alexaClientSDK::avsCommon::utils::timing::Timer Class Reference

#include <Timer.h>

Public Types
enum	PeriodType { PeriodType::ABSOLUTE, PeriodType::RELATIVE }
	Specifies different ways to apply the period of a recurring task. More...

Public Member Functions
	Timer (std::shared_ptr< sdkInterfaces::timing::TimerDelegateFactoryInterface > timerDelegateFactory=avs::initialization::SDKPrimitivesProvider::getInstance() ->getTimerDelegateFactory())
	~Timer ()
template<typename Rep , typename Period , typename Task , typename... Args>
bool	start (const std::chrono::duration< Rep, Period > &delay, const std::chrono::duration< Rep, Period > &period, PeriodType periodType, size_t maxCount, Task task, Args &&... args)
template<typename Rep , typename Period , typename Task , typename... Args>
bool	start (const std::chrono::duration< Rep, Period > &period, PeriodType periodType, size_t maxCount, Task task, Args &&... args)
template<typename Rep , typename Period , typename Task , typename... Args>
auto	start (const std::chrono::duration< Rep, Period > &delay, Task task, Args &&... args) -> std::future< decltype(task(args...))>
void	stop ()
bool	isActive () const

Static Public Member Functions
static size_t	getForever ()
	Static member function to get FOREVER. More...
static std::string	getTag ()
	Static member function to get TAG. More...

Static Public Attributes
static const size_t	FOREVER = 0

Detailed Description

A Timer is used to schedule a callable type to run in the future.

Member Enumeration Documentation

PeriodType

enum alexaClientSDK::avsCommon::utils::timing::Timer::PeriodType

strong

Specifies different ways to apply the period of a recurring task.

Enumerator
ABSOLUTE	The period specifies the time from the start of one task call to the start of the next task call. This period type ensures task calls occur on a predictable cadence. Note A timer makes one task call at a time, so if a task call takes more than one period to execute, the subsequent calls which would have occured while the task was still executing will be skipped, and the next call will not occur until the next period-multiple after the original task call completes.
RELATIVE	The period specifies the time from the end of one task call to the start of the next task call. This period type ensures a specific amount of idle time between task calls.

Constructor & Destructor Documentation

Timer()

alexaClientSDK::avsCommon::utils::timing::Timer::Timer

(

std::shared_ptr< sdkInterfaces::timing::TimerDelegateFactoryInterface >

timerDelegateFactory = avs::initialization::SDKPrimitivesProvider::getInstance()->getTimerDelegateFactory()

)

Contructs a Timer.

Parameters

timerDelegateFactory

A factory to create the TimerDelegate.

~Timer()

alexaClientSDK::avsCommon::utils::timing::Timer::~Timer

(

)

Destructs a Timer.

Member Function Documentation

getForever()

static size_t alexaClientSDK::avsCommon::utils::timing::Timer::getForever ( )

inlinestatic

Static member function to get FOREVER.

getTag()

static std::string alexaClientSDK::avsCommon::utils::timing::Timer::getTag ( )

inlinestatic

Static member function to get TAG.

isActive()

bool alexaClientSDK::avsCommon::utils::timing::Timer::isActive

(

)

const

Reports whether the Timer is active. A timer is considered active if it is waiting to start a call to the task, or if a call to the task is in progress. A timer is only considered inactive if it has not been started, if all requested/scheduled calls to the task have completed, or after a call to stop().

Returns

true if the Timer is active, else false.

start() [1/3]

template<typename Rep , typename Period , typename Task , typename... Args>

bool alexaClientSDK::avsCommon::utils::timing::Timer::start	(	const std::chrono::duration< Rep, Period > &	delay,
		const std::chrono::duration< Rep, Period > &	period,
		PeriodType	periodType,
		size_t	maxCount,
		Task	task,
		Args &&...	args
	)

Submits a callable type (function, lambda expression, bind expression, or another function object) to be executed after an initial delay, and then called repeatedly on a fixed time schedule. A Timer instance manages only one running Timer at a time; calling start() on an already-running Timer will fail. Note that the template parameters are typically inferred from the function paramters when calling start().

