Chris@16: //
Chris@16: // basic_signal_set.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_BASIC_SIGNAL_SET_HPP
Chris@16: #define BOOST_ASIO_BASIC_SIGNAL_SET_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/config.hpp>
Chris@16: 
Chris@16: #include <boost/asio/basic_io_object.hpp>
Chris@16: #include <boost/asio/detail/handler_type_requirements.hpp>
Chris@16: #include <boost/asio/detail/throw_error.hpp>
Chris@16: #include <boost/asio/error.hpp>
Chris@16: #include <boost/asio/signal_set_service.hpp>
Chris@16: 
Chris@16: #include <boost/asio/detail/push_options.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace asio {
Chris@16: 
Chris@16: /// Provides signal functionality.
Chris@16: /**
Chris@16:  * The basic_signal_set class template provides the ability to perform an
Chris@16:  * asynchronous wait for one or more signals to occur.
Chris@16:  *
Chris@16:  * Most applications will use the boost::asio::signal_set typedef.
Chris@16:  *
Chris@16:  * @par Thread Safety
Chris@16:  * @e Distinct @e objects: Safe.@n
Chris@16:  * @e Shared @e objects: Unsafe.
Chris@16:  *
Chris@16:  * @par Example
Chris@16:  * Performing an asynchronous wait:
Chris@16:  * @code
Chris@16:  * void handler(
Chris@16:  *     const boost::system::error_code& error,
Chris@16:  *     int signal_number)
Chris@16:  * {
Chris@16:  *   if (!error)
Chris@16:  *   {
Chris@16:  *     // A signal occurred.
Chris@16:  *   }
Chris@16:  * }
Chris@16:  *
Chris@16:  * ...
Chris@16:  *
Chris@16:  * // Construct a signal set registered for process termination.
Chris@16:  * boost::asio::signal_set signals(io_service, SIGINT, SIGTERM);
Chris@16:  *
Chris@16:  * // Start an asynchronous wait for one of the signals to occur.
Chris@16:  * signals.async_wait(handler);
Chris@16:  * @endcode
Chris@16:  *
Chris@16:  * @par Queueing of signal notifications
Chris@16:  *
Chris@16:  * If a signal is registered with a signal_set, and the signal occurs when
Chris@16:  * there are no waiting handlers, then the signal notification is queued. The
Chris@16:  * next async_wait operation on that signal_set will dequeue the notification.
Chris@16:  * If multiple notifications are queued, subsequent async_wait operations
Chris@16:  * dequeue them one at a time. Signal notifications are dequeued in order of
Chris@16:  * ascending signal number.
Chris@16:  *
Chris@16:  * If a signal number is removed from a signal_set (using the @c remove or @c
Chris@16:  * erase member functions) then any queued notifications for that signal are
Chris@16:  * discarded.
Chris@16:  *
Chris@16:  * @par Multiple registration of signals
Chris@16:  *
Chris@16:  * The same signal number may be registered with different signal_set objects.
Chris@16:  * When the signal occurs, one handler is called for each signal_set object.
Chris@16:  *
Chris@16:  * Note that multiple registration only works for signals that are registered
Chris@16:  * using Asio. The application must not also register a signal handler using
Chris@16:  * functions such as @c signal() or @c sigaction().
Chris@16:  *
Chris@16:  * @par Signal masking on POSIX platforms
Chris@16:  *
Chris@16:  * POSIX allows signals to be blocked using functions such as @c sigprocmask()
Chris@16:  * and @c pthread_sigmask(). For signals to be delivered, programs must ensure
Chris@16:  * that any signals registered using signal_set objects are unblocked in at
Chris@16:  * least one thread.
Chris@16:  */
Chris@16: template <typename SignalSetService = signal_set_service>
Chris@16: class basic_signal_set
Chris@16:   : public basic_io_object<SignalSetService>
Chris@16: {
Chris@16: public:
Chris@16:   /// Construct a signal set without adding any signals.
Chris@16:   /**
Chris@16:    * This constructor creates a signal set without registering for any signals.
