Deadlocks — classic algorithms: Banker's algorithm for resource allocation is used for which purpose?

Introduction / Context:
Deadlocks occur when processes wait indefinitely for resources held by each other. Operating systems employ strategies such as prevention, avoidance, detection, and recovery. Banker’s algorithm is a canonical approach; understanding its category is fundamental in OS design.

Given Data / Assumptions:

• Processes declare maximum resource needs.
• The system can simulate allocations to test for a safe state.
• A safe sequence exists if every process can finish given available and future releases.

Concept / Approach:

Banker’s algorithm is a deadlock avoidance technique. Before granting a request, the OS checks whether doing so keeps the system in a safe state. If not safe, the request is deferred. Unlike prevention, it does not structurally constrain resource usage; unlike recovery, it does not roll back after deadlock occurs.

Step-by-Step Solution:

Verification / Alternative check:

Algorithm descriptions explicitly categorize it under “avoidance” because it anticipates unsafe allocations and refuses them preemptively.

Why Other Options Are Wrong:

• Prevention: Enforces rules (e.g., ordering resources) to make deadlock impossible; not Banker’s approach.
• Recovery: Involves detection and rollback/termination after deadlock.
• Mutual exclusion: A necessary condition for deadlock, not a resolution technique.
• None of the above: Incorrect because avoidance is correct.

Common Pitfalls:

Confusing “safe state” (avoidance) with “deadlock-free state” guaranteed by prevention. Also, assuming real systems always know maximum needs; often they do not, limiting practical use.

Final Answer:

deadlock avoidance