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// detail/signal_handler.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at


#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include <boost/asio/detail/config.hpp>
#include <boost/asio/detail/bind_handler.hpp>
#include <boost/asio/detail/fenced_block.hpp>
#include <boost/asio/detail/handler_alloc_helpers.hpp>
#include <boost/asio/detail/handler_work.hpp>
#include <boost/asio/detail/memory.hpp>
#include <boost/asio/detail/signal_op.hpp>

#include <boost/asio/detail/push_options.hpp>

namespace boost {
namespace asio {
namespace detail {

template <typename Handler, typename IoExecutor>
class signal_handler : public signal_op

  signal_handler(Handler& h, const IoExecutor& io_ex)
    : signal_op(&signal_handler::do_complete),
      work_(handler_, io_ex)

  static void do_complete(void* owner, operation* base,
      const boost::system::error_code& /*ec*/,
      std::size_t /*bytes_transferred*/)
    // Take ownership of the handler object.
    signal_handler* h(static_cast<signal_handler*>(base));
    ptr p = { boost::asio::detail::addressof(h->handler_), h, h };


    // Take ownership of the operation's outstanding work.
    handler_work<Handler, IoExecutor> w(
        BOOST_ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(

    // Make a copy of the handler so that the memory can be deallocated before
    // the upcall is made. Even if we're not about to make an upcall, a
    // sub-object of the handler may be the true owner of the memory associated
    // with the handler. Consequently, a local copy of the handler is required
    // to ensure that any owning sub-object remains valid until after we have
    // deallocated the memory here.
    detail::binder2<Handler, boost::system::error_code, int>
      handler(h->handler_, h->ec_, h->signal_number_);
    p.h = boost::asio::detail::addressof(handler.handler_);

    // Make the upcall if required.
    if (owner)
      fenced_block b(fenced_block::half);
      BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
      w.complete(handler, handler.handler_);

  Handler handler_;
  handler_work<Handler, IoExecutor> work_;

} // namespace detail
} // namespace asio
} // namespace boost

#include <boost/asio/detail/pop_options.hpp>