JVM and Memory Notes

Java

The class loader, the runtime data areas and the execution engine, and how a class file becomes running machine code.

Java

Classes are found, verified, prepared and initialised on first use, by a hierarchy of loaders that delegate upwards.

Java

Where each piece of data actually lives, and what runs out when each area is exhausted.

Java

The collector reclaims objects that can no longer be reached. Understanding reachability explains both leaks and pauses.

Java

Java can still leak: any object the program keeps reachable but no longer needs. Here is how to find and fix them.