unikernel/duniverse/mtime/test/test_mtime_clock.ml

@@ -0,0 +1,62 @@
+(*---------------------------------------------------------------------------
+   Copyright (c) 2015 The mtime programmers. All rights reserved.
+   SPDX-License-Identifier: ISC
+  ---------------------------------------------------------------------------*)
+
+open B0_testing
+
+(* Note nothing is being asserted in these tests. *)
+
+let test_available () = try ignore (Mtime_clock.elapsed ()) with
+| Sys_error e -> Test.failstop "No monotonic time available: %s" e
+
+let test_counters () =
+  Test.test "Mtime_clock.counter" @@ fun () ->
+  let count max =
+    let c = Mtime_clock.counter () in
+    for i = 1 to max do () done;
+    Mtime_clock.count c
+  in
+  let do_count max =
+    let span = count max in
+    let span_ns = Mtime.Span.to_uint64_ns span in
+    Test.log "Count to % 8d: %10Luns %gs %a"
+      max span_ns (Mtime.Span.to_float_ns span *. 1e-9) Mtime.Span.pp  span
+  in
+  do_count 1000000;
+  do_count 100000;
+  do_count 10000;
+  do_count 1000;
+  do_count 100;
+  do_count 10;
+  do_count 1;
+  ()
+
+let test_elapsed () =
+  Test.test "Mtime_clock.elapsed ns - s - pp - dump" @@ fun () ->
+  let span = Mtime_clock.elapsed () in
+  Test.log " %Luns - %gs - %a - %a"
+    (Mtime.Span.to_uint64_ns span)
+    (Mtime.Span.to_float_ns span *. 1e-9)
+    Mtime.Span.pp span
+    Mtime.Span.dump span;
+  ()
+
+let test_now () =
+  Test.test "Mtime_clock.now ns - s - pp - dump " @@ fun () ->
+  let t = Mtime_clock.now () in
+  let span = Mtime.(span t (of_uint64_ns 0_L)) in
+  Test.log " %Luns - %gs - %a - %a"
+    (Mtime.to_uint64_ns t) (Mtime.Span.to_float_ns span *. 1e-9)
+    Mtime.pp t Mtime.dump t;
+  ()
+
+let main () =
+  Test.main @@ fun () ->
+  test_available ();
+  test_counters ();
+  test_elapsed ();
+  test_now ();
+  ()
+
+let () = if !Sys.interactive then () else exit (main ())