ceph/src/boost/boost/asio/detail/signal_handler.hpp

   1 //
   2 // detail/signal_handler.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 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_SIGNAL_HANDLER_HPP
  12 #define BOOST_ASIO_DETAIL_SIGNAL_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/bind_handler.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/handler_work.hpp>
  24 #include <boost/asio/detail/memory.hpp>
  25 #include <boost/asio/detail/signal_op.hpp>
  26
  27 #include <boost/asio/detail/push_options.hpp>
  28
  29 namespace boost {
  30 namespace asio {
  31 namespace detail {
  32
  33 template <typename Handler, typename IoExecutor>
  34 class signal_handler : public signal_op
  35 {
  36 public:
  37   BOOST_ASIO_DEFINE_HANDLER_PTR(signal_handler);
  38
  39   signal_handler(Handler& h, const IoExecutor& io_ex)
  40     : signal_op(&signal_handler::do_complete),
  41       handler_(BOOST_ASIO_MOVE_CAST(Handler)(h)),
  42       io_executor_(io_ex)
  43   {
  44     handler_work<Handler, IoExecutor>::start(handler_, io_executor_);
  45   }
  46
  47   static void do_complete(void* owner, operation* base,
  48       const boost::system::error_code& /*ec*/,
  49       std::size_t /*bytes_transferred*/)
  50   {
  51     // Take ownership of the handler object.
  52     signal_handler* h(static_cast<signal_handler*>(base));
  53     ptr p = { boost::asio::detail::addressof(h->handler_), h, h };
  54     handler_work<Handler, IoExecutor> w(h->handler_, h->io_executor_);
  55
  56     BOOST_ASIO_HANDLER_COMPLETION((*h));
  57
  58     // Make a copy of the handler so that the memory can be deallocated before
  59     // the upcall is made. Even if we're not about to make an upcall, a
  60     // sub-object of the handler may be the true owner of the memory associated
  61     // with the handler. Consequently, a local copy of the handler is required
  62     // to ensure that any owning sub-object remains valid until after we have
  63     // deallocated the memory here.
  64     detail::binder2<Handler, boost::system::error_code, int>
  65       handler(h->handler_, h->ec_, h->signal_number_);
  66     p.h = boost::asio::detail::addressof(handler.handler_);
  67     p.reset();
  68
  69     // Make the upcall if required.
  70     if (owner)
  71     {
  72       fenced_block b(fenced_block::half);
  73       BOOST_ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
  74       w.complete(handler, handler.handler_);
  75       BOOST_ASIO_HANDLER_INVOCATION_END;
  76     }
  77   }
  78
  79 private:
  80   Handler handler_;
  81   IoExecutor io_executor_;
  82 };
  83
  84 } // namespace detail
  85 } // namespace asio
  86 } // namespace boost
  87
  88 #include <boost/asio/detail/pop_options.hpp>
  89
  90 #endif // BOOST_ASIO_DETAIL_SIGNAL_HANDLER_HPP