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