Write barrier

In operating systems, write barrier is a mechanism for enforcing a particular ordering in a sequence of writes to a storage system in a computer system. For example, a write barrier in a file system is a mechanism that ensures that in-memory file system state is written out to persistent storage in the correct order.

In garbage collection

A write barrier in a Garbage [collection (computer science)|garbage collector] is a fragment of code emitted by the compiler immediately before every store operation to ensure that generational invariants are maintained.

In computer storage

A write barrier in a memory system, also known as a memory barrier, is a hardware-specific compiler intrinsic that ensures that all preceding memory operations "happen before" all subsequent ones.