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| C ISA2+pooncerelease+poacquirerelease+poacquireonce
|
| (*
| * Result: Never
| *
| * This litmus test demonstrates that a release-acquire chain suffices
| * to order P0()'s initial write against P2()'s final read. The reason
| * that the release-acquire chain suffices is because in all but one
| * case (P2() to P0()), each process reads from the preceding process's
| * write. In memory-model-speak, there is only one non-reads-from
| * (AKA non-rf) link, so release-acquire is all that is needed.
| *)
|
| {}
|
| P0(int *x, int *y)
| {
| WRITE_ONCE(*x, 1);
| smp_store_release(y, 1);
| }
|
| P1(int *y, int *z)
| {
| int r0;
|
| r0 = smp_load_acquire(y);
| smp_store_release(z, 1);
| }
|
| P2(int *x, int *z)
| {
| int r0;
| int r1;
|
| r0 = smp_load_acquire(z);
| r1 = READ_ONCE(*x);
| }
|
| exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)
|
|
