In
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
s, 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.
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.
In Computer storage
A write barrier in a
memory system, also known as a
memory barrier
In computing, 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 b ...
, is a hardware-specific
compiler intrinsic that ensures that all preceding memory operations
"happen before" all subsequent ones.
See also
*
Native Command Queuing
References
External links
Barriers and journaling filesystems(LWN.net, May 21, 2008)
Compilers
Memory management
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