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Date: Mon, 26 Aug 2002 16:48:23 +0200
From: Corinna Vinschen <vinschen AT redhat DOT com>
To: cygwin-developers AT cygwin DOT com
Subject: Re: readv/writev
Message-ID: <20020826164823.N5475@cygbert.vinschen.de>
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On Tue, Aug 27, 2002 at 12:38:09AM +1000, Robert Collins wrote:
> On Tue, 2002-08-27 at 00:29, Corinna Vinschen wrote:
> > On Mon, Aug 26, 2002 at 03:20:00PM +0100, Conrad Scott wrote:
> > > "Christopher Faylor" <cgf AT redhat DOT com> wrote:
> > > > There shouldn't really be that much overhead to the current
> > > method for
> > > > handling text/binary reads, though.  It's just checking a bit
> > > field.
> > > 
> > > At the coal-face it ends up being a bit more messy than that.  For
> > > example, the fhandler::read code checks the readahead buffers for
> > > pending data but they will always be empty in binary-mode (AFAIK)
> > > . In fact there's a page of code before the check for whether a
> > > binary read is being done and only then does the code escape back
> > > to the caller.  Since (AFAIK) you can't change the text/binary
> > > mode of an fd once it's been opened (and thus the readahead
> > 
> > You can.  setmode(fd, O_TEXT); or setmode(fd, O_BINARY);
> 
> Which is why I was suggesting stripping O_TEXT capability for raw FD's,
> and making the TEXT translation only ever apply to the FILE * calls -
> fprintf, fscanf, fread etc...
> 
> It allows all the fd level code to be much much simpler.

Sure, I *love* the idea, but it would break applications, e. g. ash,
which opens input files on descriptor level.

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin AT cygwin DOT com
Red Hat, Inc.