Re: [Cygwin64] unloading of dlls

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Mar 15 10:14, Peter Rosin wrote:
> Hi!
> 
> I'm wondering if there is some difference in how dlls are unloaded
> on Cygwin64 vs Cygwin32?
> 
> In libggi, there's a X.dll that handles drawing on an X server.
> X.dll has the capacity to dynamically load a dbe.dll (dbe.dll is
> linked with -lXext, something which X.dll is not) helper that
> calls XdbeQueryExtension. XdbeQueryExtension happens to store
> a pointer to a hook that is supposed to be called on XCloseDisplay
> in some private area. Now, if I unload dbe.dll before I close
> XCloseDisplay, the hook appears to have disappeared from the
> address space by the time I call XCloseDisplay, but only on
> Cygwin64 (with drastic effects). While a teeny bit fragile, and
> probably a practice best avoided, this still appears to work
> fine on Cygwin32.
> 
> Is there some natural explanation for the 32/64 difference?

I don't have any.  In theory that shouldn't have worked in 32 bit
either.  Maybe the memory handling of the OS is different.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
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