1. 4 CPU : 1 2 3 n :, 4-2 1

2. 4-3 4-4 2

3. Components of an operating system 4-5 : (multiprogramming) CPU : : 4-6 3

4. I/O I/O CPU CPU 4-7 : , CPU,CPU . , : : : :, , 4-8 4

5. vs. (event-driven) (time-driven) 4-9 : :, CPU, : DOS Mac IS Windows Linux 4-10 5

6. : :, : : :, (), : 4-11 CPU : CPU CPU:,CPU CPU: (I/O) () (I/O) 4-12 6

7. CPU 1 3 5 I/O 2 I/O 4 4-13 CPU (nonpreemptive) CPU, ,CPU (preemptive) , ,CPU , CPU 4-14 7

8. CPU: :(first in first out), : () P1 1 15 P2 2 3 P3 3 3 (gantt chart): P1 P2 P3 0 15 18 21 4-15 (First Come First Serve) () () P1 0 P2 15 P3 18 11 : () P1 3 15 P2 1 3 P3 2 3 4-16 8

9. : P2 P3 P1 0 3 6 21 : () () P1 6 P2 0 P3 3 3 4-17 (Short Job First) () P1 7 P2 3 P3 5 : P2 P3 P1 0 3 8 15 4-18 9

10. () () P1 8 P2 0 P3 3 3.67 P1 P2 P3 5.67 P1 P3 P2 6.44 P2 P1 P3 4.33 P2 P3 P1 3.67 P3 P1 P2 5.67 P3 P2 P1 4.33 4-19 4-20 10

11. (Priority Scheduling) () P1 3 7 P2 1 5 P3 2 4 P2 P3 P1 0 5 9 16 4-21 Priority 4-22 11

12. (Round Robin Scheduling) CPU (time slice) CPU CPU 4-23 () P1 17 1 P2 3 2 P3 8 3 :=5 P1 P2 P3 P1 P3 P1 P1 0 5 8 13 18 21 26 28 4-24 12

13. : :, : :, 4-25 : 4-26 13

14. , CPU < 4-27 - (Partitioned Memory Management) (Mutiprogramming) ( Static partition ) ( Dynamic partition ) 4-28 14

15. - (Partitioned Memory Management) 4-29 - ( Static partition ) (1), (2) (Internal Fragmentation) 4-30 15

16. - ( Dynamic partition ) (1) (2) (External Fragmentation): 4-31 - 400k P1P2P3P4 200k300k330k150k 4-32 16

17. - ( Relocated Partitioned Memory Management) (Compaction)(Relocation) (1)(Fragmentation) (2) (1) (2) 4-33 - (a)A(90K)B(85K)C(60K) D(60K)40K50K D (b) (c)60K 60KD 4-34 17

18. - (Paged Memory Management ) () ( ) (Page) (Page) () ( ) (Frame) (Frame) 4-35 , , 20K 30K 10K 80K 1 2 70K 4-36 18

19. , 1 P1 2 P2 4-37 - ( Virtual Memory ) ()( ) 4-38 19

20. (1) (2) (3) (4)(///.) : : :, : : : : 4-39 (record) (batch file) (command) 4-40 20

21. 4-41 : 4-42 21

22. : , user1 user2 user3 user4 home- gam tem home- home- gam test test test data mail work e p work work e 4-43 :root/user1/homework/hw1.doc :/homework/hw1.doc 4-44 22