Wait for processes to exit when stopping

Author: Mikaka27

lib/observer/src/etop.erl

@@ -139,6 +139,9 @@ stop() ->
         Pid when is_pid(Pid) ->
             Result = etop_server ! stop,
             stop_etop_input_server(),
+            MonRef = monitor(process, Pid),
+            receive {'DOWN', MonRef, process, Pid, _} -> ok end,
+            demonitor(MonRef),
             Result
     end.
 
@@ -328,7 +331,13 @@ stop(Reader, Opts) ->
             etop_tr:stop_tracer(Opts),
             %% Stop reader process so it doesn't crash on deleted accumulator table
             %% when our process dies.
-            exit(Pid, stop);
+            case is_process_alive(Pid) of
+                true ->
+                    exit(Pid, stop),
+                    receive {'EXIT', Pid, stop} -> ok
+                    end;
+                false -> ok
+            end;
         _ ->
             ok
     end,