Instrumentwhile

Instrumentwhile is a proposed control-flow primitive that combines the semantics of a while loop with integrated runtime instrumentation. In theoretical discussions and some experimental tooling, instrumentwhile refers to a loop construct that automatically triggers instrumentation hooks at the start of the loop, during each iteration, and at exit, enabling precise collection of performance, resource usage, and correctness data without scattering instrumentation code throughout the body.

Semantics and design considerations typically describe instrumentwhile as behaving like a standard while loop in terms of condition evaluation, but wrapping the execution with instrumentation events. Common hooks include onEntry, onIter, and onExit. The instrumentation configuration may be static or dynamic, allowing users to enable or disable data collection, adjust granularity, or switch between low-overhead and detailed modes.

Usage scenarios for instrumentwhile emphasize profiling, runtime tracing, debugging, and verification. It can support adaptive strategies, such as selectively activating instrumentation for iterations that meet certain criteria, streaming metrics to external analyzers, or recording invariants at loop boundaries. The concept aims to reduce boilerplate while facilitating consistent data collection across loops.

Example in pseudo-code:

instrumentwhile (cond) {

onEntry();

while (cond) {

body;

onIter();

}

onExit();

}

Implementation and portability considerations: instrumentwhile is not yet standardized and would rely on language features (such as macros or compiler support) or external libraries to provide the instrumentation hooks. Key concerns include overhead, thread-safety, reentrancy, and effect on loop termination. Privacy and data-volume management are also important when collecting detailed metrics.

See also: while loop, instrumentation, profiling, tracing, aspect-oriented programming.