C WRC+poonceonces+Once (* * Result: Sometimes * * This litmus test is an extension of the message-passing pattern, * where the first write is moved to a separate process. Note that this * test has no ordering at all. *) {} P0(int *x) { WRITE_ONCE(*x, 1); } P1(int *x, int *y) { int r0; r0 = READ_ONCE(*x); WRITE_ONCE(*y, 1); } P2(int *x, int *y) { int r0; int r1; r0 = READ_ONCE(*y); r1 = READ_ONCE(*x); } exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)