
     if (nbytes == SOCKET_ERROR && (
           WSAGetLastError () == WSAENETDOWN ||

tests/Makefile.am

@@ -37,7 +37,8 @@ noinst_PROGRAMS = test_system \
                   test_req_correlate \
                   test_req_relaxed \
                   test_conflate \
-                  test_inproc_connect
+                  test_inproc_connect \
+                  test_issue_566
 
 if !ON_MINGW
 noinst_PROGRAMS += test_shutdown_stress \
@@ -82,6 +83,7 @@ test_req_correlate_SOURCES = test_req_correlate.cpp
 test_req_relaxed_SOURCES = test_req_relaxed.cpp
 test_conflate_SOURCES = test_conflate.cpp
 test_inproc_connect_SOURCES = test_inproc_connect.cpp
+test_issue_566_SOURCES = test_issue_566.cpp
 if !ON_MINGW
 test_shutdown_stress_SOURCES = test_shutdown_stress.cpp
 test_pair_ipc_SOURCES = test_pair_ipc.cpp testutil.hpp

tests/test_issue_566.cpp

@@ -0,0 +1,85 @@
+/*
+    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 "testutil.hpp"
+
+//  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.
+
+int main (void)
+{
+    setup_test_environment();
+    
+    void *ctx1 = zmq_ctx_new ();
+    assert (ctx1);
+
+    void *ctx2 = zmq_ctx_new ();
+    assert (ctx2);
+
+    void *router = zmq_socket (ctx1, ZMQ_ROUTER);    
+    int on = 1;
+    int rc = zmq_setsockopt (router, ZMQ_ROUTER_MANDATORY, &on, sizeof (on));
+    assert (rc == 0);
+    rc = zmq_bind (router, "tcp://127.0.0.1:5555");
+    assert (rc != -1);
+ 
+    //  Repeat often enough to be sure this works as it should
+    for (int cycle = 0; cycle < 100; cycle++) {
+        //  Create dealer with unique explicit identity
+        //  We assume the router learns this out-of-band
+        void *dealer = zmq_socket (ctx2, ZMQ_DEALER);
+        char identity [10];
+        sprintf (identity, "%09d", cycle);
+        rc = zmq_setsockopt (dealer, ZMQ_IDENTITY, identity, 10);
+        assert (rc == 0);
+        int rcvtimeo = 1000;
+        rc = zmq_setsockopt (dealer, ZMQ_RCVTIMEO, &rcvtimeo, sizeof (int));
+        assert (rc == 0);
+        rc = zmq_connect (dealer, "tcp://127.0.0.1:5555");
+        assert (rc == 0);
+
+        //  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 (0, 0, 2);
+            rc = zmq_send (router, identity, 10, ZMQ_SNDMORE);
+            if (rc == -1 && errno == EHOSTUNREACH)
+                continue;
+            assert (rc == 10);
+            rc = zmq_send (router, "HELLO", 5, 0);
+            assert (rc == 5);
+            break;
+        }
+        uint8_t buffer [5];
+        rc = zmq_recv (dealer, buffer, 5, 0);
+        assert (rc == 5);
+        assert (memcmp (buffer, "HELLO", 5) == 0);
+        close_zero_linger (dealer);
+    }
+    zmq_close (router);
+    zmq_ctx_destroy (ctx1);
+    zmq_ctx_destroy (ctx2);
+
+    return 0;
+}