JAVA多线程—线程死锁-蒲公英云

JAVA多线程—线程死锁

线程死锁：

创建两个字符串a和b，再创建两个线程A和B，让每个线程都用synchronized锁住字符串（A先锁a，再去锁b；B先锁b，再锁a），如果A锁住a，B锁住b，A就没办法锁住b，B也没办法锁住a，这时就陷入了死锁。直接贴代码：

/*
线程死锁
 */
public class DeadLock {
    public static String str1 = "str1";
    public static String str2 = "str2";
    public static void main(String[] args) {
        Thread t1 = new Thread(new Lock1());
        Thread t2 = new Thread(new Lock2());
        t1.start();
        t2.start();
    }
}
class  Lock1 implements Runnable{
    @Override
    public void run() {
        try {
            System.out.println("线程"+Thread.currentThread().getName()+"开始运行");
            while (true){
                synchronized (DeadLock.str1){
                    System.out.println("线程"+Thread.currentThread().getName()+"锁住str1");
                    Thread.sleep(3000);
                    synchronized (DeadLock.str2){
                        System.out.println("线程"+Thread.currentThread().getName()+"锁住str2");
                    }
                }
            }
        }catch (Exception e){
         e.printStackTrace();
        }
    }
}
class  Lock2 implements Runnable{
    @Override
    public void run() {
        try {
            System.out.println("线程"+Thread.currentThread().getName()+"开始运行");
            while (true){
                synchronized (DeadLock.str2){
                    System.out.println("线程"+Thread.currentThread().getName()+"锁住str2");
                    Thread.sleep(3000);
                    synchronized (DeadLock.str1){
                        System.out.println("线程"+Thread.currentThread().getName()+"锁住str1");
                    }
                }
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}