asio/include/asio/basic_deadline_timer.hpp - third_party/asio - Git at Google

 //
 // basic_deadline_timer.hpp
 // ~~~~~~~~~~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2015 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_BASIC_DEADLINE_TIMER_HPP
 #define ASIO_BASIC_DEADLINE_TIMER_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_HAS_BOOST_DATE_TIME) \
   || defined(GENERATING_DOCUMENTATION)

 #include <cstddef>
 #include "asio/basic_io_object.hpp"
 #include "asio/deadline_timer_service.hpp"
 #include "asio/detail/handler_type_requirements.hpp"
 #include "asio/detail/throw_error.hpp"
 #include "asio/error.hpp"

 #include "asio/detail/push_options.hpp"

 namespace asio {

 /// Provides waitable timer functionality.
 /**
  * The basic_deadline_timer class template provides the ability to perform a
  * blocking or asynchronous wait for a timer to expire.
  *
  * A deadline timer is always in one of two states: "expired" or "not expired".
  * If the wait() or async_wait() function is called on an expired timer, the
  * wait operation will complete immediately.
  *
  * Most applications will use the asio::deadline_timer typedef.
  *
  * @par Thread Safety
  * @e Distinct @e objects: Safe.@n
  * @e Shared @e objects: Unsafe.
  *
  * @par Examples
  * Performing a blocking wait:
  * @code
  * // Construct a timer without setting an expiry time.
  * asio::deadline_timer timer(io_context);
  *
  * // Set an expiry time relative to now.
  * timer.expires_from_now(boost::posix_time::seconds(5));
  *
  * // Wait for the timer to expire.
  * timer.wait();
  * @endcode
  *
  * @par
  * Performing an asynchronous wait:
  * @code
  * void handler(const asio::error_code& error)
  * {
  *   if (!error)
  *   {
  *     // Timer expired.
  *   }
  * }
  *
  * ...
  *
  * // Construct a timer with an absolute expiry time.
  * asio::deadline_timer timer(io_context,
  *     boost::posix_time::time_from_string("2005-12-07 23:59:59.000"));
  *
  * // Start an asynchronous wait.
  * timer.async_wait(handler);
  * @endcode
  *
  * @par Changing an active deadline_timer's expiry time
  *
  * Changing the expiry time of a timer while there are pending asynchronous
  * waits causes those wait operations to be cancelled. To ensure that the action
  * associated with the timer is performed only once, use something like this:
  * used:
  *
  * @code
  * void on_some_event()
  * {
  *   if (my_timer.expires_from_now(seconds(5)) > 0)
  *   {
  *     // We managed to cancel the timer. Start new asynchronous wait.
  *     my_timer.async_wait(on_timeout);
  *   }
  *   else
  *   {
  *     // Too late, timer has already expired!
  *   }
  * }
  *
  * void on_timeout(const asio::error_code& e)
  * {
  *   if (e != asio::error::operation_aborted)
  *   {
  *     // Timer was not cancelled, take necessary action.
  *   }
  * }
  * @endcode
  *
  * @li The asio::basic_deadline_timer::expires_from_now() function
  * cancels any pending asynchronous waits, and returns the number of
  * asynchronous waits that were cancelled. If it returns 0 then you were too
  * late and the wait handler has already been executed, or will soon be
  * executed. If it returns 1 then the wait handler was successfully cancelled.
  *
  * @li If a wait handler is cancelled, the asio::error_code passed to
  * it contains the value asio::error::operation_aborted.
  */
 template <typename Time,
     typename TimeTraits = asio::time_traits<Time>,
     typename TimerService = deadline_timer_service<Time, TimeTraits> >
 class basic_deadline_timer
   : public basic_io_object<TimerService>
 {
 public:
   /// The time traits type.
   typedef TimeTraits traits_type;

   /// The time type.
   typedef typename traits_type::time_type time_type;

   /// The duration type.
   typedef typename traits_type::duration_type duration_type;

