Cognitive Scaffold

Preparing your thinking workspace

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MENTAL MODEL · M6221

Polling

Polling
TechnicalHigh supportComputer Science
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Updated 2026-08-05

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INTRODUCTION

English translation pending.

CORE DEFINITION

In computing, polling is the practice of having the processor periodically read a device's status flag to determine whether it needs service. It is simple and predictable, and it suits small deterministic systems where the device is fast relative to the checking loop. Its cost is busy waiting: the processor spends cycles checking a device that usually has nothing to report, which is why interrupt-driven designs are preferred for slower or less predictable devices.

SCAFFOLDING EFFECT

psychology

Reduce cognitive load

- Check before asking: estimate how often the answer will be useful before polling again. - Use push instead: set up a signal that fires when something actually happens. - Respect the cost: count the cycles or attention your repeated checks consume.

anchor

Anchor fast decisions

Each poll spends a fixed amount of processor time to learn whether work exists. When the device is rarely ready, most of that time returns no information, so the cost scales with the polling frequency rather than with useful events. An interrupt inverts the relationship by having the device signal the processor, so cost tracks actual events instead of checks.

MINIMUM ACTION

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Source support: Explicit

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    zh.wikipedia.orghttps://zh.wikipedia.org/wiki/%E8%BC%AA%E8%A9%A2ZH · Explicit
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