Monitor object
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The document discusses the monitor object pattern, which provides a thread-safe interface for shared objects. It allows multiple threads to safely access a shared passive object by encapsulating it within a monitor class that implements locking and notification. This prevents inconsistencies by allowing only one thread to access the shared object at a time. The pattern simplifies concurrency control and scheduling execution but can lead to complex extensibility issues and inheritance anomalies when the monitor object is tightly coupled. Examples provided are a thread-safe queue and connection pool.
Monitor object
- 1. Monitor Object charsyam@naver.com
- 3. Multiple Threads Shared Object
- 4. Thread-Safe
- 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
- 14. Monitor Object is Part Of Active Object
- 15. EXAMPLE
- 16. QUEUE
- 17. IN Multi-Thread
- 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
- 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
- 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!