text: //
  // signal_set_service.hpp
  // ~~~~~~~~~~~~~~~~~~~~~~
  //
  // Copyright (c) 2003-2016 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 http://www.boost.org/LICENSE_1_0.txt)
  //
  
  #ifndef ASIO_SIGNAL_SET_SERVICE_HPP
  #define ASIO_SIGNAL_SET_SERVICE_HPP
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  # pragma once
  #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  
  #include "asio/detail/config.hpp"
  
  #if defined(ASIO_ENABLE_OLD_SERVICES)
  
  #include "asio/async_result.hpp"
  #include "asio/detail/signal_set_service.hpp"
  #include "asio/error.hpp"
  #include "asio/io_context.hpp"
  
  #include "asio/detail/push_options.hpp"
  
  namespace asio {
  
  /// Default service implementation for a signal set.
  class signal_set_service
  #if defined(GENERATING_DOCUMENTATION)
    : public asio::io_context::service
  #else
    : public asio::detail::service_base<signal_set_service>
  #endif
  {
  public:
  #if defined(GENERATING_DOCUMENTATION)
    /// The unique service identifier.
    static asio::io_context::id id;
  #endif
  
  public:
    /// The type of a signal set implementation.
  #if defined(GENERATING_DOCUMENTATION)
    typedef implementation_defined implementation_type;
  #else
    typedef detail::signal_set_service::implementation_type implementation_type;
  #endif
  
    /// Construct a new signal set service for the specified io_context.
    explicit signal_set_service(asio::io_context& io_context)
      : asio::detail::service_base<signal_set_service>(io_context),
        service_impl_(io_context)
    {
    }
  
    /// Construct a new signal set implementation.
    void construct(implementation_type& impl)
    {
      service_impl_.construct(impl);
    }
  
    /// Destroy a signal set implementation.
    void destroy(implementation_type& impl)
    {
      service_impl_.destroy(impl);
    }
  
    /// Add a signal to a signal_set.
    ASIO_SYNC_OP_VOID add(implementation_type& impl,
        int signal_number, asio::error_code& ec)
    {
      service_impl_.add(impl, signal_number, ec);
      ASIO_SYNC_OP_VOID_RETURN(ec);
    }
  
    /// Remove a signal to a signal_set.
    ASIO_SYNC_OP_VOID remove(implementation_type& impl,
        int signal_number, asio::error_code& ec)
    {
      service_impl_.remove(impl, signal_number, ec);
      ASIO_SYNC_OP_VOID_RETURN(ec);
    }
  
    /// Remove all signals from a signal_set.
    ASIO_SYNC_OP_VOID clear(implementation_type& impl,
        asio::error_code& ec)
    {
      service_impl_.clear(impl, ec);
      ASIO_SYNC_OP_VOID_RETURN(ec);
    }
  
    /// Cancel all operations associated with the signal set.
    ASIO_SYNC_OP_VOID cancel(implementation_type& impl,
        asio::error_code& ec)
    {
      service_impl_.cancel(impl, ec);
      ASIO_SYNC_OP_VOID_RETURN(ec);
    }
  
    // Start an asynchronous operation to wait for a signal to be delivered.
    template <typename SignalHandler>
    ASIO_INITFN_RESULT_TYPE(SignalHandler,
        void (asio::error_code, int))
    async_wait(implementation_type& impl,
        ASIO_MOVE_ARG(SignalHandler) handler)
    {
      async_completion<SignalHandler,
        void (asio::error_code, int)> init(handler);
  
      service_impl_.async_wait(impl, init.completion_handler);
  
      return init.result.get();
    }
  
  private:
    // Destroy all user-defined handler objects owned by the service.
    void shutdown()
    {
      service_impl_.shutdown();
    }
  
    // Perform any fork-related housekeeping.
    void notify_fork(asio::io_context::fork_event event)
    {
      service_impl_.notify_fork(event);
    }
  
    // The platform-specific implementation.
    detail::signal_set_service service_impl_;
  };
  
  } // namespace asio
  
  #include "asio/detail/pop_options.hpp"
  
  #endif // defined(ASIO_ENABLE_OLD_SERVICES)
  
  #endif // ASIO_SIGNAL_SET_SERVICE_HPP
  