blob: 4727f5aaf03b05b1c98a6d2d53ded40c8d7023e4 [file] [log] [blame]
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.)
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);
WRITE_ONCE(*x, 1);
exists (0:r0=1 /\ 1:r0=1)