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+/*
+ 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 <http://www.gnu.org/licenses/>.
+*/
+
+#include "mailbox.hpp"
+#include "platform.hpp"
+#include "err.hpp"
+#include "fd.hpp"
+#include "ip.hpp"
+
+#if defined ZMQ_HAVE_WINDOWS
+#include "windows.hpp"
+#else
+#include <unistd.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netinet/tcp.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#endif
+
+zmq::fd_t zmq::mailbox_t::get_fd ()
+{
+ return r;
+}
+
+#if defined ZMQ_HAVE_WINDOWS
+
+zmq::mailbox_t::mailbox_t ()
+{
+ // Create the socketpair for signalling.
+ int rc = make_socketpair (&r, &w);
+ errno_assert (rc == 0);
+
+ // Set the writer to non-blocking mode.
+ unsigned long argp = 1;
+ rc = ioctlsocket (w, FIONBIO, &argp);
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Set the reader to non-blocking mode.
+ argp = 1;
+ rc = ioctlsocket (r, FIONBIO, &argp);
+ wsa_assert (rc != SOCKET_ERROR);
+}
+
+zmq::mailbox_t::~mailbox_t ()
+{
+ int rc = closesocket (w);
+ wsa_assert (rc != SOCKET_ERROR);
+
+ rc = closesocket (r);
+ wsa_assert (rc != SOCKET_ERROR);
+}
+
+void zmq::mailbox_t::send (const command_t &cmd_)
+{
+ // TODO: Implement SNDBUF auto-resizing as for POSIX platforms.
+ // In the mean time, the following code with assert if the send()
+ // call would block.
+ int nbytes = ::send (w, (char *)&cmd_, sizeof (command_t), 0);
+ wsa_assert (nbytes != SOCKET_ERROR);
+ zmq_assert (nbytes == sizeof (command_t));
+}
+
+int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
+{
+ // If required, set the reader to blocking mode.
+ if (block_) {
+ unsigned long argp = 0;
+ int rc = ioctlsocket (r, FIONBIO, &argp);
+ wsa_assert (rc != SOCKET_ERROR);
+ }
+
+ // Attempt to read an entire command. Returns EAGAIN if non-blocking
+ // and a command is not available. Save value of errno if we wish to pass
+ // it to caller.
+ int err = 0;
+ int nbytes = ::recv (r, (char *)cmd_, sizeof (command_t), 0);
+ if (nbytes == -1 && WSAGetLastError () == WSAEWOULDBLOCK)
+ err = EAGAIN;
+
+ // Re-set the reader to non-blocking mode.
+ if (block_) {
+ unsigned long argp = 1;
+ int rc = ioctlsocket (r, FIONBIO, &argp);
+ wsa_assert (rc != SOCKET_ERROR);
+ }
+
+ // If the recv failed, return with the saved errno.
+ if (err != 0) {
+ errno = err;
+ return -1;
+ }
+
+ // Sanity check for success.
+ wsa_assert (nbytes != SOCKET_ERROR);
+
+ // Check whether we haven't got half of command.
+ zmq_assert (nbytes == sizeof (command_t));
+
+ return 0;
+}
+
+#else
+
+zmq::mailbox_t::mailbox_t ()
+{
+#ifdef PIPE_BUF
+ // Make sure that command can be written to the socket in atomic fashion.
+ // If this wasn't guaranteed, commands from different threads would be
+ // interleaved.
+ zmq_assert (sizeof (command_t) <= PIPE_BUF);
+#endif
+
+ // Create the socketpair for signaling.
+ int rc = make_socketpair (&r, &w);
+ errno_assert (rc == 0);
+
+ // Set the writer to non-blocking mode.
+ int flags = fcntl (w, F_GETFL, 0);
+ errno_assert (flags >= 0);
+ rc = fcntl (w, F_SETFL, flags | O_NONBLOCK);
+ errno_assert (rc == 0);
+
+#ifndef MSG_DONTWAIT
+ // Set the reader to non-blocking mode.
