116 lines
3.0 KiB
C++
116 lines
3.0 KiB
C++
//
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// pipe_select_interrupter.hpp
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// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#ifndef ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP
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#define ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP
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#if defined(_MSC_VER) && (_MSC_VER >= 1200)
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# pragma once
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#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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#include "asio/detail/push_options.hpp"
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#include "asio/detail/push_options.hpp"
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#include <boost/config.hpp>
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#include <boost/throw_exception.hpp>
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#include "asio/detail/pop_options.hpp"
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#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
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#include "asio/detail/push_options.hpp"
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#include <fcntl.h>
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#include "asio/detail/pop_options.hpp"
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#include "asio/error.hpp"
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#include "asio/system_error.hpp"
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#include "asio/detail/socket_types.hpp"
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namespace asio {
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namespace detail {
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class pipe_select_interrupter
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{
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public:
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// Constructor.
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pipe_select_interrupter()
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{
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int pipe_fds[2];
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if (pipe(pipe_fds) == 0)
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{
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read_descriptor_ = pipe_fds[0];
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::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
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write_descriptor_ = pipe_fds[1];
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::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK);
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}
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else
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{
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asio::error_code ec(errno,
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asio::error::get_system_category());
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asio::system_error e(ec, "pipe_select_interrupter");
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boost::throw_exception(e);
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}
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}
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// Destructor.
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~pipe_select_interrupter()
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{
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if (read_descriptor_ != -1)
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::close(read_descriptor_);
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if (write_descriptor_ != -1)
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::close(write_descriptor_);
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}
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// Interrupt the select call.
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void interrupt()
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{
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char byte = 0;
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int result = ::write(write_descriptor_, &byte, 1);
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(void)result;
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}
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// Reset the select interrupt. Returns true if the call was interrupted.
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bool reset()
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{
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char data[1024];
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int bytes_read = ::read(read_descriptor_, data, sizeof(data));
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bool was_interrupted = (bytes_read > 0);
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while (bytes_read == sizeof(data))
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bytes_read = ::read(read_descriptor_, data, sizeof(data));
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return was_interrupted;
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}
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// Get the read descriptor to be passed to select.
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int read_descriptor() const
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{
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return read_descriptor_;
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}
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private:
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// The read end of a connection used to interrupt the select call. This file
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// descriptor is passed to select such that when it is time to stop, a single
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// byte will be written on the other end of the connection and this
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// descriptor will become readable.
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int read_descriptor_;
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// The write end of a connection used to interrupt the select call. A single
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// byte may be written to this to wake up the select which is waiting for the
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// other end to become readable.
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int write_descriptor_;
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};
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} // namespace detail
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} // namespace asio
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#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
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#include "asio/detail/pop_options.hpp"
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#endif // ASIO_DETAIL_PIPE_SELECT_INTERRUPTER_HPP
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