A timer that can schedule itself to run on an executor at specified times in the future. More...

#include <Timer.hxx>

Inheritance diagram for Timer:

Public Types
enum	{ NONE = 0 , RESTART = 1 , DELETE = -1 }
	Special return values from the timeout function. More...

Public Member Functions
	Timer (ActiveTimers *timers)
	Constructor.

	~Timer ()
	Destructor.

void	run () override
	Callback from the executor when this timer is scheduled.

virtual long long	timeout ()=0
	Clients of timer should override this function.

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.

Protected Member Functions
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.

Private Member Functions
	DISALLOW_COPY_AND_ASSIGN (Timer)

Private Attributes
ActiveTimers *	activeTimers_
	Points to the executor's timer structure.

unsigned	priority_
	what priority to schedule this timer at

long long	when_
	when in nanoseconds timer should expire

long long	period_
	period in nanoseconds for timer

unsigned	isActive_: 1
	true when the timer is in the active timers list

unsigned	isExpired_: 1
	True when the timer is in the pending executables list of the Executor.

unsigned	isCancelled_: 1
	Was the timer cancelled or did the timer expire regularly? 1 if cancelled or triggered.

unsigned	tcRequestStop_: 1
	For children: 1 if a repeated timer should stop sending wakeups.

Friends
class	ActiveTimers

class	CountingTimer

Additional Inherited Members
Protected Attributes inherited from QMember
QMember *	next
	pointer to the next member in the queue

Detailed Description

A timer that can schedule itself to run on an executor at specified times in the future.

Definition at line 133 of file Timer.hxx.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Special return values from the timeout function.

Enumerator
NONE	Do not restart the timer.
RESTART	Restart the timer with existing period.
DELETE	delete the timer, use with extreme caution

Definition at line 159 of file Timer.hxx.

Constructor & Destructor Documentation

◆ Timer()

Timer::Timer ( ActiveTimers * timers )

inline

Constructor.

Parameters

timers list of active timers from the executor.

Definition at line 139 of file Timer.hxx.

◆ ~Timer()

Timer::~Timer ( )

Destructor.

Definition at line 39 of file Timer.cxx.

Member Function Documentation

◆ cancel()

void Timer::cancel ( )

inline

Dangerous, do not call.

Contains a race condition. Production users should use the trigger() method to cancel an active timer.

Cancels an active timer. Crashes if the timer is expired. Use in unittests only. Does nothing if the timer is not active. Can be called from outside the main executor.

Definition at line 260 of file Timer.hxx.

◆ ensure_triggered()

void Timer::ensure_triggered ( )

inline

Triggers the timer if it is not expired yet.

Definition at line 249 of file Timer.hxx.

◆ is_triggered()

bool Timer::is_triggered ( )

inline

Returns: true if the timer was triggered due to cancel() or trigger(); false if it was timed out.

Definition at line 273 of file Timer.hxx.

◆ restart()

void Timer::restart ( )

inline

Restart a timer with the existing period but from the current time.

This function must be called on the timer executor only. Calling restart on an expired timer has no effect and is ignored.

Todo:: (balazs.racz) assert here that we are on the given executor.

Definition at line 214 of file Timer.hxx.

◆ run()

void Timer::run ( )

overridevirtual

Callback from the executor when this timer is scheduled.

It will call the virtual method timeout().

Implements Executable.

Definition at line 45 of file Timer.cxx.

◆ schedule_time()

long long Timer::schedule_time ( )

inline

Returns: the time when this timer is triggered. This may be in the past, if the timer has just woken up and we are in the timeout() function. It may be in the future if this timer is scheduled. It may be zero if this timer was never scheduled.

Definition at line 175 of file Timer.hxx.

◆ set_triggered()

void Timer::set_triggered ( )

inline

Sets the timer as if it was woken up by a trigger(), even if it was never started.

This is helpful for boundary conditions.

