1 // 2 // detail/wait_handler.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_WAIT_HANDLER_HPP 12 #define BOOST_ASIO_DETAIL_WAIT_HANDLER_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 #include <boost/asio/detail/addressof.hpp> 20 #include <boost/asio/detail/fenced_block.hpp> 21 #include <boost/asio/detail/handler_alloc_helpers.hpp> 22 #include <boost/asio/detail/handler_invoke_helpers.hpp> 23 #include <boost/asio/detail/wait_op.hpp> 24 #include <boost/asio/io_service.hpp> 25 26 #include <boost/asio/detail/push_options.hpp> 27 28 namespace boost { 29 namespace asio { 30 namespace detail { 31 32 template <typename Handler> 33 class wait_handler : public wait_op 34 { 35 public: 36 BOOST_ASIO_DEFINE_HANDLER_PTR(wait_handler); 37 wait_handler(Handler & h)38 wait_handler(Handler& h) 39 : wait_op(&wait_handler::do_complete), 40 handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)) 41 { 42 } 43 do_complete(io_service_impl * owner,operation * base,const boost::system::error_code &,std::size_t)44 static void do_complete(io_service_impl* owner, operation* base, 45 const boost::system::error_code& /*ec*/, 46 std::size_t /*bytes_transferred*/) 47 { 48 // Take ownership of the handler object. 49 wait_handler* h(static_cast<wait_handler*>(base)); 50 ptr p = { boost::asio::detail::addressof(h->handler_), h, h }; 51 52 BOOST_ASIO_HANDLER_COMPLETION((h)); 53 54 // Make a copy of the handler so that the memory can be deallocated before 55 // the upcall is made. Even if we're not about to make an upcall, a 56 // sub-object of the handler may be the true owner of the memory associated 57 // with the handler. Consequently, a local copy of the handler is required 58 // to ensure that any owning sub-object remains valid until after we have 59 // deallocated the memory here. 60 detail::binder1<Handler, boost::system::error_code> 61 handler(h->handler_, h->ec_); 62 p.h = boost::asio::detail::addressof(handler.handler_); 63 p.reset(); 64 65 // Make the upcall if required. 66 if (owner) 67 { 68 fenced_block b(fenced_block::half); 69 BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_)); 70 boost_asio_handler_invoke_helpers::invoke(handler, handler.handler_); 71 BOOST_ASIO_HANDLER_INVOCATION_END; 72 } 73 } 74 75 private: 76 Handler handler_; 77 }; 78 79 } // namespace detail 80 } // namespace asio 81 } // namespace boost 82 83 #include <boost/asio/detail/pop_options.hpp> 84 85 #endif // BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP 86