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. More...
unsigned long long int	getCPUCycles () const
	Returns the number of CPU cycles (machine cycles) elapsed on this timer. More...
double	getCPUTime () const
	Returns the elapsed CPU time on this timer. More...
double	getRealTime () const
	Returns the elapsed real time on this timer. More...
void	reset ()
	Resets timer. More...
void	start ()
	Starts timer. More...
void	stop ()
	Stops (pauses) the timer. More...
bool	writeLog (Logger &logger, int logLevel=0) const
	Writes a record into the logger. More...

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 unsigned long long	rdtsc ()
	Time Stamp Counter returning number of CPU cycles since reset.
static unsigned long long int	readCPUCycles ()
	Function for counting the number of CPU cycles (machine cycles).
static double	readCPUTime ()
	Function for measuring the CPU time.
static TimePoint	readRealTime ()
	Function for measuring the real time.

Protected Attributes
unsigned long long int	initialCPUCycles
double	initialCPUTime
TimePoint	initialRealTime
bool	stopState
unsigned long long int	totalCPUCycles
double	totalCPUTime
Duration	totalRealTime

Detailed Description

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

It measures the elapsed real time, CPU time (in seconds) and CPU cycles elapsed on the timer. The timer can be paused by calling stop and start methods and reseted 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;
   std::cout << "Elapsed CPU cycles: " << time.getCPUCycles() << std::endl;
   time.reset();
   std::cout << "Real time after reset:" << time.getRealTime() << std::endl;
   std::cout << "CPU time after reset: " << time.getCPUTime() << std::endl;
   std::cout << "CPU cycles after reset: " << time.getCPUCycles() << std::endl;
}

Output

Elapsed real time: 0.5001
Elapsed CPU time: 1.5e-05
Elapsed CPU cycles: 1700288932
Real time after reset:0
CPU time after reset: 0
CPU cycles after reset: 0

Constructor & Destructor Documentation

Timer()

TNL::Timer::Timer ( )

inline

Basic constructor.

This function creates a new timer and resets it.

Member Function Documentation

getCPUCycles()

unsigned long long int TNL::Timer::getCPUCycles ( ) const

inline

Returns the number of CPU cycles (machine cycles) elapsed on this timer.

CPU cycles are counted by adding the number of CPU cycles between start and stop methods together.

getCPUTime()

double TNL::Timer::getCPUTime ( ) const

inline

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

inline

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.

reset()

void TNL::Timer::reset ( )

inline

Resets timer.

Resets all time and cycle measurements such as real time, CPU time and CPU cycles. Sets all of them to zero.

start()

void TNL::Timer::start ( )

inline

Starts timer.

Starts all time and cycle measurements such as real time, CPU time and CPU cycles. This method can be used also after using the stop method. The timer then continues measuring the time without reseting.

stop()

void TNL::Timer::stop ( )

inline

Stops (pauses) the timer.

Pauses all time and cycle measurements such as real time, CPU time and CPU cycles, but does not set them to zero.

writeLog()

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

inline

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:                             0.500071 |
| CPU time:                               1.5e-05 |
| CPU Cycles:                          1700193936 |

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

• src/TNL/Timer.h
• src/TNL/Timer.hpp