Provides waitable timer functionality. More...

#include <basic_deadline_timer.hpp>

Inheritance diagram for asio::basic_deadline_timer< Time, TimeTraits, TimerService >:

Public Types
typedef traits_type::duration_type	duration_type
	The duration type.
typedef traits_type::time_type	time_type
	The time type.
typedef TimeTraits	traits_type
	The time traits type.
Public Member Functions
template<typename WaitHandler >
void	async_wait (WaitHandler handler)
	Start an asynchronous wait on the timer.
	basic_deadline_timer (asio::io_service &io_service)
	Constructor.
	basic_deadline_timer (asio::io_service &io_service, const time_type &expiry_time)
	Constructor to set a particular expiry time as an absolute time.
	basic_deadline_timer (asio::io_service &io_service, const duration_type &expiry_time)
	Constructor to set a particular expiry time relative to now.
std::size_t	cancel ()
	Cancel any asynchronous operations that are waiting on the timer.
std::size_t	cancel (asio::error_code &ec)
	Cancel any asynchronous operations that are waiting on the timer.
time_type	expires_at () const
	Get the timer's expiry time as an absolute time.
std::size_t	expires_at (const time_type &expiry_time)
	Set the timer's expiry time as an absolute time.
std::size_t	expires_at (const time_type &expiry_time, asio::error_code &ec)
	Set the timer's expiry time as an absolute time.
duration_type	expires_from_now () const
	Get the timer's expiry time relative to now.
std::size_t	expires_from_now (const duration_type &expiry_time)
	Set the timer's expiry time relative to now.
std::size_t	expires_from_now (const duration_type &expiry_time, asio::error_code &ec)
	Set the timer's expiry time relative to now.
void	wait ()
	Perform a blocking wait on the timer.
void	wait (asio::error_code &ec)
	Perform a blocking wait on the timer.

Detailed Description

template<typename Time, typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>
class asio::basic_deadline_timer< Time, TimeTraits, TimerService >

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.

Most applications will use the asio::deadline_timer typedef.

Thread Safety: Distinct objects: Safe.
Shared objects: Unsafe.

Examples

Performing a blocking wait:

 // Construct a timer without setting an expiry time.
 asio::deadline_timer timer(io_service);

 // Set an expiry time relative to now.
 timer.expires_from_now(boost::posix_time::seconds(5));

 // Wait for the timer to expire.
 timer.wait();

Performing an asynchronous wait:

 void handler(const asio::error_code& error)
 {
   if (!error)
   {
     // Timer expired.
   }
 }

 ...

 // Construct a timer with an absolute expiry time.
 asio::deadline_timer timer(io_service,
     boost::posix_time::time_from_string("2005-12-07 23:59:59.000"));

 // Start an asynchronous wait.
 timer.async_wait(handler);

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:

 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.
   }
 }

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.

If a wait handler is cancelled, the asio::error_code passed to it contains the value asio::error::operation_aborted.

Definition at line 119 of file basic_deadline_timer.hpp.

Member Typedef Documentation

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

typedef traits_type::duration_type asio::basic_deadline_timer< Time, TimeTraits, TimerService >::duration_type

The duration type.

Definition at line 130 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

typedef traits_type::time_type asio::basic_deadline_timer< Time, TimeTraits, TimerService >::time_type

The time type.

Definition at line 127 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

typedef TimeTraits asio::basic_deadline_timer< Time, TimeTraits, TimerService >::traits_type

The time traits type.

Definition at line 124 of file basic_deadline_timer.hpp.

Constructor & Destructor Documentation

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

asio::basic_deadline_timer< Time, TimeTraits, TimerService >::basic_deadline_timer ( asio::io_service & io_service ) [inline, explicit]

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.

Parameters:

io_service The io_service object that the timer will use to dispatch handlers for any asynchronous operations performed on the timer.

Definition at line 141 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

asio::basic_deadline_timer< Time, TimeTraits, TimerService >::basic_deadline_timer	(	asio::io_service &	io_service,
		const time_type &	expiry_time
	)		`[inline]`

Constructor to set a particular expiry time as an absolute time.