   /// Constructor.
   /**
    * This constructor creates a timer without setting an expiry time. The
    * expires_at() or expires_from_now() functions must be called to set an
    * expiry time before the timer can be waited on.
    *
    * @param io_context The io_context object that the timer will use to dispatch
    * handlers for any asynchronous operations performed on the timer.
    */
   explicit basic_deadline_timer(asio::io_context& io_context)
     : basic_io_object<TimerService>(io_context)
   {
   }

   /// Constructor to set a particular expiry time as an absolute time.
   /**
    * This constructor creates a timer and sets the expiry time.
    *
    * @param io_context The io_context object that the timer will use to dispatch
    * handlers for any asynchronous operations performed on the timer.
    *
    * @param expiry_time The expiry time to be used for the timer, expressed
    * as an absolute time.
    */
   basic_deadline_timer(asio::io_context& io_context,
       const time_type& expiry_time)
     : basic_io_object<TimerService>(io_context)
   {
     asio::error_code ec;
     this->get_service().expires_at(this->get_implementation(), expiry_time, ec);
     asio::detail::throw_error(ec, "expires_at");
   }

   /// Constructor to set a particular expiry time relative to now.
   /**
    * This constructor creates a timer and sets the expiry time.
    *
    * @param io_context The io_context object that the timer will use to dispatch
    * handlers for any asynchronous operations performed on the timer.
    *
    * @param expiry_time The expiry time to be used for the timer, relative to
    * now.
    */
   basic_deadline_timer(asio::io_context& io_context,
       const duration_type& expiry_time)
     : basic_io_object<TimerService>(io_context)
   {
     asio::error_code ec;
     this->get_service().expires_from_now(
         this->get_implementation(), expiry_time, ec);
     asio::detail::throw_error(ec, "expires_from_now");
   }

   /// Cancel any asynchronous operations that are waiting on the timer.
   /**
    * This function forces the completion of any pending asynchronous wait
    * operations against the timer. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * Cancelling the timer does not change the expiry time.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @throws asio::system_error Thrown on failure.
    *
    * @note If the timer has already expired when cancel() is called, then the
    * handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t cancel()
   {
     asio::error_code ec;
     std::size_t s = this->get_service().cancel(this->get_implementation(), ec);
     asio::detail::throw_error(ec, "cancel");
     return s;
   }

   /// Cancel any asynchronous operations that are waiting on the timer.
   /**
    * This function forces the completion of any pending asynchronous wait
    * operations against the timer. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * Cancelling the timer does not change the expiry time.
    *
    * @param ec Set to indicate what error occurred, if any.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @note If the timer has already expired when cancel() is called, then the
    * handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t cancel(asio::error_code& ec)
   {
     return this->get_service().cancel(this->get_implementation(), ec);
   }

   /// Cancels one asynchronous operation that is waiting on the timer.
   /**
    * This function forces the completion of one pending asynchronous wait
    * operation against the timer. Handlers are cancelled in FIFO order. The
    * handler for the cancelled operation will be invoked with the
    * asio::error::operation_aborted error code.
    *
    * Cancelling the timer does not change the expiry time.
    *
    * @return The number of asynchronous operations that were cancelled. That is,
    * either 0 or 1.
    *
    * @throws asio::system_error Thrown on failure.
    *
    * @note If the timer has already expired when cancel_one() is called, then
    * the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t cancel_one()
   {
     asio::error_code ec;
     std::size_t s = this->get_service().cancel_one(
         this->get_implementation(), ec);
     asio::detail::throw_error(ec, "cancel_one");
     return s;
   }

