+
+ // process all currently pending events right now
+ //
+ // it is an error to call Yield() recursively unless the value of
+ // onlyIfNeeded is TRUE
+ //
+ // WARNING: this function is dangerous as it can lead to unexpected
+ // reentrancies (i.e. when called from an event handler it
+ // may result in calling the same event handler again), use
+ // with _extreme_ care or, better, don't use at all!
+ virtual bool Yield(bool onlyIfNeeded = FALSE) = 0;