volatile keyword in java 1.3

Hi,

Does the volatile keyword make a primitive safe to read/write from multiple threads without guarding it? I don't know where I read that but - something like:

public class Test
{
    public volatile m_flag;

    new Thread() {
        public void run() {
            while(...) {
                m_flag = false;
                print(m_flag);
            }
        }
    }.start();

    new Thread() {
        public void run() {
            while(...) {
                m_flag = true;
                print(m_flag);
            }
        }
    }.start();
}

I mean is setting and getting m_flag atomic now, so no thread is reading or writing it at the same time? I can put a guard object around it but it seems annoying to do for a simple boolean primitive,

Thanks