Edit: /usr/include/boost/asio/basic_waitable_timer.hpp (28528B)
//
// basic_waitable_timer.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2020 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 BOOST_ASIO_BASIC_WAITABLE_TIMER_HPP
#define BOOST_ASIO_BASIC_WAITABLE_TIMER_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#if defined(BOOST_ASIO_HAS_MOVE)
# include
#endif // defined(BOOST_ASIO_HAS_MOVE)
#include
namespace boost {
namespace asio {
#if !defined(BOOST_ASIO_BASIC_WAITABLE_TIMER_FWD_DECL)
#define BOOST_ASIO_BASIC_WAITABLE_TIMER_FWD_DECL
// Forward declaration with defaulted arguments.
template ,
typename Executor = any_io_executor>
class basic_waitable_timer;
#endif // !defined(BOOST_ASIO_BASIC_WAITABLE_TIMER_FWD_DECL)
/// Provides waitable timer functionality.
/**
* The basic_waitable_timer class template provides the ability to perform a
* blocking or asynchronous wait for a timer to expire.
*
* A waitable 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 one of the boost::asio::steady_timer,
* boost::asio::system_timer or boost::asio::high_resolution_timer typedefs.
*
* @note This waitable timer functionality is for use with the C++11 standard
* library's @c <chrono> facility, or with the Boost.Chrono library.
*
* @par Thread Safety
* @e Distinct @e objects: Safe.@n
* @e Shared @e objects: Unsafe.
*
* @par Examples
* Performing a blocking wait (C++11):
* @code
* // Construct a timer without setting an expiry time.
* boost::asio::steady_timer timer(my_context);
*
* // Set an expiry time relative to now.
* timer.expires_after(std::chrono::seconds(5));
*
* // Wait for the timer to expire.
* timer.wait();
* @endcode
*
* @par
* Performing an asynchronous wait (C++11):
* @code
* void handler(const boost::system::error_code& error)
* {
* if (!error)
* {
* // Timer expired.
* }
* }
*
* ...
*
* // Construct a timer with an absolute expiry time.
* boost::asio::steady_timer timer(my_context,
* std::chrono::steady_clock::now() + std::chrono::seconds(60));
*
* // Start an asynchronous wait.
* timer.async_wait(handler);
* @endcode
*
* @par Changing an active waitable 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_after(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 boost::system::error_code& e)
* {
* if (e != boost::asio::error::operation_aborted)
* {
* // Timer was not cancelled, take necessary action.
* }
* }
* @endcode
*
* @li The boost::asio::basic_waitable_timer::expires_after() 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 boost::system::error_code passed to
* it contains the value boost::asio::error::operation_aborted.
*/
template
class basic_waitable_timer
{
public:
/// The type of the executor associated with the object.
typedef Executor executor_type;
/// Rebinds the timer type to another executor.
template
struct rebind_executor
{
/// The timer type when rebound to the specified executor.
typedef basic_waitable_timer other;
};
/// The clock type.
typedef Clock clock_type;
/// The duration type of the clock.
typedef typename clock_type::duration duration;
/// The time point type of the clock.
typedef typename clock_type::time_point time_point;
/// The wait traits type.
typedef WaitTraits traits_type;
/// Constructor.
/**
* This constructor creates a timer without setting an expiry time. The
* expires_at() or expires_after() functions must be called to set an expiry
* time before the timer can be waited on.
*
* @param ex The I/O executor that the timer will use, by default, to
* dispatch handlers for any asynchronous operations performed on the timer.
*/
explicit basic_waitable_timer(const executor_type& ex)
: impl_(ex)
{
}
/// Constructor.
/**
* This constructor creates a timer without setting an expiry time. The
* expires_at() or expires_after() functions must be called to set an expiry
* time before the timer can be waited on.
*
* @param context An execution context which provides the I/O executor that
* the timer will use, by default, to dispatch handlers for any asynchronous
* operations performed on the timer.
*/
template
explicit basic_waitable_timer(ExecutionContext& context,
typename enable_if<
is_convertible::value
>::type* = 0)
: impl_(context)
{
}
/// Constructor to set a particular expiry time as an absolute time.
/**
* This constructor creates a timer and sets the expiry time.
