/*
Copyright (c) 2007-2010 iMatix Corporation
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 .
*/
#include "platform.hpp"
#if defined ZMQ_HAVE_WINDOWS
#include "windows.hpp"
#endif
#include
#include
#include "zmq_engine.hpp"
#include "zmq_connecter.hpp"
#include "io_thread.hpp"
#include "i_inout.hpp"
#include "config.hpp"
#include "err.hpp"
zmq::zmq_engine_t::zmq_engine_t (fd_t fd_, const options_t &options_) :
inpos (NULL),
insize (0),
decoder (in_batch_size),
outpos (NULL),
outsize (0),
encoder (out_batch_size),
inout (NULL),
ephemeral_inout (NULL),
options (options_),
plugged (false)
{
// Initialise the underlying socket.
int rc = tcp_socket.open (fd_, options.sndbuf, options.rcvbuf);
zmq_assert (rc == 0);
}
zmq::zmq_engine_t::~zmq_engine_t ()
{
zmq_assert (!plugged);
}
void zmq::zmq_engine_t::plug (io_thread_t *io_thread_, i_inout *inout_)
{
zmq_assert (!plugged);
plugged = true;
ephemeral_inout = NULL;
// Connect to session/init object.
zmq_assert (!inout);
zmq_assert (inout_);
encoder.set_inout (inout_);
decoder.set_inout (inout_);
inout = inout_;
// Connect to I/O threads poller object.
io_object_t::plug (io_thread_);
handle = add_fd (tcp_socket.get_fd ());
set_pollin (handle);
set_pollout (handle);
// Flush all the data that may have been already received downstream.
in_event ();
}
void zmq::zmq_engine_t::unplug ()
{
zmq_assert (plugged);
plugged = false;
// Cancel all fd subscriptions.
rm_fd (handle);
// Disconnect from I/O threads poller object.
io_object_t::unplug ();
// Disconnect from init/session object.
encoder.set_inout (NULL);
decoder.set_inout (NULL);
ephemeral_inout = inout;
inout = NULL;
}
void zmq::zmq_engine_t::terminate ()
{
unplug ();
delete this;
}
void zmq::zmq_engine_t::in_event ()
{
bool disconnection = false;
// If there's no data to process in the buffer...
if (!insize) {
// Retrieve the buffer and read as much data as possible.
decoder.get_buffer (&inpos, &insize);
insize = tcp_socket.read (inpos, insize);
// Check whether the peer has closed the connection.
if (insize == (size_t) -1) {
insize = 0;
disconnection = true;
}
}
// Push the data to the decoder.
size_t processed = decoder.process_buffer (inpos, insize);
if (unlikely (processed == (size_t) -1)) {
disconnection = true;
}
else {
// Stop polling for input if we got stuck.
if (processed < insize) {
// This may happen if queue limits are in effect or when
// init object reads all required information from the socket
// and rejects to read more data.
reset_pollin (handle);
}
// Adjust the buffer.
inpos += processed;
insize -= processed;
}
// Flush all messages the decoder may have produced.
// If IO handler has unplugged engine, flush transient IO handler.
if (unlikely (!plugged)) {
zmq_assert (ephemeral_inout);
ephemeral_inout->flush ();
} else {
inout->flush ();
}
if (disconnection)
error ();
}
void zmq::zmq_engine_t::out_event ()
{
// If write buffer is empty, try to read new data from the encoder.
if (!outsize) {
outpos = NULL;
encoder.get_data (&outpos, &outsize);
// If IO handler has unplugged engine, flush transient IO handler.
if (unlikely (!plugged)) {
zmq_assert (ephemeral_inout);
ephemeral_inout->flush ();
return;
}
// If there is no data to send, stop polling for output.
if (outsize == 0) {
reset_pollout (handle);
return;
}
}
// If there are any data to write in write buffer, write as much as
// possible to the socket.
int nbytes = tcp_socket.write (outpos, outsize);
// Handle problems with the connection.
if (nbytes == -1) {
error ();
return;
}
outpos += nbytes;
outsize -= nbytes;
}
void zmq::zmq_engine_t::activate_out ()
{
set_pollout (handle);
// Speculative write: The assumption is that at the moment new message
// was sent by the user the socket is probably available for writing.
// Thus we try to write the data to socket avoiding polling for POLLOUT.
// Consequently, the latency should be better in request/reply scenarios.
out_event ();
}
void zmq::zmq_engine_t::activate_in ()
{
set_pollin (handle);
// Speculative read.
in_event ();
}
void zmq::zmq_engine_t::error ()
{
zmq_assert (inout);
inout->detach ();
unplug ();
delete this;
}