1*4882a593SmuzhiyunC S+poonceonces 2*4882a593Smuzhiyun 3*4882a593Smuzhiyun(* 4*4882a593Smuzhiyun * Result: Sometimes 5*4882a593Smuzhiyun * 6*4882a593Smuzhiyun * Starting with a two-process release-acquire chain ordering P0()'s 7*4882a593Smuzhiyun * first store against P1()'s final load, if the smp_store_release() 8*4882a593Smuzhiyun * is replaced by WRITE_ONCE() and the smp_load_acquire() replaced by 9*4882a593Smuzhiyun * READ_ONCE(), is ordering preserved? 10*4882a593Smuzhiyun *) 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun{} 13*4882a593Smuzhiyun 14*4882a593SmuzhiyunP0(int *x, int *y) 15*4882a593Smuzhiyun{ 16*4882a593Smuzhiyun WRITE_ONCE(*x, 2); 17*4882a593Smuzhiyun WRITE_ONCE(*y, 1); 18*4882a593Smuzhiyun} 19*4882a593Smuzhiyun 20*4882a593SmuzhiyunP1(int *x, int *y) 21*4882a593Smuzhiyun{ 22*4882a593Smuzhiyun int r0; 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun r0 = READ_ONCE(*y); 25*4882a593Smuzhiyun WRITE_ONCE(*x, 1); 26*4882a593Smuzhiyun} 27*4882a593Smuzhiyun 28*4882a593Smuzhiyunexists (x=2 /\ 1:r0=1) 29