Fastant

A drop-in replacement for std::time::Instant that measures time with high performance and high accuracy powered by Time Stamp Counter (TSC).

Usage

[dependencies]
fastant = "0.1"

fn main() {
    let start = fastant::Instant::now();
    let duration: std::time::Duration = start.elapsed();
}

Motivation

This library is used by a high performance tracing library fastrace. The main purpose is to use Time Stamp Counter (TSC) on x86 processors to measure time at high speed without losing much accuracy.

Platform Support

Currently, only the Linux on x86 or x86_64 is backed by Time Stamp Counter (TSC). On other platforms, Fastant falls back to std::time. If TSC is unstable, it will also fall back to std::time.

If speed is privileged over accuracy when fallback occurs, you can use fallback-coarse feature to use coarse time:

[dependencies]
fastant = { version = "0.1", features = ["fallback-coarse"] }