mmap() and gcc precompiled headers

Corinna Vinschen corinna-cygwin@cygwin.com
Thu Jul 3 14:30:00 GMT 2003


On Thu, Jul 03, 2003 at 10:19:42AM -0400, Christopher Faylor wrote:
> On Thu, Jul 03, 2003 at 11:47:28AM +0200, Corinna Vinschen wrote:
> >Do you mean something like this:
> >
> >  If addr is given, check if it's 64K aligned.  If not, align and
> >  raise the memory requirement accordingly.  Call MapViewOfFileEx
> >  with the aligned address.  If it works, return the addr given as
> >  parameter, otherwise return MapViewOfFileEx(NULL).
> 
> How about, instead, just use the address and if it fails and is not
> MAP_FIXED, use MapViewOfFileEx without the address?

Yep, that's the simple approach.  I dropped this suggestion from my
original reply since it requires addr to be on a 64k boundary.  
Unfortunately I have no idea if the chance to succeed might be better
or worse than using the more complex approach.

Either way, it's not us but gcc being on the wrong track.  If gcc relies
on getting the same address it should use MAP_FIXED at least on hosts
known to support MAP_FIXED correctly.

Corinna

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

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/



More information about the Cygwin mailing list