gul14/time_util.h

Detailed Description

Time-related functions.

Functions
std::chrono::steady_clock::time_point	gul14::tic ()
	Return the current time as a std::chrono time_point. More...
template<class TimeUnitType = std::chrono::duration<double>>
auto	gul14::toc (std::chrono::steady_clock::time_point t0)
	Return the elapsed time in seconds (or a different unit) since the given time point. More...
template<class Rep , class Period >
bool	gul14::sleep (const std::chrono::duration< Rep, Period > &duration, const Trigger &trg)
	Sleep for at least the given time span, with the option of being woken up from another thread. More...
bool	gul14::sleep (double seconds, const Trigger &trg)
	Sleep for a given number of seconds, with the option of being woken up from another thread. More...
template<class Rep , class Period >
bool	gul14::sleep (const std::chrono::duration< Rep, Period > &duration)
	Sleep for a given time span. More...
bool	gul14::sleep (double seconds)
	Sleep for a given number of seconds. More...

Function Documentation

sleep() [1/4]

template<class Rep , class Period >

bool gul14::sleep

(

const std::chrono::duration< Rep, Period > &

duration

)

Sleep for a given time span.

This is equivalent to a call of std::this_thread::sleep_for(), which means that control is handed back to the operating system's task scheduler. This may result in a somewhat bigger effective delay than expected, especially where very small sleep times are requested and the system load is high.

Example:

using namespace std::literals; // for the "ms" suffix
sleep(50ms); // Wait 50 milliseconds

Parameters

duration

Time span to wait, as a std::chrono::duration type.

Returns

true to signalize that the entire requested sleep duration has passed. This is for symmetry with the interruptible version of sleep() only.

sleep() [2/4]

template<class Rep , class Period >

bool gul14::sleep	(	const std::chrono::duration< Rep, Period > &	duration,
		const Trigger &	trg
	)

Sleep for at least the given time span, with the option of being woken up from another thread.

The sleep can be interrupted from another thread via a shared Trigger object.

Calling sleep() may lead to a context switch of the operation system. Under heavy load or resource contention, this can produce a delay that is longer than expected.

Parameters

duration	Time span to wait, as a std::chrono::duration type.
trg	Reference to a SleepInterrupt object that can be used to interrupt the delay. If such an interruption occurs, false is returned.

Returns

true if the entire requested sleep duration has passed, or false if the sleep has been interrupted prematurely via the Trigger object.

See also

Trigger

Examples

thread_pool.cc.

References gul14::Trigger::wait_for().

Referenced by gul14::sleep().

sleep() [3/4]

bool gul14::sleep ( double  seconds )

inline

Sleep for a given number of seconds.

This is equivalent to a call of std::this_thread::sleep_for(), which means that control is handed back to the operating system's task scheduler. This may result in a somewhat bigger effective delay than expected, especially where very small sleep times are requested and the system load is high.

Example:

sleep(0.05); // Wait 50 milliseconds

Parameters

seconds

Seconds to wait.

Returns

true to signalize that the entire requested sleep duration has passed. This is for symmetry with the interruptible version of sleep() only.

References gul14::sleep().

sleep() [4/4]

bool gul14::sleep ( double  seconds, const Trigger &  trg  )

inline

Sleep for a given number of seconds, with the option of being woken up from another thread.

The sleep can be interrupted from another thread via a shared Trigger object.

Calling sleep() may lead to a context switch of the operation system. Under heavy load or resource contention, this can produce a delay that is longer than expected.

Parameters

seconds	Seconds to wait.
trg	Reference to a SleepInterrupt object that can be used to interrupt the delay. If such an interruption occurs, false is returned.

Returns

true if the entire requested sleep duration has passed, or false if the sleep has been interrupted prematurely via the Trigger object.

See also

Trigger

References gul14::sleep().

tic()

std::chrono::steady_clock::time_point gul14::tic ( )

inline

Return the current time as a std::chrono time_point.

This function is intended to be used with the sister function toc() to measure elapsed time.

Example

auto t0 = tic();
// Do some work
std::cout << "Elapsed time: " << toc(t0) << " seconds.\n";

See also

toc()

Referenced by gul14::toc().

toc()

template<class TimeUnitType = std::chrono::duration<double>>

auto gul14::toc

(

std::chrono::steady_clock::time_point

t0

)

Return the elapsed time in seconds (or a different unit) since the given time point.

This function is intended to be used with the sister function tic() to measure elapsed time. toc() is a function template that returns the elapsed seconds as a double value by default; by specifying a different chrono type as a template parameter, it can also return other time units and other types.

Example

auto t0 = tic();
 
// <do some work>
 
// Default: Return seconds as a double
std::cout << "Elapsed time: " << toc(t0) << " seconds.\n";
 
// Custom type: Return milliseconds as an integer
std::cout << "Elapsed time: " << toc<std::chrono::milliseconds>(t0) << " milliseconds.\n";

Template Parameters

TimeUnitType

The type to be used for calculating the elapsed time since t0. By default, this is std::chrono::duration<double>, which means that the elapsed time is returned as a double that represents seconds.

Parameters

t0	A time point in the past that should be taken with tic().

Returns

the elapsed time in the units and base representation of TimeUnitType. By default, this is a double that represents elapsed seconds. For a TimeUnitType of std::chrono::milliseconds, it would be an integer representing elapsed milliseconds.

See also

tic()

References gul14::tic().