public class WaitTest { static class ThreadA extends Thread { public ThreadA(String name){ super(name); } @Override public void run() { synchronized (this){ System.out.println(Thread.currentThread().getName()+" call notify()"); //notify();//notify之后 要等到这个代码块结束之后才会把锁让出去，当然如果在notify之后又有wait，那就会主动把锁让出去 try { System.out.println(Thread.currentThread().getName()+" wait"); //wait(); //Thread.sleep(10000); } catch (Exception e) { e.printStackTrace(); } System.out.println(Thread.currentThread().getName()+" after notify"); } } } public static void main(String[] args) throws InterruptedException { ThreadA t1 =new ThreadA("t1"); synchronized (t1){ System.out.println(Thread.currentThread().getName()+" start t1"); t1.start(); System.out.println(Thread.currentThread().getName()+" wait"); t1.wait();// //System.out.println(Thread.currentThread().getName()+" notify"); // t1.notify(); System.out.println(t1.getName()); System.out.println(Thread.currentThread().getName()+" continue"); //t1.notify(); } } }

照理來說 t1.wait() 應該會阻塞主線程，並沒有其他地方notify
而去掉t1.start()之後，就能阻塞住了

這是什麼道理？編譯器優化？還是synchronized程式碼區塊內如果不對monitor進行操作，結束主動notify？ ？