private <C extends Command<R>, R extends Serializable> void registerExecutor(
final NodeContext nodeContext, final CommandExecutor<C, R> executor, ZNode node) {
final ZNode executorNode =
node.createChild(znode().withPath(nodeNameOf(executor.getQualifier())));
final ZNode queueNode = executorNode.createChild(znode().withPath("queue"));
executorNode.createChild(znode().withPath("result"));
log.debug("Created znodes for executor {}", executorNode.getPath());
queueNode.addChildrenWatcher(
new Watcher() {
@Override
public void process(WatchedEvent event) {
if (event.getType() != Event.EventType.NodeChildrenChanged) {
return;
}
synchronized (lock) {
if (log.isDebugEnabled()) {
log.debug(
"Children changed {} event type {}", queueNode.getPath(), event.getType());
}
List<QueueEntry<C, R>> entries = getEntries(queueNode, this);
for (final QueueEntry<C, R> entry : entries) {
Runnable run =
new Runnable() {
@Override
public void run() {
executeCommand(executor, executorNode, entry, nodeContext);
}
};
ZookeeperCoordinator.this.executor.execute(run);
}
}
}
});
}
@Override
public void process(WatchedEvent event) {
if (event.getType() != Event.EventType.NodeChildrenChanged) {
return;
}
Runnable runnable =
new Runnable() {
public void run() {
lock.lock();
try {
List<ZNode> children = node.children();
Collection<NodeId> newIds = Sets.newHashSet();
for (ZNode child : children) {
newIds.add(child.getObject(NodeId.class));
}
Collection<NodeId> copy = Sets.newHashSet(newIds);
newIds.removeAll(currentIds);
currentIds.removeAll(copy);
for (NodeId newId : newIds) {
statusChangeListener.onNodeStatusChanged(newId, NodeStatus.AVAILABLE);
}
for (NodeId newId : currentIds) {
statusChangeListener.onNodeStatusChanged(newId, NodeStatus.DISCONNECTED);
}
currentIds = copy;
} finally {
lock.unlock();
}
}
};
new Thread(runnable).run();
node.addChildrenWatcher(this);
}