Chris@16:    *
Chris@16:    * @param io_service The io_service object that the signal set will use to
Chris@16:    * dispatch handlers for any asynchronous operations performed on the set.
Chris@16:    */
Chris@16:   explicit basic_signal_set(boost::asio::io_service& io_service)
Chris@16:     : basic_io_object<SignalSetService>(io_service)
Chris@16:   {
Chris@16:   }
Chris@16: 
Chris@16:   /// Construct a signal set and add one signal.
Chris@16:   /**
Chris@16:    * This constructor creates a signal set and registers for one signal.
Chris@16:    *
Chris@16:    * @param io_service The io_service object that the signal set will use to
Chris@16:    * dispatch handlers for any asynchronous operations performed on the set.
Chris@16:    *
Chris@16:    * @param signal_number_1 The signal number to be added.
Chris@16:    *
Chris@16:    * @note This constructor is equivalent to performing:
Chris@16:    * @code boost::asio::signal_set signals(io_service);
Chris@16:    * signals.add(signal_number_1); @endcode
Chris@16:    */
Chris@16:   basic_signal_set(boost::asio::io_service& io_service, int signal_number_1)
Chris@16:     : basic_io_object<SignalSetService>(io_service)
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.add(this->implementation, signal_number_1, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:   }
Chris@16: 
Chris@16:   /// Construct a signal set and add two signals.
Chris@16:   /**
Chris@16:    * This constructor creates a signal set and registers for two signals.
Chris@16:    *
Chris@16:    * @param io_service The io_service object that the signal set will use to
Chris@16:    * dispatch handlers for any asynchronous operations performed on the set.
Chris@16:    *
Chris@16:    * @param signal_number_1 The first signal number to be added.
Chris@16:    *
Chris@16:    * @param signal_number_2 The second signal number to be added.
Chris@16:    *
Chris@16:    * @note This constructor is equivalent to performing:
Chris@16:    * @code boost::asio::signal_set signals(io_service);
Chris@16:    * signals.add(signal_number_1);
Chris@16:    * signals.add(signal_number_2); @endcode
Chris@16:    */
Chris@16:   basic_signal_set(boost::asio::io_service& io_service, int signal_number_1,
Chris@16:       int signal_number_2)
Chris@16:     : basic_io_object<SignalSetService>(io_service)
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.add(this->implementation, signal_number_1, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:     this->service.add(this->implementation, signal_number_2, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:   }
Chris@16: 
Chris@16:   /// Construct a signal set and add three signals.
Chris@16:   /**
Chris@16:    * This constructor creates a signal set and registers for three signals.
Chris@16:    *
Chris@16:    * @param io_service The io_service object that the signal set will use to
Chris@16:    * dispatch handlers for any asynchronous operations performed on the set.
Chris@16:    *
Chris@16:    * @param signal_number_1 The first signal number to be added.
Chris@16:    *
Chris@16:    * @param signal_number_2 The second signal number to be added.
Chris@16:    *
Chris@16:    * @param signal_number_3 The third signal number to be added.
Chris@16:    *
Chris@16:    * @note This constructor is equivalent to performing:
Chris@16:    * @code boost::asio::signal_set signals(io_service);
Chris@16:    * signals.add(signal_number_1);
Chris@16:    * signals.add(signal_number_2);
Chris@16:    * signals.add(signal_number_3); @endcode
Chris@16:    */
Chris@16:   basic_signal_set(boost::asio::io_service& io_service, int signal_number_1,
Chris@16:       int signal_number_2, int signal_number_3)
Chris@16:     : basic_io_object<SignalSetService>(io_service)
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.add(this->implementation, signal_number_1, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:     this->service.add(this->implementation, signal_number_2, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:     this->service.add(this->implementation, signal_number_3, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:   }
Chris@16: 
Chris@16:   /// Add a signal to a signal_set.
Chris@16:   /**
Chris@16:    * This function adds the specified signal to the set. It has no effect if the
Chris@16:    * signal is already in the set.
Chris@16:    *
Chris@16:    * @param signal_number The signal to be added to the set.
Chris@16:    *
Chris@16:    * @throws boost::system::system_error Thrown on failure.
