Upon receiving a frame the callback registered with stomp_connection/5
is called in the context of the receiving thread. More demanding
applications may decide to send incomming frames to a SWI-Prolog message
queue and have one or more worker threads processing the input.
Alternatively, frames may be inspected by the receiving thread and
either processed immediately or be dispatched to either new or running
threads. The best scenario depends on the message rate, processing time
and concurrency of the Prolog application.
All message sending predicates of this library are thread safe.
If two threads send a frame to the same connection the library ensures
that both frames are properly serialized.
