1 // 2 // posix/descriptor_base.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_POSIX_DESCRIPTOR_BASE_HPP 12 #define BOOST_ASIO_POSIX_DESCRIPTOR_BASE_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 20 #if defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR) \ 21 || defined(GENERATING_DOCUMENTATION) 22 23 #include <boost/asio/detail/io_control.hpp> 24 #include <boost/asio/detail/socket_option.hpp> 25 26 #include <boost/asio/detail/push_options.hpp> 27 28 namespace boost { 29 namespace asio { 30 namespace posix { 31 32 /// The descriptor_base class is used as a base for the descriptor class as a 33 /// place to define the associated IO control commands. 34 class descriptor_base 35 { 36 public: 37 /// Wait types. 38 /** 39 * For use with descriptor::wait() and descriptor::async_wait(). 40 */ 41 enum wait_type 42 { 43 /// Wait for a descriptor to become ready to read. 44 wait_read, 45 46 /// Wait for a descriptor to become ready to write. 47 wait_write, 48 49 /// Wait for a descriptor to have error conditions pending. 50 wait_error 51 }; 52 53 /// IO control command to get the amount of data that can be read without 54 /// blocking. 55 /** 56 * Implements the FIONREAD IO control command. 57 * 58 * @par Example 59 * @code 60 * boost::asio::posix::stream_descriptor descriptor(my_context); 61 * ... 62 * boost::asio::descriptor_base::bytes_readable command(true); 63 * descriptor.io_control(command); 64 * std::size_t bytes_readable = command.get(); 65 * @endcode 66 * 67 * @par Concepts: 68 * IoControlCommand. 69 */ 70 #if defined(GENERATING_DOCUMENTATION) 71 typedef implementation_defined bytes_readable; 72 #else 73 typedef boost::asio::detail::io_control::bytes_readable bytes_readable; 74 #endif 75 76 protected: 77 /// Protected destructor to prevent deletion through this type. ~descriptor_base()78 ~descriptor_base() 79 { 80 } 81 }; 82 83 } // namespace posix 84 } // namespace asio 85 } // namespace boost 86 87 #include <boost/asio/detail/pop_options.hpp> 88 89 #endif // defined(BOOST_ASIO_HAS_POSIX_STREAM_DESCRIPTOR) 90 // || defined(GENERATING_DOCUMENTATION) 91 92 #endif // BOOST_ASIO_POSIX_DESCRIPTOR_BASE_HPP 93