   /// Cancels one asynchronous operation that is waiting on the timer.
   /**
    * This function forces the completion of one pending asynchronous wait
    * operation against the timer. Handlers are cancelled in FIFO order. The
    * handler for the cancelled operation will be invoked with the
    * asio::error::operation_aborted error code.
    *
    * Cancelling the timer does not change the expiry time.
    *
    * @param ec Set to indicate what error occurred, if any.
    *
    * @return The number of asynchronous operations that were cancelled. That is,
    * either 0 or 1.
    *
    * @note If the timer has already expired when cancel_one() is called, then
    * the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t cancel_one(asio::error_code& ec)
   {
     return this->get_service().cancel_one(this->get_implementation(), ec);
   }

   /// Get the timer's expiry time as an absolute time.
   /**
    * This function may be used to obtain the timer's current expiry time.
    * Whether the timer has expired or not does not affect this value.
    */
   time_type expires_at() const
   {
     return this->get_service().expires_at(this->get_implementation());
   }

   /// Set the timer's expiry time as an absolute time.
   /**
    * This function sets the expiry time. Any pending asynchronous wait
    * operations will be cancelled. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * @param expiry_time The expiry time to be used for the timer.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @throws asio::system_error Thrown on failure.
    *
    * @note If the timer has already expired when expires_at() is called, then
    * the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t expires_at(const time_type& expiry_time)
   {
     asio::error_code ec;
     std::size_t s = this->get_service().expires_at(
         this->get_implementation(), expiry_time, ec);
     asio::detail::throw_error(ec, "expires_at");
     return s;
   }

   /// Set the timer's expiry time as an absolute time.
   /**
    * This function sets the expiry time. Any pending asynchronous wait
    * operations will be cancelled. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * @param expiry_time The expiry time to be used for the timer.
    *
    * @param ec Set to indicate what error occurred, if any.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @note If the timer has already expired when expires_at() is called, then
    * the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t expires_at(const time_type& expiry_time,
       asio::error_code& ec)
   {
     return this->get_service().expires_at(
         this->get_implementation(), expiry_time, ec);
   }

   /// Get the timer's expiry time relative to now.
   /**
    * This function may be used to obtain the timer's current expiry time.
    * Whether the timer has expired or not does not affect this value.
    */
   duration_type expires_from_now() const
   {
     return this->get_service().expires_from_now(this->get_implementation());
   }

   /// Set the timer's expiry time relative to now.
   /**
    * This function sets the expiry time. Any pending asynchronous wait
    * operations will be cancelled. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * @param expiry_time The expiry time to be used for the timer.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @throws asio::system_error Thrown on failure.
    *
    * @note If the timer has already expired when expires_from_now() is called,
    * then the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t expires_from_now(const duration_type& expiry_time)
   {
     asio::error_code ec;
     std::size_t s = this->get_service().expires_from_now(
         this->get_implementation(), expiry_time, ec);
     asio::detail::throw_error(ec, "expires_from_now");
     return s;
   }

   /// Set the timer's expiry time relative to now.
   /**
    * This function sets the expiry time. Any pending asynchronous wait
    * operations will be cancelled. The handler for each cancelled operation will
    * be invoked with the asio::error::operation_aborted error code.
    *
    * @param expiry_time The expiry time to be used for the timer.
    *
    * @param ec Set to indicate what error occurred, if any.
    *
    * @return The number of asynchronous operations that were cancelled.
    *
    * @note If the timer has already expired when expires_from_now() is called,
    * then the handlers for asynchronous wait operations will:
    *
    * @li have already been invoked; or
    *
    * @li have been queued for invocation in the near future.
    *
    * These handlers can no longer be cancelled, and therefore are passed an
    * error code that indicates the successful completion of the wait operation.
    */
   std::size_t expires_from_now(const duration_type& expiry_time,
       asio::error_code& ec)
   {
     return this->get_service().expires_from_now(
         this->get_implementation(), expiry_time, ec);
   }

   /// Perform a blocking wait on the timer.
   /**
    * This function is used to wait for the timer to expire. This function
    * blocks and does not return until the timer has expired.
    *
    * @throws asio::system_error Thrown on failure.
    */
   void wait()
   {
     asio::error_code ec;
     this->get_service().wait(this->get_implementation(), ec);
     asio::detail::throw_error(ec, "wait");
   }

