BenchmarkTools

BenchmarkTools is a Julia package designed for reliable microbenchmarking of code blocks. It provides tools to measure execution time and memory allocations while aiming to minimize noise from just-in-time compilation, garbage collection, and other runtime effects. The package is widely used in the Julia community to evaluate performance changes and to compare alternative implementations.

Core capabilities include the macros @btime and @benchmark. @btime offers a quick, repeatable timing of an expression for simple estimates, balancing speed and accuracy. @benchmark conducts a larger, statistically robust series of measurements and returns a detailed result object that captures timing statistics and allocations. The tool set also performs warmup iterations to trigger compilation and caches before measurement, improving stability across runs.

The results produced by BenchmarkTools are designed to be reproducible and comparable. Output commonly includes concise summaries suitable for quick assessment, while detailed runs provide more thorough reports. Users can customize the number of samples, measurement duration, and other settings to fit their benchmarking goals. The library is designed to help identify bottlenecks, compare algorithm variants, and guide optimization decisions.

Usage typically involves importing the package and applying the macros to functions or expressions of interest to benchmark performance under representative inputs. This enables developers to quantify improvements, justify changes, and maintain performance guarantees as code evolves.

Development and ecosystem: BenchmarkTools is maintained by the Julia community as part of its benchmarking workflow and is distributed via Julia’s package manager. It integrates with related tooling and serves as a foundational component for reproducible performance analysis in Julia projects.