Runtime data area & method area (permanent generation / meta space) & stack frame

Run time data area

Method area Pile up Program counter Native Method Stack Java Virtual machine stack

Method area : Storage information , Static variables , Constant , And immediately compiled code
Pile up : Class instances and arrays The heap occupies the largest memory space , It is also the main management area of garbage collector .
Program counter : Record the current thread execution position , In order to recover to the correct execution position after switching threads ;
Native Method Stack : Local method (native Method ) When executed , A stack frame will also be created in the local method stack
Java Virtual machine stack : When each method is executed ,JVM A stack frame will be created synchronously (Stack Frame) Used to store local variables 、 The stack of operands 、 Dynamic connection 、 Method exit information .

Thread private : Program counter , Virtual machine stack , Native Method Stack
Thread sharing : Pile up , Method area

Specific implementation of method area :
Forever : yes HotSpot Virtual machine to virtual machine specification in the method area of a way to achieve
Meta space : Use direct memory ; adopt NIO Class uses native Function library directly allocates out of heap memory , By storing in java Heap DirectByteBuffer Object to reference this memory ;

Stack frame : Include local variable table , The stack of operands , Dynamic links and method return addresses

The picture is from : https://www.nowcoder.com/discuss/353149635789266944