Continuations are activated when they receive an event or by
TSContSchedule (which schedules a continuation to receive an event).
Continuations might receive an event because:
Your plugin calls
The Traffic Server HTTP state machine sends an event corresponding to a particular HTTP hook
A Traffic Server IO processor (such as a cache processor or net processor) is letting a continuation know there is data (cache or network) available to read or write. These callbacks are a result of using functions such