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/*
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 <stddef.h>
#include "platform.hpp"
#include "proxy.hpp"
#include "likely.hpp"
#if defined ZMQ_FORCE_SELECT
#define ZMQ_POLL_BASED_ON_SELECT
#elif defined ZMQ_FORCE_POLL
#define ZMQ_POLL_BASED_ON_POLL
#elif defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD ||\
defined ZMQ_HAVE_OPENBSD || defined ZMQ_HAVE_SOLARIS ||\
defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_QNXNTO ||\
defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_AIX ||\
defined ZMQ_HAVE_NETBSD
#define ZMQ_POLL_BASED_ON_POLL
#elif defined ZMQ_HAVE_WINDOWS || defined ZMQ_HAVE_OPENVMS ||\
defined ZMQ_HAVE_CYGWIN
#define ZMQ_POLL_BASED_ON_SELECT
#endif
// On AIX platform, poll.h has to be included first to get consistent
// definition of pollfd structure (AIX uses 'reqevents' and 'retnevents'
// instead of 'events' and 'revents' and defines macros to map from POSIX-y
// names to AIX-specific names).
#if defined ZMQ_POLL_BASED_ON_POLL
#include <poll.h>
#endif
// These headers end up pulling in zmq.h somewhere in their include
// dependency chain
#include "socket_base.hpp"
#include "err.hpp"
// zmq.h must be included *after* poll.h for AIX to build properly
#include "../include/zmq.h"
int zmq::proxy (
class socket_base_t *frontend_,
class socket_base_t *backend_,
class socket_base_t *capture_,
class socket_base_t *control_)
{
msg_t msg;
int rc = msg.init ();
if (rc != 0)
return -1;
// The algorithm below assumes ratio of requests and replies processed
// under full load to be 1:1.
int more;
size_t moresz;
zmq_pollitem_t items [] = {
{ frontend_, 0, ZMQ_POLLIN, 0 },
{ backend_, 0, ZMQ_POLLIN, 0 },
{ control_, 0, ZMQ_POLLIN, 0 }
};
int qt_poll_items = (control_ ? 3 : 2);
// Proxy can be in these three states
enum {
active,
paused,
terminated
} state = active;
while (state != terminated) {
// Wait while there are either requests or replies to process.
rc = zmq_poll (&items [0], qt_poll_items, -1);
if (unlikely (rc < 0))
return -1;
// Process a control command if any
if (control_ && items [2].revents & ZMQ_POLLIN) {
rc = control_->recv (&msg, 0);
if (unlikely (rc < 0))
return -1;
moresz = sizeof more;
rc = control_->getsockopt (ZMQ_RCVMORE, &more, &moresz);
if (unlikely (rc < 0) || more)
return -1;
// Copy message to capture socket if any
if (capture_) {
msg_t ctrl;
int rc = ctrl.init ();
if (unlikely (rc < 0))
return -1;
rc = ctrl.copy (msg);
if (unlikely (rc < 0))
return -1;
rc = capture_->send (&ctrl, more? ZMQ_SNDMORE: 0);
if (unlikely (rc < 0))
return -1;
}
if (msg.size () == 5 && memcmp (msg.data (), "PAUSE", 5) == 0)
state = paused;
else
if (msg.size () == 6 && memcmp (msg.data (), "RESUME", 6) == 0)
state = active;
else
if (msg.size () == 9 && memcmp (msg.data (), "TERMINATE", 9) == 0)
state = terminated;
else {
// This is an API error, we should assert
puts ("E: invalid command sent to proxy");
zmq_assert (false);
}
}
// Process a request
if (items [0].revents & ZMQ_POLLIN) {
while (true) {
rc = frontend_->recv (&msg, 0);
if (unlikely (rc < 0))
return -1;
moresz = sizeof more;
rc = frontend_->getsockopt (ZMQ_RCVMORE, &more, &moresz);
if (unlikely (rc < 0))
return -1;
// Copy message to capture socket if any
if (capture_) {
msg_t ctrl;
rc = ctrl.init ();
if (unlikely (rc < 0))
return -1;
rc = ctrl.copy (msg);
if (unlikely (rc < 0))
return -1;
rc = capture_->send (&ctrl, more? ZMQ_SNDMORE: 0);
if (unlikely (rc < 0))
return -1;
}
rc = backend_->send (&msg, more? ZMQ_SNDMORE: 0);
if (unlikely (rc < 0))
return -1;
if (more == 0)
break;
}
}
// Process a reply
if (items [1].revents & ZMQ_POLLIN) {
while (true) {
rc = backend_->recv (&msg, 0);
if (unlikely (rc < 0))
return -1;
moresz = sizeof more;
rc = backend_->getsockopt (ZMQ_RCVMORE, &more, &moresz);
if (unlikely (rc < 0))
return -1;
// Copy message to capture socket if any
if (capture_) {
msg_t ctrl;
rc = ctrl.init ();
if (unlikely (rc < 0))
return -1;
rc = ctrl.copy (msg);
if (unlikely (rc < 0))
return -1;
rc = capture_->send (&ctrl, more? ZMQ_SNDMORE: 0);
if (unlikely (rc < 0))
return -1;
}
rc = frontend_->send (&msg, more? ZMQ_SNDMORE: 0);
if (unlikely (rc < 0))
return -1;
if (more == 0)
break;
}
}
}
return 0;
}
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