1 // 2 // detail/descriptor_read_op.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 ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP 12 #define 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 "asio/detail/config.hpp" 19 20 #if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__) 21 22 #include "asio/detail/bind_handler.hpp" 23 #include "asio/detail/buffer_sequence_adapter.hpp" 24 #include "asio/detail/descriptor_ops.hpp" 25 #include "asio/detail/fenced_block.hpp" 26 #include "asio/detail/handler_work.hpp" 27 #include "asio/detail/memory.hpp" 28 #include "asio/detail/reactor_op.hpp" 29 30 #include "asio/detail/push_options.hpp" 31 32 namespace asio { 33 namespace detail { 34 35 template <typename MutableBufferSequence> 36 class descriptor_read_op_base : public reactor_op 37 { 38 public: descriptor_read_op_base(int descriptor,const MutableBufferSequence & buffers,func_type complete_func)39 descriptor_read_op_base(int descriptor, 40 const MutableBufferSequence& buffers, func_type complete_func) 41 : reactor_op(&descriptor_read_op_base::do_perform, complete_func), 42 descriptor_(descriptor), 43 buffers_(buffers) 44 { 45 } 46 do_perform(reactor_op * base)47 static bool do_perform(reactor_op* base) 48 { 49 descriptor_read_op_base* o(static_cast<descriptor_read_op_base*>(base)); 50 51 buffer_sequence_adapter<asio::mutable_buffer, 52 MutableBufferSequence> bufs(o->buffers_); 53 54 bool result = descriptor_ops::non_blocking_read(o->descriptor_, 55 bufs.buffers(), bufs.count(), o->ec_, o->bytes_transferred_); 56 57 ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_read", 58 o->ec_, o->bytes_transferred_)); 59 60 return result; 61 } 62 63 private: 64 int descriptor_; 65 MutableBufferSequence buffers_; 66 }; 67 68 template <typename MutableBufferSequence, typename Handler> 69 class descriptor_read_op 70 : public descriptor_read_op_base<MutableBufferSequence> 71 { 72 public: 73 ASIO_DEFINE_HANDLER_PTR(descriptor_read_op); 74 descriptor_read_op(int descriptor,const MutableBufferSequence & buffers,Handler & handler)75 descriptor_read_op(int descriptor, 76 const MutableBufferSequence& buffers, Handler& handler) 77 : descriptor_read_op_base<MutableBufferSequence>( 78 descriptor, buffers, &descriptor_read_op::do_complete), 79 handler_(ASIO_MOVE_CAST(Handler)(handler)) 80 { 81 handler_work<Handler>::start(handler_); 82 } 83 do_complete(void * owner,operation * base,const asio::error_code &,std::size_t)84 static void do_complete(void* owner, operation* base, 85 const asio::error_code& /*ec*/, 86 std::size_t /*bytes_transferred*/) 87 { 88 // Take ownership of the handler object. 89 descriptor_read_op* o(static_cast<descriptor_read_op*>(base)); 90 ptr p = { asio::detail::addressof(o->handler_), o, o }; 91 handler_work<Handler> w(o->handler_); 92 93 ASIO_HANDLER_COMPLETION((*o)); 94 95 // Make a copy of the handler so that the memory can be deallocated before 96 // the upcall is made. Even if we're not about to make an upcall, a 97 // sub-object of the handler may be the true owner of the memory associated 98 // with the handler. Consequently, a local copy of the handler is required 99 // to ensure that any owning sub-object remains valid until after we have 100 // deallocated the memory here. 101 detail::binder2<Handler, asio::error_code, std::size_t> 102 handler(o->handler_, o->ec_, o->bytes_transferred_); 103 p.h = asio::detail::addressof(handler.handler_); 104 p.reset(); 105 106 // Make the upcall if required. 107 if (owner) 108 { 109 fenced_block b(fenced_block::half); 110 ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_)); 111 w.complete(handler, handler.handler_); 112 ASIO_HANDLER_INVOCATION_END; 113 } 114 } 115 116 private: 117 Handler handler_; 118 }; 119 120 } // namespace detail 121 } // namespace asio 122 123 #include "asio/detail/pop_options.hpp" 124 125 #endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__) 126 127 #endif // ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP 128