Deprecate current send_msg, recv_msg; test new

src/unix/lwt_bytes.mli

@@ -124,10 +124,16 @@ type io_vector = {
 val io_vector : buffer : t -> offset : int -> length : int -> io_vector
 
 val recv_msg : socket : Lwt_unix.file_descr -> io_vectors : io_vector list -> (int * Unix.file_descr list) Lwt.t
-(** Not implemented on Windows. *)
+  [@@ocaml.deprecated " Use Lwt_unix.Versioned.recv_msg_2."]
+(** Not implemented on Windows.
+
+    @deprecated Use {!Lwt_unix.Versioned.recv_msg_2}. *)
 
 val send_msg : socket : Lwt_unix.file_descr -> io_vectors : io_vector list -> fds : Unix.file_descr list -> int Lwt.t
-(** Not implemented on Windows. *)
+  [@@ocaml.deprecated " Use Lwt_unix.Versioned.send_msg_2."]
+(** Not implemented on Windows.
+
+    @deprecated Use {!Lwt_unix.Versioned.send_msg_2}. *)
 
 (** {2 Memory mapped files} *)
 

src/unix/lwt_unix.cppo.mli

@@ -928,6 +928,9 @@ val io_vector : buffer : string -> offset : int -> length : int -> io_vector
   (** Creates an io-vector *)
 
 val recv_msg : socket : file_descr -> io_vectors : io_vector list -> (int * Unix.file_descr list) Lwt.t
+  [@@ocaml.deprecated
+" Will be replaced by Lwt_unix.Versioned.recv_msg_2 in Lwt >= 5.0.0. See
+   https://github.com/ocsigen/lwt/issues/594"]
 (** [recv_msg ~socket ~io_vectors] receives data into a list of
     io-vectors, plus any file-descriptors that may accompany the
     messages. It returns a tuple whose first field is the number of
@@ -936,17 +939,26 @@ val recv_msg : socket : file_descr -> io_vectors : io_vector list -> (int * Unix
     provided [io_vectors] list. Data is written directly into the
     [iov_buffer] buffers.
 
-    Not implemented on Windows. *)
+    Not implemented on Windows.
+
+    @deprecated Will be replaced by {!Lwt_unix.Versioned.recv_msg_2} in Lwt
+                5.0.0. *)
 
 val send_msg : socket : file_descr -> io_vectors : io_vector list -> fds : Unix.file_descr list -> int Lwt.t
+  [@@ocaml.deprecated
+" Will be replaced by Lwt_unix.Versioned.send_msg_2 in Lwt >= 5.0.0. See
+   https://github.com/ocsigen/lwt/issues/594"]
 (** [send_msg ~socket ~io_vectors ~fds] sends data from a list of
     io-vectors, accompanied with a list of file-descriptors. It
     returns the number of bytes sent. If fd-passing is not possible on
     the current system and [fds] is not empty, it raises
     [Lwt_sys.Not_available "fd_passing"]. Data is written directly from
     the [iov_buffer] buffers.
 
-    Not implemented on Windows. *)
+    Not implemented on Windows.
+
+    @deprecated Will be replaced by {!Lwt_unix.Versioned.send_msg_2} in Lwt
+                5.0.0. *)
 
 type credentials = {
   cred_pid : int;

test/unix/test_lwt_bytes.ml

@@ -685,7 +685,7 @@ let suite = suite "lwt_bytes" [
       let offset = 0 in
       let io_vectors = [Lwt_bytes.io_vector ~buffer ~offset ~length:6] in
       let server_logic socket =
-        Lwt_bytes.recv_msg ~socket ~io_vectors
+        (Lwt_bytes.recv_msg [@ocaml.warning "-3"]) ~socket ~io_vectors
       in
       let client_logic socket sockaddr =
         let message = Lwt_bytes.of_string "abcdefghij" in
@@ -702,14 +702,14 @@ let suite = suite "lwt_bytes" [
       let offset = 0 in
       let server_logic socket =
         let io_vectors = [Lwt_bytes.io_vector ~buffer ~offset ~length:6] in
-        Lwt_bytes.recv_msg ~socket ~io_vectors
+        (Lwt_bytes.recv_msg [@ocaml.warning "-3"]) ~socket ~io_vectors
       in
       let client_logic socket sockaddr =
         Lwt_unix.connect socket sockaddr
         >>= fun () ->
         let message = Lwt_bytes.of_string "abcdefghij" in
         let io_vectors = [Lwt_bytes.io_vector ~buffer:message ~offset ~length:9] in
-        Lwt_bytes.send_msg ~socket ~io_vectors ~fds:[]
+        (Lwt_bytes.send_msg [@ocaml.warning "-3"]) ~socket ~io_vectors ~fds:[]
       in
       udp_server_client_exchange server_logic client_logic
       >>= fun () ->

test/unix/test_lwt_unix.cppo.ml

@@ -595,6 +595,64 @@ let send_recv_msg_tests = [
     let socket_1, socket_2 = Lwt_unix.(socketpair PF_UNIX SOCK_STREAM 0) in
     let pipe_read, pipe_write = Lwt_unix.pipe () in
 
+    let source_buffer = Bytes.of_string "_foo_bar_" in
+    let source_iovecs = Lwt_unix.IO_vectors.create () in
+    Lwt_unix.IO_vectors.append_bytes source_iovecs source_buffer 1 3;
+    Lwt_unix.IO_vectors.append_bytes source_iovecs source_buffer 5 3;
+
+    Lwt_unix.Versioned.send_msg_2
+      ~socket:socket_1
+      ~io_vectors:source_iovecs
+      ~fds:[Lwt_unix.unix_file_descr pipe_write] >>= fun n ->
+    if n <> 6 then
+      Lwt.return false
+
+    else
+      let destination_buffer = Bytes.of_string "_________" in
+      let destination_iovecs = Lwt_unix.IO_vectors.create () in
+      Lwt_unix.IO_vectors.append_bytes
+        destination_iovecs destination_buffer 5 3;
+      Lwt_unix.IO_vectors.append_bytes
+        destination_iovecs destination_buffer 1 3;
+
+      Lwt_unix.Versioned.recv_msg_2
+        ~socket:socket_2 ~io_vectors:destination_iovecs >>= fun (n, fds) ->
+      let succeeded =
+        match n, fds, Bytes.to_string destination_buffer with
+        | 6, [fd], "_bar_foo_" -> Some fd
+        | _ -> None
+      in
+      match succeeded with
+      | None ->
+        Lwt.return false
+      | Some fd ->
+
+        let n = Unix.write fd (Bytes.of_string "baz") 0 3 in
+        if n <> 3 then
+          Lwt.return false
+
+        else
+          let buffer = Bytes.create 3 in
+          Lwt_unix.read pipe_read buffer 0 3 >>= fun n ->
+          match n, Bytes.to_string buffer with
+          | 3, "baz" ->
+            Lwt_unix.close socket_1 >>= fun () ->
+            Lwt_unix.close socket_2 >>= fun () ->
+            Lwt_unix.close pipe_read >>= fun () ->
+            Lwt_unix.close pipe_write >>= fun () ->
+            Unix.close fd;
+            Lwt.return true
+
+          | _ ->
+            Lwt.return false
+  end;
+
+  test "send_msg, recv_msg (old)" ~only_if:(fun () -> not Sys.win32)
+      begin fun () ->
+
+    let socket_1, socket_2 = Lwt_unix.(socketpair PF_UNIX SOCK_STREAM 0) in
+    let pipe_read, pipe_write = Lwt_unix.pipe () in
+
     let source_buffer = "_foo_bar_" in
     let source_iovecs = Lwt_unix.[
       {
@@ -610,7 +668,7 @@ let send_recv_msg_tests = [
     ]
     in
 
-    Lwt_unix.send_msg
+    (Lwt_unix.send_msg [@ocaml.warning "-3"])
       ~socket:socket_1
       ~io_vectors:source_iovecs
       ~fds:[Lwt_unix.unix_file_descr pipe_write] >>= fun n ->
@@ -633,7 +691,7 @@ let send_recv_msg_tests = [
       ]
       in
 
-      Lwt_unix.recv_msg
+      (Lwt_unix.recv_msg [@ocaml.warning "-3"])
         ~socket:socket_2 ~io_vectors:destination_iovecs >>= fun (n, fds) ->
       let succeeded =
         match n, fds, destination_buffer with
@@ -665,7 +723,7 @@ let send_recv_msg_tests = [
             Lwt.return false
   end;
 
-  test "send_msg, recv_msg (Lwt_bytes)" ~only_if:(fun () -> not Sys.win32)
+  test "send_msg, recv_msg (Lwt_bytes, old)" ~only_if:(fun () -> not Sys.win32)
       begin fun () ->
 
     let socket_1, socket_2 = Lwt_unix.(socketpair PF_UNIX SOCK_STREAM 0) in
@@ -686,7 +744,7 @@ let send_recv_msg_tests = [
     ]
     in
 
-    Lwt_bytes.send_msg
+    (Lwt_bytes.send_msg [@ocaml.warning "-3"])
       ~socket:socket_1
       ~io_vectors:source_iovecs
       ~fds:[Lwt_unix.unix_file_descr pipe_write] >>= fun n ->
@@ -709,7 +767,7 @@ let send_recv_msg_tests = [
       ]
       in
 
-      Lwt_bytes.recv_msg
+      (Lwt_bytes.recv_msg [@ocaml.warning "-3"])
         ~socket:socket_2 ~io_vectors:destination_iovecs >>= fun (n, fds) ->
       let succeeded =
         match n, fds, Lwt_bytes.to_string destination_buffer with