C cmpxchg-fail-unordered-1 | |
(* | |
* Result: Sometimes | |
* | |
* Demonstrate that a failing cmpxchg() operation does not act as a | |
* full barrier. (In contrast, a successful cmpxchg() does act as a | |
* full barrier.) | |
*) | |
{} | |
P0(int *x, int *y, int *z) | |
{ | |
int r0; | |
int r1; | |
WRITE_ONCE(*x, 1); | |
r1 = cmpxchg(z, 1, 0); | |
r0 = READ_ONCE(*y); | |
} | |
P1(int *x, int *y, int *z) | |
{ | |
int r0; | |
int r1; | |
WRITE_ONCE(*y, 1); | |
r1 = cmpxchg(z, 1, 0); | |
r0 = READ_ONCE(*x); | |
} | |
locations[0:r1;1:r1] | |
exists (0:r0=0 /\ 1:r0=0) |