From mboxrd@z Thu Jan  1 00:00:00 1970
Received: (from weis@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id JAA01513 for caml-red; Thu, 7 Dec 2000 09:07:10 +0100 (MET)
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id BAA01773 for <caml-list@pauillac.inria.fr>; Wed, 6 Dec 2000 01:52:32 +0100 (MET)
Received: from ropas.kaist.ac.kr (ropas.kaist.ac.kr [143.248.92.105])
	by concorde.inria.fr (8.11.1/8.10.0) with ESMTP id eB60qUP21271
	for <caml-list@inria.fr>; Wed, 6 Dec 2000 01:52:31 +0100 (MET)
Received: from plus (plus.kaist.ac.kr [143.248.92.142])
	by ropas.kaist.ac.kr (8.9.3/8.9.3) with SMTP id JAA10824
	for <caml-list@inria.fr>; Wed, 6 Dec 2000 09:51:43 +0900 (KST)
Message-ID: <002c01c05f1f$55fb95b0$8e5cf88f@plus>
Reply-To: "Hyun-Goo Kang" <hgkang@ropas.kaist.ac.kr>
From: "Hyun-Goo Kang" <hgkang@ropas.kaist.ac.kr>
To: <caml-list@inria.fr>
Subject: [Q] Callbacking a ocaml function from VC++
Date: Wed, 6 Dec 2000 09:56:15 +0900
Organization: ropas
MIME-Version: 1.0
Content-Type: text/plain;
	charset="ks_c_5601-1987"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400
Sender: weis@pauillac.inria.fr

---------------------------------------------------------------------------
[Q] Callbacking a ocaml function which uses Unix socket lib from VC++
function"
---------------------------------------------------------------------------


Hello.
I'm writing a network program written in ocaml3.0 for win32(for networking)
and VC++6.0(for user interface).

My problem is using a ocaml function which uses ocaml unix library for
socket programming
in a VC++ program.

First i defined a function which use "Unix.connect" like following...

  let connect_server () =
    let ip = xxx.xxx.xxx.xxx in
    let port = 6765 in
    let sockfd = socket PF_INET SOCK_STREAM 0 in
    let target_addr = ADDR_INET(inet_addr_of_string ip,port) in
    let  _ = connect sockfd target_addr  (* try to make connection *) in
    (* sockfd *) 1;;

 (* this function was already tested in ocaml and operated properly *)


and then to use callback mechanism, i registered that function like
following...

  let _ = Callback.register "connect" connect_server

and then i compiled it like following...

  c:\project> ocamlc -output-obj -o connect.obj unix.cma threads.cma
connect.cmo

and then i appended the object(connect.obj) in VC project,
and libcamlrun.lib libunix.lib
and wsock32.lib(if i don't append this, there are many link error),  --->
(*)

and then i included whole header files needed for callback like following

  //stdafx.h
  extern "C"
  {
  #include "./ocaml_lib/mlvalues.h"
  #include "./ocaml_lib/callback.h"
  }

and then i called ocaml connect function in VC++ program like following...

int connect_it()
{
 static value *connect = NULL;
 if (connect == NULL)
  connect = caml_named_value("connect");
 return Int_val(callback(*connect,Val_unit));
}

void CDlg2Dlg::OnConnect()
{
  int v;
  char** argv = (char**)malloc(sizeof(char*));;
 char buff[100];

 *argv = NULL;  //"dummy";

  caml_startup(argv);

 sprintf(buff,"result = %d",connect_it());
 AfxMessageBox(TEXT(buff));
}



But i couldn't get proper result. (VC++ program termination in callback
point)
What is the problem?
I think it's likely that the problem is in (*) point.

Thanks in advance...


------------
Note: I succeeded in other easy example using same style,
      if i don't use Unix or Unix socket library.