Template Parameters

Rep	A type for measuring 'ticks' in a generic std::chrono::duration.
Period	A type for representing the number of ticks per second in a generic std::chrono::duration.
Task	The type of task to execute.
Args	The argument types for the task to execute.

Parameters

delay	The non-negative time to wait before making the first task call. Negative values will cause this function to return false.
period	The non-negative time to wait between subsequent task calls. Negative values will cause this function to return false.
periodType	The type of period to use when making subsequent task calls.
maxCount	The desired number of times to call task. Timer::getForever() means to call forever until stop() is called. Note that fewer than maxCount calls may occur if periodType is PeriodType::ABSOLUTE and the task runtime exceeds period.
task	A callable type representing a task.
args	The arguments to call the task with.

Returns

true if the timer started, else false.

start() [2/3]

template<typename Rep , typename Period , typename Task , typename... Args>

auto alexaClientSDK::avsCommon::utils::timing::Timer::start	(	const std::chrono::duration< Rep, Period > &	delay,
		Task	task,
		Args &&...	args
	)		-> std::future<decltype(task(args...))>

Submits a callable type (function, lambda expression, bind expression, or another function object) to be executed once, after the specified duration. A Timer instance manages only one running Timer at a time; calling start() on an already-running Timer will fail. Note that the template parameters are typically inferred from the function paramters when calling start().

Template Parameters

Rep	A type for measuring 'ticks' in a generic std::chrono::duration.
Period	A type for representing the number of ticks per second in a generic std::chrono::duration.
Task	The type of task to execute.
Args	The argument types for the task to execute.

Parameters

delay	The non-negative time to wait before calling task. Negative values will cause this function to return an invalid future.
task	A callable type representing a task.
args	The arguments to call task with.

Returns

A valid std::future for the return value of task if the timer started, else an invalid std::future. Note that the promise will be broken if stop() is called before task is called.

start() [3/3]

template<typename Rep , typename Period , typename Task , typename... Args>

bool alexaClientSDK::avsCommon::utils::timing::Timer::start	(	const std::chrono::duration< Rep, Period > &	period,
		PeriodType	periodType,
		size_t	maxCount,
		Task	task,
		Args &&...	args
	)

Submits a callable type (function, lambda expression, bind expression, or another function object) to be executed repeatedly on a fixed time schedule. A Timer instance manages only one running Timer at a time; calling start() on an already-running Timer will fail. Note that the template parameters are typically inferred from the function paramters when calling start().

Template Parameters

Rep	A type for measuring 'ticks' in a generic std::chrono::duration.
Period	A type for representing the number of ticks per second in a generic std::chrono::duration.
Task	The type of task to execute.
Args	The argument types for the task to execute.

Parameters

period	The non-negative time to wait before each task call. Negative values will cause this function to return false.
periodType	The type of period to use when making subsequent task calls.
maxCount	The desired number of times to call task. Timer::getForever() means to call forever until stop() is called. Note that fewer than maxCount calls may occur if periodType is PeriodType::ABSOLUTE and the task runtime exceeds period.
task	A callable type representing a task.
args	The arguments to call task with.

Returns

true if the timer started, else false.

stop()

void alexaClientSDK::avsCommon::utils::timing::Timer::stop

(

)

Stops the Timer (if running). This will not interrupt an active call to the task, but will prevent any subequent calls to the task. If stop() is called while the task is executing, this function will block until the task completes.

Note

In the special case that stop() is called from inside the task function, stop() will still prevent any subsequent calls to the task, but will not block as described above.

Member Data Documentation

FOREVER

const size_t alexaClientSDK::avsCommon::utils::timing::Timer::FOREVER = 0

static

Value for start()'s maxCount parameter which indicates that the Timer should continue firing indefinitely.

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

• /workplace/avs-device-sdk/AVSCommon/Utils/include/AVSCommon/Utils/Timing/Timer.h
• /workplace/avs-device-sdk/AVSCommon/Utils/src/Timer.cpp