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charset=UTF-8 Thanks for your answer! I get the same result with the following code. Note that I can open 2 connections and that the closing of the connection works as expected with a 'close connection' pattern (with one line only with a dot followed by an empty line). It is just that I cannot close the second connection while the first stays open, the 'close connection' pattern is not triggering the close. let rec accept_connection sock:Unix.file_descr = let socket_thread = Lwt.return ( Unix.accept sock ) in let _ = Lwt.bind socket_thread ( fun (fd, caller) -> ignore(Lwt_io.printf "accepted\n%!"); (*let _ = set_nonblock fd in*) Lwt.return (readall fd) >>= fun a -> ignore(Lwt_io.printf "%s\n%!" a); ignore(Lwt.async (fun () -> Lwt.return (close fd) ) ); Lwt.return 0; ); in accept_connection sock let server port = let inet_addr = inet_addr_any in let sockaddr = ADDR_INET (inet_addr, port) in let domain = domain_of_sockaddr sockaddr in let sock:Unix.file_descr = socket domain SOCK_STREAM 0 in Unix.bind sock sockaddr; listen sock 10; Lwt_main.run ( Lwt.return (accept_connection sock) ) On Sun, Nov 27, 2016 at 6:41 PM, Koen De Keyser wrote: > You need to run your lwt code within Lwt_main.run > > This starts the lwt scheduler. Otherwise your application just terminates > once it has created the lwt thread (which is a simple Ocaml value). > > Koen > > On Nov 27, 2016 18:30, "Raphael Bauduin" wrote: > >> Hi, >> >> After writing a small tcp server in ocaml, I wanted to make it work >> asynchronously with Lwt. >> I changed the function handling the accept on the socket to look like >> this: >> >> let rec accept_connection sock:Unix.file_descr = >> let socket_thread = Lwt.return ( Unix.accept sock ) in >> let _ = Lwt.bind socket_thread >> ( fun (fd, caller) -> >> ignore(Lwt_io.printf "accepted\n%!"); >> (*let _ = set_nonblock fd in*) >> Lwt.return (readall fd) >>= fun a -> >> ignore(Lwt_io.printf "%s\n%!" a); >> ignore(Lwt.async (fun () -> Lwt.return (close fd) ) ); >> Lwt.return 0; >> ); in >> accept_connection sock >> >> The complete code is at http://pastie.org/10971189 . >> >> But it doesn't seem to work. The problems are: >> - nothing is printed on stdout >> - when I open 2 connections, the second can only be closed after the >> first has been closed. >> >> In the mean time I've discovered Lwt_unix, but before looking at it, I'd >> like to understand what's wrong in my current code. Can you spot errors in >> the code? General advice is also welcome! >> >> Thanks >> >> Raphael >> >> >> -- Web database: http://www.myowndb.com Free Software Developers Meeting: http://www.fosdem.org --001a1147b4ba13408c05424cf59b Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Thanks for your answer!

I get the same = result with the following code. Note that I can open 2 connections and that= the closing of the connection works as expected with a 'close connecti= on' pattern (with one line only with a dot followed by an empty line). = It is just that I cannot close the second connection while the first stays = open, the 'close connection' pattern is not triggering the close.

let rec accept_connection sock:Unix.file_descr= =3D
=C2=A0 let socket_thread =3D Lwt.return ( Unix.accept sock )= in
=C2=A0 =C2=A0 let _ =3D Lwt.bind socket_thread
=C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0( fun (fd, caller) ->
= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0ignore(Lwt_io.printf= "accepted\n%!");
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0(*let _ =3D set_nonblock fd in*)
=C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Lwt.return (readall fd) >&g= t;=3D fun a ->
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0ignore(Lwt_io.printf "%s\n%!" a);
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0ign= ore(Lwt.async (fun () -> Lwt.return (close fd) ) );
=C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Lwt.return 0;
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0); in
=C2=A0 =C2= =A0 =C2=A0accept_connection sock
let server port =3D
= =C2=A0 let inet_addr =3D inet_addr_any in
=C2=A0 let sockaddr =3D= ADDR_INET (inet_addr, port) in
=C2=A0 let domain =3D domain_of_s= ockaddr sockaddr in
=C2=A0 let sock:Unix.file_descr =3D socket do= main SOCK_STREAM 0 in
=C2=A0 Unix.bind sock sockaddr;
= =C2=A0 listen sock 10;
=C2=A0 Lwt_main.run ( Lwt.return (accept_c= onnection sock) )


On Sun, Nov 27, 2016 at 6:41 PM, Koen De K= eyser <koen.dekeyser@gmail.com> wrote:
You need to run your lwt code within L= wt_main.run=C2=A0

This starts = the lwt scheduler. Otherwise your application just terminates once it has c= reated the lwt thread (which is a simple Ocaml value).=C2=A0

Koen

On Nov 27, 2= 016 18:30, "Raphael Bauduin" <rblists@gmail.com> wrote:
Hi,

After writing a small tcp server in ocaml, I wanted to = make it work asynchronously with Lwt.
I changed the function hand= ling the accept on the socket to look like this:

<= div>let rec accept_connection sock:Unix.file_descr =3D
=C2=A0 let= socket_thread =3D Lwt.return ( Unix.accept sock ) in
=C2=A0 let = _ =3D Lwt.bind socket_thread
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0( = fun (fd, caller) ->
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0ignore(Lwt_io.printf "accepted\n%!");
=C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0(*let _ =3D set_nonblock fd in*)
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Lwt.return (readall f= d) >>=3D fun a ->
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0ignore(Lwt_io.printf "%s\n%!" a);
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0ignore(Lwt= .async (fun () -> Lwt.return (close fd) ) );
=C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Lwt.return 0;
=C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0); in
=C2=A0 =C2=A0accept_connection = sock

The complete code is at=C2=A0http://pastie.org/10971189 .





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Web datab= ase: http://www.myownd= b.com
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