许可证

MIT 和 Apache-2.0

VoluntaryServitude 示例

• 单线程
• 多生产者，多消费者

单线程

use voluntary_servitude::vs;

fn main() {
    let (a, b, c) = (0usize, 1usize, 2usize);
    // VS alias to VoluntaryServitude
    // vs! alias to voluntary_servitude! (and operates like vec!)
    let list = vs![a, b, c];
    assert_eq!(list.iter().collect::<Vec<_>>(), vec![&a, &b, &c]);

    // Current VS's length
    // Be careful with race conditions since the value, when used, may not be true anymore
    assert_eq!(list.len(), 3);

    // The 'iter' method makes a lock-free iterator (Iter)
    for (index, element) in list.iter().enumerate() {
        assert_eq!(index, *element);
    }

    // You can get the current iteration index
    // iter.index() == iter.len() means iteration ended (iter.next() == None)
    let mut iter = &mut list.iter();
    assert_eq!(iter.index(), 0);
    assert_eq!(iter.next(), Some(&0));
    assert_eq!(iter.index(), 1);

    // List can also be cleared (but current iterators are not affected)
    list.clear();

    assert_eq!(iter.len(), 3);
    assert_eq!(list.len(), 0);
    assert_eq!(list.iter().len(), 0);
    assert_eq!((&mut list.iter()).next(), None);

    println!("Single thread example ended without errors");
}

多生产者，多消费者

use voluntary_servitude::vs;
use std::{sync::Arc, thread::spawn};

const CONSUMERS: usize = 8;
const PRODUCERS: usize = 4;
const ELEMENTS: usize = 10_000_000;

fn main() {
    let list = Arc::new(vs![]);
    let mut handlers = vec![];

    // Creates producer threads to insert 10k elements
    for _ in 0..PRODUCERS {
        let l = Arc::clone(&list);
        handlers.push(spawn(move || {
            let _ = (0..ELEMENTS).map(|i| l.append(i)).count();
        }));
    }

    // Creates consumer threads to print number of elements
    // Until all of them are inserted
    for _ in 0..CONSUMERS {
        const TOTAL: usize = PRODUCERS * ELEMENTS;
        let consumer = Arc::clone(&list);
        handlers.push(spawn(move || loop {
            let count = consumer.iter().count();
            println!("{} elements", count);
            if count >= TOTAL { break };
        }));
    }

    // Join threads
    for handler in handlers.into_iter() {
        handler.join().expect("Failed to join thread");
    }

    println!("Multi-thread example ended without errors");
}