GATE CS 2015 Set 3 — Question 45
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.MCQ+2 / -0.67MediumDeadlock PreventionDeadlocksOperating System
Operating System → Deadlocks → Deadlock Prevention
Last updated
Question
Consider the following policies for preventing deadlock in a system with mutually exclusive resources.I. Processes should acquire all their resources at the beginning of execution. If any resource is not available, all resources acquired so far are released
II. The resources are numbered uniquely, and processes are allowed to request for resources only in increasing resource numbers
III. The resources are numbered uniquely, and processes are allowed to request for resources only in decreasing resource numbers
IV. The resources are numbered uniquely. A process is allowed to request only for a resource with resource number larger than its currently held resourcesWhich of the above policies can be used for preventing deadlock?
II. The resources are numbered uniquely, and processes are allowed to request for resources only in increasing resource numbers
III. The resources are numbered uniquely, and processes are allowed to request for resources only in decreasing resource numbers
IV. The resources are numbered uniquely. A process is allowed to request only for a resource with resource number larger than its currently held resourcesWhich of the above policies can be used for preventing deadlock?
Correct answer
(D) Any one of I, II, III, and IV
Solution
Deadlock prevention involves violating at least one of the four necessary conditions for deadlock (Mutual Exclusion, Hold and Wait, No Preemption, Circular Wait).
- Policy I: Requires processes to acquire all resources at the start. This violates the Hold and Wait condition because a process does not hold resources while waiting for others (it either gets all or none). Thus, it prevents deadlock.
- Policy II: Imposes a strict ordering (increasing) on resource requests. This violates the Circular Wait condition. If a cycle existed, it would imply , which is impossible. Thus, it prevents deadlock.
- Policy III: Imposes a strict ordering (decreasing). Similar to II, this also prevents cycles and violates Circular Wait. Thus, it prevents deadlock.
- Policy IV: This is effectively the same as Policy II (requesting only resources with larger numbers). It enforces an increasing order, preventing Circular Wait.
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE CS question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Deadlocks
2026 Set 2 Q23Which one of the following CPU scheduling algorithms cannot be preemptive?2026 Set 1 Q29With respect to deadlocks in an operating system, which of the following statements is/are FALSE?2026 Set 1 Q31In the context of relational database normalization, which of the following statements is/are true?2026 Set 1 Q35Consider a system consisting of instances of a resource , being shared by 5 processes.…2026 Set 2 Q51Consider three processes P1, P2, and P3 running identical code, as shown in the pseudocode below. A…