package com.dji.sample.manage.model;

import java.util.concurrent.locks.LockSupport;

/**
 * The demo is only for functional closure, which is not recommended.
 * @author sean.zhou
 * @date 2021/11/22
 * @version 0.1
 */
public class Chan<T> {

    private static final long THREAD_WAIT_TIME = 1000_000 * 500;

    private volatile T data;

    private volatile Thread t;

    private Chan () {

    }

    public static Chan getInstance() {
        return ChanSingleton.INSTANCE;
    }

    public T get(Object blocker) {
        this.t = Thread.currentThread();
        LockSupport.parkNanos(blocker, THREAD_WAIT_TIME);
        this.t = null;
        return data;
    }

    public void put(T data) {
        this.data = data;
        if (t == null) {
            return;
        }
        LockSupport.unpark(t);
    }

    private static class ChanSingleton {
        private static final Chan<?> INSTANCE = new Chan<>();
    }
}