*
* @param ex The I/O executor object that the timer will use, by default, 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_waitable_timer(const executor_type& ex, const time_point& expiry_time)
: impl_(ex)
{
boost::system::error_code ec;
impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_at");
}
/// Constructor to set a particular expiry time as an absolute time.
/**
* This constructor creates a timer and sets the expiry time.
*
* @param context An execution context which provides the I/O executor that
* the timer will use, by default, 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.
*/
template
explicit basic_waitable_timer(ExecutionContext& context,
const time_point& expiry_time,
typename enable_if<
is_convertible::value
>::type* = 0)
: impl_(context)
{
boost::system::error_code ec;
impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
boost::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 ex The I/O executor that the timer will use, by default, 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_waitable_timer(const executor_type& ex, const duration& expiry_time)
: impl_(ex)
{
boost::system::error_code ec;
impl_.get_service().expires_after(
impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_after");
}
/// Constructor to set a particular expiry time relative to now.
/**
* This constructor creates a timer and sets the expiry time.
*
* @param context An execution context which provides the I/O executor that
* the timer will use, by default, 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.
*/
template
explicit basic_waitable_timer(ExecutionContext& context,
const duration& expiry_time,
typename enable_if<
is_convertible::value
>::type* = 0)
: impl_(context)
{
boost::system::error_code ec;
impl_.get_service().expires_after(
impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_after");
}
#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// Move-construct a basic_waitable_timer from another.
/**
* This constructor moves a timer from one object to another.
*
* @param other The other basic_waitable_timer object from which the move will
* occur.
*
* @note Following the move, the moved-from object is in the same state as if
* constructed using the @c basic_waitable_timer(const executor_type&)
* constructor.
*/
basic_waitable_timer(basic_waitable_timer&& other)
: impl_(std::move(other.impl_))
{
}
/// Move-assign a basic_waitable_timer from another.
/**
* This assignment operator moves a timer from one object to another. Cancels
* any outstanding asynchronous operations associated with the target object.
*
* @param other The other basic_waitable_timer object from which the move will
* occur.
*
* @note Following the move, the moved-from object is in the same state as if
* constructed using the @c basic_waitable_timer(const executor_type&)
* constructor.
*/
basic_waitable_timer& operator=(basic_waitable_timer&& other)
{
impl_ = std::move(other.impl_);
return *this;
}
// All timers have access to each other's implementations.
template
friend class basic_waitable_timer;
/// Move-construct a basic_waitable_timer from another.
/**
* This constructor moves a timer from one object to another.
*
* @param other The other basic_waitable_timer object from which the move will
* occur.
*
* @note Following the move, the moved-from object is in the same state as if
* constructed using the @c basic_waitable_timer(const executor_type&)
* constructor.
*/
template
basic_waitable_timer(
basic_waitable_timer&& other,
typename enable_if<
is_convertible::value
>::type* = 0)
: impl_(std::move(other.impl_))
{
}
/// Move-assign a basic_waitable_timer from another.
/**
* This assignment operator moves a timer from one object to another. Cancels
* any outstanding asynchronous operations associated with the target object.
*
* @param other The other basic_waitable_timer object from which the move will
* occur.
*
* @note Following the move, the moved-from object is in the same state as if
* constructed using the @c basic_waitable_timer(const executor_type&)
* constructor.
*/
template
typename enable_if<
is_convertible::value,
basic_waitable_timer&
>::type operator=(basic_waitable_timer&& other)
{
basic_waitable_timer tmp(std::move(other));
impl_ = std::move(tmp.impl_);
return *this;
}
#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// Destroys the timer.
/**
* This function destroys the timer, cancelling any outstanding asynchronous
* wait operations associated with the timer as if by calling @c cancel.
