多线程调用接口python

以下示例均来自jdk concurrent包。
/**
 * 有一个任务，它要等待其他几个任务
 * 执行完毕 之后才能执行
 *
 *
 * 倒计时器
 */
public class CountDownLatchTest {



public static void main(String[] args){
final CountDownLatch count = new CountDownLatch(2);
 new Thread(){
public void run(){
try {
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println("线程"+Thread.currentThread().getName()+"正在执行...");
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println("线程"+Thread.currentThread().getName()+"执行完毕 ");
 count.countDown();

 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 };
 }.start();



 //任务2
 new Thread(){
public void run(){
try {
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println("线程"+Thread.currentThread().getName()+"正在执行...");
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println("线程"+Thread.currentThread().getName()+"执行完毕 ");
 count.countDown();
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 };
 }.start();

 try {
 count.await();
 System.out.println("主线程"+Thread.currentThread().getName()+"执行完毕 ");
 } catch (InterruptedException e) {
 e.printStackTrace();
 }

 }
}

/**
 *   周末部门聚餐
 *  所有人到齐了 之后 才能开始。。。
 *
 *
 * 可循环的同步屏障 */
public class CyclicBarrierTest {


public static void main(String[] args){
final CyclicBarrier barrier = new CyclicBarrier(20);
 ExecutorService threadPool = Executors.newCachedThreadPool();
 //模拟20个用户
 for(int i=1;i<=20;i++){
final int t=i;
 Runnable r = new Runnable(){
public void run(){
//模拟每个人来的时间
 try {
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println(t+" 用户到达"+(barrier.getNumberWaiting()+1)+"人到达");
 barrier.await();
 if(t==1){ //控制打印一条
 System.out.println("人员全部到齐，开始吃饭");
 }
 Thread.sleep(300);
 System.out.println(t+"用户吃完，可以回家 了");
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
 };
 threadPool.execute(r);
 }

 threadPool.shutdown();
 }
}

/**
 * 团伙a 绑了B，放言要100万， 与家属c达到 一致意见在某个地方
 * 交换人质，于是A和c同时来到交换地点，同时一手交钱一手交货
 * 使用exchanger实现
 */
public class ExchangerTest {

public static void main(String[] args){
 ExecutorService threadPool = Executors.newCachedThreadPool();
 Exchanger<String> exchanger = new Exchanger<String>();

 threadPool.execute(new Runnable() {
@Override
 public void run() {
 String data ="人质B";
 try {
 String response = exchanger.exchange(data);
 System.out.println("绑架者用B换回"+response);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 }
 });

 //家属c
 threadPool.execute(new Runnable() {
@Override
 public void run() {
 String data ="1000万";
 try {
 String response = exchanger.exchange(data);
 System.out.println("C用1000万换回"+response);
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 }
 });

 threadPool.shutdown();
 }
}

/**
 * 信号量控制并发
 * 20个人 2个窗口买票
 *
 */
public class SemaphoreTest {
private void execute(){
 Semaphore semaphore = new Semaphore(2);
 //线程池
 ExecutorService threadPool = Executors.newCachedThreadPool();
 //模拟20个线程
 for(int i=0;i<20;i++) {
 threadPool.execute(new MyTask(semaphore,i));
 }
 }

class MyTask implements Runnable{
private Semaphore semaphore; //信号 量 2个许可
 private int userNo;
 public MyTask(Semaphore semaphore,int userNo){
this.semaphore=semaphore;
 this.userNo =userNo;
 }
public void run(){
//执行买票

 try {
//获取信号量许可，如果获取不到 在此阻塞
 semaphore.acquire();

 //如果 获取到， 可以往下执行 也就是买票
 System.out.println("用户"+userNo+" 进入窗口，准备买票");
 TimeUnit.MILLISECONDS.sleep(1000);

 System.out.println("用户"+userNo+" 买票完成，准备离开 ");
 TimeUnit.MILLISECONDS.sleep(1000);
 System.out.println("用户"+userNo+" 买票完成，离开窗口 ");
 semaphore.release();
 } catch (InterruptedException e) {
 e.printStackTrace();
 }
 }
 }
public static void main(String[] args){
 SemaphoreTest test = new SemaphoreTest();
 test.execute();

 }
}