   /// Perform a blocking wait on the timer.
   /**
    * This function is used to wait for the timer to expire. This function
    * blocks and does not return until the timer has expired.
    *
    * @param ec Set to indicate what error occurred, if any.
    */
   void wait(asio::error_code& ec)
   {
     this->get_service().wait(this->get_implementation(), ec);
   }

   /// Start an asynchronous wait on the timer.
   /**
    * This function may be used to initiate an asynchronous wait against the
    * timer. It always returns immediately.
    *
    * For each call to async_wait(), the supplied handler will be called exactly
    * once. The handler will be called when:
    *
    * @li The timer has expired.
    *
    * @li The timer was cancelled, in which case the handler is passed the error
    * code asio::error::operation_aborted.
    *
    * @param handler The handler to be called when the timer expires. Copies
    * will be made of the handler as required. The function signature of the
    * handler must be:
    * @code void handler(
    *   const asio::error_code& error // Result of operation.
    * ); @endcode
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the handler will not be invoked from within this function. Invocation
    * of the handler will be performed in a manner equivalent to using
    * asio::io_context::post().
    */
   template <typename WaitHandler>
   ASIO_INITFN_RESULT_TYPE(WaitHandler,
       void (asio::error_code))
   async_wait(ASIO_MOVE_ARG(WaitHandler) handler)
   {
     // If you get an error on the following line it means that your handler does
     // not meet the documented type requirements for a WaitHandler.
     ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;

     return this->get_service().async_wait(this->get_implementation(),
         ASIO_MOVE_CAST(WaitHandler)(handler));
   }
 };

 } // namespace asio

 #include "asio/detail/pop_options.hpp"

 #endif // defined(ASIO_HAS_BOOST_DATE_TIME)
        // || defined(GENERATING_DOCUMENTATION)

 #endif // ASIO_BASIC_DEADLINE_TIMER_HPP
	//
	// basic_deadline_timer.hpp
	// ~~~~~~~~~~~~~~~~~~~~~~~~
	//
	// Copyright (c) 2003-2015 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_BASIC_DEADLINE_TIMER_HPP
	#define ASIO_BASIC_DEADLINE_TIMER_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_HAS_BOOST_DATE_TIME) \
	\|\| defined(GENERATING_DOCUMENTATION)

	#include <cstddef>
	#include "asio/basic_io_object.hpp"
	#include "asio/deadline_timer_service.hpp"
	#include "asio/detail/handler_type_requirements.hpp"
	#include "asio/detail/throw_error.hpp"
	#include "asio/error.hpp"

	#include "asio/detail/push_options.hpp"

