操作系统多线程例子--生产者与消费者

import java.util.concurrent.locks.*;

public class ProducerandConsumer {
	private static int count = 0;
	private final int FULL = 100;// 定义最多生产100个
	private int flag = 0;// 生产者消费者切换标志

	Lock lock = new ReentrantLock();// 创建一个锁对象。

	Condition producer_lock = lock.newCondition(); // 生产者监视器
	Condition consumer_lock = lock.newCondition(); // 消费者监视器

	class Producer implements Runnable {
		public void run() {
			while (true) {
				lock.lock();
				try {
					Thread.sleep(500);
				} catch (Exception e) {
					e.printStackTrace();
				}

				try {
					while ((count == FULL) || (flag == 1)) {
						try {
							producer_lock.await();
						} catch (Exception e) {
							e.printStackTrace();
						}
					}
					count++;
					flag = 1;
					System.out.println(Thread.currentThread().getName()
							+ "生产者生产 " + count);
					consumer_lock.signal();
				} finally {
					lock.unlock();
				}
			}
		}
	}

	class Consumer implements Runnable {
		public void run() {

			while (true) {
				lock.lock();
				try {
					Thread.sleep(500);
				} catch (InterruptedException e1) {
					e1.printStackTrace();
				}

				try {
					while ((count == 0) || (flag == 0)) {
						try {
							consumer_lock.await();
						} catch (Exception e) {
						}
					}
					System.out.println(Thread.currentThread().getName()
							+ "消费者消费 " + count);

					if (count == FULL) // 重新从1开始生产消费
					{
						count = 0;
					}
					flag = 0;
					producer_lock.signal();
				} finally {
					lock.unlock();
				}
			}

		}
	}

	public static void main(String[] args) throws Exception {
		ProducerandConsumer pc = new ProducerandConsumer();

		// 生产者
		new Thread(pc.new Producer()).start();

		// 消费者
		new Thread(pc.new Consumer()).start();
	}
}