Concurrency_and_Deadlocks_Presentation.pptx

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1. Concurrency and Deadlocks in Operating Systems Concepts, Principles, and Mechanisms Your Name Date

2. Introduction to Concurrency • Management of multiple processes (multiprogramming, multiprocessing, distributed processing) • Mutual exclusion as a key requirement • Importance of Concurrency in OS

3. Principles of Concurrency • Ability to load and execute multiple programs simultaneously • Communication, synchronization, and resource allocation • Types of Concurrency: • Multiple applications • Structured applications • OS structure

4. Key Terminologies in Concurrency • Atomic Operation • Critical Section • Race Condition • Starvation

5. Process Interaction Types • Competition: Processes unaware of each other • Cooperation by Sharing: Indirect awareness • Cooperation by Communication: Direct awareness

6. Concurrency Mechanisms • Counting Semaphore • Binary Semaphore • Mutex (Mutual Exclusion) Lock • Condition Variables • Spinlocks, Monitors, Event Flags, Message Passing

7. Introduction to Deadlocks • Definition: Permanent blocking of processes • Involves competing for system resources or communication

8. Resource Categories for Deadlocks • Reusable Resources • Consumable Resources

9. Conditions for Deadlock 1. Mutual Exclusion 2. Hold and Wait 3. No Preemption 4. Circular Wait

10. Deadlock Prevention • Design system to disallow at least one of the four conditions • Prevent mutual exclusion, hold and wait, or no preemption • Circular wait can be prevented by resource ordering

11. Deadlock Avoidance • Make judicious choices to avoid deadlock • Requires knowledge of future resource requests • Methods: • Process initiation denial • Resource allocation denial

12. Deadlock Detection and Recovery • Periodically check for circular wait • Recovery Strategies: • Abort deadlocked processes • Back up and restart • Successively abort or preempt resources

13. Conclusion • Concurrency improves performance but introduces complex challenges • Deadlock prevention, avoidance, and detection strategies are essential for OS reliability