[Pharo-project] Analog to Dolphin's #forkMainIfMain?

Is there anything in Pharo that starts a new main thread to carry on for one that is about to get blocked? It might be that Pharo does not need it, since sockets are serviced by the VM, where Dolphin (at least prior to overlapped calls) did the I/O through the event loop; if the main thread stopped, so did Windows event dispatching, and hence no socket I/O. Dolphin to some extent, and WindowBuilder to (IIRC) a large extent create modal loops in Smalltalk code. I see a few references to such things in Pharo, but I'm fairly lost. Where should I start reading and/or browsing? Bill