com.amazon.carbonado.util

Class Throttle

java.lang.Object

com.amazon.carbonado.util.Throttle

public class Throttle
extends java.lang.Object

General purpose class for throttling work relative to its actual measured performance. To throttle a task, call the throttle method each time a unit of work has been performed. It computes a rolling average for the amount of time it takes to perform some work, and then it sleeps a calculated amount of time to throttle back.

Instances are intended for use by one thread, and so they are not thread-safe.

Author:

Brian S O'Neill

Constructor Summary

Constructors

Constructor and Description
Throttle(int windowSize)

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(java.lang.String[] args) Test program which exercises the CPU in an infinite loop, throttled by the amount given in args[0].
void	throttle(double desiredSpeed, long sleepPrecisionMillis)

Methods inherited from class java.lang.Object

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

Constructor Detail

Throttle

public Throttle(int windowSize)

Parameters:

windowSize - amount of samples to keep in the rolling average

Method Detail

throttle

public void throttle(double desiredSpeed,
            long sleepPrecisionMillis)
              throws java.lang.InterruptedException

Parameters:

desiredSpeed - 1.0 = perform work at full speed, 0.5 = perform work at half speed, 0.0 = fully suspend work

sleepPrecisionMillis - sleep precision, in milliseconds. Typical value is 10 to 100 milliseconds.

Throws:

java.lang.InterruptedException

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Test program which exercises the CPU in an infinite loop, throttled by the amount given in args[0]. On a machine performing no other work, the average CPU load should be about the same as the throttled speed.

Parameters:

args - args[0] - desired speed, 0.0 to 1.0

Throws:

java.lang.Exception