set_open_status

[Corinna Vinschen]

On Feb 18 16:23, Ken Brown via Cygwin-developers wrote:
> On 2/18/2021 8:07 AM, Corinna Vinschen via Cygwin-developers wrote:
> > On Feb 18 10:07, Corinna Vinschen via Cygwin-developers wrote:
> > > On Feb 17 16:35, Ken Brown via Cygwin-developers wrote:
> > > > Most fhandlers call set_open_status in their 'open' method before a
> > > > successful return.  I just noticed that fhandler_fifo::open doesn't do this.
> > > > I thought at first that it was an oversight on my part from when I
> > > > overhauled the FIFO implementation, but I just checked fhandler_fifo.cc as
> > > > of cygwin 2.9.0, and I don't see it there either.
> > > > 
> > > > Is there some reason this would be wrong for FIFOs?
> > > 
> > > I guess this was just an oversight.  It's certainly not fatal, given how
> > > open_status is used exclusively by fhandler_base::reset_to_open_binmode()
> > > in turn *only* called from setmode(fd, 0).  This is quite a bordercase.
> > > Combined with FIFOs supporting only O_BINARY mode anyway...
> > > 
> > > It won't hurt to add the set_open_mode call to FIFOs but it won't change
> > > anything, except avoiding to report O_TEXT mode after a call to
> > > setmode(fd, 0).
> > > 
> > > Maybe it would be better to change fhandler_base::reset_to_open_binmode
> > > instead.  Right now, if open_status hasn't been initialized, it prefers
> > > O_TEXT over O_BINARY.  That's unfortunate, because it forces us to call
> > > set_open_mode everywhere to make sure the mode is stored correctly for
> > > this single, and seldom, invocation of setmode(fd, 0).  It would be nice
> > > if set_open_mode would only be necessary on fhandlers supporting O_TEXT
> > > at all.
> > 
> > On second thought, this should do the trick:
> > 
> > diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
> > index e457e2785e9b..ac9ee7c9e787 100644
> > --- a/winsup/cygwin/fhandler.h
> > +++ b/winsup/cygwin/fhandler.h
> > @@ -274,7 +274,8 @@ class fhandler_base
> >     void reset_to_open_binmode ()
> >     {
> >       set_flags ((get_flags () & ~(O_TEXT | O_BINARY))
> > -	       | ((open_status.wbinary || open_status.rbinary)
> > +	       | (((open_status.wbinset ? open_status.wbinary : 1)
> > +		   || (open_status.rbinset ? open_status.rbinary : 1))
> >   		   ? O_BINARY : O_TEXT));
> >     }
> 
> Yes, this looks right.
> 
> Ken

Thanks,  I pushed it.


Corinna