monq.stuff

Class ConvinceGC

java.lang.Object

monq.stuff.ConvinceGC

All Implemented Interfaces:

java.lang.Runnable

public class ConvinceGC
extends java.lang.Object
implements java.lang.Runnable

this class should not be necessary, but I did not find a better way to get the GC release memory to the operating system.

When using java with the option -XX:MaxHeapFreeRatio, a successfull GC freeing huge percentages of memory does not immediately result in deallocation of memory. My experiments show that several (5–10) calls to the GC are necessary before memory is really given back to the operating system to comply with the given MaxHeapFreeRatio.

A typical use is

  new Thread(new ConvinceGC(10)).start();

which starts a new thread that calls the garbage collector 10 times and then exits.

Author:

© 2005 Harald Kirsch

Constructor Summary

Constructors

Constructor and Description
ConvinceGC(int count) get a thread which, after being started, calls the garbage collector the given number of times with an interval of 1 second in between.

Method Summary

Modifier and Type	Method and Description
void	run() is only public to satisfy the Runnable interface, so rather wrap an object of this class in a Thread and call its start() method.
ConvinceGC	setLogging(java.io.PrintStream out) after every call to gc, report the amount of memory allocated, used and the resulting percentage of free memory.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConvinceGC

public ConvinceGC(int count)

get a thread which, after being started, calls the garbage collector the given number of times with an interval of 1 second in between.

You need to call the start() method to get things going.

Method Detail

setLogging

public ConvinceGC setLogging(java.io.PrintStream out)

after every call to gc, report the amount of memory allocated, used and the resulting percentage of free memory.

run

public void run()

is only public to satisfy the Runnable interface, so rather wrap an object of this class in a Thread and call its start() method.

Specified by:

run in interface java.lang.Runnable