LISA auto/RW-G+RW-RB+RW-G+RW-R (* * Result: Never * * Process 0 starts (t=100000). * * P0 advances one grace period (t=200000). * * P1 advances slightly (t=200002). * * P2 advances one grace period (t=300003). * * P3 goes back a bit less than one grace period (t=201004). * * Process 0 start at t=100000, process 4 end at t=201004: Cycle forbidden. *) { } P0 | P1 | P2 | P3 ; r[once] r1 x0 | f[rcu_read_lock] | r[once] r1 x2 | f[rcu_read_lock] ; f[sync] | r[once] r1 x1 | f[sync] | r[once] r1 x3 ; w[once] x1 1 | f[mb] | w[once] x3 1 | w[once] x0 1 ; | w[once] x2 1 | | f[rcu_read_unlock] ; | f[rcu_read_unlock] | | ; Observed 3:r1=1; 2:r1=0; 1:r1=1; 0:r1=1;