	namespace asio {

	/// Provides waitable timer functionality.
	/**
	* The basic_deadline_timer class template provides the ability to perform a
	* blocking or asynchronous wait for a timer to expire.
	*
	* A deadline timer is always in one of two states: "expired" or "not expired".
	* If the wait() or async_wait() function is called on an expired timer, the
	* wait operation will complete immediately.
	*
	* Most applications will use the asio::deadline_timer typedef.
	*
	* @par Thread Safety
	* @e Distinct @e objects: Safe.@n
	* @e Shared @e objects: Unsafe.
	*
	* @par Examples
	* Performing a blocking wait:
	* @code
	* // Construct a timer without setting an expiry time.
	* asio::deadline_timer timer(io_context);
	*
	* // Set an expiry time relative to now.
	* timer.expires_from_now(boost::posix_time::seconds(5));
	*
	* // Wait for the timer to expire.
	* timer.wait();
	* @endcode
	*
	* @par
	* Performing an asynchronous wait:
	* @code
	* void handler(const asio::error_code& error)
	* {
	* if (!error)
	* {
	* // Timer expired.
	* }
	* }
	*
	* ...
	*
	* // Construct a timer with an absolute expiry time.
	* asio::deadline_timer timer(io_context,
	* boost::posix_time::time_from_string("2005-12-07 23:59:59.000"));
	*
	* // Start an asynchronous wait.
	* timer.async_wait(handler);
	* @endcode
	*
	* @par Changing an active deadline_timer's expiry time
	*
	* Changing the expiry time of a timer while there are pending asynchronous
	* waits causes those wait operations to be cancelled. To ensure that the action
	* associated with the timer is performed only once, use something like this:
	* used:
	*
	* @code
	* void on_some_event()
	* {
	* if (my_timer.expires_from_now(seconds(5)) > 0)
	* {
	* // We managed to cancel the timer. Start new asynchronous wait.
	* my_timer.async_wait(on_timeout);
	* }
	* else
	* {
	* // Too late, timer has already expired!
	* }
	* }
	*
	* void on_timeout(const asio::error_code& e)
	* {
	* if (e != asio::error::operation_aborted)
	* {
	* // Timer was not cancelled, take necessary action.
	* }
	* }
	* @endcode
	*
	* @li The asio::basic_deadline_timer::expires_from_now() function
	* cancels any pending asynchronous waits, and returns the number of
	* asynchronous waits that were cancelled. If it returns 0 then you were too
	* late and the wait handler has already been executed, or will soon be
	* executed. If it returns 1 then the wait handler was successfully cancelled.
	*
	* @li If a wait handler is cancelled, the asio::error_code passed to
	* it contains the value asio::error::operation_aborted.
	*/
	template <typename Time,
	typename TimeTraits = asio::time_traits<Time>,
	typename TimerService = deadline_timer_service<Time, TimeTraits> >
	class basic_deadline_timer
	: public basic_io_object<TimerService>
	{
	public:
	/// The time traits type.
	typedef TimeTraits traits_type;

	/// The time type.
	typedef typename traits_type::time_type time_type;

	/// The duration type.
	typedef typename traits_type::duration_type duration_type;

	/// Constructor.
	/**
	* This constructor creates a timer without setting an expiry time. The
	* expires_at() or expires_from_now() functions must be called to set an
	* expiry time before the timer can be waited on.
	*
	* @param io_context The io_context object that the timer will use to dispatch
	* handlers for any asynchronous operations performed on the timer.
	*/
	explicit basic_deadline_timer(asio::io_context& io_context)
	: basic_io_object<TimerService>(io_context)
	{
	}

	/// Constructor to set a particular expiry time as an absolute time.
	/**
	* This constructor creates a timer and sets the expiry time.
	*
	* @param io_context The io_context object that the timer will use to dispatch
	* handlers for any asynchronous operations performed on the timer.
	*
	* @param expiry_time The expiry time to be used for the timer, expressed
	* as an absolute time.
	*/
	basic_deadline_timer(asio::io_context& io_context,
	const time_type& expiry_time)
	: basic_io_object<TimerService>(io_context)
	{
	asio::error_code ec;
	this->get_service().expires_at(this->get_implementation(), expiry_time, ec);
	asio::detail::throw_error(ec, "expires_at");
	}

	/// Constructor to set a particular expiry time relative to now.
	/**
	* This constructor creates a timer and sets the expiry time.
	*
	* @param io_context The io_context object that the timer will use to dispatch
	* handlers for any asynchronous operations performed on the timer.
	*
	* @param expiry_time The expiry time to be used for the timer, relative to
	* now.
	*/
	basic_deadline_timer(asio::io_context& io_context,
	const duration_type& expiry_time)
	: basic_io_object<TimerService>(io_context)
	{
	asio::error_code ec;
	this->get_service().expires_from_now(
	this->get_implementation(), expiry_time, ec);
	asio::detail::throw_error(ec, "expires_from_now");
	}

