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authorValentin Popov <valentin@popov.link>2024-07-19 15:37:58 +0300
committerValentin Popov <valentin@popov.link>2024-07-19 15:37:58 +0300
commita990de90fe41456a23e58bd087d2f107d321f3a1 (patch)
tree15afc392522a9e85dc3332235e311b7d39352ea9 /vendor/once_cell/examples/bench_acquire.rs
parent3d48cd3f81164bbfc1a755dc1d4a9a02f98c8ddd (diff)
downloadfparkan-a990de90fe41456a23e58bd087d2f107d321f3a1.tar.xz
fparkan-a990de90fe41456a23e58bd087d2f107d321f3a1.zip
Deleted vendor folder
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-rw-r--r--vendor/once_cell/examples/bench_acquire.rs39
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diff --git a/vendor/once_cell/examples/bench_acquire.rs b/vendor/once_cell/examples/bench_acquire.rs
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--- a/vendor/once_cell/examples/bench_acquire.rs
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@@ -1,39 +0,0 @@
-//! Benchmark the overhead that the synchronization of `OnceCell::get` causes.
-//! We do some other operations that write to memory to get an imprecise but somewhat realistic
-//! measurement.
-
-use once_cell::sync::OnceCell;
-use std::sync::atomic::{AtomicUsize, Ordering};
-
-const N_THREADS: usize = 16;
-const N_ROUNDS: usize = 1_000_000;
-
-static CELL: OnceCell<usize> = OnceCell::new();
-static OTHER: AtomicUsize = AtomicUsize::new(0);
-
-fn main() {
- let start = std::time::Instant::now();
- let threads =
- (0..N_THREADS).map(|i| std::thread::spawn(move || thread_main(i))).collect::<Vec<_>>();
- for thread in threads {
- thread.join().unwrap();
- }
- println!("{:?}", start.elapsed());
- println!("{:?}", OTHER.load(Ordering::Relaxed));
-}
-
-#[inline(never)]
-fn thread_main(i: usize) {
- // The operations we do here don't really matter, as long as we do multiple writes, and
- // everything is messy enough to prevent the compiler from optimizing the loop away.
- let mut data = [i; 128];
- let mut accum = 0usize;
- for _ in 0..N_ROUNDS {
- let _value = CELL.get_or_init(|| i + 1);
- let k = OTHER.fetch_add(data[accum & 0x7F] as usize, Ordering::Relaxed);
- for j in data.iter_mut() {
- *j = (*j).wrapping_add(accum);
- accum = accum.wrapping_add(k);
- }
- }
-}