What do two semicolons mean in Java for loop?

Question

I was looking inside the AtomicInteger Class and I came across the following method:

/**
 * Atomically increments by one the current value.
 *
          


        

Answer 1

It's the same thing as

while(true) {
    //do something
}

...just a little bit less clear.
Notice that the loop will exit if compareAndSet(current, next) will evaluate as true.