@Override
protected WeakReference<Thread> computeValue(Class<?> type) {
UNSAFE.ensureClassInitialized(type);
if (UNSAFE.shouldBeInitialized(type))
// If the previous call didn't block, this can happen.
// We are executing inside <clinit>.
return new WeakReference<>(Thread.currentThread());
return null;
}
private static boolean checkInitialized(MemberName member) {
Class<?> defc = member.getDeclaringClass();
WeakReference<Thread> ref = EnsureInitialized.INSTANCE.get(defc);
if (ref == null) {
return true; // the final state
}
Thread clinitThread = ref.get();
// Somebody may still be running defc.<clinit>.
if (clinitThread == Thread.currentThread()) {
// If anybody is running defc.<clinit>, it is this thread.
if (UNSAFE.shouldBeInitialized(defc))
// Yes, we are running it; keep the barrier for now.
return false;
} else {
// We are in a random thread. Block.
UNSAFE.ensureClassInitialized(defc);
}
assert (!UNSAFE.shouldBeInitialized(defc));
// put it into the final state
EnsureInitialized.INSTANCE.remove(defc);
return true;
}