Use EventLoggerLwt in Flow

Reviewed By: samwgoldman

Differential Revision: D7272142

fbshipit-source-id: 51e90b3b3bdcb29a98971bd612cd9ec0228de02c

Author: gabelevi

src/monitor/flowServerMonitor.ml

@@ -63,8 +63,7 @@ module LogFlusher = LwtLoop.Make (struct
 
   let main () =
     let%lwt () = Lwt_unix.sleep 5.0 in
-    EventLogger.flush ();
-    Lwt.return_unit
+    EventLoggerLwt.flush ()
 
   let catch () exn =
     Logger.fatal ~exn "LogFlusher somehow hit an exception";

src/server/server.ml

@@ -183,7 +183,9 @@ let rec serve ~dfind ~genv ~env =
     ~default:(Lwt.return env)
     ~f:(process_message genv env) in
 
-  EventLogger.flush ();
+  (* Flush the logs asynchronously *)
+  Lwt.async EventLoggerLwt.flush;
+
   serve ~dfind ~genv ~env
 
 (* This code is only executed when the options --check is NOT present *)