+ flags = fcntl (r, F_GETFL, 0);
+ errno_assert (flags >= 0);
+ rc = fcntl (r, F_SETFL, flags | O_NONBLOCK);
+ errno_assert (rc == 0);
+#endif
+}
+
+zmq::mailbox_t::~mailbox_t ()
+{
+ close (w);
+ close (r);
+}
+
+void zmq::mailbox_t::send (const command_t &cmd_)
+{
+ // Attempt to write an entire command without blocking.
+ ssize_t nbytes;
+ do {
+ nbytes = ::send (w, &cmd_, sizeof (command_t), 0);
+ } while (nbytes == -1 && errno == EINTR);
+
+ // Attempt to increase mailbox SNDBUF if the send failed.
+ if (nbytes == -1 && errno == EAGAIN) {
+ int old_sndbuf, new_sndbuf;
+ socklen_t sndbuf_size = sizeof old_sndbuf;
+
+ // Retrieve current send buffer size.
+ int rc = getsockopt (w, SOL_SOCKET, SO_SNDBUF, &old_sndbuf,
+ &sndbuf_size);
+ errno_assert (rc == 0);
+ new_sndbuf = old_sndbuf * 2;
+
+ // Double the new send buffer size.
+ rc = setsockopt (w, SOL_SOCKET, SO_SNDBUF, &new_sndbuf, sndbuf_size);
+ errno_assert (rc == 0);
+
+ // Verify that the OS actually honored the request.
+ rc = getsockopt (w, SOL_SOCKET, SO_SNDBUF, &new_sndbuf, &sndbuf_size);
+ errno_assert (rc == 0);
+ zmq_assert (new_sndbuf > old_sndbuf);
+
+ // Retry the sending operation; at this point it must succeed.
+ do {
+ nbytes = ::send (w, &cmd_, sizeof (command_t), 0);
+ } while (nbytes == -1 && errno == EINTR);
+ }
+ errno_assert (nbytes != -1);
+
+ // This should never happen as we've already checked that command size is
+ // less than PIPE_BUF.
+ zmq_assert (nbytes == sizeof (command_t));
+}
+
+int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
+{
+#ifdef MSG_DONTWAIT
+
+ // Attempt to read an entire command. Returns EAGAIN if non-blocking
+ // mode is requested and a command is not available.
+ ssize_t nbytes = ::recv (r, cmd_, sizeof (command_t),
+ block_ ? 0 : MSG_DONTWAIT);
+ if (nbytes == -1 && (errno == EAGAIN || errno == EINTR))
+ return -1;
+#else
+
+ // If required, set the reader to blocking mode.
+ if (block_) {
+ int flags = fcntl (r, F_GETFL, 0);
+ errno_assert (flags >= 0);
+ int rc = fcntl (r, F_SETFL, flags & ~O_NONBLOCK);
+ errno_assert (rc == 0);
+ }
+
+ // Attempt to read an entire command. Returns EAGAIN if non-blocking
+ // and a command is not available. Save value of errno if we wish to pass
+ // it to caller.
+ int err = 0;
+ ssize_t nbytes = ::recv (r, cmd_, sizeof (command_t), 0);
+ if (nbytes == -1 && (errno == EAGAIN || errno == EINTR))
+ err = errno;
+
+ // Re-set the reader to non-blocking mode.
+ if (block_) {
+ int flags = fcntl (r, F_GETFL, 0);
+ errno_assert (flags >= 0);
+ int rc = fcntl (r, F_SETFL, flags | O_NONBLOCK);
+ errno_assert (rc == 0);
+ }
+
+ // If the recv failed, return with the saved errno if set.
+ if (err != 0) {
+ errno = err;
+ return -1;
+ }
+
+#endif
+
+ // Sanity check for success.
+ errno_assert (nbytes != -1);
+
+ // Check whether we haven't got half of command.
+ zmq_assert (nbytes == sizeof (command_t));
+
+ return 0;
+}
+
+#endif
+
+int zmq::mailbox_t::make_socketpair (fd_t *r_, fd_t *w_)
+{
+#if defined ZMQ_HAVE_WINDOWS
+
+ // Windows has no 'socketpair' function. CreatePipe is no good as pipe
+ // handles cannot be polled on. Here we create the socketpair by hand.
+ *w_ = INVALID_SOCKET;
+ *r_ = INVALID_SOCKET;
+
+ // Create listening socket.
