the Java Language Spec 12.4.2 describes the detail Initalization procedure. The step 2 says

"2. If initialization is in progress for the class or interface by some other thread,
then wait on this Class object (which temporarily releases the lock). When
the current thread awakens from the wait, repeat this step."

I wrote a small program , it shows the thread state is not Thread.WAIT, it's Thread.RUNNABLE on both solaris and windows. see below. When Thread t tries to read Init.done, the state of t should be WAIT according to language spec. however, it's RUNNABLE in fact.

class Init{

        static volatile boolean done = false;

        static {
                Thread t = new Thread() {
                        public void run() {
                                System.out.println("enter thread");
                                done = true;
                        }
                };

                t.start();

                while(!done) {
                        try {
                                Thread.sleep(3000);
                        } catch (Exception e) {}

                        System.out.println("state " + t.getState());
                }
        }

        public static void main(String[] args) {}
}