java5中的线程同步_JAVA_程序员俱乐部

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java5中的线程同步

2014/7/7 21:45:14 a67474506 程序员俱乐部我要评论(0)

摘要：packagecn.zto.countdownlatch;importjava.util.concurrent.CountDownLatch;importjava.util.concurrent.ExecutorService;importjava.util.concurrent.Executors;//使用countdownLathch类实现线程同步publicclassCountdownLatchTest{publicstaticvoidmain(String[]args)
标签：Java 线程同步

class="java" name="code">package cn.zto.countdownlatch;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

//使用countdownLathch类实现线程同步
public class CountdownLatchTest {

	public static void main(String[] args) {
		ExecutorService service = Executors.newCachedThreadPool();
		final CountDownLatch cdOrder = new CountDownLatch(1);
		final CountDownLatch cdAnswer = new CountDownLatch(3);

		for (int i = 1; i <= 3; i++) {
			Runnable runnable = new Runnable() {
				@Override
				public void run() {
					try {
						System.out.println("线程"
								+ Thread.currentThread().getName() + "正准备接受命令");
						cdOrder.await();
						System.out.println("线程"
								+ Thread.currentThread().getName() + "已接受命令");
						Thread.sleep((long) (Math.random() * 10000));
						System.out
								.println("线程"
										+ Thread.currentThread().getName()
										+ "回应命令处理结果");
						cdAnswer.countDown();
					} catch (Exception e) {

					}
				}
			};
			service.execute(runnable);
		}
		try {
			Thread.sleep((long) (Math.random() * 10000));

			System.out.println("线程" + Thread.currentThread().getName()
					+ "即将发布命令");
			cdOrder.countDown();
			System.out.println("线程" + Thread.currentThread().getName()
					+ "已发送命令，正在等待结果");
			cdAnswer.await();
			System.out.println("线程" + Thread.currentThread().getName()
					+ "已收到所有响应结果");
		} catch (Exception e) {
			e.printStackTrace();
		}
		service.shutdown();

	}
}

运行结果：

线程pool-1-thread-2正准备接受命令
线程pool-1-thread-3正准备接受命令
线程pool-1-thread-1正准备接受命令
线程main即将发布命令
线程main已发送命令，正在等待结果
线程pool-1-thread-2已接受命令
线程pool-1-thread-3已接受命令
线程pool-1-thread-1已接受命令
线程pool-1-thread-3回应命令处理结果
线程pool-1-thread-2回应命令处理结果
线程pool-1-thread-1回应命令处理结果
线程main已收到所有响应结果

package cn.zto.cyclicbarrier;

import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

//使用CyclicBarrier实现线程同步
public class CyclicBarrierTest {
	
	public static void main(String[] args) {
		ExecutorService service = Executors.newCachedThreadPool();
		
		final CyclicBarrier cb = new CyclicBarrier(3);
		for (int i = 1; i <= 3; i++) {
			Runnable runnable = new Runnable() {
				@Override
				public void run() {
					try {
						Thread.sleep((long) (Math.random()*10000));
					
						System.out.println("线程" + Thread.currentThread().getName() + 
								"即将到达集合地点1，当前已有" + (cb.getNumberWaiting()+1) +
								"个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，继续走啊":"正在等候"));
						cb.await();
						
						Thread.sleep((long) (Math.random()*10000));
						System.out.println("线程" + Thread.currentThread().getName() + 
								"即将到达集合地点2，当前已有" + (cb.getNumberWaiting()+1) +
								"个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，继续走啊":"正在等候"));
						cb.await();
						
						Thread.sleep((long) (Math.random()*10000));
						System.out.println("线程" + Thread.currentThread().getName() + 
								"即将到达集合地点3，当前已有" + (cb.getNumberWaiting()+1) +
								"个已经到达，" + (cb.getNumberWaiting()==2?"都到齐了，回家吧":"正在等候"));
						cb.await();
					} catch (Exception e) {
						e.printStackTrace();
					}
				}
			};
			
			service.execute(runnable);
		}
		
		service.shutdown();
	}
}

运行结果：

线程pool-1-thread-2即将到达集合地点1，当前已有1个已经到达，正在等候
线程pool-1-thread-1即将到达集合地点1，当前已有2个已经到达，正在等候
线程pool-1-thread-3即将到达集合地点1，当前已有3个已经到达，都到齐了，继续走啊
线程pool-1-thread-3即将到达集合地点2，当前已有1个已经到达，正在等候
线程pool-1-thread-1即将到达集合地点2，当前已有2个已经到达，正在等候
线程pool-1-thread-2即将到达集合地点2，当前已有3个已经到达，都到齐了，继续走啊
线程pool-1-thread-3即将到达集合地点3，当前已有1个已经到达，正在等候
线程pool-1-thread-2即将到达集合地点3，当前已有2个已经到达，正在等候
线程pool-1-thread-1即将到达集合地点3，当前已有3个已经到达，都到齐了，回家吧

package cn.zto.exchanger;

import java.util.concurrent.Exchanger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

