src/Pure/PIDE/protocol.ML

     (fn [serial, result] =>
       Active.dialog_result (Value.parse_int serial) result
         handle exn => if Exn.is_interrupt exn then () (*sic!*) else Exn.reraise exn);
 
 val _ =
+  Isabelle_Process.protocol_command "ML_Heap.full_gc"
+    (fn [] => ML_Heap.full_gc ());
+
+val _ =
   Isabelle_Process.protocol_command "ML_Heap.share_common_data"
     (fn [] => ML_Heap.share_common_data ());
 
 end;