Merge pull request #733 from alyssais/listening

Add Eio_unix.Net.import_socket_listening

lib_eio/unix/net.ml

@@ -61,18 +61,23 @@ type t = [`Generic | `Unix] Eio.Net.ty r
 
 type _ Effect.t +=
   | Import_socket_stream : Switch.t * bool * Unix.file_descr -> [`Unix_fd | stream_socket_ty] r Effect.t
+  | Import_socket_listening : Switch.t * bool * Unix.file_descr -> [`Unix_fd | listening_socket_ty] r Effect.t
   | Import_socket_datagram : Switch.t * bool * Unix.file_descr -> [`Unix_fd | datagram_socket_ty] r Effect.t
   | Socketpair_stream : Switch.t * Unix.socket_domain * int ->
       ([`Unix_fd | stream_socket_ty] r * [`Unix_fd | stream_socket_ty] r) Effect.t
   | Socketpair_datagram : Switch.t * Unix.socket_domain * int ->
       ([`Unix_fd | datagram_socket_ty] r * [`Unix_fd | datagram_socket_ty] r) Effect.t
 
 let open_stream s = (s : _ stream_socket :> [< `Unix_fd | stream_socket_ty] r)
+let open_listening s = (s : _ listening_socket :> [< `Unix_fd | listening_socket_ty] r)
 let open_datagram s = (s : _ datagram_socket :> [< `Unix_fd | datagram_socket_ty] r)
 
 let import_socket_stream ~sw ~close_unix fd =
   open_stream @@ Effect.perform (Import_socket_stream (sw, close_unix, fd))
 
+let import_socket_listening ~sw ~close_unix fd =
+  open_listening @@ Effect.perform (Import_socket_listening (sw, close_unix, fd))
+
 let import_socket_datagram ~sw ~close_unix fd =
   open_datagram @@ Effect.perform (Import_socket_datagram (sw, close_unix, fd))
 

lib_eio/unix/net.mli

@@ -56,15 +56,22 @@ end
 (** {2 Creating or importing sockets} *)
 
 val import_socket_stream : sw:Switch.t -> close_unix:bool -> Unix.file_descr -> [`Unix_fd | stream_socket_ty] r
-(** [import_socket_stream ~sw ~close_unix:true fd] is an Eio flow that uses [fd].
+(** [import_socket_stream ~sw ~close_unix fd] is an Eio flow that uses [fd].
 
     It can be cast to e.g. {!source} for a one-way flow.
     The socket object will be closed when [sw] finishes.
 
     The [close_unix] and [sw] arguments are passed to {!Fd.of_unix}. *)
 
+val import_socket_listening : sw:Switch.t -> close_unix:bool -> Unix.file_descr -> [`Unix_fd | listening_socket_ty] r
+(** [import_socket_listening ~sw ~close_unix fd] is an Eio listening socket that uses [fd].
+
+    The socket object will be closed when [sw] finishes.
+
+    The [close_unix] and [sw] arguments are passed to {!Fd.of_unix}. *)
+
 val import_socket_datagram : sw:Switch.t -> close_unix:bool -> Unix.file_descr -> [`Unix_fd | datagram_socket_ty] r
-(** [import_socket_datagram ~sw ~close_unix:true fd] is an Eio datagram socket that uses [fd].
+(** [import_socket_datagram ~sw ~close_unix fd] is an Eio datagram socket that uses [fd].
 
     The socket object will be closed when [sw] finishes.
 
