ceph/src/boost/libs/asio/include/boost/asio/detail/win_fd_set_adapter.hpp

   1 //
   2 // detail/win_fd_set_adapter.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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
  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
  48   ~win_fd_set_adapter()
  49   {
  50     ::operator delete(fd_set_);
  51   }
  52
  53   void reset()
  54   {
  55     fd_set_->fd_count = 0;
  56     max_descriptor_ = invalid_socket;
  57   }
  58
  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
  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
  81   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
  87   operator fd_set*()
  88   {
  89     return reinterpret_cast<fd_set*>(fd_set_);
  90   }
  91
  92   socket_type max_descriptor() const
  93   {
  94     return max_descriptor_;
  95   }
  96
  97   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.
 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