tracing/tracing-subscriber/benches/support/mod.rs
2022-11-03 22:13:18 -04:00

75 lines
1.8 KiB
Rust

use std::{
io,
sync::{Arc, Barrier},
thread,
time::{Duration, Instant},
};
use tracing::dispatch::Dispatch;
#[derive(Clone)]
pub(super) struct MultithreadedBench {
start: Arc<Barrier>,
end: Arc<Barrier>,
dispatch: Dispatch,
}
#[allow(dead_code)]
impl MultithreadedBench {
pub(super) fn new(dispatch: Dispatch) -> Self {
Self {
start: Arc::new(Barrier::new(5)),
end: Arc::new(Barrier::new(5)),
dispatch,
}
}
pub(super) fn thread(&self, f: impl FnOnce() + Send + 'static) -> &Self {
self.thread_with_setup(|start| {
start.wait();
f()
})
}
pub(super) fn thread_with_setup(&self, f: impl FnOnce(&Barrier) + Send + 'static) -> &Self {
let this = self.clone();
thread::spawn(move || {
let dispatch = this.dispatch.clone();
tracing::dispatch::with_default(&dispatch, move || {
f(&this.start);
this.end.wait();
})
});
self
}
pub(super) fn run(&self) -> Duration {
self.start.wait();
let t0 = Instant::now();
self.end.wait();
t0.elapsed()
}
}
/// A fake writer that doesn't actually do anything.
///
/// We want to measure the collectors's overhead, *not* the performance of
/// stdout/file writers. Using a no-op Write implementation lets us only measure
/// the collectors's overhead.
pub(super) struct NoWriter;
#[allow(dead_code)]
impl io::Write for NoWriter {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
#[allow(dead_code)]
impl NoWriter {
pub(super) fn new() -> Self {
Self
}
}