Consider the statements given below: I) There are two queues for accommodating processes...
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Consider the statements given below:
I) There are two queues for accommodating processes named as NEW and ACCEPTED.
II) The CPU time slice is only available to the processes in the ACCEPTED queue.
III) A limit is mandatory for the number of processes which can be present in the process queue at a time.
Which one of the scheduling algorithms given in options does the information given in the statements points to?
Show answer & explanation
The Selfish Round Robin (SRR) algorithm maintains two separate queues: a NEW queue for incoming processes and an ACCEPTED queue for processes eligible for CPU time allocation. Only processes in the ACCEPTED queue receive CPU time slices, while a limit is enforced on how many processes can exist in each queue at any time. This matches all three statements perfectly. In contrast, standard Round Robin uses a single queue, Skip Round Robin skips processes meeting certain criteria, and Multilevel Queue Scheduling uses multiple queues with different priority levels but doesn't specifically implement the NEW/ACCEPTED distinction with time-slice restriction.
Step-by-step Derivation:
Analysis of each statement:
Statement I: Two queues (NEW and ACCEPTED) → Eliminates standard Round Robin (single queue).
Statement II: CPU time slice only for ACCEPTED queue → Indicates a pre-acceptance filtering mechanism not found in standard Round Robin or Skip Round Robin.
Statement III: Limit on queue size → Enforces bounded queue capacity, preventing unlimited process accumulation.
SRR specifically implements this design: processes start in NEW queue, gradually transition to ACCEPTED queue based on a fairness criterion, and only ACCEPTED processes compete for CPU time. Queue sizes are bounded to prevent system overload. This three-part structure uniquely identifies Selfish Round Robin among the options.