34 lines
564 B
Plaintext
34 lines
564 B
Plaintext
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C MP+unlocklockonceonce+fencermbonceonce
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(*
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* Result: Never
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*
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* If two locked critical sections execute on the same CPU, stores in the
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* first must propagate to each CPU before stores in the second do, even if
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* the critical sections are protected by different locks.
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*)
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{}
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P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
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{
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spin_lock(s);
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WRITE_ONCE(*x, 1);
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spin_unlock(s);
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spin_lock(t);
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WRITE_ONCE(*y, 1);
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spin_unlock(t);
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}
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P1(int *x, int *y)
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{
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int r1;
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int r2;
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r1 = READ_ONCE(*y);
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smp_rmb();
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r2 = READ_ONCE(*x);
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}
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exists (1:r1=1 /\ 1:r2=0)
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