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| C MP+polockonce+poacquiresilsil
|
| (*
| * Result: Sometimes
| *
| * Do spinlocks provide order to outside observers using spin_is_locked()
| * to sense the lock-held state, ordered by acquire? Note that when the
| * first spin_is_locked() returns false and the second true, we know that
| * the smp_load_acquire() executed before the lock was acquired (loosely
| * speaking).
| *)
|
| {
| }
|
| P0(spinlock_t *lo, int *x)
| {
| spin_lock(lo);
| WRITE_ONCE(*x, 1);
| spin_unlock(lo);
| }
|
| P1(spinlock_t *lo, int *x)
| {
| int r1;
| int r2;
| int r3;
|
| r1 = smp_load_acquire(x);
| r2 = spin_is_locked(lo);
| r3 = spin_is_locked(lo);
| }
|
| exists (1:r1=1 /\ 1:r2=0 /\ 1:r3=1)
|
|
