java - 競合状態を見つける

Question

競合状態がこのコードのどこにあるのか誰か説明できますか? 私の講師はそれを設定しましたが、それらを見つける方法、または与えられた結果がなぜ起こるのかをまだ完全には理解していません.

public class SlowRace {

      public static void main(String args []) throws Exception {

          MyThread.count = 0 ;

          MyThread thread1 = new MyThread() ;
          thread1.name = "A" ;

          MyThread thread2 = new MyThread() ;
          thread2.name = "B" ;

          thread1.start() ;
          thread2.start() ;

          thread2.join() ;
          thread1.join() ;

          System.out.println("MyThread.count = " + MyThread.count) ;
      }
  }

  class MyThread extends Thread {

      volatile static int count ;

      String name ;

      public void run() {

          for(int i = 0 ; i < 10 ; i++) {
              delay() ;
              int x = count ;
              System.out.println("Thread " + name + " read " + x) ;
              delay() ;
              count = x + 1;
              System.out.println("Thread " + name + " wrote " + (x + 1)) ;
          }
      }

      static void delay() {

          int delay = (int) (1000000000 * Math.random()) ;
          for(int i = 0 ; i < delay ; i++) {}
      }
  } 

返される結果:

Thread A read 0
Thread A wrote 1
Thread B read 0
Thread A read 1
Thread B wrote 1
Thread A wrote 2
Thread B read 2
Thread A read 2
Thread B wrote 3
Thread A wrote 3
Thread B read 3
Thread A read 3
Thread B wrote 4
Thread A wrote 4
Thread B read 4
Thread A read 4
Thread B wrote 5
Thread A wrote 5
Thread B read 5
Thread A read 5
Thread B wrote 6
Thread A wrote 6
Thread B read 6
Thread A read 6
Thread B wrote 7
Thread A wrote 7
Thread B read 7
Thread A read 7
Thread B wrote 8
Thread A wrote 8
Thread B read 8
Thread A read 8
Thread B wrote 9
Thread A wrote 9
Thread B read 9
Thread A read 9
Thread B wrote 10
Thread A wrote 10
Thread B read 10
Thread B wrote 11
MyThread.count = 11