tools/memory-model/litmus-tests/S+fencewmbonceonce+poacquireonce.litmus


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 S+fencewmbonceonce+poacquireonce

(*
 * Result: Never
 *
 * Can a smp_wmb(), instead of a release, and an acquire order a prior
 * store against a subsequent store?
 *)

{
	int x;
	int y;
}

P0(int *x, int *y)
{
	WRITE_ONCE(*x, 2);
	smp_wmb();
	WRITE_ONCE(*y, 1);
}

P1(int *x, int *y)
{
	int r0;

	r0 = smp_load_acquire(y);
	WRITE_ONCE(*x, 1);
}

exists (x=2 /\ 1:r0=1)