xref: /OK3568_Linux_fs/kernel/tools/memory-model/litmus-tests/CoRR+poonceonce+Once.litmus (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593SmuzhiyunC CoRR+poonceonce+Once
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun(*
4*4882a593Smuzhiyun * Result: Never
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Test of read-read coherence, that is, whether or not two successive
7*4882a593Smuzhiyun * reads from the same variable are ordered.
8*4882a593Smuzhiyun *)
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun{}
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunP0(int *x)
13*4882a593Smuzhiyun{
14*4882a593Smuzhiyun	WRITE_ONCE(*x, 1);
15*4882a593Smuzhiyun}
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunP1(int *x)
18*4882a593Smuzhiyun{
19*4882a593Smuzhiyun	int r0;
20*4882a593Smuzhiyun	int r1;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	r0 = READ_ONCE(*x);
23*4882a593Smuzhiyun	r1 = READ_ONCE(*x);
24*4882a593Smuzhiyun}
25*4882a593Smuzhiyun
26*4882a593Smuzhiyunexists (1:r0=1 /\ 1:r1=0)
27