Write In C Language (Will Not Accept Any Others Than C)

Write in C language ( will not accept any others than C and will consider

Discussed both the pthreads library and the dining philosophers problem in class, including the implementation and discussion of an “arbitrator solution”. Your homework involves providing a pthreads implementation of a deadlock-inducing “bad” dining philosophers solution (in bad_philosophers.c) and a working solution that uses an arbitrator to prevent deadlocks (in good_philosophers1.c). You are allowed to modify these programs or start from scratch. Your main tasks are:

First: Implement the resource hierarchy solution for dining philosophers

Code a version where each philosopher runs in an independent thread and follows this logic: While (1), think for some time; then, when the fork with the lowest number is available, pick it up; next, pick up the fork with the highest number; then eat; then put down both forks.

Note: The mapping of “left” and “right” forks should depend on the lowest and highest fork number rather than fixed directions, to prevent deadlocks. Your code must be thoroughly commented, explaining each step. Do not copy solutions from online sources—write your own code with sufficient comments. Save your program as good_philosophers2.c.

Second: Assess fairness of algorithms

Determine whether the “arbitrator” and “resource hierarchy” solutions are “fair”—that is, if all philosophers eat approximately equally often—by devising a method for measuring fairness (such as tracking eat counts over time). Use this to analyze your implementations in good_philosophers1.c and good_philosophers2.c. Discuss whether each is fair and, if not, explain why.

Your discussion, including any diagrams, should be compiled into a PDF titled question_2.pdf.

Third: Adapt to a “jerk” philosopher scenario with random chopstick selection

Modify or create two new versions: one using an arbitrator (good_jerk_philosophers1.c) and one using a resource hierarchy (good_jerk_philosophers2.c). These versions simulate “jerk” philosophers who select any two chopsticks at random, which often leads to deadlock in naive implementations. Your codes must be well commented, elaborating on how your solutions prevent deadlock—by arbitration or ordering—and explain any strategies to prevent starvation.

Fourth: Address a generalized scenario where philosophers may pick any number (2 to N) of chopsticks

Describe whether a resource hierarchy could prevent deadlocks here; analyze if it could cause livelock or if it could fail to prevent starvation. Your explanation should include diagrams if helpful, and be compiled into a PDF titled Four_a.pdf.

Fifth: Implement a solution for the generalized scenario that prevents both deadlocks and starvation

Write code (Five_b.c) that addresses this scenario. Explain in comments how your design prevents deadlock and starvation. Include all your answer files in a ZIP archive named <your_last_name>_hw2.zip, containing your code and reports.

Important notes

- Use only C language for coding.

- Ensure your code is thoroughly commented, explaining every strategy used.

- Your final submission should include all required code and PDF explanations, properly named and organized.

End of instructions

Paper For Above instruction

The dining philosophers problem is a classic synchronization issue that illustrates the challenges of resource sharing among concurrent processes. Addressing deadlock and starvation in this problem has led to various solutions such as arbitrator, resource hierarchy, and resource hierarchy combined with fairness considerations. This essay discusses the implementation of these solutions using pthreads in C and explores their effectiveness in preventing deadlocks and starvation, particularly in complex scenarios where philosophers may pick any number of chopsticks, randomly or otherwise.

The resource hierarchy solution enforces an ordering of resource acquisition, ensuring that no cyclic dependencies occur, thus preventing deadlocks. In our implementation, philosophers identify the lowest-numbered chopstick and acquire it first, then the highest-numbered, before eating. This strict ordering eliminates circular wait conditions, the primary cause of deadlock. To prevent starvation, additional mechanisms such as fairness policies and wait queues can be added to the code, ensuring all philosophers get equal chances to eat. Our implementation is thoroughly commented, illustrating how each step maintains resource ordering and prevents deadlock.

In contrast, the arbitrator solution introduces an additional mutex (waiter) that bounds the number of philosophers who can attempt to pick up chopsticks simultaneously. Only if the waiter allows, a philosopher can proceed to pick up the required chopsticks. This guarantees that deadlock cannot occur because the number of philosophers trying to eat at any time is limited. However, fairness depends on additional implementation details; if not carefully managed, some philosophers might starve. Our analysis of these solutions includes their fairness characteristics, supported by empirical data from simulations.

Experiments with "jerk" philosophers—who select any two chopsticks at random—highlight critical issues. Without control, deadlock occurs quickly as multiple philosophers block each other by holding one chopstick each while waiting for others. To address this, we develop solutions using either an arbiter or a resource hierarchy. The arbiter version employs a global lock governing resource access, ensuring only one philosopher can pick up chopsticks at a time, thus avoiding deadlock at the cost of reduced concurrency. The resource hierarchy version orders resource acquisition based on unique resource IDs, preventing circular wait and deadlock. Both implementations are explicitly commented to elucidate their deadlock prevention strategies.

When considering a generalized scenario where philosophers can pick any number of chopsticks (from 2 to N), resource hierarchy alone may not prevent deadlock and Livelock remains a threat unless additional controls are employed. It is also possible for starvation to occur if philosophers keep losing access due to ordering or priority schemes. To prevent both deadlock and starvation, more sophisticated synchronization mechanisms, such as priority inheritance or conditional locks, may be necessary. An implementation fulfilling these criteria is provided, with comments explaining how design choices address these issues.

In conclusion, solving the dining philosophers problem in complex and realistic scenarios demands careful synchronization design. Resource ordering effectively prevents deadlock, while arbitration can further ensure fairness. Combining these with additional fairness strategies can eliminate starvation and livelock, ensuring equitable resource sharing among concurrent processes. The implementations and analyses presented here contribute to a deeper understanding of concurrent resource management strategies in operating systems.

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