Write barrier explained

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 (program logic) that ensures that in-memory file system state is written out to persistent storage in the correct order.^{[1] [2] [3]}

In garbage collection

A write barrier in a garbage collector is a fragment of code emitted by the compiler immediately before every store operation to ensure that (e.g.) generational invariants are maintained.^{[4] [5]}

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.

See also

• Native Command Queuing

External links

• Barriers and journaling filesystems (LWN.net, May 21, 2008)

Notes and References

1. Web site: Chapter 16. Write Barriers . http://web.archive.org/web/20220608144201/https://docs.fedoraproject.org/en-US/Fedora/14/html/Storage_Administration_Guide/writebarr.html . docs.fedoraproject.org . 2022-06-08 . dead . 2014-01-24.
2. Web site: I/O Barriers . Tejun Heo . kernel/git/torvalds/linux.git - Linux kernel source tree . git.kernel.org . 2005-07-22 . 2014-01-24.
3. Web site: The end of block barriers . Jonathan Corbet . . 2010-08-18 . 2014-01-24.
4. Book: Zorn . Benjamin . Barrier methods for Garbage Collection . 1990 . Citeseer . Department of Computer Science, University of Colorado in Boulder . 11–18 . 10.1.1.52.8857 .
5. Web site: GC FAQ -- algorithms. 2020-06-30. www.iecc.com.