Chris@16:    */
Chris@16:   void add(int signal_number)
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.add(this->implementation, signal_number, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "add");
Chris@16:   }
Chris@16: 
Chris@16:   /// Add a signal to a signal_set.
Chris@16:   /**
Chris@16:    * This function adds the specified signal to the set. It has no effect if the
Chris@16:    * signal is already in the set.
Chris@16:    *
Chris@16:    * @param signal_number The signal to be added to the set.
Chris@16:    *
Chris@16:    * @param ec Set to indicate what error occurred, if any.
Chris@16:    */
Chris@16:   boost::system::error_code add(int signal_number,
Chris@16:       boost::system::error_code& ec)
Chris@16:   {
Chris@16:     return this->service.add(this->implementation, signal_number, ec);
Chris@16:   }
Chris@16: 
Chris@16:   /// Remove a signal from a signal_set.
Chris@16:   /**
Chris@16:    * This function removes the specified signal from the set. It has no effect
Chris@16:    * if the signal is not in the set.
Chris@16:    *
Chris@16:    * @param signal_number The signal to be removed from the set.
Chris@16:    *
Chris@16:    * @throws boost::system::system_error Thrown on failure.
Chris@16:    *
Chris@16:    * @note Removes any notifications that have been queued for the specified
Chris@16:    * signal number.
Chris@16:    */
Chris@16:   void remove(int signal_number)
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.remove(this->implementation, signal_number, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "remove");
Chris@16:   }
Chris@16: 
Chris@16:   /// Remove a signal from a signal_set.
Chris@16:   /**
Chris@16:    * This function removes the specified signal from the set. It has no effect
Chris@16:    * if the signal is not in the set.
Chris@16:    *
Chris@16:    * @param signal_number The signal to be removed from the set.
Chris@16:    *
Chris@16:    * @param ec Set to indicate what error occurred, if any.
Chris@16:    *
Chris@16:    * @note Removes any notifications that have been queued for the specified
Chris@16:    * signal number.
Chris@16:    */
Chris@16:   boost::system::error_code remove(int signal_number,
Chris@16:       boost::system::error_code& ec)
Chris@16:   {
Chris@16:     return this->service.remove(this->implementation, signal_number, ec);
Chris@16:   }
Chris@16: 
Chris@16:   /// Remove all signals from a signal_set.
Chris@16:   /**
Chris@16:    * This function removes all signals from the set. It has no effect if the set
Chris@16:    * is already empty.
Chris@16:    *
Chris@16:    * @throws boost::system::system_error Thrown on failure.
Chris@16:    *
Chris@16:    * @note Removes all queued notifications.
Chris@16:    */
Chris@16:   void clear()
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.clear(this->implementation, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "clear");
Chris@16:   }
Chris@16: 
Chris@16:   /// Remove all signals from a signal_set.
Chris@16:   /**
Chris@16:    * This function removes all signals from the set. It has no effect if the set
Chris@16:    * is already empty.
Chris@16:    *
Chris@16:    * @param ec Set to indicate what error occurred, if any.
Chris@16:    *
Chris@16:    * @note Removes all queued notifications.
Chris@16:    */
Chris@16:   boost::system::error_code clear(boost::system::error_code& ec)
Chris@16:   {
Chris@16:     return this->service.clear(this->implementation, ec);
Chris@16:   }
Chris@16: 
Chris@16:   /// Cancel all operations associated with the signal set.
Chris@16:   /**
Chris@16:    * This function forces the completion of any pending asynchronous wait
Chris@16:    * operations against the signal set. The handler for each cancelled
Chris@16:    * operation will be invoked with the boost::asio::error::operation_aborted
Chris@16:    * error code.
Chris@16:    *
Chris@16:    * Cancellation does not alter the set of registered signals.
Chris@16:    *
Chris@16:    * @throws boost::system::system_error Thrown on failure.
Chris@16:    *
Chris@16:    * @note If a registered signal occurred before cancel() is called, then the
Chris@16:    * handlers for asynchronous wait operations will:
Chris@16:    *
Chris@16:    * @li have already been invoked; or
Chris@16:    *
Chris@16:    * @li have been queued for invocation in the near future.
