public synchronized void updateAll() {
HashSet<UpdatableNode> seenNodes = new HashSet<UpdatableNode>();
// make a copy of _all, since UpdatableNode.update can add to it
for (UpdatableNode node : new ArrayList<UpdatableNode>(_all)) {
node.update(seenNodes);
}
if (seenNodes.size() > 0) {
// not empty, means that at least 1 server gave node list
// remove unused hosts
Iterator<UpdatableNode> it = _all.iterator();
while (it.hasNext()) {
if (!seenNodes.contains(it.next())) it.remove();
}
}
}