@@ -100,6 +107,8 @@ val getnameinfo : Eio.Net.Sockaddr.t -> (string * string)
 type _ Effect.t +=
   | Import_socket_stream :
       Switch.t * bool * Unix.file_descr -> [`Unix_fd | stream_socket_ty] r Effect.t     (** See {!import_socket_stream} *)
+  | Import_socket_listening :
+      Switch.t * bool * Unix.file_descr -> [`Unix_fd | listening_socket_ty] r Effect.t  (** See {!import_socket_listening} *)
   | Import_socket_datagram :
       Switch.t * bool * Unix.file_descr -> [`Unix_fd | datagram_socket_ty] r Effect.t   (** See {!import_socket_datagram} *)
   | Socketpair_stream : Eio.Switch.t * Unix.socket_domain * int ->

lib_eio_linux/eio_linux.ml

@@ -504,6 +504,10 @@ let run_event_loop (type a) ?fallback config (main : _ -> a) arg : a =
           let fd = Fd.of_unix ~sw ~seekable:false ~close_unix fd in
           continue k (Flow.of_fd fd :> _ Eio_unix.Net.stream_socket)
         )
+      | Eio_unix.Net.Import_socket_listening (sw, close_unix, fd) -> Some (fun k ->
+          let fd = Fd.of_unix ~sw ~seekable:false ~close_unix fd in
+          continue k (listening_socket fd)
+        )
       | Eio_unix.Net.Import_socket_datagram (sw, close_unix, fd) -> Some (fun k ->
           let fd = Fd.of_unix ~sw ~seekable:false ~close_unix fd in
           continue k (datagram_socket fd)

lib_eio_posix/domain_mgr.ml

@@ -48,6 +48,11 @@ let run_event_loop fn x =
           Unix.set_nonblock unix_fd;
           continue k (Flow.of_fd fd :> _ Eio_unix.Net.stream_socket)
         )
+      | Eio_unix.Net.Import_socket_listening (sw, close_unix, unix_fd) -> Some (fun k ->
+          let fd = Fd.of_unix ~sw ~blocking:false ~close_unix unix_fd in
+          Unix.set_nonblock unix_fd;
+          continue k (Net.listening_socket ~hook:Switch.null_hook fd)
+        )
       | Eio_unix.Net.Import_socket_datagram (sw, close_unix, unix_fd) -> Some (fun k ->
           let fd = Fd.of_unix ~sw ~blocking:false ~close_unix unix_fd in
           Unix.set_nonblock unix_fd;

lib_eio_windows/domain_mgr.ml

@@ -48,6 +48,11 @@ let run_event_loop fn x =
           (try Unix.set_nonblock unix_fd with Unix.Unix_error (Unix.ENOTSOCK, _, _) -> ());
           continue k (Flow.of_fd fd :> _ Eio_unix.Net.stream_socket)
         )
+      | Eio_unix.Net.Import_socket_listening (sw, close_unix, unix_fd) -> Some (fun k ->
+          let fd = Fd.of_unix ~sw ~blocking:false ~close_unix unix_fd in
+          Unix.set_nonblock unix_fd;
+          continue k (Net.listening_socket ~hook:Switch.null_hook fd)
+        )
       | Eio_unix.Net.Import_socket_datagram (sw, close_unix, unix_fd) -> Some (fun k ->
           let fd = Fd.of_unix ~sw ~blocking:false ~close_unix unix_fd in
           Unix.set_nonblock unix_fd;

tests/network.md

@@ -373,6 +373,29 @@ Wrapping a Unix FD as an Eio stream socket:
 - : unit = ()
 ```
 
+Wrapping a Unix FD as a listening Eio socket:
+
+```ocaml
+# run @@ fun ~net sw ->
+  let l = Unix.(socket PF_INET SOCK_STREAM 0) in
+  Unix.bind l (Unix.ADDR_INET (Unix.inet_addr_loopback, 8082));
+  Unix.listen l 40;
+  let l = Eio_unix.Net.import_socket_listening ~sw ~close_unix:true l in
+  Fiber.both
+    (fun () -> run_server ~sw l)
+    (fun () ->
+      run_client ~sw ~net ~addr:(`Tcp (Eio.Net.Ipaddr.V4.loopback, 8082));
+      traceln "Client finished - cancelling server";
+      raise Graceful_shutdown
+    );;
++Connecting to server...
++Server accepted connection from client
++Server received: "Hello from client"
++Client received: "Bye"
++Client finished - cancelling server
+Exception: Graceful_shutdown.
+```
+
 Wrapping a Unix FD as an datagram Eio socket:
 
 ```ocaml