28 lines
831 B
Rust
28 lines
831 B
Rust
use std::mem::size_of;
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use once_cell::sync::OnceCell;
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const N_THREADS: usize = 32;
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const N_ROUNDS: usize = 100_000_000;
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static CELL: OnceCell<usize> = OnceCell::new();
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fn main() {
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let start = std::time::Instant::now();
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let threads =
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(0..N_THREADS).map(|i| std::thread::spawn(move || thread_main(i))).collect::<Vec<_>>();
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for thread in threads {
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thread.join().unwrap();
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}
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println!("{:?}", start.elapsed());
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println!("size_of::<OnceCell<()>>() = {:?}", size_of::<OnceCell<()>>());
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println!("size_of::<OnceCell<bool>>() = {:?}", size_of::<OnceCell<bool>>());
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println!("size_of::<OnceCell<u32>>() = {:?}", size_of::<OnceCell<u32>>());
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}
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fn thread_main(i: usize) {
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for _ in 0..N_ROUNDS {
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let &value = CELL.get_or_init(|| i);
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assert!(value < N_THREADS)
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}
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}
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