Outdated: GC Test - Releasing Old vs. New Objects

This section provides a tutorial example on testing garbage collection by comparing performances between release old objects and new objects.

In the previous tests, objects were released from the tail of the list. So old objects were released first. To see if there are any differences between releasing old objects and new objects, I changed the code to use the objList.removeHead() method. 4 tests were conducted to compare with the previous tests:

java -Xms2m -Xmx8m GCTest 16 1 > head_16_01.out
java -Xms2m -Xmx8m GCTest 16 8 > head_16_08.out
java -Xms2m -Xmx8m GCTest 16 16 > head_16_16.out
java -Xms2m -Xmx8m GCTest 16 24 > head_16_24.out

The outputs were very similar to those using objList.removeTail() method. head_16_24.out also showed a memory crash at second 43.

Last update: 2003.

Table of Contents

 About This Book

 Downloading and Installing JDK 1.8.0 on Windows

 Downloading and Installing JDK 1.7.0 on Windows

 java.lang.Runtime Class - The JVM Instance

 java.lang.System Class - The Operating System

 ClassLoader Class - Class Loaders

 Class Class - Class Reflections

 Sun's JVM - Java HotSpot VM

 JRockit JVM 28.2.7 by Oracle Corporation

 JVM Runtime Data Areas

 Memory Management and Garbage Collectors

 Garbage Collection Tests

 JVM Stack, Frame and Stack Overflow

 Thread Testing Program and Result

 CPU Impact of Multi-Thread Applications

 I/O Impact of Multi-Thread Applications

 CDS (Class Data Sharing)

 Micro Benchmark Runner and JVM Options

 Micro Benchmark Tests on "int" Operations

 Micro Benchmark Tests on "long" Operations

 Micro Benchmark Tests in JIT Compilation Mode

 Micro Benchmark Tests on "float" and "double" Operations

Outdated Tutorials

 Outdated: Download and Install Java SE 1.6 Update 2

 Outdated: Installing JRockit JVM 8.0

 Outdated: Testing with LongWhile.java

 Outdated: Testing with LongSleep.java

 Outdated: GCTest.java - Garbage Collection Test Program

 Outdated: GC Test - Constant Memory Requirement

 Outdated: GC Test - Periodical Memory Requirement

Outdated: GC Test - Releasing Old vs. New Objects

 Outdated: GC Test - JDK 1.4.0 vs. JDK 1.3.1

 Outdated: GC Test - Client vs. Server

 Outdated: StringBuffer Testing Program

 Outdated: Installing JRockit JVM 7.0

 Outdated: Running JRockit JVM with Management Console

 References

 PDF Printing Version