Difficulty: Easy
Correct Answer: spooling
Explanation:
Introduction / Context:
Operating systems often decouple the production of data from its consumption by slow peripherals (like printers). A classic technique is to queue output to disk and process it later, improving throughput and user responsiveness.
Given Data / Assumptions:
Concept / Approach:
SPOOL stands for Simultaneous Peripheral Operations On-Line. The OS writes jobs (for example, print jobs) to a spool directory on disk. A background service (spooler) then feeds the device at its own pace. This design prevents applications from blocking on slow device operations and allows job reordering or prioritization.
Step-by-Step Solution:
Verification / Alternative check:
Printer queues and mail queues are standard examples of spooling; system administration tools show jobs in the spool directory being processed asynchronously.
Why Other Options Are Wrong:
Multiprogramming: CPU scheduling concept. Caching: performance optimization in fast memory, not disk queuing for devices. Virtual programming: not a recognized OS concept.
Common Pitfalls:
Confusing caching with spooling because both improve responsiveness; caching is about read performance, spooling is about deferred writes/outputs.
Final Answer:
spooling
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