多线程之多生产多消费者

import java.util.concurrent.locks.*;

public class Test23 {
	public static void main(String[] args) {
		Resource r = new Resource();
		String x = "黄焖鸡";

		PutX px = new PutX(r, x);
		TakeX tx = new TakeX(r, x);
		Thread t0 = new Thread(px);
		Thread t1 = new Thread(px);
		Thread t2 = new Thread(tx);
		Thread t3 = new Thread(tx);

		t0.start();
		t1.start();
		t2.start();
		t3.start();
	}
}

class Resource {

	Lock lock = new ReentrantLock();
	Condition full = lock.newCondition();
	Condition empty = lock.newCondition();

	private String[] item = new String[400];
	private int taker = 0;
	private int puter = 0;
	private int count = 0;

	public void put(String x) {
		while (true) {
			lock.lock();
			//用while不用if是由于当多个线程在这里等待后，被唤醒，须要又一次推断这个条件
			while (count == item.length) {
				try {
					full.await();
				} catch (InterruptedException e) {
				}
			}
			item[puter] = x;
			System.out.println(Thread.currentThread().getName() + "..." + count
					+ "...put.." + x);
			if (puter == item.length - 1) {
				puter = -1;
				empty.signalAll();
			}
			++count;
			++puter;
			lock.unlock();
		}
	}

	public void take(String x) {
		while (true) {
			lock.lock();
			while (count == 0) {
				try {
					empty.await();
				} catch (InterruptedException e) {
				}
			}
			x = item[taker];
			System.out.println(Thread.currentThread().getName() + "..."
					+ (count - 1) + "..take......" + x);
			if (taker == item.length - 1) {
				taker = -1;
				full.signalAll();
			}
			--count;
			++taker;
			lock.unlock();
		}
	}
}

class PutX implements Runnable {
	Resource r;
	String x;

	PutX(Resource r, String x) {
		this.r = r;
		this.x = x;
	}

	public void run() {
		r.put(x);
	}
}

class TakeX implements Runnable {
	Resource r;
	String x;

	TakeX(Resource r, String x) {
		this.r = r;
		this.x = x;
	}

	public void run() {
		r.take(x);
	}
}