C WRC+pooncerelease+fencermbonceonce+Once
(*
* Result: Never
*
* This litmus test is an extension of the message-passing pattern, where
* the first write is moved to a separate process. Because it features
* a release and a read memory barrier, it should be forbidden. More
* specifically, this litmus test is forbidden because smp_store_release()
* is A-cumulative in LKMM.
*)
{}
P0(int *x)
{
WRITE_ONCE(*x, 1);
}
P1(int *x, int *y)
{
int r0;
r0 = READ_ONCE(*x);
smp_store_release(y, 1);
}
P2(int *x, int *y)
{
int r0;
int r1;
r0 = READ_ONCE(*y);
smp_rmb();
r1 = READ_ONCE(*x);
}
exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)