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@arturmkrtchyan
arturmkrtchyan / ObjectHeader32.txt
Last active April 8, 2024 02:03
Java Object Header
|----------------------------------------------------------------------------------------|--------------------|
| Object Header (64 bits) | State |
|-------------------------------------------------------|--------------------------------|--------------------|
| Mark Word (32 bits) | Klass Word (32 bits) | |
|-------------------------------------------------------|--------------------------------|--------------------|
| identity_hashcode:25 | age:4 | biased_lock:1 | lock:2 | OOP to metadata object | Normal |
|-------------------------------------------------------|--------------------------------|--------------------|
| thread:23 | epoch:2 | age:4 | biased_lock:1 | lock:2 | OOP to metadata object | Biased |
|-------------------------------------------------------|--------------------------------|--------------------|
|
@raphw
raphw / UnsafeTest.java
Last active January 10, 2023 20:12
A demonstration of sun.misc.Unsafe
import org.junit.Before;
import org.junit.Test;
import sun.misc.Unsafe;
import sun.reflect.ReflectionFactory;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import static org.junit.Assert.assertEquals;