GATE CS 2026 Set 1 Q19 — Deadlock

To determine which statements are FALSE, let us analyze each option individually:

• Statement A: "Banker's algorithm is used to prevent deadlocks" — FALSE. Banker's algorithm is a deadlock avoidance algorithm, which dynamically checks the resource-allocation state to ensure that a circular-wait condition cannot occur. Deadlock prevention, on the other hand, is achieved by structurally eliminating at least one of the four Coffman conditions (mutual exclusion, hold and wait, no preemption, or circular wait).
• Statement B: "Deadlock formation can be prevented by ensuring that the hold and wait condition is not allowed" — TRUE. Eliminating the "hold and wait" condition (for example, by requiring a process to request all its required resources at once before execution starts) is a standard deadlock prevention strategy.
• Statement C: "An assignment edge in a resource allocation graph is marked from a process to a resource" — FALSE. In a Resource Allocation Graph (RAG):
  • A request edge is directed from a process to a resource ($P_i \to R_j$).
  • An assignment edge is directed from a resource to a process ($R_j \to P_i$).
• Statement D: "A safe state guarantees that all processes can finish without formation of a deadlock" — TRUE. By definition, a state is safe if the system can allocate resources to each process (up to its maximum claim) in some order and still avoid a deadlock. The existence of such a "safe sequence" guarantees that all processes can run to completion.

Since the question asks for the FALSE statements, the correct options are A and C.