LISA auto/RW-GH+RW-R+RW-R+RW-R (* * Result: Never * * Process 0 starts (t=100000). * * P0 advances three grace periods (t=400000). * * P1 goes back a bit less than one grace period (t=301001). * * P2 goes back a bit less than one grace period (t=202002). * * P3 goes back a bit less than one grace period (t=103003). * * Process 0 start at t=100000, process 4 end at t=103003: Cycle forbidden. *) { } P0 | P1 | P2 | P3 ; r[once] r1 x0 | f[rcu_read_lock] | f[rcu_read_lock] | f[rcu_read_lock] ; f[sync] | r[once] r1 x1 | r[once] r1 x2 | r[once] r1 x3 ; f[sync] | w[once] x2 1 | w[once] x3 1 | w[once] x0 1 ; f[sync] | f[rcu_read_unlock] | f[rcu_read_unlock] | f[rcu_read_unlock] ; w[once] x1 1 | | | ; Observed 3:r1=0; 2:r1=1; 1:r1=1; 0:r1=1;