Internal architecture of JVM
- Classloader: Classloader is a subsystem of JVM that is used to load class files.
- Class or Method Area : Class or Method Area stores per class structures such as the runtime constant pool, field and method data, the code for methods.
- Heap: It is the runtime data area in which objects are allocated.
- Stack: Java Stack stores frames.It holds local variables and partial results, and plays part in method invocation and return.
- Program Counter Register: PC (program counter) register. It contains the address of the Java virtual machine instruction currently being executed.
- Native Method Stack: It contains all the native methods used in the application.
- Execution Engine: It contains :
- A virtual processor
- Interpreter: Read bytecode stream then execute the instructions.
- Just In Time(JIT) compiler: It is used to improve the performance.JIT compiles parts of the byte code that have similar functionality at the same time, and hence reduces the amount of time needed for compilation. compiler refers to a translator from a instruction set of Java Virtual machine (JVM) to the instruction set of a specific CPU.
