structure
Class Clock

java.lang.Object
  |
  +--structure.Clock

public class Clock

extends Object

A simple object for measuring time. This Clock allows one to measure time between events. Events may be from several milliseconds to several seconds apart. When measuring events that take considerable time (> 1/10th of a second) it is important to counteract the effect of scheduling of other system processes. A Clock has the following operations:

• reset - clear the clock and reset accumulated time to zero
• start - start the clock and accumulate time
• stop - stop the clock (and therefore stop accumulating time)
• read - read a stopped clock to get accumulated time in milliseconds.

typical use:

    Clock timer = new Clock();
    timer.start();
    for (i = 0; i < 100000; i++);
    timer.stop();
    System.out.println("Time to count to 100000: "+timer.read()+" seconds.");
 

Field Summary

protected long	accum The total number of milliseconds elapsed.
protected boolean	running An indication of whether or not the clock is running
protected long	strt The millisecond that the clock started.

Constructor Summary

Clock()
Constructs a stopwatch for timing events to the milliseconds.

Method Summary

double	read() Read the value on the stop watch.
void	reset() Resets the time on the clock to zero.
void	start() Start the clock running.
void	stop() Stop the clock.
String	toString() Generates string representation of clock.

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Field Detail

running

protected boolean running

An indication of whether or not the clock is running

strt

protected long strt

The millisecond that the clock started.

accum

protected long accum

The total number of milliseconds elapsed.

Constructor Detail

Clock

public Clock()

Constructs a stopwatch for timing events to the milliseconds.

Method Detail

start

public void start()

Start the clock running.

Precondition:

starts clock, begins measuring possibly accumulated time

Postcondition:

clock is stopped

stop

public void stop()

Stop the clock. Time does not accumulate.

Precondition:

clock is running

Postcondition:

stops clock, and accumulates time

read

public double read()

Read the value on the stop watch.

Precondition:

clock is stopped

Postcondition:

returns the accumulated time on the clock

Returns:

A double representing the number of seconds elapsed.

reset

public void reset()

Resets the time on the clock to zero.

Postcondition:

stops running clock and clears the accumulated time

toString

public String toString()

Generates string representation of clock.

Overrides:

toString in class Object

Postcondition:

returns a string representation of the clock

Returns:

A string representing this clock.