AW: [Caml-list] Re: Select on channels (again)

AW: [Caml-list] Re: Select on channels (again)

[Christoph Bauer]

 

> Why can't you just use the unix file opening functions since 
> you're using unix select? And if you need the ocaml in/out 
> channels, convert the unix file descriptors to ocaml ones 
> instead of the other way around. Seems simple enough to me.

I did this, but on windows with two programs communicating over
a pipe this isn't enough. select on windows and on a pipe doesn't
work. Therefore I wrote a stub for PeekNamedPipe():

#include <caml/unixsupport.h>
#include <windows.h>

CAMLprim value peeknamedpipe_stub( value fd ) {
  CAMLparam1( fd );
  DWORD available;
  if( !PeekNamedPipe( Handle_val( fd ), NULL, 0, NULL, &available, NULL ) )
{
    failwith( "peeknamedpipe failed");
  }
  CAMLreturn( Val_int( available ) );
}

I use select on Unix and peednamedpipe on windows. 


Communication over sockets could be another solution, because then select
should work on windows, too.

Christoph Bauer

Re: AW: [Caml-list] Re: Select on channels (again)

[Robert Roessler]

Christoph Bauer wrote:
> ...
> I did this, but on windows with two programs communicating over
> a pipe this isn't enough. select on windows and on a pipe doesn't
> work. Therefore I wrote a stub for PeekNamedPipe():

"Select on windows" certainly does work... and why not use a socket 
pair, just as one might on a *nix system?  That way, it will work on both.

And the fact that socketpair has been left out of the Windows version 
of the Unix module is not an impediment - it is easy to write a useful 
implementation in OCaml (I can supply one if needed).

Robert Roessler
roessler@rftp.com
http://www.rftp.com