LimitTimer Class Reference

This timer takes care of limiting the number of speed updates we send out in a second. More...

#include <LimitTimer.hxx>

Inheritance diagram for LimitTimer:

Public Member Functions
	LimitTimer (ExecutorBase *ex, uint16_t update_delay_msec, uint8_t max_tokens, std::function< void()> callback)
	Constructor.
	~LimitTimer ()
	Destructor.
bool	try_take ()
	Attempts to take a token out of the bucket.
void	take_no_callback ()
	Takes one entry from the bucket, and does not give a callback if there is no entry left.
Public Member Functions inherited from Timer
	Timer (ActiveTimers *timers)
	Constructor.
	~Timer ()
	Destructor.
void	run () override
	Callback from the executor when this timer is scheduled.
long long	schedule_time ()
void	start (long long period=-1)
	Starts a timer.
void	start_absolute (long long expiry_time_nsec)
	Starts the timer with an absolute deadline.
void	restart ()
	Restart a timer with the existing period but from the current time.
void	trigger ()
	This will wakeup the timer prematurely, immediately.
void	ensure_triggered ()
	Triggers the timer if it is not expired yet.
void	cancel ()
	Dangerous, do not call.
bool	is_triggered ()
void	set_triggered ()
	Sets the timer as if it was woken up by a trigger(), even if it was never started.
Public Member Functions inherited from Executable
void	test_deletion ()
void	notify () override
	Crashes the program – everyone who is expecting notify calls must override this function.
virtual void	alloc_result (QMember *item)
	Return the result of an alloc_async() from a memory Pool.
Public Member Functions inherited from QMember
void	init ()
	Initiailize a QMember, in place of a public placement construction.

Private Member Functions
long long	timeout () override
	Callback from the timer infrastructure. Called periodically.

Private Attributes
uint16_t	updateDelayMsec_
	cooldown delay in msec
uint8_t	bucket_
	number of available tokens
uint8_t	bucketMax_: 7
	maximum number of tokens in the bucket
uint8_t	needUpdate_: 1
	if non-zero, wake up parent when token is available.
std::function< void()>	callback_
	callback after cooldown period.

Additional Inherited Members
Public Types inherited from Timer
enum	{ NONE = 0 , RESTART = 1 , DELETE = -1 }
	Special return values from the timeout function. More...
Protected Member Functions inherited from Timer
void	update_period (long long period)
	Updates the period, to be used after the next expiration of the timer in order to restart it.
Protected Member Functions inherited from QMember
	QMember ()
	Constructor.
	~QMember ()
	Destructor.
Protected Attributes inherited from QMember
QMember *	next
	pointer to the next member in the queue

Detailed Description

This timer takes care of limiting the number of speed updates we send out in a second.

It is a token bucket filter.

Definition at line 45 of file LimitTimer.hxx.

Constructor & Destructor Documentation

LimitTimer()

LimitTimer::LimitTimer ( ExecutorBase *  ex, uint16_t  update_delay_msec, uint8_t  max_tokens, std::function< void()>  callback  )

inline

Constructor.

Parameters

ex	executor to run on
update_delay_msec	cooldown time delay in milliseconds
max_tokens	number of available tokens, <= 127 max
callback	callback called once after cooldown time delay

Definition at line 53 of file LimitTimer.hxx.

~LimitTimer()

LimitTimer::~LimitTimer ( )

inline

Destructor.

Definition at line 66 of file LimitTimer.hxx.

Member Function Documentation

take_no_callback()

void LimitTimer::take_no_callback ( )

inline

Takes one entry from the bucket, and does not give a callback if there is no entry left.

Must be called from the same executor that was passed in the object construction.

Definition at line 97 of file LimitTimer.hxx.

timeout()

long long LimitTimer::timeout ( )

inlineoverrideprivatevirtual

Callback from the timer infrastructure. Called periodically.

Implements Timer.

Definition at line 107 of file LimitTimer.hxx.

try_take()

bool LimitTimer::try_take ( )

inline

Attempts to take a token out of the bucket.

Must be called from the same executor that was passed in the object construction.

Returns

true if the take is successful, false if there are no available tokens, in which case there will be a callback generated when tokens become available.

Definition at line 76 of file LimitTimer.hxx.

Member Data Documentation

bucket_

uint8_t LimitTimer::bucket_

private

number of available tokens

Definition at line 129 of file LimitTimer.hxx.

bucketMax_

uint8_t LimitTimer::bucketMax_

private

maximum number of tokens in the bucket

Definition at line 132 of file LimitTimer.hxx.

callback_

std::function<void()> LimitTimer::callback_

private

callback after cooldown period.

Definition at line 138 of file LimitTimer.hxx.

needUpdate_

uint8_t LimitTimer::needUpdate_

private

if non-zero, wake up parent when token is available.

Definition at line 135 of file LimitTimer.hxx.

updateDelayMsec_

uint16_t LimitTimer::updateDelayMsec_

private

cooldown delay in msec

Definition at line 126 of file LimitTimer.hxx.

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

• LimitTimer.hxx