*/
~basic_waitable_timer()
{
}
/// Get the executor associated with the object.
executor_type get_executor() BOOST_ASIO_NOEXCEPT
{
return impl_.get_executor();
}
/// 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 boost::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 boost::system::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()
{
boost::system::error_code ec;
std::size_t s = impl_.get_service().cancel(impl_.get_implementation(), ec);
boost::asio::detail::throw_error(ec, "cancel");
return s;
}
#if !defined(BOOST_ASIO_NO_DEPRECATED)
/// (Deprecated: Use non-error_code overload.) 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 boost::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(boost::system::error_code& ec)
{
return impl_.get_service().cancel(impl_.get_implementation(), ec);
}
#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
/// 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
* boost::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 boost::system::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()
{
boost::system::error_code ec;
std::size_t s = impl_.get_service().cancel_one(
impl_.get_implementation(), ec);
boost::asio::detail::throw_error(ec, "cancel_one");
return s;
}
#if !defined(BOOST_ASIO_NO_DEPRECATED)
/// (Deprecated: Use non-error_code overload.) 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
* boost::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(boost::system::error_code& ec)
{
return impl_.get_service().cancel_one(impl_.get_implementation(), ec);
}
/// (Deprecated: Use expiry().) 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_point expires_at() const
{
return impl_.get_service().expires_at(impl_.get_implementation());
}
#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
/// 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_point expiry() const
{
return impl_.get_service().expiry(impl_.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 boost::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 boost::system::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_point& expiry_time)
{
boost::system::error_code ec;
std::size_t s = impl_.get_service().expires_at(
impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_at");
return s;
}
#if !defined(BOOST_ASIO_NO_DEPRECATED)
/// (Deprecated: Use non-error_code overload.) 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 boost::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_point& expiry_time,
boost::system::error_code& ec)
{
return impl_.get_service().expires_at(
impl_.get_implementation(), expiry_time, ec);
}
#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
/// 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 boost::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 boost::system::system_error Thrown on failure.
*
* @note If the timer has already expired when expires_after() 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_after(const duration& expiry_time)
{
boost::system::error_code ec;
std::size_t s = impl_.get_service().expires_after(
impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_after");
return s;
}
#if !defined(BOOST_ASIO_NO_DEPRECATED)
/// (Deprecated: Use expiry().) 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 expires_from_now() const
{
return impl_.get_service().expires_from_now(impl_.get_implementation());
}
/// (Deprecated: Use expires_after().) 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 boost::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 boost::system::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& expiry_time)
{
boost::system::error_code ec;
std::size_t s = impl_.get_service().expires_from_now(
impl_.get_implementation(), expiry_time, ec);
boost::asio::detail::throw_error(ec, "expires_from_now");
return s;
}
/// (Deprecated: Use expires_after().) 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 boost::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& expiry_time,
boost::system::error_code& ec)
{
return impl_.get_service().expires_from_now(
impl_.get_implementation(), expiry_time, ec);
}
#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
/// 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 boost::system::system_error Thrown on failure.
*/
void wait()
{
boost::system::error_code ec;
impl_.get_service().wait(impl_.get_implementation(), ec);
boost::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(boost::system::error_code& ec)
{
impl_.get_service().wait(impl_.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 boost::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 boost::system::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. On
* immediate completion, invocation of the handler will be performed in a
* manner equivalent to using boost::asio::post().
*/
template <
BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code))
WaitHandler BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(WaitHandler,
void (boost::system::error_code))
async_wait(
BOOST_ASIO_MOVE_ARG(WaitHandler) handler
BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
{
return async_initiate(
initiate_async_wait(this), handler);
}
private:
// Disallow copying and assignment.
basic_waitable_timer(const basic_waitable_timer&) BOOST_ASIO_DELETED;
basic_waitable_timer& operator=(
const basic_waitable_timer&) BOOST_ASIO_DELETED;
class initiate_async_wait
{
public:
typedef Executor executor_type;
explicit initiate_async_wait(basic_waitable_timer* self)
: self_(self)
{
}
executor_type get_executor() const BOOST_ASIO_NOEXCEPT
{
return self_->get_executor();
}
template
void operator()(BOOST_ASIO_MOVE_ARG(WaitHandler) handler) const
{
// If you get an error on the following line it means that your handler
// does not meet the documented type requirements for a WaitHandler.
BOOST_ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
detail::non_const_lvalue handler2(handler);
self_->impl_.get_service().async_wait(
self_->impl_.get_implementation(),
handler2.value, self_->impl_.get_executor());
}
private:
basic_waitable_timer* self_;
};
detail::io_object_impl<
detail::deadline_timer_service<
detail::chrono_time_traits >,
executor_type > impl_;
};
} // namespace asio
} // namespace boost
#include
#endif // BOOST_ASIO_BASIC_WAITABLE_TIMER_HPP