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45 lines
731 B
45 lines
731 B
C IRIW+fencembonceonces+OnceOnce |
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(* |
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* Result: Never |
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* |
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* Test of independent reads from independent writes with smp_mb() |
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* between each pairs of reads. In other words, is smp_mb() sufficient to |
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* cause two different reading processes to agree on the order of a pair |
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* of writes, where each write is to a different variable by a different |
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* process? This litmus test exercises LKMM's "propagation" rule. |
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*) |
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{} |
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P0(int *x) |
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{ |
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WRITE_ONCE(*x, 1); |
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} |
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P1(int *x, int *y) |
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{ |
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int r0; |
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int r1; |
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r0 = READ_ONCE(*x); |
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smp_mb(); |
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r1 = READ_ONCE(*y); |
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} |
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P2(int *y) |
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{ |
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WRITE_ONCE(*y, 1); |
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} |
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P3(int *x, int *y) |
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{ |
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int r0; |
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int r1; |
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r0 = READ_ONCE(*y); |
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smp_mb(); |
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r1 = READ_ONCE(*x); |
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} |
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exists (1:r0=1 /\ 1:r1=0 /\ 3:r0=1 /\ 3:r1=0)
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