	/// Cancel any asynchronous operations that are waiting on the timer.
	/**
	* This function forces the completion of any pending asynchronous wait
	* operations against the timer. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* Cancelling the timer does not change the expiry time.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @throws asio::system_error Thrown on failure.
	*
	* @note If the timer has already expired when cancel() is called, then the
	* handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t cancel()
	{
	asio::error_code ec;
	std::size_t s = this->get_service().cancel(this->get_implementation(), ec);
	asio::detail::throw_error(ec, "cancel");
	return s;
	}

	/// Cancel any asynchronous operations that are waiting on the timer.
	/**
	* This function forces the completion of any pending asynchronous wait
	* operations against the timer. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* Cancelling the timer does not change the expiry time.
	*
	* @param ec Set to indicate what error occurred, if any.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @note If the timer has already expired when cancel() is called, then the
	* handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t cancel(asio::error_code& ec)
	{
	return this->get_service().cancel(this->get_implementation(), ec);
	}

	/// Cancels one asynchronous operation that is waiting on the timer.
	/**
	* This function forces the completion of one pending asynchronous wait
	* operation against the timer. Handlers are cancelled in FIFO order. The
	* handler for the cancelled operation will be invoked with the
	* asio::error::operation_aborted error code.
	*
	* Cancelling the timer does not change the expiry time.
	*
	* @return The number of asynchronous operations that were cancelled. That is,
	* either 0 or 1.
	*
	* @throws asio::system_error Thrown on failure.
	*
	* @note If the timer has already expired when cancel_one() is called, then
	* the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t cancel_one()
	{
	asio::error_code ec;
	std::size_t s = this->get_service().cancel_one(
	this->get_implementation(), ec);
	asio::detail::throw_error(ec, "cancel_one");
	return s;
	}

	/// Cancels one asynchronous operation that is waiting on the timer.
	/**
	* This function forces the completion of one pending asynchronous wait
	* operation against the timer. Handlers are cancelled in FIFO order. The
	* handler for the cancelled operation will be invoked with the
	* asio::error::operation_aborted error code.
	*
	* Cancelling the timer does not change the expiry time.
	*
	* @param ec Set to indicate what error occurred, if any.
	*
	* @return The number of asynchronous operations that were cancelled. That is,
	* either 0 or 1.
	*
	* @note If the timer has already expired when cancel_one() is called, then
	* the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t cancel_one(asio::error_code& ec)
	{
	return this->get_service().cancel_one(this->get_implementation(), ec);
	}

	/// Get the timer's expiry time as an absolute time.
	/**
	* This function may be used to obtain the timer's current expiry time.
	* Whether the timer has expired or not does not affect this value.
	*/
	time_type expires_at() const
	{
	return this->get_service().expires_at(this->get_implementation());
	}

	/// Set the timer's expiry time as an absolute time.
	/**
	* This function sets the expiry time. Any pending asynchronous wait
	* operations will be cancelled. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* @param expiry_time The expiry time to be used for the timer.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @throws asio::system_error Thrown on failure.
	*
	* @note If the timer has already expired when expires_at() is called, then
	* the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t expires_at(const time_type& expiry_time)
	{
	asio::error_code ec;
	std::size_t s = this->get_service().expires_at(
	this->get_implementation(), expiry_time, ec);
	asio::detail::throw_error(ec, "expires_at");
	return s;
	}

	/// Set the timer's expiry time as an absolute time.
	/**
	* This function sets the expiry time. Any pending asynchronous wait
	* operations will be cancelled. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* @param expiry_time The expiry time to be used for the timer.
	*
	* @param ec Set to indicate what error occurred, if any.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @note If the timer has already expired when expires_at() is called, then
	* the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t expires_at(const time_type& expiry_time,
	asio::error_code& ec)
	{
	return this->get_service().expires_at(
	this->get_implementation(), expiry_time, ec);
	}

	/// Get the timer's expiry time relative to now.
	/**
	* This function may be used to obtain the timer's current expiry time.
	* Whether the timer has expired or not does not affect this value.
	*/
	duration_type expires_from_now() const
	{
	return this->get_service().expires_from_now(this->get_implementation());
	}

