nachos.machine
Class Timer

java.lang.Object
  |
  +--nachos.machine.Timer

public final class Timer

extends Object

A hardware timer generates a CPU timer interrupt approximately every 500 clock ticks. This means that it can be used for implementing time-slicing, or for having a thread go to sleep for a specific period of time. The Timer class emulates a hardware timer by scheduling a timer interrupt to occur every time approximately 500 clock ticks pass. There is a small degree of randomness here, so interrupts do not occur exactly every 500 ticks.

Constructor Summary

Timer(Privilege privilege)
Allocate a new timer.

Method Summary

long	getTime() Get the current time.
void	setInterruptHandler(Runnable handler) Set the callback to use as a timer interrupt handler.

Methods inherited from class java.lang.Object

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

Constructor Detail

Timer

public Timer(Privilege privilege)

Allocate a new timer.

Parameters:

privilege - encapsulates privileged access to the Nachos machine.

Method Detail

setInterruptHandler

public void setInterruptHandler(Runnable handler)

Set the callback to use as a timer interrupt handler. The timer interrupt handler will be called approximately every 500 clock ticks.

Parameters:

handler - the timer interrupt handler.

getTime

public long getTime()

Get the current time.

Returns:

the number of clock ticks since Nachos started.