C IRIW+poonceonces+OnceOnce | |
(* | |
* Result: Sometimes | |
* | |
* Test of independent reads from independent writes with nothing | |
* between each pairs of reads. In other words, is anything at all | |
* needed to cause two different reading processes to agree on the order | |
* of a pair of writes, where each write is to a different variable by a | |
* different process? | |
*) | |
{} | |
P0(int *x) | |
{ | |
WRITE_ONCE(*x, 1); | |
} | |
P1(int *x, int *y) | |
{ | |
int r0; | |
int r1; | |
r0 = READ_ONCE(*x); | |
r1 = READ_ONCE(*y); | |
} | |
P2(int *y) | |
{ | |
WRITE_ONCE(*y, 1); | |
} | |
P3(int *x, int *y) | |
{ | |
int r0; | |
int r1; | |
r0 = READ_ONCE(*y); | |
r1 = READ_ONCE(*x); | |
} | |
exists (1:r0=1 /\ 1:r1=0 /\ 3:r0=1 /\ 3:r1=0) |