asio/detail/initiate_dispatch.hpp

0001 //
0002 // detail/initiate_dispatch.hpp
0003 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0004 //
0005 // Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009 //
0010
0011 #ifndef BOOST_ASIO_DETAIL_INITIATE_DISPATCH_HPP
0012 #define BOOST_ASIO_DETAIL_INITIATE_DISPATCH_HPP
0013
0014 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
0015 # pragma once
0016 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
0017
0018 #include <boost/asio/detail/config.hpp>
0019 #include <boost/asio/associated_allocator.hpp>
0020 #include <boost/asio/associated_executor.hpp>
0021 #include <boost/asio/detail/work_dispatcher.hpp>
0022 #include <boost/asio/execution/allocator.hpp>
0023 #include <boost/asio/execution/blocking.hpp>
0024 #include <boost/asio/prefer.hpp>
0025
0026 #include <boost/asio/detail/push_options.hpp>
0027
0028 namespace boost {
0029 namespace asio {
0030 namespace detail {
0031
0032 class initiate_dispatch
0033 {
0034 public:
0035   template <typename CompletionHandler>
0036   void operator()(CompletionHandler&& handler,
0037       enable_if_t<
0038         execution::is_executor<
0039           associated_executor_t<decay_t<CompletionHandler>>
0040         >::value
0041       >* = 0) const
0042   {
0043     associated_executor_t<decay_t<CompletionHandler>> ex(
0044         (get_associated_executor)(handler));
0045
0046     associated_allocator_t<decay_t<CompletionHandler>> alloc(
0047         (get_associated_allocator)(handler));
0048
0049     boost::asio::prefer(ex, execution::allocator(alloc)).execute(
0050         boost::asio::detail::bind_handler(
0051           static_cast<CompletionHandler&&>(handler)));
0052   }
0053
0054   template <typename CompletionHandler>
0055   void operator()(CompletionHandler&& handler,
0056       enable_if_t<
0057         !execution::is_executor<
0058           associated_executor_t<decay_t<CompletionHandler>>
0059         >::value
0060       >* = 0) const
0061   {
0062     associated_executor_t<decay_t<CompletionHandler>> ex(
0063         (get_associated_executor)(handler));
0064
0065     associated_allocator_t<decay_t<CompletionHandler>> alloc(
0066         (get_associated_allocator)(handler));
0067
0068     ex.dispatch(boost::asio::detail::bind_handler(
0069           static_cast<CompletionHandler&&>(handler)), alloc);
0070   }
0071 };
0072
0073 template <typename Executor>
0074 class initiate_dispatch_with_executor
0075 {
0076 public:
0077   typedef Executor executor_type;
0078
0079   explicit initiate_dispatch_with_executor(const Executor& ex)
0080     : ex_(ex)
0081   {
0082   }
0083
0084   executor_type get_executor() const noexcept
0085   {
0086     return ex_;
0087   }
0088
0089   template <typename CompletionHandler>
0090   void operator()(CompletionHandler&& handler,
0091       enable_if_t<
0092         execution::is_executor<
0093           conditional_t<true, executor_type, CompletionHandler>
0094         >::value
0095       >* = 0,
0096       enable_if_t<
0097         !detail::is_work_dispatcher_required<
0098           decay_t<CompletionHandler>,
0099           Executor
0100         >::value
0101       >* = 0) const
0102   {
0103     associated_allocator_t<decay_t<CompletionHandler>> alloc(
0104         (get_associated_allocator)(handler));
0105
0106     boost::asio::prefer(ex_, execution::allocator(alloc)).execute(
0107         boost::asio::detail::bind_handler(
0108           static_cast<CompletionHandler&&>(handler)));
0109   }
0110
0111   template <typename CompletionHandler>
0112   void operator()(CompletionHandler&& handler,
0113       enable_if_t<
0114         execution::is_executor<
0115           conditional_t<true, executor_type, CompletionHandler>
0116         >::value
0117       >* = 0,
0118       enable_if_t<
0119         detail::is_work_dispatcher_required<
0120           decay_t<CompletionHandler>,
0121           Executor
0122         >::value
0123       >* = 0) const
0124   {
0125     typedef decay_t<CompletionHandler> handler_t;
0126
0127     typedef associated_executor_t<handler_t, Executor> handler_ex_t;
0128     handler_ex_t handler_ex((get_associated_executor)(handler, ex_));
0129
0130     associated_allocator_t<handler_t> alloc(
0131         (get_associated_allocator)(handler));
0132
0133     boost::asio::prefer(ex_, execution::allocator(alloc)).execute(
0134         detail::work_dispatcher<handler_t, handler_ex_t>(
0135           static_cast<CompletionHandler&&>(handler), handler_ex));
0136   }
0137
0138   template <typename CompletionHandler>
0139   void operator()(CompletionHandler&& handler,
0140       enable_if_t<
0141         !execution::is_executor<
0142           conditional_t<true, executor_type, CompletionHandler>
0143         >::value
0144       >* = 0,
0145       enable_if_t<
0146         !detail::is_work_dispatcher_required<
0147           decay_t<CompletionHandler>,
0148           Executor
0149         >::value
0150       >* = 0) const
0151   {
0152     associated_allocator_t<decay_t<CompletionHandler>> alloc(
0153         (get_associated_allocator)(handler));
0154
0155     ex_.dispatch(boost::asio::detail::bind_handler(
0156           static_cast<CompletionHandler&&>(handler)), alloc);
0157   }
0158
0159   template <typename CompletionHandler>
0160   void operator()(CompletionHandler&& handler,
0161       enable_if_t<
0162         !execution::is_executor<
0163           conditional_t<true, executor_type, CompletionHandler>
0164         >::value
0165       >* = 0,
0166       enable_if_t<
0167         detail::is_work_dispatcher_required<
0168           decay_t<CompletionHandler>,
0169           Executor
0170         >::value
0171       >* = 0) const
0172   {
0173     typedef decay_t<CompletionHandler> handler_t;
0174
0175     typedef associated_executor_t<handler_t, Executor> handler_ex_t;
0176     handler_ex_t handler_ex((get_associated_executor)(handler, ex_));
0177
0178     associated_allocator_t<handler_t> alloc(
0179         (get_associated_allocator)(handler));
0180
0181     ex_.dispatch(detail::work_dispatcher<handler_t, handler_ex_t>(
0182           static_cast<CompletionHandler&&>(handler), handler_ex), alloc);
0183   }
0184
0185 private:
0186   Executor ex_;
0187 };
0188
0189 } // namespace detail
0190 } // namespace asio
0191 } // namespace boost
0192
0193 #include <boost/asio/detail/pop_options.hpp>
0194
0195 #endif // BOOST_ASIO_DETAIL_INITIATE_DISPATCH_HPP