[fpc-devel] Access Violation with nested DLL's compiled byFPC(andsome more info on bug #4538)

[Jonas Maebe]

On 11 Dec 2005, at 14:51, L505 wrote:

> I apologize, I should have said that you'd not have exactly the  
> same problems with
> returning a string - they are different problems but the basic  
> point and idea remains
> the same: no matter what you do, strings will cause problems. What  
> I should have said
> was there would still be all sorts of problems with returning a  
> string - not
> necessarily the reference count problem, but other issues that  
> cause similar havoc,
> such as two memory managers not communicating with each other.  
> There are so many
> problems to consider, that a programmer once again spends more time  
> thinking about
> the possible problems instead of programming a solution that works  
> reliably.

I still have not seen a single actual problem mentioned with an  
explanation by what exactly it is caused, only vague hand waving  
warning for strange and inexplicable problems. I'm really interested  
by what these problems are and can be caused. Does every dll have its  
own memory manager data structures and is indeed the problem that  
memory allocated by one is free "to" another (as I described in my  
previous mail)?

That would seem very strange to me though, since this could be easily  
solved by making the RTL/system unit a dynamically linked library and  
linking all other libraries to that (so there is only one system unit  
with only one memory manager).

Or is it something else?


Jonas