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