walberla::timing::Timer< TP > Class Template Reference

Detailed Description

template<typename TP>
class walberla::timing::Timer< TP >

Progress timer for time and performance measurements.

The Timer class offers timing & benchmarking functionality for all kinds of applications. The following example code demonstrates the use of the WcTimer class, which combines the Timer class template with the WcPolicy for wall clock time measurements, for a single time measurement:

// Creating a new wall clock timer immediately starts a new time measurement
WcTimer timer;
 
...  // program or code fragment to be measured
 
// Stopping the time measurement
timer.end();
 
// Evaluation of the measured time
double time = timer.last();

The timer class additionally offers the functionality to start several time measurements in order to evaluate minimal, maximal or average times. The next example demonstrates a possible setup for such a series of time measurements:

// Creating a new wall clock timer
WcTimer timer;
 
...  // Additional setup code
 
// Starting 10 wall clock time measurements
for( unsigned int i=0; i<10; ++i ) {
   timer.start();
   ...  // program or code fragment to be measured
   timer.end();
}
 
// After the measurements, the desired timing results can be calculated, as for instance the
// average wall clock time
double average = timer.average();

#include <Timer.h>

Public Types
using	TimingPolicy = TP
	Timing policy of the Timer. More...

Public Member Functions
Constructor
	Timer ()
	Constructor of the Timer class. More...
	Timer (uint_t counter, double min, double max, double total, double sumOfSquares)
	Constructor of the Timer class. More...
Timing functions
void	start ()
	Starting a single time measurement. More...
void	end ()
	Ending a single time measurement. More...
void	reset ()
	Resetting the timer. More...
Get functions
uint_t	getCounter () const
	Returns the total number of time measurements performed by this timer. More...
Time evaluation functions
double	total () const
	Returns the total elapsed time of all performed time measurements. More...
double	sumOfSquares () const
	Returns the sum of each (time measurement)^2. More...
double	average () const
	Returns the average time of all performed time measurements. More...
double	variance () const
	Returns the variance of all performed time measurements. More...
double	min () const
	Returns the minimal time of all performed time measurements. More...
double	max () const
	Returns the maximal time of all performed time measurements. More...
double	last () const
	Returns the last measured time. More...

Friends
template<typename T , typename G , typename TP2 >
mpi::GenericSendBuffer< T, G > &	operator<< (mpi::GenericSendBuffer< T, G > &buf, const Timer< TP2 > &t)
template<typename T , typename TP2 >
mpi::GenericRecvBuffer< T > &	operator>> (mpi::GenericRecvBuffer< T > &buf, Timer< TP2 > &t)

Related Functions
(Note that these are not member functions.)
template<typename TP >
void	to_json (nlohmann::json &j, const Timer< TP > &timer)
	Converts timer to json The signature is required by the json library. More...

Utility functions for Timers
uint_t	counter_
	Number of performed time measurements. More...
double	start_
	Start of the current time measurement. More...
double	end_
	End of the current time measurement. More...
double	time_
	The total elapsed time of all measurements. More...
double	sumOfSquares_
	Sum of each (time measurement)^2. More...
double	min_
	The minimal time of all measurements. More...
double	max_
	The maximal time of all measurements. More...
double	last_
	The last measured time. More...
void	merge (const Timer &other)
	Adds results of an other Timer to own results. More...

Member Typedef Documentation

TimingPolicy

template<typename TP >

using walberla::timing::Timer< TP >::TimingPolicy = TP

Timing policy of the Timer.

Constructor & Destructor Documentation

Timer() [1/2]

template<typename TP >

walberla::timing::Timer< TP >::Timer

inlineexplicit

Constructor of the Timer class.

The creation of a new timer immediately starts a new time measurement. It is possible to either restart the time measurement at a specific point of time or to continue the time measurement and to end it via the end() function.

Timer() [2/2]

template<typename TP >

walberla::timing::Timer< TP >::Timer ( uint_t  _counter, double  _min, double  _max, double  _total, double  _sumOfSquares  )

inlineexplicit

Constructor of the Timer class.

