src/Pure/PIDE/document_status.scala

     private val sum_finished: Time
   ) {
     def is_empty: Boolean = running.isEmpty && finished.isEmpty
 
     def has_running: Boolean = running.nonEmpty
+    def long_running(now: Date, threshold: Time): List[Command_Running] =
+      List.from(for (run <- running.valuesIterator if run.time(now) >= threshold) yield run)
     def add_running(entry: Command_Timings.Entry_Running): Command_Timings =
       new Command_Timings(running + entry, finished, sum_finished)
 
     def count_finished: Int = finished.size
     def get_finished(offset: Symbol.Offset): Time = finished.getOrElse(offset, Time.zero)