C cmpxchg-fail-ordered-1
(*
* Result: Never
*
* Demonstrate that a failing cmpxchg() operation will act as a full
* barrier when followed by smp_mb__after_atomic().
*)
{}
P0(int *x, int *y, int *z)
{
int r0;
int r1;
WRITE_ONCE(*x, 1);
r1 = cmpxchg(z, 1, 0);
smp_mb__after_atomic();
r0 = READ_ONCE(*y);
}
P1(int *x, int *y, int *z)
{
int r0;
int r1;
WRITE_ONCE(*y, 1);
r1 = cmpxchg(z, 1, 0);
smp_mb__after_atomic();
r0 = READ_ONCE(*x);
}
locations[0:r1;1:r1]
exists (0:r0=0 /\ 1:r0=0)