SJSU CS 149 HW5 Fall 2017 Reminder: Each Homework Including

1sjsu Cs 149 Hw5 Fall 2017reminder Each Homework Including Programmi

Given resource type X with two instances, resource type Y with a single instance, and three threads. As illustrated in the resource allocation graph,

  • Thread 0 owns resource type Y’s instance and is waiting for resource type X.
  • Thread 1 owns one instance of resource type X.
  • Thread 2 owns the other instance of resource type X and is waiting for resource type Y.

a. Are Coffman conditions true in this state?

b. Is there any deadlock? Why or why not?

Paper For Above instruction

The question involves analyzing a resource allocation graph with specific resource and thread states to determine the presence of deadlock and the validity of Coffman conditions. This analysis is vital in understanding process synchronization, resource management, and deadlock prevention in operating systems.

Introduction

Coffman conditions refer to the necessary criteria for a deadlock to occur in a resource allocation system. Specifically, they include mutual exclusion, hold and wait, no preemption, and circular wait. When these conditions hold simultaneously, deadlock is possible. This paper examines whether these conditions are satisfied in the given scenario, and evaluates if a deadlock exists.

Analysis of the Resource Allocation State

The resource allocation graph provides a visual representation of resource ownership and waiting states among threads. Given that resource type X has two instances and Y has just one, we analyze each thread's state:

  • Thread 0 owns Y and waits for X: It holds one resource (Y) and is waiting for resources (X) which it does not currently hold.
  • Thread 1 owns one instance of X, and likely is not waiting for any resources (not specified in the prompt but assumed).
  • Thread 2 owns the other instance of X and waits for Y: It holds one X but is waiting for Y elsewhere.

Evaluating Coffman Conditions

Mutual exclusion holds because resources are assigned exclusively: each resource instance is owned by a single thread at a time. The hold and wait condition also holds, as threads hold resources while waiting for additional ones. No preemption condition holds, as resource ownership cannot be forcibly taken away; threads must release resources voluntarily. Circular wait condition is evaluated by tracing possible wait cycles. Here, Thread 0 waits for X, which is owned by Thread 1 or 2, and Thread 2 waits for Y owned by Thread 0, forming a cycle. Therefore, all four Coffman conditions are satisfied, indicating the potential for deadlock.

Deadlock Analysis

Despite all conditions being true, whether deadlock actually occurs depends on the specific state of resource allocation and process execution. Given the described scenario where each thread owns resources and is waiting for others, a circular wait cycle exists, confirming the presence of deadlock. The system is in a deadlock state if none of the threads can proceed because each is waiting for resources held by others, creating a cycle with no resource preemption or process termination mechanisms in place.

Conclusion

In this particular resource allocation state, all Coffman conditions are satisfied, and a deadlock is present. This highlights the importance of deadlock detection and prevention mechanisms such as resource ordering or early detection algorithms to avoid system stalling.

References

  • Silberschatz, A., Galvin, P. B., & Gagne, G. (2018). Operating System Concepts (10th ed.). Wiley.
  • Stallings, W. (2018). Operating Systems: Internals and Design Principles (9th ed.). Pearson.
  • Tanenbaum, A. S., & Bos, H. (2015). Modern Operating Systems (4th ed.). Pearson.
  • Coffman Jr, E. G., Elphick, M. J., & Shoshani, A. (1971). System deadlocks. ACM Computing Surveys (CSUR), 3(2), 67-78.
  • Holt, R. C. (1972). Some deadlock properties of computer systems. ACM Computing Surveys (CSUR), 4(2), 151-182.
  • Lea, D. (2011). Concurrent Programming in Java: Design Principles and Patterns. Addison-Wesley.
  • Harsh, M., & Garg, R. (2020). Operating System: A Study of Deadlock Detection and Prevention Techniques. International Journal of Computer Science and Engineering, 8(3), 45-54.
  • Peterson, J. L. (1981). Operating System Concepts. McGraw-Hill.
  • Kaur, P., & Singh, S. (2017). Deadlock Handling in Operating Systems: A Review. International Journal of Advanced Research in Computer Science, 8(2), 123-127.
  • Rajkumar, R., & Lehoczky, J. P. (1988). Resource management in real-time systems. IEEE Computer, 20(10), 14-25.

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