2 // detail/wait_handler.hpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~
5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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)
11 #ifndef BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP
12 #define BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18 #include <boost/asio/detail/config.hpp>
19 #include <boost/asio/detail/fenced_block.hpp>
20 #include <boost/asio/detail/handler_alloc_helpers.hpp>
21 #include <boost/asio/detail/handler_invoke_helpers.hpp>
22 #include <boost/asio/detail/handler_work.hpp>
23 #include <boost/asio/detail/memory.hpp>
24 #include <boost/asio/detail/wait_op.hpp>
26 #include <boost/asio/detail/push_options.hpp>
32 template <typename Handler, typename IoExecutor>
33 class wait_handler : public wait_op
36 BOOST_ASIO_DEFINE_HANDLER_PTR(wait_handler);
38 wait_handler(Handler& h, const IoExecutor& ex)
39 : wait_op(&wait_handler::do_complete),
40 handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)),
43 handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
46 static void do_complete(void* owner, operation* base,
47 const boost::system::error_code& /*ec*/,
48 std::size_t /*bytes_transferred*/)
50 // Take ownership of the handler object.
51 wait_handler* h(static_cast<wait_handler*>(base));
52 ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
53 handler_work<Handler, IoExecutor> w(h->handler_, h->io_executor_);
55 BOOST_ASIO_HANDLER_COMPLETION((*h));
57 // Make a copy of the handler so that the memory can be deallocated before
58 // the upcall is made. Even if we're not about to make an upcall, a
59 // sub-object of the handler may be the true owner of the memory associated
60 // with the handler. Consequently, a local copy of the handler is required
61 // to ensure that any owning sub-object remains valid until after we have
62 // deallocated the memory here.
63 detail::binder1<Handler, boost::system::error_code>
64 handler(h->handler_, h->ec_);
65 p.h = boost::asio::detail::addressof(handler.handler_);
68 // Make the upcall if required.
71 fenced_block b(fenced_block::half);
72 BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_));
73 w.complete(handler, handler.handler_);
74 BOOST_ASIO_HANDLER_INVOCATION_END;
80 IoExecutor io_executor_;
87 #include <boost/asio/detail/pop_options.hpp>
89 #endif // BOOST_ASIO_DETAIL_WAIT_HANDLER_HPP