From b3bac1760735703a11297df3d0e2a2e5252aa45e Mon Sep 17 00:00:00 2001 From: Martin Sustrik Date: Tue, 16 Aug 2011 12:44:34 +0200 Subject: tcp_engine renamed to stream engine The engine was not used exclusively for TCP connections. Rather it was used to handle any socket with SOCK_STREAM semantics. The class was renamed to reflect its true function. Signed-off-by: Martin Sustrik --- src/stream_engine.cpp | 374 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 374 insertions(+) create mode 100644 src/stream_engine.cpp (limited to 'src/stream_engine.cpp') diff --git a/src/stream_engine.cpp b/src/stream_engine.cpp new file mode 100644 index 0000000..15e7c21 --- /dev/null +++ b/src/stream_engine.cpp @@ -0,0 +1,374 @@ +/* + 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 . +*/ + +#include "platform.hpp" +#if defined ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#else +#include +#include +#include +#include +#include +#include +#include +#endif + +#include +#include + +#include "stream_engine.hpp" +#include "io_thread.hpp" +#include "session.hpp" +#include "config.hpp" +#include "err.hpp" +#include "ip.hpp" + +zmq::stream_engine_t::stream_engine_t (fd_t fd_, const options_t &options_) : + s (fd_), + inpos (NULL), + insize (0), + decoder (in_batch_size, options_.maxmsgsize), + outpos (NULL), + outsize (0), + encoder (out_batch_size), + session (NULL), + leftover_session (NULL), + options (options_), + plugged (false) +{ + // Get the socket into non-blocking mode. + unblock_socket (s); + + // Set the socket buffer limits for the underlying socket. + if (options.sndbuf) { + int rc = setsockopt (s, SOL_SOCKET, SO_SNDBUF, + (char*) &options.sndbuf, sizeof (int)); +#ifdef ZMQ_HAVE_WINDOWS + wsa_assert (rc != SOCKET_ERROR); +#else + errno_assert (rc == 0); +#endif + } + if (options.rcvbuf) { + int rc = setsockopt (s, SOL_SOCKET, SO_RCVBUF, + (char*) &options.rcvbuf, sizeof (int)); +#ifdef ZMQ_HAVE_WINDOWS + wsa_assert (rc != SOCKET_ERROR); +#else + errno_assert (rc == 0); +#endif + } + +#if defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_FREEBSD + // Make sure that SIGPIPE signal is not generated when writing to a + // connection that was already closed by the peer. + int set = 1; + int rc = setsockopt (s, SOL_SOCKET, SO_NOSIGPIPE, &set, sizeof (int)); + errno_assert (rc == 0); +#endif +} + +zmq::stream_engine_t::~stream_engine_t () +{ + zmq_assert (!plugged); + + if (s != retired_fd) { +#ifdef ZMQ_HAVE_WINDOWS + int rc = closesocket (s); + wsa_assert (rc != SOCKET_ERROR); +#else + int rc = close (s); + errno_assert (rc == 0); +#endif + s = retired_fd; + } +} + +void zmq::stream_engine_t::plug (io_thread_t *io_thread_, session_t *session_) +{ + zmq_assert (!plugged); + plugged = true; + leftover_session = NULL; + + // Connect to session object. + zmq_assert (!session); + zmq_assert (session_); + encoder.set_session (session_); + decoder.set_session (session_); + session = session_; + + // Connect to I/O threads poller object. + io_object_t::plug (io_thread_); + handle = add_fd (s); + set_pollin (handle); + set_pollout (handle); + + // Flush all the data that may have been already received downstream. + in_event (); +} + +void zmq::stream_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 session object. + encoder.set_session (NULL); + decoder.set_session (NULL); + leftover_session = session; + session = NULL; +} + +void zmq::stream_engine_t::terminate () +{ + unplug (); + delete this; +} + +void zmq::stream_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. + // Note that buffer can be arbitrarily large. However, we assume + // the underlying TCP layer has fixed buffer size and thus the + // number of bytes read will be always limited. + decoder.get_buffer (&inpos, &insize); + insize = 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. + if (plugged) + 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 (leftover_session); + leftover_session->flush (); + } else { + session->flush (); + } + + if (session && disconnection) + error (); +} + +void zmq::stream_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 (leftover_session); + leftover_session->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. Note that amount of data to write can be + // arbitratily large. However, we assume that underlying TCP layer has + // limited transmission buffer and thus the actual number of bytes + // written should be reasonably modest. + int nbytes = write (outpos, outsize); + + // Handle problems with the connection. + if (nbytes == -1) { + error (); + return; + } + + outpos += nbytes; + outsize -= nbytes; +} + +void zmq::stream_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::stream_engine_t::activate_in () +{ + set_pollin (handle); + + // Speculative read. + in_event (); +} + +void zmq::stream_engine_t::error () +{ + zmq_assert (session); + session->detach (); + unplug (); + delete this; +} + +int zmq::stream_engine_t::write (const void *data_, size_t size_) +{ +#ifdef ZMQ_HAVE_WINDOWS + + int nbytes = send (s, (char*) data_, (int) size_, 0); + + // If not a single byte can be written to the socket in non-blocking mode + // we'll get an error (this may happen during the speculative write). + if (nbytes == SOCKET_ERROR && WSAGetLastError () == WSAEWOULDBLOCK) + return 0; + + // Signalise peer failure. + if (nbytes == -1 && ( + WSAGetLastError () == WSAENETDOWN || + WSAGetLastError () == WSAENETRESET || + WSAGetLastError () == WSAEHOSTUNREACH || + WSAGetLastError () == WSAECONNABORTED || + WSAGetLastError () == WSAETIMEDOUT || + WSAGetLastError () == WSAECONNRESET)) + return -1; + + wsa_assert (nbytes != SOCKET_ERROR); + return (size_t) nbytes; + +#else + + ssize_t nbytes = send (s, data_, size_, 0); + + // Several errors are OK. When speculative write is being done we may not + // be able to write a single byte from the socket. Also, SIGSTOP issued + // by a debugging tool can result in EINTR error. + if (nbytes == -1 && (errno == EAGAIN || errno == EWOULDBLOCK || + errno == EINTR)) + return 0; + + // Signalise peer failure. + if (nbytes == -1 && (errno == ECONNRESET || errno == EPIPE)) + return -1; + + errno_assert (nbytes != -1); + return (size_t) nbytes; + +#endif +} + +int zmq::stream_engine_t::read (void *data_, size_t size_) +{ +#ifdef ZMQ_HAVE_WINDOWS + + int nbytes = recv (s, (char*) data_, (int) size_, 0); + + // If not a single byte can be read from the socket in non-blocking mode + // we'll get an error (this may happen during the speculative read). + if (nbytes == SOCKET_ERROR && WSAGetLastError () == WSAEWOULDBLOCK) + return 0; + + // Connection failure. + if (nbytes == -1 && ( + WSAGetLastError () == WSAENETDOWN || + WSAGetLastError () == WSAENETRESET || + WSAGetLastError () == WSAECONNABORTED || + WSAGetLastError () == WSAETIMEDOUT || + WSAGetLastError () == WSAECONNRESET || + WSAGetLastError () == WSAECONNREFUSED || + WSAGetLastError () == WSAENOTCONN)) + return -1; + + wsa_assert (nbytes != SOCKET_ERROR); + + // Orderly shutdown by the other peer. + if (nbytes == 0) + return -1; + + return (size_t) nbytes; + +#else + + ssize_t nbytes = recv (s, data_, size_, 0); + + // Several errors are OK. When speculative read is being done we may not + // be able to read a single byte from the socket. Also, SIGSTOP issued + // by a debugging tool can result in EINTR error. + if (nbytes == -1 && (errno == EAGAIN || errno == EWOULDBLOCK || + errno == EINTR)) + return 0; + + // Signalise peer failure. + if (nbytes == -1 && (errno == ECONNRESET || errno == ECONNREFUSED || + errno == ETIMEDOUT || errno == EHOSTUNREACH)) + return -1; + + errno_assert (nbytes != -1); + + // Orderly shutdown by the peer. + if (nbytes == 0) + return -1; + + return (size_t) nbytes; + +#endif +} + -- cgit v1.2.3