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/*
Copyright (c) 2007-2011 iMatix Corporation
Copyright (c) 2007-2011 Other 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 <string.h>
#include "zmq_init.hpp"
#include "transient_session.hpp"
#include "named_session.hpp"
#include "socket_base.hpp"
#include "zmq_engine.hpp"
#include "io_thread.hpp"
#include "session.hpp"
#include "uuid.hpp"
#include "blob.hpp"
#include "err.hpp"
zmq::zmq_init_t::zmq_init_t (io_thread_t *io_thread_,
socket_base_t *socket_, session_t *session_, fd_t fd_,
const options_t &options_) :
own_t (io_thread_, options_),
ephemeral_engine (NULL),
sent (false),
received (false),
socket (socket_),
session (session_),
io_thread (io_thread_)
{
// Create the engine object for this connection.
engine = new (std::nothrow) zmq_engine_t (fd_, options);
alloc_assert (engine);
}
zmq::zmq_init_t::~zmq_init_t ()
{
if (engine)
engine->terminate ();
}
bool zmq::zmq_init_t::read (::zmq_msg_t *msg_)
{
// If the identity was already sent, do nothing.
if (sent)
return false;
// Send the identity.
int rc = zmq_msg_init_size (msg_, options.identity.size ());
zmq_assert (rc == 0);
memcpy (zmq_msg_data (msg_), options.identity.c_str (),
options.identity.size ());
sent = true;
// Try finalize initialization.
finalise_initialisation ();
return true;
}
bool zmq::zmq_init_t::write (::zmq_msg_t *msg_)
{
// If identity was already received, we are not interested
// in subsequent messages.
if (received)
return false;
// Retreieve the remote identity. If it's empty, generate a unique name.
if (!zmq_msg_size (msg_)) {
unsigned char identity [uuid_t::uuid_blob_len + 1];
identity [0] = 0;
memcpy (identity + 1, uuid_t ().to_blob (), uuid_t::uuid_blob_len);
peer_identity.assign (identity, uuid_t::uuid_blob_len + 1);
}
else {
peer_identity.assign ((const unsigned char*) zmq_msg_data (msg_),
zmq_msg_size (msg_));
}
int rc = zmq_msg_close (msg_);
zmq_assert (rc == 0);
received = true;
// Try finalize initialization.
finalise_initialisation ();
return true;
}
void zmq::zmq_init_t::flush ()
{
// Check if there's anything to flush.
if (!received)
return;
// Initialization is done, dispatch engine.
if (ephemeral_engine)
dispatch_engine ();
}
void zmq::zmq_init_t::detach ()
{
// This function is called by engine when disconnection occurs.
// If there is an associated session, send it a null engine to let it know
// that connection process was unsuccesful.
if (session)
send_attach (session, NULL, blob_t (), true);
// The engine will destroy itself, so let's just drop the pointer here and
// start termination of the init object.
engine = NULL;
terminate ();
}
void zmq::zmq_init_t::process_plug ()
{
zmq_assert (engine);
engine->plug (io_thread, this);
}
void zmq::zmq_init_t::process_unplug ()
{
if (engine)
engine->unplug ();
}
void zmq::zmq_init_t::finalise_initialisation ()
{
// Unplug and prepare to dispatch engine.
if (sent && received) {
ephemeral_engine = engine;
engine = NULL;
ephemeral_engine->unplug ();
return;
}
}
void zmq::zmq_init_t::dispatch_engine ()
{
if (sent && received) {
// Engine must be detached.
zmq_assert (!engine);
zmq_assert (ephemeral_engine);
// If we know what session we belong to, it's easy, just send the
// engine to that session and destroy the init object. Note that we
// know about the session only if this object is owned by it. Thus,
// lifetime of this object in contained in the lifetime of the session
// so the pointer cannot become invalid without notice.
if (session) {
send_attach (session, ephemeral_engine, peer_identity, true);
terminate ();
return;
}
// All the cases below are listener-based. Therefore we need the socket
// reference so that new sessions can bind to that socket.
zmq_assert (socket);
// We have no associated session. If the peer has no identity we'll
// create a transient session for the connection. Note that
// seqnum is incremented to account for attach command before the
// session is launched. That way we are sure it won't terminate before
// being attached.
if (peer_identity [0] == 0) {
session = new (std::nothrow) transient_session_t (io_thread,
socket, options);
alloc_assert (session);
session->inc_seqnum ();
launch_sibling (session);
send_attach (session, ephemeral_engine, peer_identity, false);
terminate ();
return;
}
// Try to find the session corresponding to the peer's identity.
// If found, send the engine to that session and destroy this object.
// Note that session's seqnum is incremented by find_session rather
// than by send_attach.
session = socket->find_session (peer_identity);
if (session) {
send_attach (session, ephemeral_engine, peer_identity, false);
terminate ();
return;
}
// There's no such named session. We have to create one. Note that
// seqnum is incremented to account for attach command before the
// session is launched. That way we are sure it won't terminate before
// being attached.
session = new (std::nothrow) named_session_t (io_thread, socket,
options, peer_identity);
alloc_assert (session);
session->inc_seqnum ();
launch_sibling (session);
send_attach (session, ephemeral_engine, peer_identity, false);
terminate ();
return;
}
}
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