What Is Memory Barrier Java

Memory barriers, or fences, are a set of processor instructions used to apply ordering limitations on memory operations. … It is assumed the reader has a solid understanding of these concepts and the Java memory model.

What does a memory barrier do?

A memory barrier, also known as a membar, memory fence or fence instruction, is a type of barrier instruction that causes a central processing unit (CPU) or compiler to enforce an ordering constraint on memory operations issued before and after the barrier instruction.

What is a load barrier?

A LoadLoad barrier effectively prevents reordering of loads performed before the barrier with loads performed after the barrier. In our analogy, the #LoadLoad fence instruction is basically equivalent to a pull from the central repository.