Function easybench::bench_env

source ·
pub fn bench_env<F, I, O>(env: I, f: F) -> Statswhere
    F: FnMut(&mut I) -> O,
    I: Clone,
Expand description

Run a benchmark with an environment.

The value env is a clonable prototype for the “benchmark environment”. Each iteration receives a freshly-cloned mutable copy of this environment. The time taken to clone the environment is not included in the results.

Nb: it’s very possible that we will end up allocating many (>10,000) copies of env at the same time. Probably best to keep it small.

See bench and the module docs for more.


Every iteration, bench_env performs a lookup into a big vector in order to get the environment for that iteration. If your benchmark is memory-intensive then this could, in the worst case, amount to a systematic cache-miss (ie. this vector would have to be fetched from DRAM at the start of every iteration). In this case the results could be affected by a hundred nanoseconds. This is a worst-case scenario however, and I haven’t actually been able to trigger it in practice… but it’s good to be aware of the possibility.