This constructor creates a timer and sets the expiry time.

Parameters:

io_service	The io_service object that the timer will use to dispatch handlers for any asynchronous operations performed on the timer.
expiry_time	The expiry time to be used for the timer, expressed as an absolute time.

Definition at line 156 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

asio::basic_deadline_timer< Time, TimeTraits, TimerService >::basic_deadline_timer	(	asio::io_service &	io_service,
		const duration_type &	expiry_time
	)		`[inline]`

Constructor to set a particular expiry time relative to now.

This constructor creates a timer and sets the expiry time.

Parameters:

io_service	The io_service object that the timer will use to dispatch handlers for any asynchronous operations performed on the timer.
expiry_time	The expiry time to be used for the timer, relative to now.

Definition at line 175 of file basic_deadline_timer.hpp.

Member Function Documentation

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

template<typename WaitHandler >

void asio::basic_deadline_timer< Time, TimeTraits, TimerService >::async_wait ( WaitHandler handler ) [inline]

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:

The timer has expired.

The timer was cancelled, in which case the handler is passed the error code asio::error::operation_aborted.

Parameters:

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:

 void handler(
   const asio::error_code& error // Result of operation.
 );

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_service::post().

Definition at line 371 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::cancel ( ) [inline]

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.

Returns:: The number of asynchronous operations that were cancelled.

Exceptions:

asio::system_error Thrown on failure.

Definition at line 196 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::cancel ( asio::error_code & ec ) [inline]

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.

Parameters:

ec	Set to indicate what error occurred, if any.

Returns:: The number of asynchronous operations that were cancelled.

Definition at line 216 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

time_type asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_at ( ) const [inline]

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.

Definition at line 226 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_at ( const time_type & expiry_time ) [inline]

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.

Parameters:

expiry_time The expiry time to be used for the timer.

Returns:: The number of asynchronous operations that were cancelled.

Exceptions:

asio::system_error Thrown on failure.

Definition at line 243 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_at	(	const time_type &	expiry_time,
		asio::error_code &	ec
	)		`[inline]`

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.

Parameters:

expiry_time	The expiry time to be used for the timer.
ec	Set to indicate what error occurred, if any.

Returns:: The number of asynchronous operations that were cancelled.

Definition at line 264 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

duration_type asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_from_now ( ) const [inline]

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.

Definition at line 275 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_from_now ( const duration_type & expiry_time ) [inline]

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.

Parameters:

expiry_time The expiry time to be used for the timer.

Returns:: The number of asynchronous operations that were cancelled.

Exceptions:

asio::system_error Thrown on failure.

Definition at line 292 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

std::size_t asio::basic_deadline_timer< Time, TimeTraits, TimerService >::expires_from_now	(	const duration_type &	expiry_time,
		asio::error_code &	ec
	)		`[inline]`

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.

Parameters:

expiry_time	The expiry time to be used for the timer.
ec	Set to indicate what error occurred, if any.

Returns:: The number of asynchronous operations that were cancelled.

Definition at line 313 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

void asio::basic_deadline_timer< Time, TimeTraits, TimerService >::wait ( ) [inline]

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.

Exceptions:

asio::system_error Thrown on failure.

Definition at line 327 of file basic_deadline_timer.hpp.

template<typename Time , typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>

void asio::basic_deadline_timer< Time, TimeTraits, TimerService >::wait ( asio::error_code & ec ) [inline]

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.

Parameters:

ec	Set to indicate what error occurred, if any.

Definition at line 341 of file basic_deadline_timer.hpp.

The documentation for this class was generated from the following file:

basic_deadline_timer.hpp

Public Types

Public Member Functions

Detailed Description

template<typename Time, typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>> class asio::basic_deadline_timer< Time, TimeTraits, TimerService >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

template<typename Time, typename TimeTraits = asio::time_traits<Time>, typename TimerService = deadline_timer_service<Time, TimeTraits>>
class asio::basic_deadline_timer< Time, TimeTraits, TimerService >