Archived: GC Test - Releasing Old vs. New Objects

JVM Tutorials - Herong's Tutorial Examples

∟Archived Tutorials

∟Archived: 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.

Table of Contents

About This Book

JVM (Java Virtual Machine) Specification

Java HotSpot VM - JVM by Oracle/Sun

java.lang.Runtime Class - The JVM Instance

java.lang.System Class - The Operating System

ClassLoader Class - Class Loaders

Class Class - Class Reflections

JVM Runtime Data Areas

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

OpenJ9 by Eclipse Foundation

JRockit JVM 28.2.7 by Oracle Corporation

►Archived Tutorials

archived: Download and Install JDK 14 on macOS

Archived: Download and Install Latest JDK 10 on Windows

Archived: Download and Install JDK 1.8.0 on Windows

Archived: Download and Install JDK 1.7.0 on Windows

Archived: Download and Install Java SE 1.6 Update 2

Archived: Installing JRockit JVM 8.0

Archived: Testing with LongWhile.java

Archived: Testing with LongSleep.java

Archived: GCTest.java - Garbage Collection Test Program

Archived: GC Test - Constant Memory Requirement

Archived: GC Test - Periodical Memory Requirement

►Archived: GC Test - Releasing Old vs. New Objects

Archived: GC Test - JDK 1.4.0 vs. JDK 1.3.1

Archived: GC Test - Client vs. Server

Archived: StringBuffer Testing Program

Archived: Installing JRockit JVM 7.0

Archived: Running JRockit JVM with Management Console

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