timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler > Class Template Reference

A engine for timer wheel mechanism. More...

#include <all.hpp>

Inheritance diagram for timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >:

Classes
struct	timer_type
	Type of wheel timer. More...
struct	wheel_item
	Type of wheel's item. More...

Public Types
using	defaults_type = timer_wheel_engine_defaults
	Type with default parameters for this engine.
using	timer_action = typename base_type::timer_action
	Alias for timer_action type.
using	scoped_timer_object
	Alias for scoped timer object.
Public Types inherited from timertt::details::engine_common< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >
using	thread_safety = Thread_Safety
	Indicator of thread-safety.
using	timer_action = Timer_Action
	Alias for Timer_Action.

Public Member Functions
	timer_wheel_engine (unsigned int wheel_size, monotonic_clock::duration granularity, Error_Logger error_logger, Actor_Exception_Handler exception_handler)
	Constructor with all parameters.
	~timer_wheel_engine ()
	Destructor.
timer_object_holder< Thread_Safety >	allocate ()
	Create timer to be activated later.
template<class Duration_1 , class Duration_2 >
bool	activate (timer_object_holder< Thread_Safety > timer, Duration_1 pause, Duration_2 period, timer_action action)
	Activate timer and schedule it for execution.
template<class Duration_1 , class Duration_2 >
bool	reschedule (timer_object_holder< Thread_Safety > timer, Duration_1 pause, Duration_2 period, timer_action action)
	Perform an attempt to reschedule a timer.
void	deactivate (timer_object_holder< Thread_Safety > timer)
	Deactivate timer and remove it from the wheel.
template<typename Unique_Lock >
void	process_expired_timers (Unique_Lock &lock)
	Build sublist of elapsed timers and process them all.
bool	empty () const
	Is empty timer list?
monotonic_clock::time_point	nearest_time_point () const
	Get time point of the next timer.
void	clear_all ()
	Deactivate all timers and cleanup internal data structures.
Public Member Functions inherited from timertt::details::engine_common< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >
	engine_common (Error_Logger error_logger, Actor_Exception_Handler exception_handler)
	Initializing constructor.
timer_quantities	get_timer_quantities () const
	Get the quantities of timers of various types.

Private Types
using	base_type
	An alias for base class.

Private Member Functions
template<class Duration_1 , class Duration_2 >
void	perform_insertion_info_wheel (timer_type *wheel_timer, Duration_1 pause, Duration_2 period)
	Perform insertion of a timer into wheel data structure.
template<class Duration >
unsigned int	duration_to_ticks (Duration d) const
	Converion of duration to number of time steps.
void	set_position_in_the_wheel (timer_type *wheel_timer, unsigned int pause_in_ticks) const
	Calculate and fill up wheel position for the timer.
void	insert_demand_to_wheel (timer_type *wheel_timer)
	Insert timer to the wheel.
void	remove_timer_from_wheel (timer_type *wheel_timer)
	Remove timer from the timer_wheel.
template<class Unique_Lock >
void	process_current_wheel_position (Unique_Lock &lock)
	Detect elapsed timers for the current time step and process them all.
timer_type *	make_exec_list ()
	Make list of elapsed timers to be executed.
template<class Unique_Lock >
void	exec_actions (Unique_Lock &lock, timer_type *head) TIMERTT_NOEXCEPT
	Execute all active timers from the list.
void	utilize_exec_list (timer_type *head)
	Process list of elapsed timers after execution of its actions.

Static Private Member Functions
static void	ensure_timer_deactivated (const timer_type *timer)
	Hard check for deactivation state of the timer.

Private Attributes
Object's attributes.
const unsigned int	m_wheel_size
	Size of the wheel.
const monotonic_clock::duration	m_granularity
	Granularity of one time step.
unsigned int	m_current_position = 0
	Index of the current position in the wheel.
monotonic_clock::time_point	m_current_tick_border
	Right border of the current tick.
bool	m_current_tick_processed = false
	Has the current tick been processed?
std::vector< wheel_item >	m_wheel
	The wheel data.

Additional Inherited Members
Protected Member Functions inherited from timertt::details::engine_common< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >
void	inc_timer_count (timer_kind kind)
	Helper method for increment the count of timers of the specific type.
void	dec_timer_count (timer_kind kind)
	Helper method for decrement the count of timers of the specific type.
void	reset_timer_count ()
	Helper method for reseting quantities of timers to zero.
Protected Attributes inherited from timertt::details::engine_common< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >
Error_Logger	m_error_logger
	Error logger.
Actor_Exception_Handler	m_exception_handler
	Exception handler.
timer_quantities	m_timer_quantities
	Quantities of timers of various types.

Detailed Description

template<typename Thread_Safety, typename Timer_Action, typename Error_Logger, typename Actor_Exception_Handler>
class timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >

A engine for timer wheel mechanism.

This class uses timer_wheel mechanism to work with timers. This mechanism is efficient for working with big amount of timers. But it requires that timer thread is working always, even in case when there is no timers. Another price for timer_wheel is the granularity of timer steps.

Timer wheel data structure consists from one fixed size vector (the wheel) and several double-linked list (one list for every wheel slot).

At the start of next time step thread switches to next wheel position and handles timers from this position list. After processing all elapsed single-shot timers will be removed and deactivated, and all elapsed periodic timers will be rescheduled for the new time steps.

Note

At the beginnig of time step thread detects elapsed timers, then unblocks object mutex and calls timer actors for those timers. It means that actors call call timer thread object. And there won't be frequent mutex locking/unlocking operations for building and processing list of elapsed timers. This allows to process millions of timer actor per second.

Template Parameters

Thread_Safety	Thread-safety indicator. Must be timertt::thread_safety::unsafe or timertt::thread_safety::safe.
Timer_Action	type of functor to perform an user-defined action when timer expires. This must be Moveable and MoveConstructible type.
Error_Logger	type of logger for errors detected during timer thread execution. Interface for error logger is defined by default_error_logger class.
Actor_Exception_Handler	type of handler for dealing with exceptions thrown from timer actors. Interface for exception handler is defined by default_actor_exception_handler.

Definition at line 889 of file 3rd_party/timertt/all.hpp.

Member Typedef Documentation

base_type

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

using timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::base_type

private

Initial value:

 engine_common<
      Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >

An alias for base class.

Definition at line 894 of file 3rd_party/timertt/all.hpp.

defaults_type

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

using timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::defaults_type = timer_wheel_engine_defaults

Type with default parameters for this engine.

Definition at line 901 of file 3rd_party/timertt/all.hpp.

scoped_timer_object

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

using timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::scoped_timer_object

Initial value:

 
      scoped_timer_object_holder< timer_type >

Alias for scoped timer object.

Definition at line 907 of file 3rd_party/timertt/all.hpp.

timer_action

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

using timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::timer_action = typename base_type::timer_action

Alias for timer_action type.

Definition at line 904 of file 3rd_party/timertt/all.hpp.

Constructor & Destructor Documentation

timer_wheel_engine()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::timer_wheel_engine ( unsigned int wheel_size, monotonic_clock::duration granularity, Error_Logger error_logger, Actor_Exception_Handler exception_handler )

inline

Constructor with all parameters.

Parameters

wheel_size	Size of the wheel.
granularity	Size of time step for the timer_wheel.
error_logger	An error logger for timer thread.
exception_handler	An actor exception handler for timer thread.

Definition at line 911 of file 3rd_party/timertt/all.hpp.

~timer_wheel_engine()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::~timer_wheel_engine ( )

inline

Destructor.

Definition at line 930 of file 3rd_party/timertt/all.hpp.

Member Function Documentation

activate()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Duration_1 , class Duration_2 >

bool timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::activate ( timer_object_holder< Thread_Safety > timer, Duration_1 pause, Duration_2 period, timer_action action )

inline

Activate timer and schedule it for execution.

Returns

Value true is returned only when the first timer is added to the empty wheel.

Exceptions

std::exception	If timer thread is not started.
std::exception	If timer is already activated.

Template Parameters

Duration_1	actual type which represents time duration.
Duration_2	actual type which represents time duration.

Parameters

timer	Timer to be activated.
pause	Pause for timer execution.
period	Repetition period. If Duration_2::zero() == period then timer will be single-shot.
action	Action for the timer.

Definition at line 955 of file 3rd_party/timertt/all.hpp.

allocate()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

timer_object_holder< Thread_Safety > timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::allocate ( )

inline

Create timer to be activated later.

Definition at line 937 of file 3rd_party/timertt/all.hpp.

clear_all()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::clear_all ( )

inline

Deactivate all timers and cleanup internal data structures.

Definition at line 1164 of file 3rd_party/timertt/all.hpp.

deactivate()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::deactivate ( timer_object_holder< Thread_Safety > timer )

inline

Deactivate timer and remove it from the wheel.

Definition at line 1067 of file 3rd_party/timertt/all.hpp.

duration_to_ticks()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Duration >

unsigned int timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::duration_to_ticks ( Duration d ) const

inlineprivate

Converion of duration to number of time steps.

Note

This implementation performs rounding up for duration values. For example if granularity is 10ms and duration is 15ms then result will be 2 time steps.

Never return 0. If duration is less then granularity (even after rounding up) the value 1 will be returned. E.g. timer will be scheduled for the next time step.

Template Parameters

Duration

actual type for duration representation.

Parameters

d	Time duration to be converted in time steps count.

Definition at line 1337 of file 3rd_party/timertt/all.hpp.

empty()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

bool timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::empty ( ) const

inline

Is empty timer list?

Definition at line 1140 of file 3rd_party/timertt/all.hpp.

ensure_timer_deactivated()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

static void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::ensure_timer_deactivated ( const timer_type * timer )

inlinestaticprivate

Hard check for deactivation state of the timer.

Exceptions

std::runtimer_error

if timer is not deactivated.

Definition at line 1274 of file 3rd_party/timertt/all.hpp.

exec_actions()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Unique_Lock >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::exec_actions ( Unique_Lock & lock, timer_type * head )

inlineprivate

Execute all active timers from the list.

Parameters

lock	Object lock. This lock will be unlocked before execution of actions and locked back after.
head	Head of execution list. Cannot be nullptr.

Definition at line 1492 of file 3rd_party/timertt/all.hpp.

insert_demand_to_wheel()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::insert_demand_to_wheel ( timer_type * wheel_timer )

inlineprivate

Insert timer to the wheel.

If there is a non-empty timer list for the timer wheel position the wheel_timer will be added to the end of that list.

Definition at line 1384 of file 3rd_party/timertt/all.hpp.

make_exec_list()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

timer_type * timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::make_exec_list ( )

inlineprivate

Make list of elapsed timers to be executed.

Definition at line 1448 of file 3rd_party/timertt/all.hpp.

nearest_time_point()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

monotonic_clock::time_point timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::nearest_time_point ( ) const

inline

Get time point of the next timer.

Attention

Must be called only when !empty().

Definition at line 1152 of file 3rd_party/timertt/all.hpp.

perform_insertion_info_wheel()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Duration_1 , class Duration_2 >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::perform_insertion_info_wheel ( timer_type * wheel_timer, Duration_1 pause, Duration_2 period )

inlineprivate

Perform insertion of a timer into wheel data structure.

This method added to remove the duplication of code in activate() and reschedule() methods.

Note

This method doesn't change reference count to timer object.

Since

v.1.2.1

Parameters

wheel_timer	Timer to be inserted.
pause	Pause for timer execution.
period	Repetition period. If Duration_2::zero() == period then timer will be single-shot.

Definition at line 1294 of file 3rd_party/timertt/all.hpp.

process_current_wheel_position()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Unique_Lock >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::process_current_wheel_position ( Unique_Lock & lock )

inlineprivate

Detect elapsed timers for the current time step and process them all.

Object lock will be unlocked and then locked back.

Definition at line 1431 of file 3rd_party/timertt/all.hpp.

process_expired_timers()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<typename Unique_Lock >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::process_expired_timers ( Unique_Lock & lock )

inline

Build sublist of elapsed timers and process them all.

Parameters

lock	Object's lock.

Definition at line 1097 of file 3rd_party/timertt/all.hpp.

remove_timer_from_wheel()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::remove_timer_from_wheel ( timer_type * wheel_timer )

inlineprivate

Remove timer from the timer_wheel.

Definition at line 1410 of file 3rd_party/timertt/all.hpp.

reschedule()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

template<class Duration_1 , class Duration_2 >

bool timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::reschedule ( timer_object_holder< Thread_Safety > timer, Duration_1 pause, Duration_2 period, timer_action action )

inline

Perform an attempt to reschedule a timer.

Before v.1.2.1 there was just one way to reschedule a timer: method deactivate() must be called first and then method activate() must be called for the same timer. This approach is not fast because in the case of thread-safe engines it requires two operations on a mutex.

Since v.1.2.1 there is a reschedule() method which does deactivation of a timer (if it is active) and then new activation of this timer. All actions are performed by using just one operation on a mutex.

Note

This operation can fail if the timer to be rescheduled is in processing. Because of that it is recommended to use such operation for timer_managers only. But even with timer_managers this operation should be used with care.

Attention

It move operator for a timer_action throws then timer will be deactivated. The state for a timer_action itself will be unknown.

Exceptions

std::exception	If timer thread is not started.
std::exception	If timer is in processing right now.

Template Parameters

Duration_1	actual type which represents time duration.
Duration_2	actual type which represents time duration.

Since

v.1.2.1

Parameters

timer	Timer to be rescheduled. Must be in activated or deactivated state.
pause	Pause for timer execution.
period	Repetition period. If Duration_2::zero() == period then timer will be single-shot.
action	Action for the timer.

Definition at line 1019 of file 3rd_party/timertt/all.hpp.

set_position_in_the_wheel()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::set_position_in_the_wheel ( timer_type * wheel_timer, unsigned int pause_in_ticks ) const

inlineprivate

Calculate and fill up wheel position for the timer.

timer_type::m_position and timer_type::m_full_rolls_left will be set for wheel_timer.

Parameters

wheel_timer	Timer to modify.
pause_in_ticks	Timeout for the timer is time steps.

Definition at line 1366 of file 3rd_party/timertt/all.hpp.

utilize_exec_list()

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

void timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::utilize_exec_list ( timer_type * head )

inlineprivate

Process list of elapsed timers after execution of its actions.

Active periodic timers will be rescheduled. All other timers will be deactivated and removed.

Parameters

head	Head of execution list. Cannot be null.

Definition at line 1548 of file 3rd_party/timertt/all.hpp.

Member Data Documentation

m_current_position

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

unsigned int timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_current_position = 0

private

Index of the current position in the wheel.

Definition at line 1251 of file 3rd_party/timertt/all.hpp.

m_current_tick_border

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

monotonic_clock::time_point timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_current_tick_border

private

Right border of the current tick.

This is the time point at which new tick must be started.

Definition at line 1257 of file 3rd_party/timertt/all.hpp.

m_current_tick_processed

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

bool timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_current_tick_processed = false

private

Has the current tick been processed?

Definition at line 1260 of file 3rd_party/timertt/all.hpp.

m_granularity

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

const monotonic_clock::duration timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_granularity

private

Granularity of one time step.

Definition at line 1248 of file 3rd_party/timertt/all.hpp.

m_wheel

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

std::vector< wheel_item > timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_wheel

private

The wheel data.

Definition at line 1263 of file 3rd_party/timertt/all.hpp.

m_wheel_size

template<typename Thread_Safety , typename Timer_Action , typename Error_Logger , typename Actor_Exception_Handler >

const unsigned int timertt::details::timer_wheel_engine< Thread_Safety, Timer_Action, Error_Logger, Actor_Exception_Handler >::m_wheel_size

private

Size of the wheel.

Definition at line 1245 of file 3rd_party/timertt/all.hpp.

---

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

• 3rd_party/timertt/all.hpp