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Diffstat (limited to 'src/select.cpp')
| -rw-r--r-- | src/select.cpp | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/src/select.cpp b/src/select.cpp new file mode 100644 index 0000000..b5cb972 --- /dev/null +++ b/src/select.cpp @@ -0,0 +1,219 @@ +/* + 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 "select.hpp" +#if defined ZMQ_USE_SELECT + +#include "platform.hpp" +#if defined ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#elif defined ZMQ_HAVE_HPUX +#include <sys/param.h> +#include <sys/types.h> +#include <sys/time.h> +#elif defined ZMQ_HAVE_OPENVMS +#include <sys/types.h> +#include <sys/time.h> +#else +#include <sys/select.h> +#endif + +#include <string.h> +#include <algorithm> + +#include "err.hpp" +#include "config.hpp" +#include "i_poll_events.hpp" + +zmq::select_t::select_t () : + maxfd (retired_fd), + retired (false), + stopping (false) +{ + // Clear file descriptor sets. + FD_ZERO (&source_set_in); + FD_ZERO (&source_set_out); + FD_ZERO (&source_set_err); +} + +zmq::select_t::~select_t () +{ + worker.stop (); +} + +zmq::select_t::handle_t zmq::select_t::add_fd (fd_t fd_, i_poll_events *events_) +{ + // Store the file descriptor. + fd_entry_t entry = {fd_, events_}; + fds.push_back (entry); + + // Ensure we do not attempt to select () on more than FD_SETSIZE + // file descriptors. + zmq_assert (fds.size () <= FD_SETSIZE); + + // Start polling on errors. + FD_SET (fd_, &source_set_err); + + // Adjust maxfd if necessary. + if (fd_ > maxfd) + maxfd = fd_; + + // Increase the load metric of the thread. + adjust_load (1); + + return fd_; +} + +void zmq::select_t::rm_fd (handle_t handle_) +{ + // Mark the descriptor as retired. + fd_set_t::iterator it; + for (it = fds.begin (); it != fds.end (); ++it) + if (it->fd == handle_) + break; + zmq_assert (it != fds.end ()); + it->fd = retired_fd; + retired = true; + + // Stop polling on the descriptor. + FD_CLR (handle_, &source_set_in); + FD_CLR (handle_, &source_set_out); + FD_CLR (handle_, &source_set_err); + + // Discard all events generated on this file descriptor. + FD_CLR (handle_, &readfds); + FD_CLR (handle_, &writefds); + FD_CLR (handle_, &exceptfds); + + // Adjust the maxfd attribute if we have removed the + // highest-numbered file descriptor. + if (handle_ == maxfd) { + maxfd = retired_fd; + for (fd_set_t::iterator it = fds.begin (); it != fds.end (); ++it) + if (it->fd > maxfd) + maxfd = it->fd; + } + + // Decrease the load metric of the thread. + adjust_load (-1); +} + +void zmq::select_t::set_pollin (handle_t handle_) +{ + FD_SET (handle_, &source_set_in); +} + +void zmq::select_t::reset_pollin (handle_t handle_) +{ + FD_CLR (handle_, &source_set_in); +} + +void zmq::select_t::set_pollout (handle_t handle_) +{ + FD_SET (handle_, &source_set_out); +} + +void zmq::select_t::reset_pollout (handle_t handle_) +{ + FD_CLR (handle_, &source_set_out); +} + +void zmq::select_t::start () +{ + worker.start (worker_routine, this); +} + +void zmq::select_t::stop () +{ + stopping = true; +} + +int zmq::select_t::max_fds () +{ + return FD_SETSIZE; +} + +void zmq::select_t::loop () +{ + while (!stopping) { + + // Execute any due timers. + int timeout = (int) execute_timers (); + + // Intialise the pollsets. + memcpy (&readfds, &source_set_in, sizeof source_set_in); + memcpy (&writefds, &source_set_out, sizeof source_set_out); + memcpy (&exceptfds, &source_set_err, sizeof source_set_err); + + // Wait for events. + struct timeval tv = {(long) (timeout / 1000), + (long) (timeout % 1000 * 1000)}; +#ifdef ZMQ_HAVE_WINDOWS + int rc = select (0, &readfds, &writefds, &exceptfds, + timeout ? &tv : NULL); + wsa_assert (rc != SOCKET_ERROR); +#else + int rc = select (maxfd + 1, &readfds, &writefds, &exceptfds, + timeout ? &tv : NULL); + if (rc == -1) { + errno_assert (errno == EINTR); + continue; + } +#endif + + // If there are no events (i.e. it's a timeout) there's no point + // in checking the pollset. + if (rc == 0) + continue; + + for (fd_set_t::size_type i = 0; i < fds.size (); i ++) { + if (fds [i].fd == retired_fd) + continue; + if (FD_ISSET (fds [i].fd, &exceptfds)) + fds [i].events->in_event (); + if (fds [i].fd == retired_fd) + continue; + if (FD_ISSET (fds [i].fd, &writefds)) + fds [i].events->out_event (); + if (fds [i].fd == retired_fd) + continue; + if (FD_ISSET (fds [i].fd, &readfds)) + fds [i].events->in_event (); + } + + // Destroy retired event sources. + if (retired) { + fds.erase (std::remove_if (fds.begin (), fds.end (), + zmq::select_t::is_retired_fd), fds.end ()); + retired = false; + } + } +} + +void zmq::select_t::worker_routine (void *arg_) +{ + ((select_t*) arg_)->loop (); +} + +bool zmq::select_t::is_retired_fd (const fd_entry_t &entry) +{ + return (entry.fd == retired_fd); +} + +#endif |