1 // 2 // detail/win_fd_set_adapter.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2015 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_DETAIL_WIN_FD_SET_ADAPTER_HPP 12 #define BOOST_ASIO_DETAIL_WIN_FD_SET_ADAPTER_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_WINDOWS) || defined(__CYGWIN__) 21 22 #include <boost/asio/detail/noncopyable.hpp> 23 #include <boost/asio/detail/reactor_op_queue.hpp> 24 #include <boost/asio/detail/socket_types.hpp> 25 26 #include <boost/asio/detail/push_options.hpp> 27 28 namespace boost { 29 namespace asio { 30 namespace detail { 31 32 // Adapts the FD_SET type to meet the Descriptor_Set concept's requirements. 33 class win_fd_set_adapter : noncopyable 34 { 35 public: 36 enum { default_fd_set_size = 1024 }; 37 win_fd_set_adapter()38 win_fd_set_adapter() 39 : capacity_(default_fd_set_size), 40 max_descriptor_(invalid_socket) 41 { 42 fd_set_ = static_cast<win_fd_set*>(::operator new( 43 sizeof(win_fd_set) - sizeof(SOCKET) 44 + sizeof(SOCKET) * (capacity_))); 45 fd_set_->fd_count = 0; 46 } 47 ~win_fd_set_adapter()48 ~win_fd_set_adapter() 49 { 50 ::operator delete(fd_set_); 51 } 52 reset()53 void reset() 54 { 55 fd_set_->fd_count = 0; 56 max_descriptor_ = invalid_socket; 57 } 58 set(socket_type descriptor)59 bool set(socket_type descriptor) 60 { 61 for (u_int i = 0; i < fd_set_->fd_count; ++i) 62 if (fd_set_->fd_array[i] == descriptor) 63 return true; 64 65 reserve(fd_set_->fd_count + 1); 66 fd_set_->fd_array[fd_set_->fd_count++] = descriptor; 67 return true; 68 } 69 set(reactor_op_queue<socket_type> & operations,op_queue<operation> &)70 void set(reactor_op_queue<socket_type>& operations, op_queue<operation>&) 71 { 72 reactor_op_queue<socket_type>::iterator i = operations.begin(); 73 while (i != operations.end()) 74 { 75 reactor_op_queue<socket_type>::iterator op_iter = i++; 76 reserve(fd_set_->fd_count + 1); 77 fd_set_->fd_array[fd_set_->fd_count++] = op_iter->first; 78 } 79 } 80 is_set(socket_type descriptor) const81 bool is_set(socket_type descriptor) const 82 { 83 return !!__WSAFDIsSet(descriptor, 84 const_cast<fd_set*>(reinterpret_cast<const fd_set*>(fd_set_))); 85 } 86 operator fd_set*()87 operator fd_set*() 88 { 89 return reinterpret_cast<fd_set*>(fd_set_); 90 } 91 max_descriptor() const92 socket_type max_descriptor() const 93 { 94 return max_descriptor_; 95 } 96 perform(reactor_op_queue<socket_type> & operations,op_queue<operation> & ops) const97 void perform(reactor_op_queue<socket_type>& operations, 98 op_queue<operation>& ops) const 99 { 100 for (u_int i = 0; i < fd_set_->fd_count; ++i) 101 operations.perform_operations(fd_set_->fd_array[i], ops); 102 } 103 104 private: 105 // This structure is defined to be compatible with the Windows API fd_set 106 // structure, but without being dependent on the value of FD_SETSIZE. We use 107 // the "struct hack" to allow the number of descriptors to be varied at 108 // runtime. 109 struct win_fd_set 110 { 111 u_int fd_count; 112 SOCKET fd_array[1]; 113 }; 114 115 // Increase the fd_set_ capacity to at least the specified number of elements. reserve(u_int n)116 void reserve(u_int n) 117 { 118 if (n <= capacity_) 119 return; 120 121 u_int new_capacity = capacity_ + capacity_ / 2; 122 if (new_capacity < n) 123 new_capacity = n; 124 125 win_fd_set* new_fd_set = static_cast<win_fd_set*>(::operator new( 126 sizeof(win_fd_set) - sizeof(SOCKET) 127 + sizeof(SOCKET) * (new_capacity))); 128 129 new_fd_set->fd_count = fd_set_->fd_count; 130 for (u_int i = 0; i < fd_set_->fd_count; ++i) 131 new_fd_set->fd_array[i] = fd_set_->fd_array[i]; 132 133 ::operator delete(fd_set_); 134 fd_set_ = new_fd_set; 135 capacity_ = new_capacity; 136 } 137 138 win_fd_set* fd_set_; 139 u_int capacity_; 140 socket_type max_descriptor_; 141 }; 142 143 } // namespace detail 144 } // namespace asio 145 } // namespace boost 146 147 #include <boost/asio/detail/pop_options.hpp> 148 149 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__) 150 151 #endif // BOOST_ASIO_DETAIL_WIN_FD_SET_ADAPTER_HPP 152