????finalizer??????
?????????????????????????????????л????.?????????????????????register(object)????finalizer???????.?????????????鵱?У?????????????????.????????????????????:
static {
ThreadGroup tg = Thread.currentThread().getThreadGroup();
for (ThreadGroup tgn = tg;
tgn != null;
tg = tgn?? tgn = tg.getParent());
Thread finalizer = new FinalizerThread(tg);
finalizer.setPriority(Thread.MAX_PRIORITY - 2);
finalizer.setDaemon(true);
finalizer.start();
}
?????????static??????????飬??????Finalizer????????????????????.?????????????????????飬?????????????????????????.
?????????jstack?????????????????????????????????????????????.????????

???????
????????Finalizer???????finalReference????JVM???????java?????????Э?????.???????????jvm???????????????????????????????????????????????????.??ж?????????java????????jvm???.????????????????java????????л??????????.