Timer Class Reference

Records elasped wall time between two events. More...

#include <timer.h>

Public Member Functions
	Timer ()
	constructor for Timer
	~Timer ()
	Destructor for Timer.
void	start ()
	Starts the timer.
void	stop ()
	Stops the timer.
double	elapsed () const
	Returns the elapsed time in seconds.

Static Protected Member Functions
static double	get_wall_time ()
	Returns the wall time since the epoch.

Protected Attributes
double	start_time
double	stop_time

Detailed Description

Records elasped wall time between two events.

The measured time is the wall time, not the process time of the CPU.

Example:

Timer timer;
timer.start();

// Some CPU threads here.
// ...

// Note, this Time measures wall time, so the sleep() time
// counts toward the measured time.
sleep(1);

timer.stop();
double elapsed_time = timer.elapsed();

Note

The start and stop time variables inside this class must be declared as double, and not float to have enough precision for the subtraction of stop minus start time. However, the elapsed time outside of this class can be declared as float.

See also

CudaTimer

Definition at line 49 of file timer.h.

Constructor & Destructor Documentation

Timer()

Timer::Timer

(

)

constructor for Timer

Definition at line 40 of file timer.cpp.

            :
    start_time(0),
    stop_time(0)
{
}

~Timer()

Timer::~Timer

(

)

Destructor for Timer.

Definition at line 54 of file timer.cpp.

{
}

Member Function Documentation

elapsed()

double Timer::elapsed

(

)

const

Returns the elapsed time in seconds.

Definition at line 92 of file timer.cpp.

{
    return this->stop_time - this->start_time;
}

References start_time, and stop_time.

Referenced by cTraceEstimator< DataType >::c_trace_estimator().

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get_wall_time()

double Timer::get_wall_time ( )

staticprotected

Returns the wall time since the epoch.

Definition at line 105 of file timer.cpp.

{
    #if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && \
            !defined(__CYGWIN__)
 
        LARGE_INTEGER time, freq;
        if (!QueryPerformanceFrequency(&freq))
        {
            std::runtime_error("Cannot obtain system's time frequency.");
            return NAN;
        }
 
        if (!QueryPerformanceCounter(&time))
        {
            std::runtime_error("Cannot obtain elapsed time.");
            return NAN;
        }
 
        return static_cast<double>(time.QuadPart) / \
               static_cast<double>(freq.QuadPart);
 
    #elif defined(__unix__) || defined(__unix) || \
        (defined(__APPLE__) && defined(__MACH__))
 
        struct timeval time;
        if (gettimeofday(&time, NULL))
        {
            std::runtime_error("Cannot obtain elapsed time.");
            return NAN;
        }
 
        return static_cast<double>(time.tv_sec) + \
               static_cast<double>(time.tv_usec) * 1e-6;
 
    #else
            #error "Unknown compiler"
    #endif
}

Referenced by start(), and stop().

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start()

void Timer::start

(

)

Starts the timer.

Definition at line 66 of file timer.cpp.

{
    this->start_time = Timer::get_wall_time();
}

References get_wall_time(), and start_time.

Referenced by cTraceEstimator< DataType >::c_trace_estimator().

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stop()

void Timer::stop

(

)

Stops the timer.

Definition at line 79 of file timer.cpp.

{
    this->stop_time = Timer::get_wall_time();
}

References get_wall_time(), and stop_time.

Referenced by cTraceEstimator< DataType >::c_trace_estimator().

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Member Data Documentation

start_time

double Timer::start_time

protected

Definition at line 64 of file timer.h.

Referenced by elapsed(), and start().

stop_time

double Timer::stop_time

protected

Definition at line 65 of file timer.h.

Referenced by elapsed(), and stop().

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

• /home/runner/work/imate/imate/imate/_utilities/timer.h
• /home/runner/work/imate/imate/imate/_utilities/timer.cpp