Deal with lock : Deadlock « Thread « Java Tutorial

1. Java Tutorial
2. Thread
3. Deadlock

public class DeadlockDemo {
  public static void main(String[] args) throws Exception {
    UseShared s1 = new UseShared("x");
    UseShared s2 = new UseShared("y");

    s1.start();
    s2.start();

    s1.join();
    s2.join();
  }
}


class UseShared extends Thread {
  String s1 = "", s2 = "";

  UseShared(String name) {
    setName(name);
  }

  public void run() {
    for (int i = 0; i < 100; i++) {
      if (getName().equals("x"))
        method1();
      else
        method2();

      try {
        Thread.sleep(1000);
      } catch (Exception e) {
      }
    }
  }

  void method1() {
    synchronized (s1) {
      System.out.println("method1: s1");
      synchronized (s2) {
        System.out.println("method1: s2");
      }
    }
  }

  void method2() {
    synchronized (s2) {
      System.out.println("method2: s1");

      synchronized (s1) {
        System.out.println("method2: s2");
      }
    }
  }
}