| C MP+poonceonces | |
| (* | |
| * Result: Sometimes | |
| * | |
| * Can the counter-intuitive message-passing outcome be prevented with | |
| * no ordering at all? | |
| *) | |
| { | |
| int buf; | |
| int flag; | |
| } | |
| P0(int *buf, int *flag) // Producer | |
| { | |
| WRITE_ONCE(*buf, 1); | |
| WRITE_ONCE(*flag, 1); | |
| } | |
| P1(int *buf, int *flag) // Consumer | |
| { | |
| int r0; | |
| int r1; | |
| r0 = READ_ONCE(*flag); | |
| r1 = READ_ONCE(*buf); | |
| } | |
| exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *) |