unikernel/duniverse/dune_/test/expect-tests/dune_util/dune

@@ -0,0 +1,19 @@
+(library
+ (name flock_tests)
+ (inline_tests
+  (enabled_if
+   (<> %{system} win))
+  (deps
+   (sandbox always)))
+ (libraries
+  dune_util
+  dyn
+  stdune
+  ;; This is because of the (implicit_transitive_deps false)
+  ;; in dune-project
+  ppx_expect.config
+  ppx_expect.config_types
+  base
+  ppx_inline_test.config)
+ (preprocess
+  (pps ppx_expect)))

unikernel/duniverse/dune_/test/expect-tests/dune_util/flock_tests.ml

@@ -0,0 +1,67 @@
+open Stdune
+
+let%expect_test "blocking lock" =
+  let fd = Unix.openfile "tlc1" [ Unix.O_CREAT ] 0o777 in
+  let lock = Flock.create fd in
+  print_endline "acquiring lock";
+  (match Flock.lock_block lock Exclusive with
+   | Ok () -> print_endline "acquired lock"
+   | Error _ -> assert false);
+  (match Flock.unlock lock with
+   | Ok () -> print_endline "released lock"
+   | Error _ -> assert false);
+  Unix.close fd;
+  [%expect
+    {|
+    acquiring lock
+    acquired lock
+    released lock |}]
+;;
+
+let%expect_test "nonblocking lock" =
+  let fd flag = Unix.openfile "tlc2" [ flag ] 0o777 in
+  let fd1 = fd Unix.O_CREAT in
+  let lock1 = Flock.create fd1 in
+  print_endline "acquiring lock";
+  (match Flock.lock_non_block lock1 Exclusive with
+   | Ok `Success -> print_endline "acquired lock"
+   | Ok `Failure | Error _ -> assert false);
+  let fd2 = fd Unix.O_RDONLY in
+  let lock2 = Flock.create fd2 in
+  (match Flock.lock_non_block lock2 Exclusive with
+   | Ok `Failure -> print_endline "verified that we can't lock again"
+   | Ok `Success -> Code_error.raise "acquired lock again" []
+   | Error err ->
+     Code_error.raise "err" [ "message", Dyn.string @@ Unix.error_message err ]);
+  (match Flock.unlock lock1 with
+   | Ok () -> print_endline "released lock"
+   | Error _ -> assert false);
+  let lock2 = Flock.create fd2 in
+  (match Flock.lock_non_block lock2 Exclusive with
+   | Ok `Success -> print_endline "managed to lock after unlock"
+   | Ok `Failure | Error _ -> assert false);
+  Unix.close fd1;
+  Unix.close fd2;
+  [%expect
+    {|
+    acquiring lock
+    acquired lock
+    verified that we can't lock again
+    released lock
+    managed to lock after unlock |}]
+;;
+
+let%expect_test "double lock" =
+  let fd = Unix.openfile "tlc3" [ Unix.O_CREAT ] 0o600 in
+  let lock = Flock.create fd in
+  (match Flock.lock_non_block lock Exclusive with
+   | Ok `Success -> print_endline "lock 1 worked"
+   | _ -> assert false);
+  (match Flock.lock_non_block lock Exclusive with
+   | Ok `Success -> print_endline "lock 2 worked"
+   | _ -> assert false);
+  [%expect
+    {|
+    lock 1 worked
+    lock 2 worked |}]
+;;