mirror of https://github.com/axmolengine/axmol.git
128 lines
3.5 KiB
C++
128 lines
3.5 KiB
C++
//////////////////////////////////////////////////////////////////////////////////////////
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// A multi-platform support c++11 library with focus on asynchronous socket I/O for any
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// client application.
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//////////////////////////////////////////////////////////////////////////////////////////
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//
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// detail/pipe_select_interrupter.hpp
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// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2012-2021 halx99 (halx99 at live dot com)
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// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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// Copyright (c) 2008 Roelof Naude (roelof.naude at gmail 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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// see also: https://github.com/chriskohlhoff/asio
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//
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#ifndef YASIO__PIPE_SELECT_INTERRUPTER_HPP
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#define YASIO__PIPE_SELECT_INTERRUPTER_HPP
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#include "yasio/compiler/feature_test.hpp"
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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namespace yasio
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{
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YASIO__NS_INLINE
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namespace inet
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{
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class pipe_select_interrupter {
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public:
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// Constructor.
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inline pipe_select_interrupter() { open_descriptors(); }
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// Destructor.
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inline ~pipe_select_interrupter() { close_descriptors(); }
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// Recreate the interrupter's descriptors. Used after a fork.
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inline void recreate()
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{
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close_descriptors();
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write_descriptor_ = -1;
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read_descriptor_ = -1;
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open_descriptors();
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}
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// Interrupt the select call.
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inline void interrupt()
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{
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char byte = 0;
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auto result = ::write(write_descriptor_, &byte, 1);
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(void)result;
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}
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// Reset the select interrupter. Returns true if the reset was successful.
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inline bool reset()
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{
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char data[1024];
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for (;;)
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{
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// Clear all data from the pipe.
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int bytes_read = static_cast<int>(::read(read_descriptor_, data, sizeof(data)));
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if (bytes_read == sizeof(data))
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continue;
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if (bytes_read > 0)
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return true;
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if (bytes_read == 0)
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return false;
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int ec = errno;
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if (ec == EINTR)
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continue;
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return (ec == EWOULDBLOCK || ec == EAGAIN);
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}
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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 { return read_descriptor_; }
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private:
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// Open the descriptors. Throws on error.
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inline void open_descriptors()
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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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#if defined(FD_CLOEXEC)
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::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
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::fcntl(write_descriptor_, F_SETFD, FD_CLOEXEC);
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#endif // defined(FD_CLOEXEC)
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}
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}
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// Close the descriptors.
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inline void close_descriptors()
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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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// 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 inet
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} // namespace yasio
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#endif // YASIO__PIPE_SELECT_INTERRUPTER_HPP
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