libzmq/src/dealer.cpp
Doron Somech 93da6763b0 problem: ZMQ_HEARTBEAT is not useful without sending an hello message
When using ZMQ_HEARTBEAT one still needs to implement application-level heartbeat in order to know when to send a hello message.
For example, with the majordomo protocol, the worker needs to send a READY message when connecting to a broker. If the connection to the broker drops, and the heartbeat recognizes it the worker won't know about it and won't send the READY msg.
To solve that, the majordomo worker still has to implement heartbeat. With this new option, whenever the connection drops and reconnects the hello message will be sent, greatly simplify the majordomo protocol, as now READY and HEARTBEAT can be handled by zeromq.
2020-04-17 14:54:58 +03:00

146 lines
3.7 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 "precompiled.hpp"
#include "macros.hpp"
#include "dealer.hpp"
#include "err.hpp"
#include "msg.hpp"
zmq::dealer_t::dealer_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
socket_base_t (parent_, tid_, sid_),
_probe_router (false)
{
options.type = ZMQ_DEALER;
options.can_send_hello_msg = true;
}
zmq::dealer_t::~dealer_t ()
{
}
void zmq::dealer_t::xattach_pipe (pipe_t *pipe_,
bool subscribe_to_all_,
bool locally_initiated_)
{
LIBZMQ_UNUSED (subscribe_to_all_);
LIBZMQ_UNUSED (locally_initiated_);
zmq_assert (pipe_);
if (_probe_router) {
msg_t probe_msg;
int rc = probe_msg.init ();
errno_assert (rc == 0);
rc = pipe_->write (&probe_msg);
// zmq_assert (rc) is not applicable here, since it is not a bug.
LIBZMQ_UNUSED (rc);
pipe_->flush ();
rc = probe_msg.close ();
errno_assert (rc == 0);
}
_fq.attach (pipe_);
_lb.attach (pipe_);
}
int zmq::dealer_t::xsetsockopt (int option_,
const void *optval_,
size_t optvallen_)
{
const bool is_int = (optvallen_ == sizeof (int));
int value = 0;
if (is_int)
memcpy (&value, optval_, sizeof (int));
switch (option_) {
case ZMQ_PROBE_ROUTER:
if (is_int && value >= 0) {
_probe_router = (value != 0);
return 0;
}
break;
default:
break;
}
errno = EINVAL;
return -1;
}
int zmq::dealer_t::xsend (msg_t *msg_)
{
return sendpipe (msg_, NULL);
}
int zmq::dealer_t::xrecv (msg_t *msg_)
{
return recvpipe (msg_, NULL);
}
bool zmq::dealer_t::xhas_in ()
{
return _fq.has_in ();
}
bool zmq::dealer_t::xhas_out ()
{
return _lb.has_out ();
}
void zmq::dealer_t::xread_activated (pipe_t *pipe_)
{
_fq.activated (pipe_);
}
void zmq::dealer_t::xwrite_activated (pipe_t *pipe_)
{
_lb.activated (pipe_);
}
void zmq::dealer_t::xpipe_terminated (pipe_t *pipe_)
{
_fq.pipe_terminated (pipe_);
_lb.pipe_terminated (pipe_);
}
int zmq::dealer_t::sendpipe (msg_t *msg_, pipe_t **pipe_)
{
return _lb.sendpipe (msg_, pipe_);
}
int zmq::dealer_t::recvpipe (msg_t *msg_, pipe_t **pipe_)
{
return _fq.recvpipe (msg_, pipe_);
}