linux/tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus
Paul E. McKenney 1947bfcf81 tools/memory-model: Add types to litmus tests
This commit adds type information for global variables in the litmus
tests in order to allow easier use with klitmus7.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-06 17:25:16 -08:00

38 lines
711 B
Plaintext

C LB+fencembonceonce+ctrlonceonce
(*
* Result: Never
*
* This litmus test demonstrates that lightweight ordering suffices for
* the load-buffering pattern, in other words, preventing all processes
* reading from the preceding process's write. In this example, the
* combination of a control dependency and a full memory barrier are enough
* to do the trick. (But the full memory barrier could be replaced with
* another control dependency and order would still be maintained.)
*)
{
int x;
int y;
}
P0(int *x, int *y)
{
int r0;
r0 = READ_ONCE(*x);
if (r0)
WRITE_ONCE(*y, 1);
}
P1(int *x, int *y)
{
int r0;
r0 = READ_ONCE(*y);
smp_mb();
WRITE_ONCE(*x, 1);
}
exists (0:r0=1 /\ 1:r0=1)