Consistency models

special case of memory coherence

synchronization barrier that forces an ordering constraint on memory accesses

consistency model used in distributed computing to achieve high availability

thumb|In grey a linear sub-history, processes beginning in do not have a linearizable history because or may complete in either order before occurs.

a set of formally specified rules that guarantee (or explicitly disclaim) certain consistencies in the event of concurrent reads or writes to shared memory

Consistency model used in concurrent computing

order of accesses to computer memory by a CPU