sas::Clock Class Reference

Clock utility for timing and statistics in control loops. More...

#include <sas_clock.hpp>

Inheritance diagram for sas::Clock:

Public Types
enum class	TimeType { Computational , EffectiveSampling , Idle }
	Enumeration of time types, see get_time() and get_statistics(). More...

Public Member Functions
	Clock (const int &)=delete
	Clock (const double &sampling_time_in_seconds, const bool &enable_statistics=true)
	Construct a Clock.
void	init ()
	Initialize the clock internal state and timers.
void	update_and_sleep ()
	Update internal timing measurements and sleep to respect target sampling time.
double	get_elapsed_time_sec () const
	Get elapsed time since last update in seconds.
std::chrono::time_point< std::chrono::system_clock, std::chrono::nanoseconds >	get_initial_time () const
	Get the initial time point recorded by the clock.
std::chrono::time_point< std::chrono::system_clock, std::chrono::nanoseconds >	get_last_update_time () const
	Get the time point of the last update.
void	safe_sleep_seconds (const double &seconds, std::atomic_bool *break_loop)
	Sleep for the specified duration while allowing early exit via break_loop.
void	blocking_sleep_seconds (const double &seconds)
	Block the calling thread for the specified duration (no early exit).
double	get_desired_thread_sampling_time_sec () const
	Return the desired sampling time for the thread in seconds.
long	get_overrun_count () const
	Return the number of times the sampling has overrun the target period.
double	get_time (const TimeType &time_type) const
	Get a time value for the provided TimeType.
double	get_statistics (const Statistics &statistics, const TimeType &time_type) const
	Get a statistic value for the given statistic type and TimeType.
double	get_computation_time () const
	Deprecated.
double	get_sleep_time () const
double	get_effective_thread_sampling_time_sec () const

Detailed Description

Clock utility for timing and statistics in control loops.

Member Enumeration Documentation

TimeType

enum class sas::Clock::TimeType

strong

Enumeration of time types, see get_time() and get_statistics().

Enumerator
Computational	Time spent between when the instant the previous sleep ended and the instant when the current one started.
EffectiveSampling	The effective sampling time between sleeps (EffectiveSampling = Computational + Idle).
Idle	Time spent between the instant when the previous sleep started and the instant when it ended.

Constructor & Destructor Documentation

Clock()

sas::Clock::Clock ( const double & sampling_time_in_seconds, const bool & enable_statistics = true )

explicit

Construct a Clock.

Parameters

sampling_time_in_seconds	Desired sampling time in seconds
enable_statistics	Whether to enable internal statistics collection (default: true)

Member Function Documentation

blocking_sleep_seconds()

void sas::Clock::blocking_sleep_seconds

(

const double &

seconds

)

Block the calling thread for the specified duration (no early exit).

Parameters

seconds

Sleep duration in seconds

get_desired_thread_sampling_time_sec()

double sas::Clock::get_desired_thread_sampling_time_sec

(

)

const

Return the desired sampling time for the thread in seconds.

Returns

Desired sampling time in seconds

get_elapsed_time_sec()

double sas::Clock::get_elapsed_time_sec

(

)

const

Get elapsed time since last update in seconds.

Returns

Elapsed time in seconds

get_initial_time()

std::chrono::time_point< std::chrono::system_clock, std::chrono::nanoseconds > sas::Clock::get_initial_time

(

)

const

Get the initial time point recorded by the clock.

Returns

time_point of the initial time

get_last_update_time()

std::chrono::time_point< std::chrono::system_clock, std::chrono::nanoseconds > sas::Clock::get_last_update_time

(

)

const

Get the time point of the last update.

Returns

time_point of the last update

get_overrun_count()

long sas::Clock::get_overrun_count

(

)

const

Return the number of times the sampling has overrun the target period.

Returns

Overrun count

get_statistics()

double sas::Clock::get_statistics	(	const Statistics &	statistics,
		const TimeType &	time_type ) const

Get a statistic value for the given statistic type and TimeType.

Parameters

statistics	The statistic to query (see sas::Statistics)
time_type	The TimeType to which the statistic applies

Returns

The requested statistic value as a double

Exceptions

std::runtime_error

if statistics collection was not enabled at construction or if the requested statistic is not available for the provided TimeType.

get_time()

double sas::Clock::get_time

(

const TimeType &

time_type

)

const

Get a time value for the provided TimeType.

Parameters

time_type

The TimeType (Computational, EffectiveSampling, Idle)

Returns

Time value in seconds corresponding to time_type

safe_sleep_seconds()

void sas::Clock::safe_sleep_seconds	(	const double &	seconds,
		std::atomic_bool *	break_loop )

Sleep for the specified duration while allowing early exit via break_loop.

Parameters

seconds	Sleep duration in seconds
break_loop	Pointer to an atomic boolean that will interrupt the sleep if set

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

• src/sas_core/include/sas_core/sas_clock.hpp
• src/sas_core/src/sas_clock.cpp