diff options
Diffstat (limited to 'src/select.cpp')
| -rw-r--r-- | src/select.cpp | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/src/select.cpp b/src/select.cpp new file mode 100644 index 0000000..be5cd47 --- /dev/null +++ b/src/select.cpp @@ -0,0 +1,234 @@ +/* + 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 Lesser GNU 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 + Lesser GNU General Public License for more details. + + You should have received a copy of the Lesser GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "platform.hpp" + +#include <string.h> +#include <algorithm> + +#ifdef ZMQ_HAVE_WINDOWS +#include "winsock2.h" +#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 "select.hpp" +#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 (); + + // Make sure there are no fds registered on shutdown. + zmq_assert (load.get () == 0); +} + +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); + + // 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. + load.add (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. + load.sub (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::add_timer (i_poll_events *events_) +{ + timers.push_back (events_); +} + +void zmq::select_t::cancel_timer (i_poll_events *events_) +{ + timers_t::iterator it = std::find (timers.begin (), timers.end (), events_); + if (it != timers.end ()) + timers.erase (it); +} + +int zmq::select_t::get_load () +{ + return load.get (); +} + +void zmq::select_t::start () +{ + worker.start (worker_routine, this); +} + +void zmq::select_t::stop () +{ + stopping = true; +} + +void zmq::select_t::loop () +{ + while (!stopping) { + + // 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); + + // Compute the timout interval. Select is free to overwrite the + // value so we have to compute it each time anew. + timeval timeout = {max_timer_period / 1000, + (max_timer_period % 1000) * 1000}; + + // Wait for events. + int rc = select (maxfd + 1, &readfds, &writefds, &exceptfds, + timers.empty () ? NULL : &timeout); + +#ifdef ZMQ_HAVE_WINDOWS + wsa_assert (rc != SOCKET_ERROR); +#else + if (rc == -1 && errno == EINTR) + continue; + errno_assert (rc != -1); +#endif + + // Handle timer. + if (!rc) { + + // Use local list of timers as timer handlers may fill new timers + // into the original array. + timers_t t; + std::swap (timers, t); + + // Trigger all the timers. + for (timers_t::iterator it = t.begin (); it != t.end (); it ++) + (*it)->timer_event (); + + 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) { + for (fd_set_t::size_type i = 0; i < fds.size (); i ++) { + if (fds [i].fd == retired_fd) { + fds.erase (fds.begin () + i); + i --; + } + } + retired = false; + } + } +} + +void zmq::select_t::worker_routine (void *arg_) +{ + ((select_t*) arg_)->loop (); +} |