Macro duration_span

macro_rules! duration_span {
    ($name:literal) => { ... };
    ($name:literal, $($arg:tt)+) => { ... };
}

Creates a event-based span that traces a certain duration (lifetime of the guard). It’s not a real span, which means it can be used across threads.

It will trace a duration and not the time the cpu is doing actual work. This way it can be used to trace non-cpu-time or time that is spend in other processes.