[Zope-dev] persistent threads ?

Yo, We have some computational expensive task that we execute as a result of some HTTPRequest. So we spawn a thread and return immediately. Future requests can get the status and thus we can monitor progress at the client side. So far so good. But what should we do when the server restarts before the task finishes ? Onfortunately, pickling the thread and restarting it is not an option (Threads are not picklable (pickleable, pickable ??? ah well what's in a name) :( ) So what are our options here ? Should we turn to Stackless python as a vm or what ? TIA, Sloot