optimistic_lock_coupling 0.2.5

A General Lock following paper 'Optimistic Lock Coupling: A Scalable and Efficient General-Purpose Synchronization Method'
Documentation
use super::*;
#[test]
fn read_lock() {
    let lock = OptimisticLockCoupling::new(1);
    let r = lock.read().and_then(|r| {
        println!("{}", r);
        assert_eq!(*r, 1);
        r.try_sync()
    });
    assert_eq!(r, Ok(()));
}
#[test]
fn write_lock() {
    let lock = OptimisticLockCoupling::new(1);
    let _w = lock.write().and_then(|mut w| {
        *w += 1;
        Ok(())
    });
    assert_eq!(lock.version_lock_outdate.load(Acquire), 0b100);
    let _r = lock.read().and_then(|r| {
        println!("{}", r);
        assert_eq!(*r, 2);
        r.try_sync()
    });
}
#[test]
#[should_panic]
fn read_while_write() {
    let lock = OptimisticLockCoupling::new(1);
    let _w = lock.write().unwrap();
    // will fail due to its blocked
    let _r = lock.read().unwrap();
}

#[test]
fn lots_thread_write() {
    static mut lock: Option<OptimisticLockCoupling<i32>> = None;
    unsafe { lock = Some(OptimisticLockCoupling::from(0)) };
    let add_10000 = move || {
        println!("{:?} started!", std::thread::current().id());
        for _i in 0..10000 {
            loop {
                unsafe {
                    match (&lock).as_ref().unwrap().write() {
                        Ok(mut guard) => {
                            *guard += 1;
                            break;
                        }
                        Err(err) => {
                            println!("{:?}: {:?}", std::thread::current().id(), err);
                            continue;
                        }
                    }
                }
            }
        }
        println!("{:?} finished!", std::thread::current().id());
    };
    std::thread::spawn(add_10000);
    std::thread::spawn(add_10000);
    std::thread::spawn(add_10000);
    // should be finished
    std::thread::sleep_ms(5000);
    unsafe {
        let read = lock.as_ref().unwrap().read().unwrap();
        assert_eq!(*read, 30000);
        read.try_sync().unwrap();
    }
}