+ SOCKET listener;
+ listener = socket (AF_INET, SOCK_STREAM, 0);
+ wsa_assert (listener != INVALID_SOCKET);
+
+ // Set SO_REUSEADDR and TCP_NODELAY on listening socket.
+ BOOL so_reuseaddr = 1;
+ int rc = setsockopt (listener, SOL_SOCKET, SO_REUSEADDR,
+ (char *)&so_reuseaddr, sizeof (so_reuseaddr));
+ wsa_assert (rc != SOCKET_ERROR);
+ BOOL tcp_nodelay = 1;
+ rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY,
+ (char *)&tcp_nodelay, sizeof (tcp_nodelay));
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Bind listening socket to any free local port.
+ struct sockaddr_in addr;
+ memset (&addr, 0, sizeof (addr));
+ addr.sin_family = AF_INET;
+ addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+ addr.sin_port = 0;
+ rc = bind (listener, (const struct sockaddr*) &addr, sizeof (addr));
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Retrieve local port listener is bound to (into addr).
+ int addrlen = sizeof (addr);
+ rc = getsockname (listener, (struct sockaddr*) &addr, &addrlen);
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Listen for incomming connections.
+ rc = listen (listener, 1);
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Create the writer socket.
+ *w_ = WSASocket (AF_INET, SOCK_STREAM, 0, NULL, 0, 0);
+ wsa_assert (*w_ != INVALID_SOCKET);
+
+ // Set TCP_NODELAY on writer socket.
+ rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY,
+ (char *)&tcp_nodelay, sizeof (tcp_nodelay));
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Connect writer to the listener.
+ rc = connect (*w_, (sockaddr *) &addr, sizeof (addr));
+ wsa_assert (rc != SOCKET_ERROR);
+
+ // Accept connection from writer.
+ *r_ = accept (listener, NULL, NULL);
+ wsa_assert (*r_ != INVALID_SOCKET);
+
+ // We don't need the listening socket anymore. Close it.
+ rc = closesocket (listener);
+ wsa_assert (rc != SOCKET_ERROR);
+
+ return 0;
+
+#elif defined ZMQ_HAVE_OPENVMS
+
+ // Whilst OpenVMS supports socketpair - it maps to AF_INET only. Further,
+ // it does not set the socket options TCP_NODELAY and TCP_NODELACK which
+ // can lead to performance problems.
+ //
+ // The bug will be fixed in V5.6 ECO4 and beyond. In the meantime, we'll
+ // create the socket pair manually.
+ sockaddr_in lcladdr;
+ memset (&lcladdr, 0, sizeof (lcladdr));
+ lcladdr.sin_family = AF_INET;
+ lcladdr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+ lcladdr.sin_port = 0;
+
+ int listener = socket (AF_INET, SOCK_STREAM, 0);
+ errno_assert (listener != -1);
+
+ int on = 1;
+ int rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on));
+ errno_assert (rc != -1);
+
+ rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on));
+ errno_assert (rc != -1);
+
+ rc = bind(listener, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
+ errno_assert (rc != -1);
+
+ socklen_t lcladdr_len = sizeof (lcladdr);
+
+ rc = getsockname (listener, (struct sockaddr*) &lcladdr, &lcladdr_len);
+ errno_assert (rc != -1);
+
+ rc = listen (listener, 1);
+ errno_assert (rc != -1);
+
+ *w_ = socket (AF_INET, SOCK_STREAM, 0);
+ errno_assert (*w_ != -1);
+
+ rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on));
+ errno_assert (rc != -1);
+
+ rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on));
+ errno_assert (rc != -1);
+
+ rc = connect (*w_, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
+ errno_assert (rc != -1);
+
+ *r_ = accept (listener, NULL, NULL);
+ errno_assert (*r_ != -1);
+
+ close (listener);
+
+ return 0;
+
+#else // All other implementations support socketpair()
+
+ int sv [2];
+ int rc = socketpair (AF_UNIX, SOCK_STREAM, 0, sv);
+ errno_assert (rc == 0);
+ *w_ = sv [0];
+ *r_ = sv [1];
+ return 0;
+
+#endif
+}
+
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