1. Monitor Object
charsyam@naver.com

2. Multiple Threads

3. Multiple Threads
Shared Object

4. Thread-Safe

5. Passive-Object

6. Thread-Safe
Passive-Object
Pattern

7. Active Object
THREAD 1 THREAD 2
Processor
Caller ITEM 1
ITEM 1
ITEM 1

8. Active Object
Caller Thread
other-Threads
Process Thread

9. Passive Object
THREAD 1 THREAD 2
Processor Processor
ITEM 1
ITEM 1
ITEM 1

10. Passive Object
Each Thread Process
Shared Object

11. Active Object
VS
Monitor Object

12. Active Object
VS
Monitor Object

13. Monitor Object is

14. Monitor Object is
Part Of Active Object

15. EXAMPLE

16. QUEUE

17. IN
Multi-Thread

18. NEED
Synchronization
Mechanisms

19. THREAD 1 ITEM 1 THREAD 2
ITEM 2
ITEM 3
ITEM 4
ITEM 5

20. THREAD 1 ITEM 1 THREAD 2
ITEM 2
INSERT
ITEM 3
ITEM 4
ITEM 5

21. THREAD 1 ITEM 1 THREAD 2
ITEM 2
INSERT
ITEM 3 INSERT
ITEM 4
ITEM 5

22. THREAD 1 ITEM 1 THREAD 2
ITEM 2
INSERT
ITEM 3 INSERT
ITEM 4
ITEM 5
BROKEN

23. No Item
In
Queue

24. THREAD 1 THREAD 2
Pop
No Items

25. THREAD 1 THREAD 2
Pop
No Items
WAIT

26. THREAD 1 ITEM 1 THREAD 2
Insert
Pop
WAIT

27. THREAD 1 ITEM 1 THREAD 2
Insert
Pop
NOTIFY

28. THREAD 1 ITEM 1 THREAD 2
Pop

29. Monitor
Object

32. With
Thread-Safe
Interface

33. External Interface

34. Thread-Safe Interface

35. Lock and Notify – 1/2

36. Lock and Notify – 2/2

37. Lock and Notify – 2/2

38. Empty and Full

39. put

40. Get

41. SYNCH_STRATEGY 1/2

42. SYNCH_STRATEGY 2/2

43. Connection
Pool

44. Multi-Thread
Queue

45. Benefits
Simplification of concurrency control
Simplification of scheduling method
execution

46. Benefits
Simplification of concurrency control
Simplification of scheduling method
execution

47. Liabilities
Complicated extensibility of coupling
with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout

48. Liabilities
Complicated extensibility of coupling
with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout

49. Liabilities
Complicated extensibility of coupling
with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout

50. THANK
YOU!