36 lines
508 B
Plaintext
36 lines
508 B
Plaintext
C cmpxchg-fail-ordered-1
|
|
|
|
(*
|
|
* Result: Never
|
|
*
|
|
* Demonstrate that a failing cmpxchg() operation will act as a full
|
|
* barrier when followed by smp_mb__after_atomic().
|
|
*)
|
|
|
|
{}
|
|
|
|
P0(int *x, int *y, int *z)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
WRITE_ONCE(*x, 1);
|
|
r1 = cmpxchg(z, 1, 0);
|
|
smp_mb__after_atomic();
|
|
r0 = READ_ONCE(*y);
|
|
}
|
|
|
|
P1(int *x, int *y, int *z)
|
|
{
|
|
int r0;
|
|
int r1;
|
|
|
|
WRITE_ONCE(*y, 1);
|
|
r1 = cmpxchg(z, 1, 0);
|
|
smp_mb__after_atomic();
|
|
r0 = READ_ONCE(*x);
|
|
}
|
|
|
|
locations[0:r1;1:r1]
|
|
exists (0:r0=0 /\ 1:r0=0)
|