| C MP+onceassign+derefonce |
| |
| (* |
| * Result: Never |
| * |
| * This litmus test demonstrates that rcu_assign_pointer() and |
| * rcu_dereference() suffice to ensure that an RCU reader will not see |
| * pre-initialization garbage when it traverses an RCU-protected data |
| * structure containing a newly inserted element. |
| *) |
| |
| { |
| int *p=y; |
| int x; |
| int y=0; |
| } |
| |
| P0(int *x, int **p) // Producer |
| { |
| WRITE_ONCE(*x, 1); |
| rcu_assign_pointer(*p, x); |
| } |
| |
| P1(int *x, int **p) // Consumer |
| { |
| int *r0; |
| int r1; |
| |
| rcu_read_lock(); |
| r0 = rcu_dereference(*p); |
| r1 = READ_ONCE(*r0); |
| rcu_read_unlock(); |
| } |
| |
| exists (1:r0=x /\ 1:r1=0) (* Bad outcome. *) |
