Monitor object
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Monitor Object [email protected]
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description
Transcript of Monitor object
Multiple Threads
Multiple Threads
Shared Object
Thread-Safe
Passive-Object
Thread-Safe
Passive-Object Pattern
Active Object
THREAD 1
THREAD 2
Caller ITEM 1
ITEM 1
ITEM 1
Processor
Active Object
Caller Thread
other-Threads
Process Thread
Passive Object
THREAD 1
THREAD 2
ITEM 1
ITEM 1
ITEM 1
Processor Processor
Passive Object
Each Thread Process
Shared Object
Active Object
Monitor Object
VS
Active Object
Monitor Object
VS
Monitor Object is
Monitor Object is
Part Of Active Object
EXAMPLE
QUEUE
IN Multi-Thread
NEED Synchronization
Mechanisms
ITEM 1
ITEM 2
ITEM 3
ITEM 4
ITEM 5
THREAD 1 THREAD 2
ITEM 1
ITEM 2
ITEM 3
ITEM 4
ITEM 5
THREAD 1 THREAD 2
INSERT
ITEM 1
ITEM 2
ITEM 3
ITEM 4
ITEM 5
THREAD 1 THREAD 2
INSERT INSERT
ITEM 1
ITEM 2
ITEM 3
ITEM 4
ITEM 5
THREAD 1 THREAD 2
INSERT INSERT
BROKEN
No Item In
Queue
No Items
THREAD 1 THREAD 2
Pop
No Items
THREAD 1 THREAD 2
Pop
WAIT
THREAD 1 THREAD 2
Pop
WAIT
ITEM 1
Insert
THREAD 1 THREAD 2
Pop
NOTIFY
ITEM 1
Insert
THREAD 1 THREAD 2
Pop
ITEM 1
Monitor Object
With Thread-Safe Interface
External Interface
Thread-Safe Interface
Lock and Notify – 1/2
Lock and Notify – 2/2
Lock and Notify – 2/2
Empty and Full
put
Get
SYNCH_STRATEGY 1/2
SYNCH_STRATEGY 2/2
Connection Pool
Multi-Thread Queue
Benefits
Simplification of concurrency control
Simplification of scheduling method execution
Benefits
Simplification of concurrency control
Simplification of scheduling method execution
Liabilities
Complicated extensibility of coupling with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout
Liabilities
Complicated extensibility of coupling with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout
Liabilities
Complicated extensibility of coupling with Monitor Object’s
Inheritance anomaly
Nested Monitor Lockout
THANK YOU!
