TNL::Timer Class Reference

Class for real time, CPU time and CPU cycles measuring. More...

#include <TNL/Timer.h>

Public Member Functions
	Timer ()
	Basic constructor creating a new timer and resets it.
double	getCPUTime () const
	Returns the elapsed CPU time on this timer.
double	getRealTime () const
	Returns the elapsed real time on this timer.
void	reset ()
	Reset the CPU and real-time timers.
void	start ()
	Starts timer.
void	stop ()
	Stops (pauses) the CPU and the real-time timers, but does not set them to zero.
bool	writeLog (Logger &logger, int logLevel=0) const
	Writes a record into the logger.

Protected Types
using	Duration = typename std::chrono::high_resolution_clock::duration
using	TimePoint = typename std::chrono::high_resolution_clock::time_point

Static Protected Member Functions
static double	durationToDouble (const Duration &duration)
	Converts the real time into seconds as a floating point number.
static double	readCPUTime ()
	Function for measuring the CPU time.
static TimePoint	readRealTime ()
	Function for measuring the real time.

Protected Attributes
double	initialCPUTime
TimePoint	initialRealTime
bool	stopState
double	totalCPUTime
Duration	totalRealTime

Detailed Description

Class for real time, CPU time and CPU cycles measuring.

It measures the elapsed real time and CPU time (in seconds) elapsed on the timer. The timer can be paused by calling stop and start methods and reset by calling reset.

Example

#include <iostream>
#include <chrono>
#include <thread>
 
#include <TNL/Timer.h>
 
int
main()
{
   const int milliseconds = 0.5e3;
   TNL::Timer time;
   time.start();
   std::this_thread::sleep_for( std::chrono::milliseconds( milliseconds ) );
   time.stop();
 
   std::cout << "Elapsed real time: " << time.getRealTime() << std::endl;
   std::cout << "Elapsed CPU time: " << time.getCPUTime() << std::endl;
   time.reset();
   std::cout << "Real time after reset:" << time.getRealTime() << std::endl;
   std::cout << "CPU time after reset: " << time.getCPUTime() << std::endl;
}

Output

Elapsed real time: 0.500074
Elapsed CPU time: 1.5e-05
Real time after reset:0
CPU time after reset: 0

Member Function Documentation

getCPUTime()

double TNL::Timer::getCPUTime ( ) const

nodiscard

Returns the elapsed CPU time on this timer.

This method returns the CPU time (i.e. time the CPU spent by processing this process) elapsed so far (in seconds). This method can be called while the timer is running, there is no need to use stop method first.

getRealTime()

double TNL::Timer::getRealTime ( ) const

nodiscard

Returns the elapsed real time on this timer.

This method returns the real time elapsed so far (in seconds). This method can be called while the timer is running, there is no need to use stop method first.

start()

void TNL::Timer::start

(

)

Starts timer.

Starts the CPU and real-time timers. This method can be used also after using the stop method. The timer then continues measuring the time without resetting.

writeLog()

bool TNL::Timer::writeLog	(	Logger &	logger,
		int	logLevel = 0 ) const

Writes a record into the logger.

Parameters

logger	Name of Logger object.
logLevel	A non-negative integer recording the log record indent.

Example

#include <iostream>
#include <chrono>
#include <thread>
 
#include <TNL/Timer.h>
#include <TNL/Logger.h>
 
int
main()
{
   const int milliseconds = 0.5e3;
   TNL::Timer time;
   time.start();
   std::this_thread::sleep_for( std::chrono::milliseconds( milliseconds ) );
   time.stop();
 
   TNL::Logger logger( 50, std::cout );
   time.writeLog( logger, 0 );
}

Output

| Real time:                             0.501511 |
| CPU time:                               1.7e-05 |

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

• src/TNL/Timer.h