	/// Set the timer's expiry time relative to now.
	/**
	* This function sets the expiry time. Any pending asynchronous wait
	* operations will be cancelled. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* @param expiry_time The expiry time to be used for the timer.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @throws asio::system_error Thrown on failure.
	*
	* @note If the timer has already expired when expires_from_now() is called,
	* then the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t expires_from_now(const duration_type& expiry_time)
	{
	asio::error_code ec;
	std::size_t s = this->get_service().expires_from_now(
	this->get_implementation(), expiry_time, ec);
	asio::detail::throw_error(ec, "expires_from_now");
	return s;
	}

	/// Set the timer's expiry time relative to now.
	/**
	* This function sets the expiry time. Any pending asynchronous wait
	* operations will be cancelled. The handler for each cancelled operation will
	* be invoked with the asio::error::operation_aborted error code.
	*
	* @param expiry_time The expiry time to be used for the timer.
	*
	* @param ec Set to indicate what error occurred, if any.
	*
	* @return The number of asynchronous operations that were cancelled.
	*
	* @note If the timer has already expired when expires_from_now() is called,
	* then the handlers for asynchronous wait operations will:
	*
	* @li have already been invoked; or
	*
	* @li have been queued for invocation in the near future.
	*
	* These handlers can no longer be cancelled, and therefore are passed an
	* error code that indicates the successful completion of the wait operation.
	*/
	std::size_t expires_from_now(const duration_type& expiry_time,
	asio::error_code& ec)
	{
	return this->get_service().expires_from_now(
	this->get_implementation(), expiry_time, ec);
	}

	/// Perform a blocking wait on the timer.
	/**
	* This function is used to wait for the timer to expire. This function
	* blocks and does not return until the timer has expired.
	*
	* @throws asio::system_error Thrown on failure.
	*/
	void wait()
	{
	asio::error_code ec;
	this->get_service().wait(this->get_implementation(), ec);
	asio::detail::throw_error(ec, "wait");
	}

	/// Perform a blocking wait on the timer.
	/**
	* This function is used to wait for the timer to expire. This function
	* blocks and does not return until the timer has expired.
	*
	* @param ec Set to indicate what error occurred, if any.
	*/
	void wait(asio::error_code& ec)
	{
	this->get_service().wait(this->get_implementation(), ec);
	}

	/// Start an asynchronous wait on the timer.
	/**
	* This function may be used to initiate an asynchronous wait against the
	* timer. It always returns immediately.
	*
	* For each call to async_wait(), the supplied handler will be called exactly
	* once. The handler will be called when:
	*
	* @li The timer has expired.
	*
	* @li The timer was cancelled, in which case the handler is passed the error
	* code asio::error::operation_aborted.
	*
	* @param handler The handler to be called when the timer expires. Copies
	* will be made of the handler as required. The function signature of the
	* handler must be:
	* @code void handler(
	* const asio::error_code& error // Result of operation.
	* ); @endcode
	* Regardless of whether the asynchronous operation completes immediately or
	* not, the handler will not be invoked from within this function. Invocation
	* of the handler will be performed in a manner equivalent to using
	* asio::io_context::post().
	*/
	template <typename WaitHandler>
	ASIO_INITFN_RESULT_TYPE(WaitHandler,
	void (asio::error_code))
	async_wait(ASIO_MOVE_ARG(WaitHandler) handler)
	{
	// If you get an error on the following line it means that your handler does
	// not meet the documented type requirements for a WaitHandler.
	ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;

	return this->get_service().async_wait(this->get_implementation(),
	ASIO_MOVE_CAST(WaitHandler)(handler));
	}
	};

	} // namespace asio

	#include "asio/detail/pop_options.hpp"

	#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
	// \|\| defined(GENERATING_DOCUMENTATION)

	#endif // ASIO_BASIC_DEADLINE_TIMER_HPP