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) |