xref: /OK3568_Linux_fs/kernel/tools/memory-model/litmus-tests/SB+rfionceonce-poonceonces.litmus (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593SmuzhiyunC SB+rfionceonce-poonceonces
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun(*
4*4882a593Smuzhiyun * Result: Sometimes
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * This litmus test demonstrates that LKMM is not fully multicopy atomic.
7*4882a593Smuzhiyun *)
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun{}
10*4882a593Smuzhiyun
11*4882a593SmuzhiyunP0(int *x, int *y)
12*4882a593Smuzhiyun{
13*4882a593Smuzhiyun	int r1;
14*4882a593Smuzhiyun	int r2;
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun	WRITE_ONCE(*x, 1);
17*4882a593Smuzhiyun	r1 = READ_ONCE(*x);
18*4882a593Smuzhiyun	r2 = READ_ONCE(*y);
19*4882a593Smuzhiyun}
20*4882a593Smuzhiyun
21*4882a593SmuzhiyunP1(int *x, int *y)
22*4882a593Smuzhiyun{
23*4882a593Smuzhiyun	int r3;
24*4882a593Smuzhiyun	int r4;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun	WRITE_ONCE(*y, 1);
27*4882a593Smuzhiyun	r3 = READ_ONCE(*y);
28*4882a593Smuzhiyun	r4 = READ_ONCE(*x);
29*4882a593Smuzhiyun}
30*4882a593Smuzhiyun
31*4882a593Smuzhiyunlocations [0:r1; 1:r3; x; y] (* Debug aid: Print things not in "exists". *)
32*4882a593Smuzhiyunexists (0:r2=0 /\ 1:r4=0)
33