Operating systems that react in actual time What is the name of an operating system that reads inputs and reacts within strict time constraints (actual time)?

Introduction / Context:
Real time operating systems (RTOS) are designed for deterministic response. They are used in embedded control, aerospace, medical devices, and industrial automation where missing a deadline can degrade quality or cause failure. This question asks for the correct term for such systems.

Given Data / Assumptions:

• Deterministic timing is required, not merely high throughput.
• Deadlines may be hard (must meet) or soft (prefer to meet).
• OS must provide predictable scheduling and interrupt handling.

Concept / Approach:

An RTOS schedules tasks based on deadlines and priorities to guarantee bounded latency. This differs from time sharing, which optimizes fairness and interactivity but not strict deadlines, and from batch systems, which optimize throughput without interactive or real time guarantees.

Step-by-Step Solution:

Verification / Alternative check:

Examples include VxWorks, QNX, FreeRTOS, and RT Linux variants. Their documentation emphasizes bounded interrupt latency and priority based preemptive schedulers.

Why Other Options Are Wrong:

a: batch focuses on throughput. b: “quick response” is a vague description without deterministic guarantees. d: time sharing provides responsiveness but not hard deadlines.

Common Pitfalls:

Confusing fast average response with deterministic worst case response; ignoring that real time systems can be low power and small footprint.

Final Answer:

Real time system.