生产者消费者场景下用显式条件队列简单实现如果容器满存放阻塞等待，如果容器空取等待

生产者消费者场景下用显式条件队列简单实现如果容器满存放阻塞等待，如果容器空取等待实现条件；

取操作:当容器元素没多余时，读取操作挂起，释放CPU资源；阻塞

 

存操作:当容器内的容量达到上限后，存操作挂起，释放CPU资源，阻塞

 

import net.jcip.annotations.GuardedBy;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer.ConditionObject;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ConditionDemo<T> {

	Lock lock = new ReentrantLock();

	//条件谓词 count<array.length
	private Condition notFull = lock.newCondition();

	//条件谓词 count>0
	private Condition notEmpty = lock.newCondition();

	private T[] items = (T[]) new Object[3];

	@GuardedBy("lock")
	private int tails, head, count;


	public void put(T x) {
		lock.lock();

		try {

			while (count == items.length) {
				System.out.println("当前容器已满,没有足够空间存放更多元素，请先释放...");
				notFull.await();
			}
			items[tails] = x;
			if (++tails == items.length) {
				tails = 0;
			}
			count++;
			notEmpty.signal();

		} catch (InterruptedException e) {
			System.out.println(e.getMessage());

		} finally {
			lock.unlock();
		}

	}

	public T take() {
		lock.lock();

		try {

			while (count == 0) {
				System.out.println("当期容器没有任何元素可供读取,请先存放元素到容器中...");
				notEmpty.await();
			}
			T x = items[head];
			items[head] = null;
			if (++head == items.length) {
				head = 0;
			}
			--count;
			notFull.signal();
			System.out.println("取出元素:" + x);
			return x;

		} catch (InterruptedException e) {
			System.out.println(e.getMessage());

		} finally {
			lock.unlock();
		}
		return null;

	}


	public static void main(String[] args) {
		ConditionDemo<String> conditionDemo = new ConditionDemo<>();
		
		new Thread(() -> {
			conditionDemo.take();
		}).start();

		new Thread(() -> {
			conditionDemo.put("hello");
		}).start();

	}
}