Timewhile

Timewhile is a programming concept describing a loop that runs for a bounded period based on time rather than an internal logical condition. It repeats the body while the current time is before a predefined deadline or until a duration has elapsed. This makes time constraints explicit and portable across event-driven and real-time contexts.

Implementation commonly uses a time bound: set end = now() + duration, then loop while now() < end. Pseudo-code example:

timewhile end = now() + 5 seconds

perform task

end

The construct is useful for real-time data collection, UI timeouts, and controlled polling where a fixed wall-clock duration is required. It helps prevent unbounded looping when a condition may not be met promptly and aligns with deadline-driven scheduling in some systems.

Key considerations include clock choice and granularity. Monotonic clocks are preferred to avoid issues if system time changes. To avoid high CPU usage, the loop should yield or sleep between iterations and handle potential drift by re-checking the end condition periodically. Support for cancellation or external abort signals can improve robustness.

Timewhile is not a standard keyword in major languages; instead, developers implement it using traditional while or for loops combined with time API calls. In some real-time and embedded environments, timer-based or deadline-driven constructs resemble timewhile.

Related concepts include timeouts, polling loops, and deadline scheduling. It is typically discussed in the context of real-time programming and event-driven architectures.