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| lunch-box. ./bar --bench | |
| running 3 tests | |
| test cas ... bench: 561344 ns/iter (+/- 116303) | |
| test check ... bench: 194280 ns/iter (+/- 18843) | |
| test inc ... bench: 156670 ns/iter (+/- 4068) | |
| test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured | |
| lunch-box. ./bar --bench | |
| running 3 tests | |
| test cas ... bench: 520250 ns/iter (+/- 82140) | |
| test check ... bench: 172600 ns/iter (+/- 1340) | |
| test inc ... bench: 154067 ns/iter (+/- 1998) | |
| test result: ok. 0 passed; 0 failed; 0 ignored; 3 measured | |
| so somewhere around 10%-20% hit on this machine, acrichto saw better results. |
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| #![feature(core)] | |
| #![feature(test)] | |
| extern crate test; | |
| use std::intrinsics::abort; | |
| use std::thread; | |
| use std::sync::Arc; | |
| use std::sync::atomic::{AtomicIsize, Ordering}; | |
| const N: isize = 1000; | |
| const M: isize = 5; | |
| fn cas_inc(slot: &AtomicIsize) { | |
| loop { | |
| let val = slot.load(Ordering::SeqCst); | |
| if slot.compare_and_swap(val, val + 1, Ordering::SeqCst) == val { | |
| break | |
| } | |
| } | |
| } | |
| fn atomic_inc(slot: &AtomicIsize) { | |
| slot.fetch_add(1, Ordering::SeqCst); | |
| } | |
| fn atomic_inc_check(slot: &AtomicIsize) { | |
| let x = slot.fetch_add(1, Ordering::SeqCst); | |
| if x < 0 { | |
| unsafe { abort(); } | |
| } | |
| } | |
| fn doit(inc: fn(&AtomicIsize)) { | |
| let n = Arc::new(AtomicIsize::new(0)); | |
| let children = (0..M).map(|_| { | |
| let n = n.clone(); | |
| thread::spawn(move || { | |
| for _ in 0..N { | |
| inc(&n); | |
| } | |
| }) | |
| }).collect::<Vec<_>>(); | |
| for child in children { | |
| let _ = child.join(); | |
| } | |
| assert_eq!(n.load(Ordering::SeqCst), N * M); | |
| } | |
| #[bench] | |
| fn cas(b: &mut test::Bencher) { | |
| b.iter(|| doit(cas_inc)); | |
| } | |
| #[bench] | |
| fn inc(b: &mut test::Bencher) { | |
| b.iter(|| doit(atomic_inc)); | |
| } | |
| #[bench] | |
| fn check(b: &mut test::Bencher) { | |
| b.iter(|| doit(atomic_inc_check)); | |
| } |
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