// basic task graph model from // Bouyer, Fahrenberg, Larsen and Markey // Quantitative analysis of real-time systems using priced timed automata // Communications of the ACM, 54(9):78–87, 2011 pta // model is a PTA module scheduler task1 : [0..3]; // A+B task2 : [0..3]; // CxD task3 : [0..3]; // Cx(A+B) task4 : [0..3]; // (A+B)+(CxD) task5 : [0..3]; // DxCx(A+B) task6 : [0..3]; // (DxCx(A+B)) + ((A+B)+(CxD)) // task status: // 0 - not started // 1 - running on processor 1 // 2 - running on processor 2 // 3 - task complete // start task 1 [p1_add] task1=0 -> (task1'=1); [p2_add] task1=0 -> (task1'=2); // start task 2 [p1_mult] task2=0 -> (task2'=1); [p2_mult] task2=0 -> (task2'=2); // start task 3 (must wait for task 1 to complete) [p1_mult] task3=0 & task1=3 -> (task3'=1); [p2_mult] task3=0 & task1=3 -> (task3'=2); // start task 4 (must wait for tasks 1 and 2 to complete) [p1_add] task4=0 & task1=3 & task2=3 -> (task4'=1); [p2_add] task4=0 & task1=3 & task2=3 -> (task4'=2); // start task 5 (must wait for task 3 to complete) [p1_mult] task5=0 & task3=3 -> (task5'=1); [p2_mult] task5=0 & task3=3 -> (task5'=2); // start task 6 (must wait for tasks 4 and 5 to complete) [p1_add] task6=0 & task4=3 & task5=3 -> (task6'=1); [p2_add] task6=0 & task4=3 & task5=3 -> (task6'=2); // a task finishes on processor 1 [p1_done] task1=1 -> (task1'=3); [p1_done] task2=1 -> (task2'=3); [p1_done] task3=1 -> (task3'=3); [p1_done] task4=1 -> (task4'=3); [p1_done] task5=1 -> (task5'=3); [p1_done] task6=1 -> (task6'=3); // a task finishes on processor 2 [p2_done] task1=2 -> (task1'=3); [p2_done] task2=2 -> (task2'=3); [p2_done] task3=2 -> (task3'=3); [p2_done] task4=2 -> (task4'=3); [p2_done] task5=2 -> (task5'=3); [p2_done] task6=2 -> (task6'=3); endmodule // processor 1 module P1 p1 : [0..2]; // 0 - idle // 1 - add // 2 - multiply x1 : clock; // local clock invariant (p1=1 => x1<=2) & (p1=2 => x1<=3) endinvariant // addition [p1_add] p1=0 -> (p1'=1) & (x1'=0); // start [p1_done] p1=1 & x1=2 -> (p1'=0) & (x1'=0); // finish // multiplication [p1_mult] p1=0 -> (p1'=2) & (x1'=0); // start [p1_done] p1=2 & x1=3 -> (p1'=0) & (x1'=0); // finish endmodule // processor 2 module P2 p2 : [0..2]; // 0 - idle // 1 - add // 2 - multiply x2 : clock; // local clock invariant (p2=1 => x2<=5) & (p2=2 => x2<=7) endinvariant // addition [p2_add] p2=0 -> (p2'=1) & (x2'=0); // start [p2_done] p2=1 & x2=5 -> (p2'=0) & (x2'=0); // finish // multiplication [p2_mult] p2=0 -> (p2'=2) & (x2'=0); // start [p2_done] p2=2 & x2=7 -> (p2'=0) & (x2'=0); // finish endmodule // reward structure: elapsed time rewards "time" true : 1; endrewards // reward structures: energy consumption rewards "energy" p1=0 : 10/1000; p1>0 : 90/1000; p2=0 : 20/1000; p2>0 : 30/1000; endrewards // target state (all tasks complete) label "tasks_complete" = (task6=3);