What is Sequential consistency?
The most intuitive memory consistency model: all cores' operations appear in one order in which each core's operations keep their program order.
Field: Multicore & Synchronization
Sequential consistency in the explanations
Under sequential consistency, the operations of all cores appear interleaved into one sequence, like shuffling cards, with each core's operations keeping their program order within it.
Which describes sequential consistency?Under sequential consistency one of the writes happens first, so at least one read must see 1.
The two threads above run simultaneously on different cores…Atomic operations default to sequential consistency (memory_order_seq_cst), which is easiest to reason about but costs the most in barriers.
Why do C11 _Atomic and C++11 std::atomic let programmers sp…
Questions that mention Sequential consistency (3)
- Which describes sequential consistency?
- The two threads above run simultaneously on different cores (assume no compiler reordering). Which outcome cannot occur under sequential consistency but can occur on real CPUs such as x86?
- Why do C11 _Atomic and C++11 std::atomic let programmers specify a memory order?
Related terms
Store buffer Memory barrier ABA problem Acquire-release semantics Atomic instruction Barrier synchronization Bus snooping Compare-and-swap Condition variable Critical section