unikernel/duniverse/lwt/test/unix/ocaml_runtime_exc_2.ml

@@ -0,0 +1,30 @@
+(* This file is part of Lwt, released under the MIT license. See LICENSE.md for
+   details, or visit https://github.com/ocsigen/lwt/blob/master/LICENSE.md. *)
+
+(* set the exception filter being tested *)
+let () = Lwt.Exception_filter.(set handle_all_except_runtime)
+
+(* OCaml runtime exceptions (out-of-memory, stack-overflow) are fatal in a
+   different way than other exceptions and they leave the Lwt main loop in an
+   inconsistent state where it cannot be restarted. Indeed, attempting to call
+   [Lwt_main.run] again after it has crashed with a runtime exception causes a
+   "Nested calls to Lwt_main.run are not allowed" error.
+
+   For this reason, we run this test as its own executable rather than as part
+   of a larger suite. *)
+
+open Lwt.Syntax
+
+let test () =
+  try
+    let () = Lwt_main.run (
+      let* () = Lwt_unix.sleep 0.001 in
+      if true then raise Out_of_memory else Lwt.return_unit
+    ) in
+    Printf.eprintf "Test run+raise failure\n";
+    Stdlib.exit 1
+  with
+    | Out_of_memory -> ()
+
+let () = test ()
+