libzmq/tests/test_poller.cpp
Patrik Wenger 621c965fae Problem: tricky return value from zmq::socket_poller_t::wait when poller is empty
Solution: return -1 (no event) instead of 0 (event)

For some reason, this just returns 0 if there are no sockets registered
on the poller. Usually this would mean there has been an event. So the
caller would have to check the return value AND the event, or write code
that takes the number of registered sockets into consideration.

By returning -1 and setting errno = ETIMEDOUT like in the usual timeout
cases, it's more consistent and convenient.

Test case included.
2016-04-12 20:11:50 +02:00

160 lines
4.8 KiB
C++

/*
Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
This file is part of libzmq, the ZeroMQ core engine in C++.
libzmq is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
As a special exception, the Contributors give you permission to link
this library with independent modules to produce an executable,
regardless of the license terms of these independent modules, and to
copy and distribute the resulting executable under terms of your choice,
provided that you also meet, for each linked independent module, the
terms and conditions of the license of that module. An independent
module is a module which is not derived from or based on this library.
If you modify this library, you must extend this exception to your
version of the library.
libzmq 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"
int main (void)
{
setup_test_environment ();
void *ctx = zmq_ctx_new ();
assert (ctx);
// Create few sockets
void *vent = zmq_socket (ctx, ZMQ_PUSH);
assert (vent);
int rc = zmq_bind (vent, "tcp://127.0.0.1:55556");
assert (rc == 0);
void *sink = zmq_socket (ctx, ZMQ_PULL);
assert (sink);
rc = zmq_connect (sink, "tcp://127.0.0.1:55556");
assert (rc == 0);
void *bowl = zmq_socket (ctx, ZMQ_PULL);
assert (bowl);
void *server = zmq_socket (ctx, ZMQ_SERVER);
assert (server);
rc = zmq_bind (server, "tcp://127.0.0.1:55557");
assert (rc == 0);
void *client = zmq_socket (ctx, ZMQ_CLIENT);
assert (client);
// Set up poller
void* poller = zmq_poller_new ();
zmq_poller_event_t event;
// waiting on poller with no registered sockets should report error
rc = zmq_poller_wait(poller, &event, 0);
assert (rc == -1);
assert (errno == ETIMEDOUT);
// register sink
rc = zmq_poller_add (poller, sink, sink, ZMQ_POLLIN);
assert (rc == 0);
// Send a message
char data[1] = {'H'};
rc = zmq_send_const (vent, data, 1, 0);
assert (rc == 1);
// We expect a message only on the sink
rc = zmq_poller_wait (poller, &event, -1);
assert (rc == 0);
assert (event.socket == sink);
assert (event.user_data == sink);
rc = zmq_recv (sink, data, 1, 0);
assert (rc == 1);
// We expect timed out
rc = zmq_poller_wait (poller, &event, 0);
assert (rc == -1);
assert (errno == ETIMEDOUT);
// Stop polling sink
rc = zmq_poller_remove (poller, sink);
assert (rc == 0);
// Check we can poll an FD
rc = zmq_connect (bowl, "tcp://127.0.0.1:55556");
assert (rc == 0);
#if defined _WIN32
SOCKET fd;
size_t fd_size = sizeof (SOCKET);
#else
int fd;
size_t fd_size = sizeof (int);
#endif
rc = zmq_getsockopt (bowl, ZMQ_FD, &fd, &fd_size);
assert (rc == 0);
rc = zmq_poller_add_fd (poller, fd, bowl, ZMQ_POLLIN);
assert (rc == 0);
rc = zmq_poller_wait (poller, &event, 500);
assert (rc == 0);
assert (event.socket == NULL);
assert (event.fd == fd);
assert (event.user_data == bowl);
zmq_poller_remove_fd (poller, fd);
// Polling on thread safe sockets
rc = zmq_poller_add (poller, server, NULL, ZMQ_POLLIN);
assert (rc == 0);
rc = zmq_connect (client, "tcp://127.0.0.1:55557");
assert (rc == 0);
rc = zmq_send_const (client, data, 1, 0);
assert (rc == 1);
rc = zmq_poller_wait (poller, &event, 500);
assert (rc == 0);
assert (event.socket == server);
assert (event.user_data == NULL);
rc = zmq_recv (server, data, 1, 0);
assert (rc == 1);
// Polling on pollout
rc = zmq_poller_modify (poller, server, ZMQ_POLLOUT | ZMQ_POLLIN);
assert (rc == 0);
rc = zmq_poller_wait (poller, &event, 0);
assert (rc == 0);
assert (event.socket == server);
assert (event.user_data == NULL);
assert (event.events == ZMQ_POLLOUT);
// Destory poller, sockets and ctx
rc = zmq_poller_destroy (&poller);
assert (rc == 0);
rc = zmq_close (sink);
assert (rc == 0);
rc = zmq_close (vent);
assert (rc == 0);
rc = zmq_close (bowl);
assert (rc == 0);
rc = zmq_close (server);
assert (rc == 0);
rc = zmq_close (client);
assert (rc == 0);
rc = zmq_ctx_term (ctx);
assert (rc == 0);
return 0;
}