Processor Consistency PC
Goodman's processor consistency: PRAM consistency together with cache consistency — writes by each process are seen by all processes in the order issued, and all writes to a single location are seen in one sequential order. Strictly weaker than SC; strictly stronger than both PRAM and cache consistency; incomparable to causal consistency.
Properties
Property vector author-extrapolated — set only where the model’s definition pins the cell down (unknown cells are omitted); cells citing a specific source are marked.
- Reasoning guarantees
- yes Coherence
- Atomicity guarantees
- no Multicopy atomic
Ordering relationships
- Strictly weaker than
- Sequential Consistency (SC) — Sequential consistency is strictly stronger than processor consistency (Goodman 1989; Steinke & Nutt 2004).
- Strictly stronger than
- PRAM (Pipelined RAM) Consistency — Processor consistency is strictly stronger than PRAM consistency (Goodman 1989; Steinke & Nutt 2004).
- Cache Coherence — Processor consistency is strictly stronger than cache consistency (Goodman 1989; Steinke & Nutt 2004). The Coherence node is Goodman's cache consistency.
- Incomparable with
- Causal Consistency — Processor and causal consistency are incomparable: each forbids a behaviour the other allows (Steinke & Nutt 2004).
References
- James R. Goodman. Cache Consistency and Sequential Consistency. Technical Report 61, IEEE Scalable Coherent Interface Working Group / University of Wisconsin-Madison, 1989.
- Robert C. Steinke, Gary J. Nutt. A Unified Theory of Shared Memory Consistency. Journal of the ACM 51(5), 2004. arxiv.org/abs/cs/0208027
- Sarita V. Adve, Kourosh Gharachorloo. Shared Memory Consistency Models: A Tutorial. IEEE Computer 29(12), 1996. doi:10.1109/2.546611