Initializes the timer with

Parameters

_counter	number of timing measurements already done
_min	the minimum time of the measurements
_max	the maximum time of the measurements
_total	the total time of all measurements
_sumOfSquares	each measurement time squared, then summed

Member Function Documentation

average()

template<typename TP >

double walberla::timing::Timer< TP >::average

inline

Returns the average time of all performed time measurements.

Returns

The average time.

end()

template<typename TP >

void walberla::timing::Timer< TP >::end

inline

Ending a single time measurement.

Returns

void

This function ends the currently running time measurement and performs the necessary statistical calculations.

getCounter()

template<typename TP >

uint_t walberla::timing::Timer< TP >::getCounter

inline

Returns the total number of time measurements performed by this timer.

Returns

The number of performed time measurements.

last()

template<typename TP >

double walberla::timing::Timer< TP >::last

inline

Returns the last measured time.

Returns

The last measured time.

max()

template<typename TP >

double walberla::timing::Timer< TP >::max

inline

Returns the maximal time of all performed time measurements.

Returns

The maximal time.

merge()

template<typename TP >

void walberla::timing::Timer< TP >::merge ( const Timer< TP > &  other )

inline

Adds results of an other Timer to own results.

min()

template<typename TP >

double walberla::timing::Timer< TP >::min

inline

Returns the minimal time of all performed time measurements.

Returns

The minimal time.

reset()

template<typename TP >

void walberla::timing::Timer< TP >::reset

inline

Resetting the timer.

Returns

void

This function completely resets the timer and all information on the performed time measurements. In order to start a new time measurement, the start() function has to be used.

start()

template<typename TP >

void walberla::timing::Timer< TP >::start

inline

Starting a single time measurement.

Returns

void

This function starts a single time measurement.

sumOfSquares()

template<typename TP >

double walberla::timing::Timer< TP >::sumOfSquares

inline

Returns the sum of each (time measurement)^2.

Can be used to calculate the variance using the formula Var(x) = 1/N * ( E(x^2) - E(x)^2)

Returns

sum of each (time measurement)^2

total()

template<typename TP >

double walberla::timing::Timer< TP >::total

inline

Returns the total elapsed time of all performed time measurements.

Returns

The total elapsed time of all time measurements.

variance()

template<typename TP >

double walberla::timing::Timer< TP >::variance

inline

Returns the variance of all performed time measurements.

Returns

The variance 1/N * ( E(x^2) - E(x)^2 ) where E is the expectation or average value

Friends And Related Function Documentation

operator<<

template<typename TP >

template<typename T , typename G , typename TP2 >

mpi::GenericSendBuffer<T,G>& operator<< ( mpi::GenericSendBuffer< T, G > &  buf, const Timer< TP2 > &  t  )

friend

operator>>

template<typename TP >

template<typename T , typename TP2 >

mpi::GenericRecvBuffer<T>& operator>> ( mpi::GenericRecvBuffer< T > &  buf, Timer< TP2 > &  t  )

friend

to_json()

template<typename TP >

void to_json ( nlohmann::json &  j, const Timer< TP > &  timer  )

related

Converts timer to json The signature is required by the json library.

Member Data Documentation

counter_

template<typename TP >

uint_t walberla::timing::Timer< TP >::counter_

private

Number of performed time measurements.

end_

template<typename TP >

double walberla::timing::Timer< TP >::end_

private

End of the current time measurement.

last_

template<typename TP >

double walberla::timing::Timer< TP >::last_

private

The last measured time.

max_

template<typename TP >

double walberla::timing::Timer< TP >::max_

private

The maximal time of all measurements.

min_

template<typename TP >

double walberla::timing::Timer< TP >::min_

private

The minimal time of all measurements.

start_

template<typename TP >

double walberla::timing::Timer< TP >::start_

private

Start of the current time measurement.

sumOfSquares_

template<typename TP >

double walberla::timing::Timer< TP >::sumOfSquares_

private

Sum of each (time measurement)^2.

time_

template<typename TP >

double walberla::timing::Timer< TP >::time_

private

The total elapsed time of all measurements.

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

• /builds/administration/walberla-website/walberla/src/core/timing/Timer.h
• /builds/administration/walberla-website/walberla/src/core/timing/TimingJSON.h