Chris@16:    *
Chris@16:    * These handlers can no longer be cancelled, and therefore are passed an
Chris@16:    * error code that indicates the successful completion of the wait operation.
Chris@16:    */
Chris@16:   void cancel()
Chris@16:   {
Chris@16:     boost::system::error_code ec;
Chris@16:     this->service.cancel(this->implementation, ec);
Chris@16:     boost::asio::detail::throw_error(ec, "cancel");
Chris@16:   }
Chris@16: 
Chris@16:   /// Cancel all operations associated with the signal set.
Chris@16:   /**
Chris@16:    * This function forces the completion of any pending asynchronous wait
Chris@16:    * operations against the signal set. The handler for each cancelled
Chris@16:    * operation will be invoked with the boost::asio::error::operation_aborted
Chris@16:    * error code.
Chris@16:    *
Chris@16:    * Cancellation does not alter the set of registered signals.
Chris@16:    *
Chris@16:    * @param ec Set to indicate what error occurred, if any.
Chris@16:    *
Chris@16:    * @note If a registered signal occurred before cancel() is called, then the
Chris@16:    * handlers for asynchronous wait operations will:
Chris@16:    *
Chris@16:    * @li have already been invoked; or
Chris@16:    *
Chris@16:    * @li have been queued for invocation in the near future.
Chris@16:    *
Chris@16:    * These handlers can no longer be cancelled, and therefore are passed an
Chris@16:    * error code that indicates the successful completion of the wait operation.
Chris@16:    */
Chris@16:   boost::system::error_code cancel(boost::system::error_code& ec)
Chris@16:   {
Chris@16:     return this->service.cancel(this->implementation, ec);
Chris@16:   }
Chris@16: 
Chris@16:   /// Start an asynchronous operation to wait for a signal to be delivered.
Chris@16:   /**
Chris@16:    * This function may be used to initiate an asynchronous wait against the
Chris@16:    * signal set. It always returns immediately.
Chris@16:    *
Chris@16:    * For each call to async_wait(), the supplied handler will be called exactly
Chris@16:    * once. The handler will be called when:
Chris@16:    *
Chris@16:    * @li One of the registered signals in the signal set occurs; or
Chris@16:    *
Chris@16:    * @li The signal set was cancelled, in which case the handler is passed the
Chris@16:    * error code boost::asio::error::operation_aborted.
Chris@16:    *
Chris@16:    * @param handler The handler to be called when the signal occurs. Copies
Chris@16:    * will be made of the handler as required. The function signature of the
Chris@16:    * handler must be:
Chris@16:    * @code void handler(
Chris@16:    *   const boost::system::error_code& error, // Result of operation.
Chris@16:    *   int signal_number // Indicates which signal occurred.
Chris@16:    * ); @endcode
Chris@16:    * Regardless of whether the asynchronous operation completes immediately or
Chris@16:    * not, the handler will not be invoked from within this function. Invocation
Chris@16:    * of the handler will be performed in a manner equivalent to using
Chris@16:    * boost::asio::io_service::post().
Chris@16:    */
Chris@16:   template <typename SignalHandler>
Chris@16:   BOOST_ASIO_INITFN_RESULT_TYPE(SignalHandler,
Chris@16:       void (boost::system::error_code, int))
Chris@16:   async_wait(BOOST_ASIO_MOVE_ARG(SignalHandler) handler)
Chris@16:   {
Chris@16:     // If you get an error on the following line it means that your handler does
Chris@16:     // not meet the documented type requirements for a SignalHandler.
Chris@16:     BOOST_ASIO_SIGNAL_HANDLER_CHECK(SignalHandler, handler) type_check;
Chris@16: 
Chris@16:     return this->service.async_wait(this->implementation,
Chris@16:         BOOST_ASIO_MOVE_CAST(SignalHandler)(handler));
Chris@16:   }
Chris@16: };
Chris@16: 
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_BASIC_SIGNAL_SET_HPP