| 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) |