Write barrier

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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]

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. 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.[citation needed]


  1. ^ "Chapter 16. Write Barriers". docs.fedoraproject.org. Retrieved 2014-01-24. 
  2. ^ "Documentation/block/barrier.txt". kernel/git/torvalds/linux.git - Linux kernel source tree. git.kernel.org. 2005-07-22. Retrieved 2014-01-24. 
  3. ^ "The end of block barriers". LWN.net. 2010-08-18. Retrieved 2014-01-24. 

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