xref: /linux/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-2.litmus (revision 621cde16e49b3ecf7d59a8106a20aaebfb4a59a9) 
1C cmpxchg-fail-unordered-2
2
3(*
4 * Result: Sometimes
5 *
6 * Demonstrate that a failing cmpxchg() operation does not act as either
7 * an acquire release operation.  (In contrast, a successful cmpxchg()
8 * does act as both an acquire and a release operation.)
9 *)
10
11{}
12
13P0(int *x, int *y)
14{
15	int r1;
16
17	WRITE_ONCE(*x, 1);
18	r1 = cmpxchg(y, 0, 1);
19}
20
21P1(int *x, int *y)
22{
23	int r1;
24	int r2;
25
26	r1 = cmpxchg(y, 0, 1);
27	r2 = READ_ONCE(*x);
28}
29
30exists (0:r1=0 /\ 1:r1=1 /\ 1:r2=0)
31