At creation, a connection is scheduled on the current thread (the one where the creation takes place) in the default mode. That can be changed to add or remove runloop + mode pairs using the following methods. It is permissible to be scheduled on multiple run loops and modes, or on the same run loop in multiple modes, so scheduling in one place does not cause unscheduling in another.
You may call these methods after the connection has started. However, if the connection is scheduled on multiple threads or if you are not calling these methods from the thread where the connection is scheduled, there is a race between these methods and the delivery of delegate methods on the other threads. The caller must either be prepared for additional delegation messages on the other threads, or must halt the run loops on the other threads before calling these methods to guarantee that no further callbacks will occur.
—Jens
