Any concept of shared memory in Java

Question

AFAIK, memory in Java is based on heap from which the memory is allotted to objects dynamically and there is no concept of shared memory.

If there is no concept of s

Answer 1

The easiest way to do that is to have two processes instantiate the same memory-mapped file. In practice they will be sharing the same off-heap memory space. You can grab the physical address of this memory and use sun.misc.Unsafe to write/read primitives. It supports concurrency through the putXXXVolatile/getXXXVolatile methods. Take a look on CoralQueue which offers IPC easily as well as inter-thread communication inside the same JVM.

Disclaimer: I am one of the developers of CoralQueue.