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Diffstat (limited to 'src/pgm_receiver.cpp')
| -rw-r--r-- | src/pgm_receiver.cpp | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/src/pgm_receiver.cpp b/src/pgm_receiver.cpp new file mode 100644 index 0000000..4068969 --- /dev/null +++ b/src/pgm_receiver.cpp @@ -0,0 +1,296 @@ +/* + 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 "platform.hpp" + +#if defined ZMQ_HAVE_OPENPGM + +#include <new> + +#ifdef ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#endif + +#include "pgm_receiver.hpp" +#include "session_base.hpp" +#include "v1_decoder.hpp" +#include "stdint.hpp" +#include "wire.hpp" +#include "err.hpp" + +zmq::pgm_receiver_t::pgm_receiver_t (class io_thread_t *parent_, + const options_t &options_) : + io_object_t (parent_), + has_rx_timer (false), + pgm_socket (true, options_), + options (options_), + session (NULL), + active_tsi (NULL), + insize (0) +{ +} + +zmq::pgm_receiver_t::~pgm_receiver_t () +{ + // Destructor should not be called before unplug. + zmq_assert (peers.empty ()); +} + +int zmq::pgm_receiver_t::init (bool udp_encapsulation_, const char *network_) +{ + return pgm_socket.init (udp_encapsulation_, network_); +} + +void zmq::pgm_receiver_t::plug (io_thread_t *io_thread_, + session_base_t *session_) +{ + // Retrieve PGM fds and start polling. + fd_t socket_fd = retired_fd; + fd_t waiting_pipe_fd = retired_fd; + pgm_socket.get_receiver_fds (&socket_fd, &waiting_pipe_fd); + socket_handle = add_fd (socket_fd); + pipe_handle = add_fd (waiting_pipe_fd); + set_pollin (pipe_handle); + set_pollin (socket_handle); + + session = session_; + + // If there are any subscriptions already queued in the session, drop them. + drop_subscriptions (); +} + +void zmq::pgm_receiver_t::unplug () +{ + // Delete decoders. + for (peers_t::iterator it = peers.begin (); it != peers.end (); ++it) { + if (it->second.decoder != NULL) + delete it->second.decoder; + } + peers.clear (); + active_tsi = NULL; + + if (has_rx_timer) { + cancel_timer (rx_timer_id); + has_rx_timer = false; + } + + rm_fd (socket_handle); + rm_fd (pipe_handle); + + session = NULL; +} + +void zmq::pgm_receiver_t::terminate () +{ + unplug (); + delete this; +} + +void zmq::pgm_receiver_t::restart_output () +{ + drop_subscriptions (); +} + +void zmq::pgm_receiver_t::restart_input () +{ + zmq_assert (session != NULL); + zmq_assert (active_tsi != NULL); + + const peers_t::iterator it = peers.find (*active_tsi); + zmq_assert (it != peers.end ()); + zmq_assert (it->second.joined); + + // Push the pending message into the session. + int rc = session->push_msg (it->second.decoder->msg ()); + errno_assert (rc == 0); + + if (insize > 0) { + rc = process_input (it->second.decoder); + if (rc == -1) { + // HWM reached; we will try later. + if (errno == EAGAIN) { + session->flush (); + return; + } + // Data error. Delete message decoder, mark the + // peer as not joined and drop remaining data. + it->second.joined = false; + delete it->second.decoder; + it->second.decoder = NULL; + insize = 0; + } + } + + // Resume polling. + set_pollin (pipe_handle); + set_pollin (socket_handle); + + active_tsi = NULL; + in_event (); +} + +void zmq::pgm_receiver_t::in_event () +{ + // Read data from the underlying pgm_socket. + const pgm_tsi_t *tsi = NULL; + + if (has_rx_timer) { + cancel_timer (rx_timer_id); + has_rx_timer = false; + } + + // TODO: This loop can effectively block other engines in the same I/O + // thread in the case of high load. + while (true) { + + // Get new batch of data. + // Note the workaround made not to break strict-aliasing rules. + void *tmp = NULL; + ssize_t received = pgm_socket.receive (&tmp, &tsi); + inpos = (unsigned char*) tmp; + + // No data to process. This may happen if the packet received is + // neither ODATA nor ODATA. + if (received == 0) { + if (errno == ENOMEM || errno == EBUSY) { + const long timeout = pgm_socket.get_rx_timeout (); + add_timer (timeout, rx_timer_id); + has_rx_timer = true; + } + break; + } + + // Find the peer based on its TSI. + peers_t::iterator it = peers.find (*tsi); + + // Data loss. Delete decoder and mark the peer as disjoint. + if (received == -1) { + if (it != peers.end ()) { + it->second.joined = false; + if (it->second.decoder != NULL) { + delete it->second.decoder; + it->second.decoder = NULL; + } + } + break; + } + + // New peer. Add it to the list of know but unjoint peers. + if (it == peers.end ()) { + peer_info_t peer_info = {false, NULL}; + it = peers.insert (peers_t::value_type (*tsi, peer_info)).first; + } + + insize = static_cast <size_t> (received); + + // Read the offset of the fist message in the current packet. + zmq_assert (insize >= sizeof (uint16_t)); + uint16_t offset = get_uint16 (inpos); + inpos += sizeof (uint16_t); + insize -= sizeof (uint16_t); + + // Join the stream if needed. + if (!it->second.joined) { + + // There is no beginning of the message in current packet. + // Ignore the data. + if (offset == 0xffff) + continue; + + zmq_assert (offset <= insize); + zmq_assert (it->second.decoder == NULL); + + // We have to move data to the begining of the first message. + inpos += offset; + insize -= offset; + + // Mark the stream as joined. + it->second.joined = true; + + // Create and connect decoder for the peer. + it->second.decoder = new (std::nothrow) + v1_decoder_t (0, options.maxmsgsize); + alloc_assert (it->second.decoder); + } + + int rc = process_input (it->second.decoder); + if (rc == -1) { + if (errno == EAGAIN) { + active_tsi = tsi; + + // Stop polling. + reset_pollin (pipe_handle); + reset_pollin (socket_handle); + + break; + } + + it->second.joined = false; + delete it->second.decoder; + it->second.decoder = NULL; + insize = 0; + } + } + + // Flush any messages decoder may have produced. + session->flush (); +} + +int zmq::pgm_receiver_t::process_input (v1_decoder_t *decoder) +{ + zmq_assert (session != NULL); + + while (insize > 0) { + size_t n = 0; + int rc = decoder->decode (inpos, insize, n); + if (rc == -1) + return -1; + inpos += n; + insize -= n; + if (rc == 0) + break; + rc = session->push_msg (decoder->msg ()); + if (rc == -1) { + errno_assert (errno == EAGAIN); + return -1; + } + } + return 0; +} + + +void zmq::pgm_receiver_t::timer_event (int token) +{ + zmq_assert (token == rx_timer_id); + + // Timer cancels on return by poller_base. + has_rx_timer = false; + in_event (); +} + +void zmq::pgm_receiver_t::drop_subscriptions () +{ + msg_t msg; + msg.init (); + while (session->pull_msg (&msg)) + msg.close (); +} + +#endif + |