1. Thread Model of Java

2. Thread model of Java
• All the class libraries are designed multithreading in
mind
• Java uses threads to enable entire system to be
asynchronous
• Once a thread has been started
• It can be suspended
• Suspended thread can be resumed
• It may be stopped
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3. Thread model of Java contd..
• Thread features
• Creation of threads
• Context switch
• Thread priorities
• Synchronization
• Messaging
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4. Creation of Threads
• Java provides two ways for creating threads by
• Extending Thread class
• Implementing Runnable interface
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5. Context Switch
• Switch from one thread to other
• Two ways of context switch
• Thread can voluntarily relinquish control by
• Explicitly yielding
• Sleeping
• Blocking on pending I/O
• Context switch is done by selecting the highest priority thread
• Pre-emption
• Occurs when a high priority enters while executing a low
priority thread
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6. Thread Priorities
• Thread priorities are simple integers
• Ranging from 1 to 10
• A relative measure
• Higher the priority – brighter the chances of getting
executed first
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7. Synchronization
• As threads introduces asynchronous behavior in Java
programs
• Synchronization is needed when two or more
threads work with a shared resource
• ‘Monitor’ feature is used in Java to implement
Synchronization
• Monitors are used mutually exclusive
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8. Synchronization contd..
• There is no special monitor class in Java
• Every object has its own implicit monitor
• Two ways to show synchronization
• synchronized methods
• synchronized statements
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9. Messaging
• Java threads communicate with each other through
• notify() method
• wait() method
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10. Summary
In this class ,you have learnt
• Thread basics
• Process
• Definition of thread
• Comparison of process and thread
• Thread model of Java
• Features of Java that implemented threads
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11. Frequently Asked Questions
1. Compare a process and a thread
2. Which methods are useful for messaging in Java
3. Explain the thread model of Java
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12. Quiz
1. Which one of the following is a thread ?
a) MS-Word
b) Windows Explorer
c) Spell checker in MS-Word
d) Notepad
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13. Quiz Contd..
2. Which statement is true?
a) Thread does not depend on resources of any
process
b) Each Thread has its own heap memory
c) A Thread share heap with other threads
d) None

14. Home
Exception Handling
Graphical User Interface Programming (GUI)
Previous Java question papers with Answers for polytechnic
diploma (jntu)
OCT/NOV-2012 QUESTION PAPER
April / May 2012 c-09
October/ November-2011 c-09
April/ May 2011 c-09
APRIL/MAY-2011 (C-05)
Internal Lab question paper
External Lab question paper
BTECH JNTU LAB MANUAL
Lab practice
Core java interview questions