1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
| C R+fencembonceonces
|
| (*
| * Result: Never
| *
| * This is the fully ordered (via smp_mb()) version of one of the classic
| * counterintuitive litmus tests that illustrates the effects of store
| * propagation delays. Note that weakening either of the barriers would
| * cause the resulting test to be allowed.
| *)
|
| {}
|
| P0(int *x, int *y)
| {
| WRITE_ONCE(*x, 1);
| smp_mb();
| WRITE_ONCE(*y, 1);
| }
|
| P1(int *x, int *y)
| {
| int r0;
|
| WRITE_ONCE(*y, 2);
| smp_mb();
| r0 = READ_ONCE(*x);
| }
|
| exists (y=2 /\ 1:r0=0)
|
|
