有没有示例显示JVM参数UnsyncloadClass的工作方式？

Question

I am new to Java, I learned that there is a setting for JVM "UnsyncloadClass", I googled it here

http://stas-blogspot.blogspot.com/2011/07/most-complete-list-of-xx-options-for.html

"UnsyncloadClass    Unstable: VM calls loadClass unsynchronized. Custom classloader must call VM synchronized for findClass & defineClass   false   bool"

So I am not sure what does this mean, is there any code to illustrate how it works? BTW, is this stable in Java7 or Java8 ? From literal meaning, I thought this might enable the JVM load classes in an async way, am I right? It will be great if any code illustrated how it works.

Answer 1

When this option is ON, loadClass method does acquire a ClassLoader lock, no matter if this ClassLoader is registered as parallel capable or not.

This option is never going to be "stable" nor recommended for production, since its behavior obviously violates the ClassLoader API specification .