use std::panic::{catch_unwind, AssertUnwindSafe};
use std::sync::{Arc, Mutex};
use std::time::{Duration, Instant};
use std::{cmp, io};
use super::event::CompletedTest;
use super::options::BenchMode;
use super::test_result::TestResult;
use super::types::{TestDesc, TestId};
use super::Sender;
use crate::stats;
#[inline(always)]
pub fn black_box<T>(dummy: T) -> T {
std::hint::black_box(dummy)
}
#[derive(Clone)]
pub struct Bencher {
mode: BenchMode,
summary: Option<stats::Summary>,
pub bytes: u64,
}
impl Bencher {
pub fn iter<T, F>(&mut self, mut inner: F)
where
F: FnMut() -> T,
{
if self.mode == BenchMode::Single {
ns_iter_inner(&mut inner, 1);
return;
}
self.summary = Some(iter(&mut inner));
}
pub fn bench<F>(&mut self, mut f: F) -> Result<Option<stats::Summary>, String>
where
F: FnMut(&mut Bencher) -> Result<(), String>,
{
let result = f(self);
result.map(|_| self.summary)
}
}
#[derive(Debug, Clone, PartialEq)]
pub struct BenchSamples {
pub ns_iter_summ: stats::Summary,
pub mb_s: usize,
}
pub fn fmt_bench_samples(bs: &BenchSamples) -> String {
use std::fmt::Write;
let mut output = String::new();
let median = bs.ns_iter_summ.median;
let deviation = bs.ns_iter_summ.max - bs.ns_iter_summ.min;
write!(
output,
"{:>14} ns/iter (+/- {})",
fmt_thousands_sep(median, ','),
fmt_thousands_sep(deviation, ',')
)
.unwrap();
if bs.mb_s != 0 {
write!(output, " = {} MB/s", bs.mb_s).unwrap();
}
output
}
fn fmt_thousands_sep(mut n: f64, sep: char) -> String {
use std::fmt::Write;
let mut output = String::new();
let mut trailing = false;
for &pow in &[9, 6, 3, 0] {
let base = 10_usize.pow(pow);
if pow == 0 || trailing || n / base as f64 >= 1.0 {
match (pow, trailing) {
(0, true) => write!(output, "{:06.2}", n / base as f64).unwrap(),
(0, false) => write!(output, "{:.2}", n / base as f64).unwrap(),
(_, true) => write!(output, "{:03}", n as usize / base).unwrap(),
_ => write!(output, "{}", n as usize / base).unwrap(),
}
if pow != 0 {
output.push(sep);
}
trailing = true;
}
n %= base as f64;
}
output
}
fn ns_iter_inner<T, F>(inner: &mut F, k: u64) -> u64
where
F: FnMut() -> T,
{
let start = Instant::now();
for _ in 0..k {
black_box(inner());
}
start.elapsed().as_nanos() as u64
}
pub fn iter<T, F>(inner: &mut F) -> stats::Summary
where
F: FnMut() -> T,
{
let ns_single = ns_iter_inner(inner, 1);
let ns_target_total = 1_000_000; let mut n = ns_target_total / cmp::max(1, ns_single);
n = cmp::max(1, n);
let mut total_run = Duration::new(0, 0);
let samples: &mut [f64] = &mut [0.0_f64; 50];
loop {
let loop_start = Instant::now();
for p in &mut *samples {
*p = ns_iter_inner(inner, n) as f64 / n as f64;
}
stats::winsorize(samples, 5.0);
let summ = stats::Summary::new(samples);
for p in &mut *samples {
let ns = ns_iter_inner(inner, 5 * n);
*p = ns as f64 / (5 * n) as f64;
}
stats::winsorize(samples, 5.0);
let summ5 = stats::Summary::new(samples);
let loop_run = loop_start.elapsed();
if loop_run > Duration::from_millis(100)
&& summ.median_abs_dev_pct < 1.0
&& summ.median - summ5.median < summ5.median_abs_dev
{
return summ5;
}
total_run += loop_run;
if total_run > Duration::from_secs(3) {
return summ5;
}
n = match n.checked_mul(10) {
Some(_) => n * 2,
None => {
return summ5;
}
};
}
}
pub fn benchmark<F>(
id: TestId,
desc: TestDesc,
monitor_ch: Sender<CompletedTest>,
nocapture: bool,
f: F,
) where
F: FnMut(&mut Bencher) -> Result<(), String>,
{
let mut bs = Bencher { mode: BenchMode::Auto, summary: None, bytes: 0 };
let data = Arc::new(Mutex::new(Vec::new()));
if !nocapture {
io::set_output_capture(Some(data.clone()));
}
let result = catch_unwind(AssertUnwindSafe(|| bs.bench(f)));
io::set_output_capture(None);
let test_result = match result {
Ok(Ok(Some(ns_iter_summ))) => {
let ns_iter = cmp::max(ns_iter_summ.median as u64, 1);
let mb_s = bs.bytes * 1000 / ns_iter;
let bs = BenchSamples { ns_iter_summ, mb_s: mb_s as usize };
TestResult::TrBench(bs)
}
Ok(Ok(None)) => {
let samples: &mut [f64] = &mut [0.0_f64; 1];
let bs = BenchSamples { ns_iter_summ: stats::Summary::new(samples), mb_s: 0 };
TestResult::TrBench(bs)
}
Err(_) => TestResult::TrFailed,
Ok(Err(_)) => TestResult::TrFailed,
};
let stdout = data.lock().unwrap().to_vec();
let message = CompletedTest::new(id, desc, test_result, None, stdout);
monitor_ch.send(message).unwrap();
}
pub fn run_once<F>(f: F) -> Result<(), String>
where
F: FnMut(&mut Bencher) -> Result<(), String>,
{
let mut bs = Bencher { mode: BenchMode::Single, summary: None, bytes: 0 };
bs.bench(f).map(|_| ())
}