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©Copyright 1996 Rogue Wave Software

RWTimer

• Synopsis
• Description
• Persistence
• Example
• Public Constructor
• Public Member Functions

#include <rw/timer.h>

RWTimer timer;

This class can measure elapsed CPU (user) time. The timer has two states: running and stopped. The timer measures the total amount of time spent in the "running" state since it was either constructed or reset.

The timer is put into the "running" state by calling member function start(). It is put into the "stopped" state by calling stop().

RWTimer uses the system-dpendent function clock() which returns the number of "ticks" since it was first called. As a result, RWTimer will not be able to measure intervals longer than some system-dependent value. (For instance, on several common UNIX systems, this value is just under 36 minutes.)

None

This example prints out the amount of CPU time used while looping for 5 seconds (as measured using class RWTime).

#include <rw/timer.h>

#include <rw/rwtime.h>
#include <rw/rstream.h>

main()
{RWTimer t;
 t.start();                 // Start the timer

 RWTime start;
 start.now();               // Record starting time

 // Loop for 5 seconds:
 for (RWTime current; current.seconds() - start.seconds() < 5;
      current = RWTime::now())
 {;}

 t.stop();                  // Stop the timer

 cout << t.elapsedTime() << endl;
 return 0;
}
 

Program output (exact value may differ):

5.054945

RWTimer();

Constructs a new timer. The timer will not start running until start() is called.

double
elapsedTime() const;

Returns the amount of (CPU) time that has accumulated while the timer was in the running state.

void
reset();

Resets (and stops) the timer.

void
start();

Puts the timer in the "running" state. Time accumulates while in this state.

void
stop();

Puts the timer in the "stopped" state. Time will not accumulate while in this state.