Android / java: synchronized object wait and notify

Question

I get confused on the synchronized method. Look at this code below:

public void waitOne() throws InterruptedException
{
    synchronized (monitor)
    {
        while (!signaled)
        {
           monitor.wait();
        }
    }
}

public void set()
{
    synchronized (monitor)
    {
        signaled = true;
        monitor.notifyAll();
    }
}

Now, from what I understand, synchronized means only 1 thread can access the code inside. If waitOne() is called by main thread and set() is called by child thread, then (from what I understand) it will create deadlock.

This is because main thread never exit synchronized (monitor) because of while (!signaled) { monitor.wait(); } and therefore calling set() from child thread will never able to get into synchronized (monitor)?

Am I right? Or did I miss something? The full code is in here: What is java's equivalent of ManualResetEvent?

Thanks

Answer 1

When you call wait on an object that you use to synchronize on, it will release the monitor, allowing​ another thread to obtain it. This code will not deadlock.