Chris@16: //
Chris@16: // detail/impl/strand_service.hpp
Chris@16: // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chris@16: //
Chris@101: // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: 
Chris@16: #ifndef BOOST_ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP
Chris@16: #define BOOST_ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: # pragma once
Chris@16: #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
Chris@16: 
Chris@16: #include <boost/asio/detail/addressof.hpp>
Chris@16: #include <boost/asio/detail/call_stack.hpp>
Chris@16: #include <boost/asio/detail/completion_handler.hpp>
Chris@16: #include <boost/asio/detail/fenced_block.hpp>
Chris@16: #include <boost/asio/detail/handler_alloc_helpers.hpp>
Chris@16: #include <boost/asio/detail/handler_invoke_helpers.hpp>
Chris@16: 
Chris@16: #include <boost/asio/detail/push_options.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace asio {
Chris@16: namespace detail {
Chris@16: 
Chris@16: inline strand_service::strand_impl::strand_impl()
Chris@16:   : operation(&strand_service::do_complete),
Chris@16:     locked_(false)
Chris@16: {
Chris@16: }
Chris@16: 
Chris@16: struct strand_service::on_dispatch_exit
Chris@16: {
Chris@16:   io_service_impl* io_service_;
Chris@16:   strand_impl* impl_;
Chris@16: 
Chris@16:   ~on_dispatch_exit()
Chris@16:   {
Chris@16:     impl_->mutex_.lock();
Chris@16:     impl_->ready_queue_.push(impl_->waiting_queue_);
Chris@16:     bool more_handlers = impl_->locked_ = !impl_->ready_queue_.empty();
Chris@16:     impl_->mutex_.unlock();
Chris@16: 
Chris@16:     if (more_handlers)
Chris@16:       io_service_->post_immediate_completion(impl_, false);
Chris@16:   }
Chris@16: };
Chris@16: 
Chris@16: template <typename Handler>
Chris@16: void strand_service::dispatch(strand_service::implementation_type& impl,
Chris@16:     Handler& handler)
Chris@16: {
Chris@16:   // If we are already in the strand then the handler can run immediately.
Chris@16:   if (call_stack<strand_impl>::contains(impl))
Chris@16:   {
Chris@16:     fenced_block b(fenced_block::full);
Chris@16:     boost_asio_handler_invoke_helpers::invoke(handler, handler);
Chris@16:     return;
Chris@16:   }
Chris@16: 
Chris@16:   // Allocate and construct an operation to wrap the handler.
Chris@16:   typedef completion_handler<Handler> op;
Chris@16:   typename op::ptr p = { boost::asio::detail::addressof(handler),
Chris@16:     boost_asio_handler_alloc_helpers::allocate(
Chris@16:       sizeof(op), handler), 0 };
Chris@16:   p.p = new (p.v) op(handler);
Chris@16: 
Chris@16:   BOOST_ASIO_HANDLER_CREATION((p.p, "strand", impl, "dispatch"));
Chris@16: 
Chris@16:   bool dispatch_immediately = do_dispatch(impl, p.p);
Chris@16:   operation* o = p.p;
Chris@16:   p.v = p.p = 0;
Chris@16: 
Chris@16:   if (dispatch_immediately)
Chris@16:   {
Chris@16:     // Indicate that this strand is executing on the current thread.
Chris@16:     call_stack<strand_impl>::context ctx(impl);
Chris@16: 
Chris@16:     // Ensure the next handler, if any, is scheduled on block exit.
Chris@16:     on_dispatch_exit on_exit = { &io_service_, impl };
Chris@16:     (void)on_exit;
Chris@16: 
Chris@16:     completion_handler<Handler>::do_complete(
Chris@16:         &io_service_, o, boost::system::error_code(), 0);
Chris@16:   }
Chris@16: }
Chris@16: 
Chris@16: // Request the io_service to invoke the given handler and return immediately.
Chris@16: template <typename Handler>
Chris@16: void strand_service::post(strand_service::implementation_type& impl,
Chris@16:     Handler& handler)
Chris@16: {
Chris@16:   bool is_continuation =
Chris@16:     boost_asio_handler_cont_helpers::is_continuation(handler);
Chris@16: 
Chris@16:   // Allocate and construct an operation to wrap the handler.
Chris@16:   typedef completion_handler<Handler> op;
Chris@16:   typename op::ptr p = { boost::asio::detail::addressof(handler),
Chris@16:     boost_asio_handler_alloc_helpers::allocate(
Chris@16:       sizeof(op), handler), 0 };
Chris@16:   p.p = new (p.v) op(handler);
Chris@16: 
Chris@16:   BOOST_ASIO_HANDLER_CREATION((p.p, "strand", impl, "post"));
Chris@16: 
Chris@16:   do_post(impl, p.p, is_continuation);
Chris@16:   p.v = p.p = 0;
Chris@16: }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } // namespace asio
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/asio/detail/pop_options.hpp>
Chris@16: 
Chris@16: #endif // BOOST_ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP