Provides a Timing Wheel version of ACE_Timer_Queue. More...

#include <Timer_Wheel_T.h>

Collaboration diagram for ACE_Timer_Wheel_T:

[legend]

Public Types
typedef ACE_Timer_Wheel_Iterator_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >	Iterator
	Type of iterator. More...

typedef ACE_Timer_Node_T< TYPE >	Node

typedef ACE_Timer_Queue_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >	Base_Timer_Queue
	Type inherited from. More...

typedef ACE_Free_List< Node >	FreeList

Public Member Functions
	ACE_Timer_Wheel_T (FUNCTOR upcall_functor=0, FreeList freelist=0, TIME_POLICY const &time_policy=TIME_POLICY())
	Default constructor. More...

	ACE_Timer_Wheel_T (u_int spoke_count, u_int resolution, size_t prealloc=0, FUNCTOR upcall_functor=0, FreeList freelist=0, TIME_POLICY const &time_policy=TIME_POLICY())
	Constructor with opportunities to set the wheelsize and resolution. More...

virtual	~ACE_Timer_Wheel_T (void)
	Destructor. More...

virtual bool	is_empty (void) const
	True if queue is empty, else false. More...

virtual const ACE_Time_Value &	earliest_time (void) const

virtual int	reset_interval (long timer_id, const ACE_Time_Value &interval)

virtual int	cancel (const TYPE &type, int dont_call_handle_close=1)

virtual int	cancel (long timer_id, const void **act=0, int dont_call_handle_close=1)

virtual int	close (void)

virtual int	expire (void)

int	expire (const ACE_Time_Value &current_time)

virtual ACE_Timer_Queue_Iterator_T< TYPE > &	iter (void)
	Returns a pointer to this <ACE_Timer_Queue_T>'s iterator. More...

virtual ACE_Timer_Node_T< TYPE > *	remove_first (void)
	Removes the earliest node from the queue and returns it. More...

virtual void	dump (void) const
	Dump the state of an object. More...

virtual ACE_Timer_Node_T< TYPE > *	get_first (void)
	Reads the earliest node from the queue and returns it. More...

Protected Member Functions
virtual long	schedule_i (const TYPE &type, const void *act, const ACE_Time_Value &future_time, const ACE_Time_Value &interval)
	Schedules a timer. More...

Private Member Functions
ACE_Timer_Node_T< TYPE > *	get_first_i (void) const

ACE_Timer_Node_T< TYPE > *	remove_first_expired (const ACE_Time_Value &now)

void	open_i (size_t prealloc, u_int spokes, u_int res)

virtual void	reschedule (ACE_Timer_Node_T< TYPE > *)

ACE_Timer_Node_T< TYPE > *	find_spoke_node (u_int spoke, long timer_id) const
	Searches for a node by timer_id within one spoke. More...

ACE_Timer_Node_T< TYPE > *	find_node (long timer_id) const

u_int	calculate_spoke (const ACE_Time_Value &expire) const

long	generate_timer_id (u_int spoke)

void	schedule_i (ACE_Timer_Node_T< TYPE > *n, u_int spoke, const ACE_Time_Value &expire)
	The shared scheduling functionality between schedule() and reschedule() More...

void	cancel_i (ACE_Timer_Node_T< TYPE > *n)
	Shared subset of the two cancel() methods. More...

void	unlink (ACE_Timer_Node_T< TYPE > *n)

void	recalc_earliest (const ACE_Time_Value &last)

int	power2bits (int n, int min_bits, int max_bits)

Private Attributes
ACE_Timer_Node_T< TYPE > **	spokes_
	Timing Wheel. More...

u_int	spoke_count_
	Size of the timing wheel. More...

int	spoke_bits_
	Number of timer_id bits used for the spoke. More...

int	res_bits_
	Resolution (in microsoconds) of the timing wheel. More...

u_int	earliest_spoke_
	Index of the list with the earliest time. More...

Iterator *	iterator_
	Iterator used to expire timers. More...

ACE_Time_Value	wheel_time_
	The total amount of time in one iteration of the wheel. (resolution * spoke_count) More...

u_int	timer_count_
	The total number of timers currently scheduled. More...

Friends
class	ACE_Timer_Wheel_Iterator_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >
	Iterator is a friend. More...

Detailed Description

Provides a Timing Wheel version of ACE_Timer_Queue.

This implementation uses a hash table of ordered doubly- linked lists of absolute times. The enhancements over the ACE_Timer_List include adding a free list and the ability to preallocate nodes. Timer Wheel is based on the timing wheel implementation used in Adam M. Costello and George Varghese's paper "Redesigning the BSD Callout and Timer Facilities" (http://dworkin.wustl.edu/~varghese/PAPERS/newbsd.ps.Z)

Member Typedef Documentation

◆ Base_Timer_Queue

typedef ACE_Timer_Queue_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY> ACE_Timer_Wheel_T::Base_Timer_Queue

Type inherited from.

◆ FreeList

typedef ACE_Free_List<Node> ACE_Timer_Wheel_T::FreeList

◆ Iterator

typedef ACE_Timer_Wheel_Iterator_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY> ACE_Timer_Wheel_T::Iterator

Type of iterator.

◆ Node

typedef ACE_Timer_Node_T<TYPE> ACE_Timer_Wheel_T::Node

Constructor & Destructor Documentation

◆ ACE_Timer_Wheel_T() [1/2]

ACE_Timer_Wheel_T::ACE_Timer_Wheel_T	(	FUNCTOR *	upcall_functor = `0`,
		FreeList *	freelist = `0`,
		TIME_POLICY const &	time_policy = `TIME_POLICY()`
	)

Default constructor.

◆ ACE_Timer_Wheel_T() [2/2]

ACE_Timer_Wheel_T::ACE_Timer_Wheel_T	(	u_int	spoke_count,
		u_int	resolution,
		size_t	prealloc = `0`,
		FUNCTOR *	upcall_functor = `0`,
		FreeList *	freelist = `0`,
		TIME_POLICY const &	time_policy = `TIME_POLICY()`
	)

Constructor with opportunities to set the wheelsize and resolution.

◆ ~ACE_Timer_Wheel_T()

ACE_Timer_Wheel_T::~ACE_Timer_Wheel_T ( void )

virtual

Destructor.

Destructor just cleans up its memory.

Member Function Documentation

◆ calculate_spoke()

u_int ACE_Timer_Wheel_T::calculate_spoke ( const ACE_Time_Value & t ) const

private

Uses a simple hash to find which spoke to use based on when the timer is due to expire. Hopefully the 64bit int operations avoid any overflow problems.

◆ cancel() [1/2]

virtual int ACE_Timer_Wheel_T::cancel	(	const TYPE &	type,
		int	dont_call_handle_close = `1`
	)

virtual

Cancel all timer associated with type. If dont_call_handle_close is 0 then the <functor> will be invoked. Returns number of timers cancelled.

◆ cancel() [2/2]

virtual int ACE_Timer_Wheel_T::cancel	(	long	timer_id,
		const void **	act = `0`,
		int	dont_call_handle_close = `1`
	)

virtual

◆ cancel_i()

void ACE_Timer_Wheel_T::cancel_i ( ACE_Timer_Node_T< TYPE > * n )

private

Shared subset of the two cancel() methods.

◆ close()

int ACE_Timer_Wheel_T::close ( void )

virtual

Destroy timer queue. Cancels all timers.

◆ dump()

void ACE_Timer_Wheel_T::dump ( void ) const

virtual

Dump the state of an object.

Dumps out the size of the wheel, the resolution, and the contents of the wheel.

◆ earliest_time()

const ACE_Time_Value & ACE_Timer_Wheel_T::earliest_time ( void ) const

virtual

Returns the time of the earlier node in the ACE_Timer_Wheel. Must be called on a non-empty queue.

Returns: First (earliest) node in the wheel_'s earliest_spoke_ list

◆ expire() [1/2]

int ACE_Timer_Wheel_T::expire ( const ACE_Time_Value & current_time )

◆ expire() [2/2]

virtual int ACE_Timer_Wheel_T::expire ( void )

virtual

Run the <functor> for all timers whose values are <= <ACE_OS::gettimeofday>. Also accounts for <timer_skew>. Returns the number of timers canceled.

◆ find_node()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::find_node ( long timer_id ) const

private

Searches all spokes for a node matching the specified timer_id Uses the spoke encoded in the timer_id as a starting place.

◆ find_spoke_node()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::find_spoke_node	(	u_int	spoke,
		long	timer_id
	)		const

private

Searches for a node by timer_id within one spoke.

◆ generate_timer_id()

long ACE_Timer_Wheel_T::generate_timer_id ( u_int spoke )

private

Generates a unique timer_id for the given spoke. It should be pretty fast until the point where the counter overflows. At that time you have to do exhaustive searches within the spoke to ensure that a particular timer id is not already in use. Some optimizations are in place so that this hopefully doesn't have to happen often.

◆ get_first()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::get_first ( void )

virtual

Reads the earliest node from the queue and returns it.

Returns the earliest node without removing it

Returns: The earliest timer node.

◆ get_first_i()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::get_first_i ( void ) const

private

◆ is_empty()

bool ACE_Timer_Wheel_T::is_empty ( void ) const

virtual

True if queue is empty, else false.

Check to see if the wheel is empty

Returns: True if empty

◆ iter()

ACE_Timer_Queue_Iterator_T< TYPE > & ACE_Timer_Wheel_T::iter ( void )

virtual

Returns a pointer to this <ACE_Timer_Queue_T>'s iterator.

Returns: The iterator

◆ open_i()

void ACE_Timer_Wheel_T::open_i	(	size_t	prealloc,
		u_int	spokes,
		u_int	res
	)

private

Initialize the queue. Uses the established members for all needed information.

◆ power2bits()

int ACE_Timer_Wheel_T::power2bits	(	int	n,
		int	min_bits,
		int	max_bits
	)

private

◆ recalc_earliest()

void ACE_Timer_Wheel_T::recalc_earliest ( const ACE_Time_Value & last )

private

There are a few places where we have to figure out which timer will expire next. This method makes the assumption that spokes are always sorted, and that timers are always in the correct spoke determined from their expiration time. The last time is always passed in, even though you can often calculate it as get_first()->get_timer_value().

◆ remove_first()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::remove_first ( void )

virtual

Removes the earliest node from the queue and returns it.

Removes the earliest node and then find the new <earliest_spoke_>

Returns: The earliest timer node.

◆ remove_first_expired()

ACE_Timer_Node_T< TYPE > * ACE_Timer_Wheel_T::remove_first_expired ( const ACE_Time_Value & now )

private

◆ reschedule()

void ACE_Timer_Wheel_T::reschedule ( ACE_Timer_Node_T< TYPE > * n )

privatevirtual

Takes an ACE_Timer_Node and inserts it into the correct position in the correct list. Also makes sure to update the earliest time.

Parameters

n	The timer node to reschedule

◆ reset_interval()

int ACE_Timer_Wheel_T::reset_interval	(	long	timer_id,
		const ACE_Time_Value &	interval
	)

virtual

Changes the interval of a timer (and can make it periodic or non periodic by setting it to ACE_Time_Value::zero or not).

Find the timer node by using the id as a pointer. Then use set_interval() on the node to update the interval.

Parameters

timer_id	The timer identifier
interval	The new interval

Returns: 0 if successful, -1 if no.

◆ schedule_i() [1/2]

void ACE_Timer_Wheel_T::schedule_i	(	ACE_Timer_Node_T< TYPE > *	n,
		u_int	spoke,
		const ACE_Time_Value &	expire
	)

private

The shared scheduling functionality between schedule() and reschedule()

◆ schedule_i() [2/2]

long ACE_Timer_Wheel_T::schedule_i	(	const TYPE &	type,
		const void *	act,
		const ACE_Time_Value &	future_time,
		const ACE_Time_Value &	interval
	)

protectedvirtual

Schedules a timer.

Creates a ACE_Timer_Node_T based on the input parameters. Then inserts the node into the wheel using reschedule (). Then returns a timer_id.

Parameters

type	The data of the timer node
act	Asynchronous Completion Token (AKA magic cookie)
future_time	The time the timer is scheduled for (absolute time)
interval	If not ACE_Time_Value::zero, then this is a periodic timer and interval is the time period

Returns: Unique identifier (can be used to cancel the timer). -1 on failure.

◆ unlink()

void ACE_Timer_Wheel_T::unlink ( ACE_Timer_Node_T< TYPE > * n )

private

Friends And Related Function Documentation

◆ ACE_Timer_Wheel_Iterator_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >

friend class ACE_Timer_Wheel_Iterator_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >

friend

Iterator is a friend.

Member Data Documentation

◆ earliest_spoke_

u_int ACE_Timer_Wheel_T::earliest_spoke_

private

Index of the list with the earliest time.

◆ iterator_

Iterator* ACE_Timer_Wheel_T::iterator_

private

Iterator used to expire timers.

◆ res_bits_

int ACE_Timer_Wheel_T::res_bits_

private

Resolution (in microsoconds) of the timing wheel.

◆ spoke_bits_

int ACE_Timer_Wheel_T::spoke_bits_

private

Number of timer_id bits used for the spoke.

◆ spoke_count_

u_int ACE_Timer_Wheel_T::spoke_count_

private

Size of the timing wheel.

◆ spokes_

ACE_Timer_Node_T<TYPE>** ACE_Timer_Wheel_T::spokes_

private

Timing Wheel.

◆ timer_count_

u_int ACE_Timer_Wheel_T::timer_count_

private

The total number of timers currently scheduled.

◆ wheel_time_

ACE_Time_Value ACE_Timer_Wheel_T::wheel_time_

private

The total amount of time in one iteration of the wheel. (resolution * spoke_count)

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

Public Types

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ Base_Timer_Queue

◆ FreeList

◆ Iterator

◆ Node

Constructor & Destructor Documentation

◆ ACE_Timer_Wheel_T() [1/2]

◆ ACE_Timer_Wheel_T() [2/2]

◆ ~ACE_Timer_Wheel_T()

Member Function Documentation

◆ calculate_spoke()

◆ cancel() [1/2]

◆ cancel() [2/2]

◆ cancel_i()

◆ close()

◆ dump()

◆ earliest_time()

◆ expire() [1/2]

◆ expire() [2/2]

◆ find_node()

◆ find_spoke_node()

◆ generate_timer_id()

◆ get_first()

◆ get_first_i()

◆ is_empty()

◆ iter()

◆ open_i()

◆ power2bits()

◆ recalc_earliest()

◆ remove_first()

◆ remove_first_expired()

◆ reschedule()

◆ reset_interval()

◆ schedule_i() [1/2]

◆ schedule_i() [2/2]

◆ unlink()

Friends And Related Function Documentation

◆ ACE_Timer_Wheel_Iterator_T< TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY >

Member Data Documentation

◆ earliest_spoke_

◆ iterator_

◆ res_bits_

◆ spoke_bits_

◆ spoke_count_

◆ spokes_

◆ timer_count_

◆ wheel_time_