//通过exchanger实现线程同步
public class ExchangerTest {
	
	public static void main(String[] args) {
		ExecutorService service = Executors.newCachedThreadPool();
		final Exchanger exchanger = new Exchanger();
		
		service.execute(new Runnable(){
			public void run() {
				try {				

					String data1 = "XXXXX";
					System.out.println("线程" + Thread.currentThread().getName() + 
					"正在把数据" + data1 +"换出去");
					Thread.sleep((long)(Math.random()*10000));
					String data2 = (String)exchanger.exchange(data1);
					System.out.println("线程" + Thread.currentThread().getName() + 
					"换回的数据为" + data2);
				}catch(Exception e){
					
				}
			}	
		});
		service.execute(new Runnable(){
			public void run() {
				try {				

					String data1 = "YYYYY";
					System.out.println("线程" + Thread.currentThread().getName() + 
					"正在把数据" + data1 +"换出去");
					Thread.sleep((long)(Math.random()*10000));					
					String data2 = (String)exchanger.exchange(data1);
					System.out.println("线程" + Thread.currentThread().getName() + 
					"换回的数据为" + data2);
				}catch(Exception e){
					
				}				
			}	
		});	
	}
}

运行结果：

线程pool-1-thread-1正在把数据XXXXX换出去
线程pool-1-thread-2正在把数据YYYYY换出去
线程pool-1-thread-2换回的数据为XXXXX
线程pool-1-thread-1换回的数据为YYYYY

package cn.zto.semaphore;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

//信号灯
public class SemaphoreTest {
	
	public static void main(String[] args) {
		ExecutorService service = Executors.newCachedThreadPool();
		
		final Semaphore sp = new Semaphore(3);
		
		for (int i = 1; i < 10; i++) {
			Runnable runnable = new Runnable() {
				
				@Override
				public void run() {
					try {
						sp.acquire();
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
					System.out.println("线程" + Thread.currentThread().getName() + 
							"进入，当前已有" + (3-sp.availablePermits()) + "个并发");
					try {
						Thread.sleep((long)(Math.random()*10000));
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
					System.out.println("线程" + Thread.currentThread().getName() + 
							"即将离开");					
					sp.release();
					//下面代码有时候执行不准确，因为其没有和上面的代码合成原子单元
					System.out.println("线程" + Thread.currentThread().getName() + 
							"已离开，当前已有" + (3-sp.availablePermits()) + "个并发");		
				}
			};

			service.execute(runnable);
			
		}
	}
}

运行结果：

线程pool-1-thread-1进入，当前已有2个并发
线程pool-1-thread-2进入，当前已有2个并发
线程pool-1-thread-4进入，当前已有3个并发
线程pool-1-thread-2即将离开
线程pool-1-thread-5进入，当前已有3个并发
线程pool-1-thread-2已离开，当前已有3个并发
线程pool-1-thread-1即将离开
线程pool-1-thread-1已离开，当前已有2个并发
线程pool-1-thread-6进入，当前已有3个并发
线程pool-1-thread-4即将离开
线程pool-1-thread-4已离开，当前已有2个并发
线程pool-1-thread-9进入，当前已有3个并发
线程pool-1-thread-5即将离开
线程pool-1-thread-8进入，当前已有3个并发
线程pool-1-thread-5已离开，当前已有3个并发
线程pool-1-thread-6即将离开
线程pool-1-thread-6已离开，当前已有2个并发
线程pool-1-thread-3进入，当前已有3个并发
线程pool-1-thread-9即将离开
线程pool-1-thread-7进入，当前已有3个并发
线程pool-1-thread-9已离开，当前已有3个并发
线程pool-1-thread-3即将离开
线程pool-1-thread-3已离开，当前已有2个并发
线程pool-1-thread-8即将离开
线程pool-1-thread-8已离开，当前已有1个并发
线程pool-1-thread-7即将离开
线程pool-1-thread-7已离开，当前已有0个并发