ceph/src/boost/boost/asio/detail/descriptor_read_op.hpp

   1 //
   2 // detail/descriptor_read_op.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2020 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_DESCRIPTOR_READ_OP_HPP
  12 #define BOOST_ASIO_DETAIL_DESCRIPTOR_READ_OP_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/bind_handler.hpp>
  23 #include <boost/asio/detail/buffer_sequence_adapter.hpp>
  24 #include <boost/asio/detail/descriptor_ops.hpp>
  25 #include <boost/asio/detail/fenced_block.hpp>
  26 #include <boost/asio/detail/handler_work.hpp>
  27 #include <boost/asio/detail/memory.hpp>
  28 #include <boost/asio/detail/reactor_op.hpp>
  29
  30 #include <boost/asio/detail/push_options.hpp>
  31
  32 namespace boost {
  33 namespace asio {
  34 namespace detail {
  35
  36 template <typename MutableBufferSequence>
  37 class descriptor_read_op_base : public reactor_op
  38 {
  39 public:
  40   descriptor_read_op_base(int descriptor,
  41       const MutableBufferSequence& buffers, func_type complete_func)
  42     : reactor_op(&descriptor_read_op_base::do_perform, complete_func),
  43       descriptor_(descriptor),
  44       buffers_(buffers)
  45   {
  46   }
  47
  48   static status do_perform(reactor_op* base)
  49   {
  50     descriptor_read_op_base* o(static_cast<descriptor_read_op_base*>(base));
  51
  52     buffer_sequence_adapter<boost::asio::mutable_buffer,
  53         MutableBufferSequence> bufs(o->buffers_);
  54
  55     status result = descriptor_ops::non_blocking_read(o->descriptor_,
  56         bufs.buffers(), bufs.count(), o->ec_, o->bytes_transferred_)
  57       ? done : not_done;
  58
  59     BOOST_ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_read",
  60           o->ec_, o->bytes_transferred_));
  61
  62     return result;
  63   }
  64
  65 private:
  66   int descriptor_;
  67   MutableBufferSequence buffers_;
  68 };
  69
  70 template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
  71 class descriptor_read_op
  72   : public descriptor_read_op_base<MutableBufferSequence>
  73 {
  74 public:
  75   BOOST_ASIO_DEFINE_HANDLER_PTR(descriptor_read_op);
  76
  77   descriptor_read_op(int descriptor, const MutableBufferSequence& buffers,
  78       Handler& handler, const IoExecutor& io_ex)
  79     : descriptor_read_op_base<MutableBufferSequence>(
  80         descriptor, buffers, &descriptor_read_op::do_complete),
  81       handler_(BOOST_ASIO_MOVE_CAST(Handler)(handler)),
  82       io_executor_(io_ex)
  83   {
  84     handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
  85   }
  86
  87   static void do_complete(void* owner, operation* base,
  88       const boost::system::error_code& /*ec*/,
  89       std::size_t /*bytes_transferred*/)
  90   {
  91     // Take ownership of the handler object.
  92     descriptor_read_op* o(static_cast<descriptor_read_op*>(base));
  93     ptr p = { boost::asio::detail::addressof(o->handler_), o, o };
  94     handler_work<Handler, IoExecutor> w(o->handler_, o->io_executor_);
  95
  96     BOOST_ASIO_HANDLER_COMPLETION((*o));
  97
  98     // Make a copy of the handler so that the memory can be deallocated before
  99     // the upcall is made. Even if we're not about to make an upcall, a
 100     // sub-object of the handler may be the true owner of the memory associated
 101     // with the handler. Consequently, a local copy of the handler is required
 102     // to ensure that any owning sub-object remains valid until after we have
 103     // deallocated the memory here.
 104     detail::binder2<Handler, boost::system::error_code, std::size_t>
 105       handler(o->handler_, o->ec_, o->bytes_transferred_);
 106     p.h = boost::asio::detail::addressof(handler.handler_);
 107     p.reset();
 108
 109     // Make the upcall if required.
 110     if (owner)
 111     {
 112       fenced_block b(fenced_block::half);
 113       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
 114       w.complete(handler, handler.handler_);
 115       BOOST_ASIO_HANDLER_INVOCATION_END;
 116     }
 117   }
 118
 119 private:
 120   Handler handler_;
 121   IoExecutor io_executor_;
 122 };
 123
 124 } // namespace detail
 125 } // namespace asio
 126 } // namespace boost
 127
 128 #include <boost/asio/detail/pop_options.hpp>
 129
 130 #endif // !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
 131
 132 #endif // BOOST_ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP