onMessage and a very long running task
I want to perform a long running task in ratchet , so I did: 

```
public function onMessage(ConnectionInterface $from, $msg)
    {
//      if message is from this server,broadcast message, and end it there
        echo "on message    $msg";
        sleep(1000);

    }
```

to simulate a long running task. 
I have a php script that uses pawl library to send a message to ratchet. 
However, that script runs fine the first time, but second time onwards , it waits. 
Why is this synchronous ? 

I had expected to receive some message from client , and performing an HTTP request internally. 
The http request will be a fairly long running task (few hundred ms). Is what Im looking for not possible ?
