Java objects designed as Oop-klass__java

Hotspot in the source code why the Java object is designed to oop-klass this structure. Just to avoid the creation of a virtual function table for each Java object.

Http://hg.openjdk.java.net/jdk8/jdk8/hotspot/file/87ee5ee27509/src/share/vm/oops/klass.hpp

VTBL is the main feature of polymorphism, if all instances of a class are common to one vtbl? The polymorphism of this implementation will not be problematic

An instance of an object does not have a virtual function table, and the Klass object to which the instance belongs has a virtual function table

The Oop-klass model is designed to reduce the consumption of a virtual function table for each object https://code.google.com/archive/p/strongtalk/wikis/ Vmtypesforsmalltalkobjects.wiki hotspot is using this design method here is the history of this model

This is the Java design concept, where polymorphism relies on dynamic binding, while distribution is static. So Java generates bytecode invokevirtual is very common. Public VTBL should be more profitable.

So ultimately, the call to the method, the traditional stack structure and Java based on the operand stack structure, are all for the function call service. There's no function call, everything's not working.

Learn the JVM good URL: http://www.open-open.com/lib/view/open1352431526366.html