16 lines
549 B
Markdown
16 lines
549 B
Markdown
Let us define $op ->_{proc} op'$ to hold whenever there exists a process p that issues both operations with `res[op]` happening before `inv[op']`.
|
||
|
||
**Def:** a complete history is sequentially consistent if there exists a sequential history $𝑆$ s.t.
|
||
![[Pasted image 20250324082534.png]]
|
||
|
||
![[Pasted image 20250324082545.png]]
|
||
|
||
>[!warning]
|
||
>The problem with sequential consistency is that it is NOT compositional.
|
||
|
||
Consider for example the following two processes:
|
||
```
|
||
p1: Q.enq(a); Q'.enq(b'); Q'deq()->b'
|
||
p2: Q'.enq(a'); Q.enq(b); Q.deq()->b
|
||
```
|
||
|