Definition at line 280 of file Timer.hxx.

◆ start()

void Timer::start ( long long period = -1 )

inline

Starts a timer.

The timer must not be active, and neither expired at the time of call.

Parameters

period period in nanoseconds before expiration. If not specified, the timer will expire immediately.

Definition at line 185 of file Timer.hxx.

◆ start_absolute()

void Timer::start_absolute ( long long expiry_time_nsec )

inline

Starts the timer with an absolute deadline.

The timer must not be active, and neither expired at the time of call.

Parameters

expiry_time_nsec absolute time when the timer should expire in nanoseconds. If less than the current time, the timer will expire immediately.

Definition at line 199 of file Timer.hxx.

◆ timeout()

virtual long long Timer::timeout ( )

pure virtual

Clients of timer should override this function.

It will be called on the executor of the timer.

Returns: the new timer period, or one of the above special values.

Implemented in dcc::LogonHandler< Module >::LogonSelect, ExecutorGuard, StateFlowBase::StateFlowTimer, SyncTimeout, MCP23017::RefreshTimer, openlcb::MemoryConfigHandler::RebootTimer, ActivityLed, BufferPort::BufferTimer, ESPWifiClient::BufferTimer, and LimitTimer.

◆ trigger()

void Timer::trigger ( )

inline

This will wakeup the timer prematurely, immediately.

The timer must be active or expired at the time of call. This function must be called on the timer executor only. The timer period remains unchanged in case it is restarted.

Todo:: (balazs.racz) assert here that we are on the given executor.

Definition at line 237 of file Timer.hxx.

◆ update_period()

void Timer::update_period ( long long period )

inlineprotected

Updates the period, to be used after the next expiration of the timer in order to restart it.

Definition at line 288 of file Timer.hxx.

Friends And Related Symbol Documentation

◆ ActiveTimers

friend class ActiveTimers

friend

Definition at line 294 of file Timer.hxx.

◆ CountingTimer

friend class CountingTimer

friend

Definition at line 295 of file Timer.hxx.

Member Data Documentation

◆ activeTimers_

ActiveTimers* Timer::activeTimers_

private

Points to the executor's timer structure.

Not owned.

Definition at line 298 of file Timer.hxx.

◆ isActive_

unsigned Timer::isActive_

private

true when the timer is in the active timers list

Definition at line 306 of file Timer.hxx.

◆ isCancelled_

unsigned Timer::isCancelled_

private

Was the timer cancelled or did the timer expire regularly? 1 if cancelled or triggered.

Definition at line 312 of file Timer.hxx.

◆ isExpired_

unsigned Timer::isExpired_

private

True when the timer is in the pending executables list of the Executor.

Definition at line 309 of file Timer.hxx.

◆ period_

long long Timer::period_

private

period in nanoseconds for timer

Definition at line 304 of file Timer.hxx.

◆ priority_

unsigned Timer::priority_

private

what priority to schedule this timer at

Definition at line 300 of file Timer.hxx.

◆ tcRequestStop_

unsigned Timer::tcRequestStop_

private

For children: 1 if a repeated timer should stop sending wakeups.

Definition at line 314 of file Timer.hxx.

◆ when_

long long Timer::when_

private

when in nanoseconds timer should expire

Definition at line 302 of file Timer.hxx.

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

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ Timer()

◆ ~Timer()

Member Function Documentation

◆ cancel()

◆ ensure_triggered()

◆ is_triggered()

◆ restart()

◆ run()

◆ schedule_time()

◆ set_triggered()

◆ start()

◆ start_absolute()

◆ timeout()

◆ trigger()

◆ update_period()

Friends And Related Symbol Documentation

◆ ActiveTimers

◆ CountingTimer

Member Data Documentation

◆ activeTimers_

◆ isActive_

◆ isCancelled_

◆ isExpired_

◆ period_

◆ priority_

◆ tcRequestStop_

◆ when_