CODEWITHSUNDEEP
java
ccc
ccc

Reputation: 75

Why thread object wait method don't need notify method to wake up?

When I call wait() method on a thread object, the waiting thread will be waken up when the synchrized thread finishes run, why is the thread object behaviors different from plain object where wait()?

Thread thread1 = new Thread(()-> {
            System.out.println("thread 1 start");
            try {
            Thread.sleep(3000);
            System.out.println("thread over");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }});
thread1.start();

synchronized (thread1) {
            try {
                thread1.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("main thread wake up");

I expected main thread does not wake up after 3s, but not.

Upvotes: 0

Views: 42

Answers (1)

JB Nizet
JB Nizet

Reputation: 692121

The javadoc says:

As a thread terminates the this.notifyAll method is invoked. It is recommended that applications not use wait, notify, or notifyAll on Thread instances.

Upvotes: 5

Related Questions