COP 4600 /EEL 4882 Project 4

1. COP 4600 /EEL 4882Project 4

2. Task • I/O Request processing • SIO • WIO • Process state • Active (only one) • Ready (multiple) • Block • Done University of Central Florida

3. Input • Input files are the same • This time we need actually run instructions inside program script • Simulation of SIO, WIO instruction University of Central Florida

4. Instruction “SIO” and “WIO” • Review SIO 40 DSK2 10 -- Start Dsk2, requesting 10 bytes …… WIO 0 REQ [1,1] -- See if I/O request at [1,1] has finished, if not, block • How do we handle that? • Whenever we execute SIO, generate EIO event in a future time • When WIO occur first: • Check if I/O request still there, if so, block • When EIO occur first: • Remove I/O request University of Central Florida

5. Interrupt Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Obj1.c: Get EVENT from event queue: LOGON STARTIO WAITIO ENDIO PGMEND Simulator.c: Call event handler: Logon_Service Sio_Service Wio_Service Eio_Service End_Service University of Central Florida

6. Events • Logon • Generated by Obj1.c: Load_events() • When read logon.dat • SIO/WIO/PGMEND • Generated by Obj2.c:Cpu() • When execute SIO/WIO/END instruction • EIO • Generated by Obj4.c:Sio_Service() University of Central Florida

7. Scheduler Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Select process to run Which Process to run: FCFS P2 ‘B’ P5 ‘B’ P4 ‘R’ P1 ‘R’ P3 ‘R’ Ready Queue University of Central Florida

8. Dispatcher Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Obj2.c: XPGM() Obj2.c: Cpu() Run one or several instructions (one cpu burst) University of Central Florida

9. Event Flow SIO Event Queue: Logon Logon Logon Logon Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Obj3:Logon_Service Script: Editor Editor Logoff P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 Obj3: Next_pgm University of Central Florida

10. Event Flow Event Queue: Logon SIO Logon SIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Script: Printer Logoff P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 P2: SIO 27 DISK 3000 SIO 15 PRNT 100 END 30 University of Central Florida

11. Event Flow EIO Event Queue: SIO WIO Logon SIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 Obj4:SIO_Service University of Central Florida

12. Event Flow Event Queue: WIO EIO Logon SIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() I/O have not finished Obj4:WIO_Service P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 P2: SIO 27 DISK 3000 SIO 15 PRNT 100 END 30 P1 PRNT Block University of Central Florida

13. Event Flow Event Queue: EIO Logon SIO WIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Obj4:EIO_Service P2: SIO 27 DISK 3000 SIO 15 PRNT 100 END 30 P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 Ready P1 PRNT Active Ready University of Central Florida

14. Event Flow Event Queue: PGMEND Logon SIO WIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Script: Editor Printer Logoff P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,1] END 17 Ready queue: P3: SIO 10 DISK 1000 WIO 0 REQ [0,1] END 37 P2 P3 University of Central Florida

15. Event Flow Event Queue: PGMEND SIO WIO Interrupt() Interrupt_ Handler() Scheduler() Dispatcher() Obj3: End_Service Script: Editor Editor Logoff P1: SIO 23 PRNT 100 SIO 32 DISK 300 WIO 0 REQ [0,3] END 17 P4: SIO 18 PRNT 200 SIO 5 PRNT 200 WIO 19 REQ [0,1] END 13 Obj3: Next_pgm Ready Queue P2 P3 P4 University of Central Florida

16. Device List SIO(R5) SIO(R7) EIO(R1) R1 R5 R7 DSK1 R3 DSK2 R6 PRNT University of Central Florida

17. Deadline • Deadline is Arp 4 (Friday) midnight • Late assignments are accepted five days after the due date with a penalty of 20 % off. After five days, assignments will not be accepted. The grade for those assignments will be zero. University of Central Florida