[fpc-pascal]ReAlloc Question

[James Mills]

On Fri, May 16, 2003 at 01:41:35PM +0200, Michael Van Canneyt wrote:
> 
> 
> On Fri, 16 May 2003, James Mills wrote:
> 
> > Hi,
> >
> > Can any problems with stringsclass.pas ?
> > Reason I ask is that, yes my fairly large program works that uses
> > dynamic memory allocation, however it has memory leaks galore! :(
> > stringsclass.pas is a dynamic string class I created which I take pride
> > in, but I'm not convinced I wrote the: procedure del(index: Integer);
> > correctly...
> > Could someone have a look and comment on that please ? It will aid
> > greatly in my efforts to debug my memory leaks...
> 
> With all due respect, but this is not exactly the most efficient code ever.
> Did you have a look at the standard TStringList class ? It works very well,
> and does all you do.

Yeah I found out there was TStringList after I wrote it. And I'll agree
with you, it's not the best code. However other classes that dynamically
allocate objects in memory use similar code to that of stringsclass.pas
so I need to get this right :)

> 
> 
> Also, Class destructors MUST be called 'Destroy', not 'done'.
Okay.

> 
> Your method of calling init/done is also not quite correct, you're not
> supposed to call the destructor unless you actually want to free your
> class.
> 
> If you want to stick to your class, try replacing your code with this=
> 
> procedure TStrings.del(index: Integer);
> var
>  I : Integer;
> 
> begin
>  For I:=index to nstrings-1 do
>    Strings[i]:=Strings[i+1];
>  Dec(nstrings);
>  ReallocMem(strings,sizeof(Shortstring)*nstrings);
> end;

Would this same technique work for a general dynamic array of objects ?

> 
> Using this I get no memory leaks.

I get none with my version either (don't know why) ...

James

> 
> Michael.
> 
> 
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