11c27b644SPaul E. McKenneyC MP+poonceonces 21c27b644SPaul E. McKenney 38f32543bSPaul E. McKenney(* 446f52b1fSAndrea Parri * Result: Sometimes 58f32543bSPaul E. McKenney * 68f32543bSPaul E. McKenney * Can the counter-intuitive message-passing outcome be prevented with 78f32543bSPaul E. McKenney * no ordering at all? 88f32543bSPaul E. McKenney *) 98f32543bSPaul E. McKenney 10*5c587f9bSAkira Yokosawa{} 111c27b644SPaul E. McKenney 12b6ff3084SPaul E. McKenneyP0(int *buf, int *flag) // Producer 131c27b644SPaul E. McKenney{ 14acc4bdc5SPaul E. McKenney WRITE_ONCE(*buf, 1); 15acc4bdc5SPaul E. McKenney WRITE_ONCE(*flag, 1); 161c27b644SPaul E. McKenney} 171c27b644SPaul E. McKenney 18b6ff3084SPaul E. McKenneyP1(int *buf, int *flag) // Consumer 191c27b644SPaul E. McKenney{ 201c27b644SPaul E. McKenney int r0; 211c27b644SPaul E. McKenney int r1; 221c27b644SPaul E. McKenney 23acc4bdc5SPaul E. McKenney r0 = READ_ONCE(*flag); 24acc4bdc5SPaul E. McKenney r1 = READ_ONCE(*buf); 251c27b644SPaul E. McKenney} 261c27b644SPaul E. McKenney 27b6ff3084SPaul E. McKenneyexists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *) 28