JVM structure

JVM structure can be described in terms of the runtime data structure in the memory and in terms of the two subsystems that use the runtime data – the classloader and the execution engine.

Runtime data areas

Each of the runtime data areas of JVM memory belongs to one of two categories:

• Shared areas that include the following:
  • Method area: Class metadata, static fields, and method bytecodes
  • Heap area: Objects (states)
• Unshared areas dedicated to a particular application thread, which includes the following:
  • Java stack: Current and caller frames, each frame keeping the state of Java (non native) method invocation:
    • Values of local variables
    • Method parameter values
    • Values of operands for intermediate...