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C R+fencembonceonces
(*
* Result: Never
*
* This is the fully ordered (via smp_mb()) version of one of the classic
* counterintuitive litmus tests that illustrates the effects of store
* propagation delays. Note that weakening either of the barriers would
* cause the resulting test to be allowed.
*)
{}
P0(int *x, int *y)
{
WRITE_ONCE(*x, 1);
smp_mb();
WRITE_ONCE(*y, 1);
}
P1(int *x, int *y)
{
int r0;
WRITE_ONCE(*y, 2);
smp_mb();
r0 = READ_ONCE(*x);
}
exists (y=2 /\ 1:r0=0)
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