Frank Ingermann wrote:

>
> Hi Senthil / Raymond,
>
> two pointers that might help:
> http://firebird.sourceforge.net/index.php?op=useful&id=geldenhuis
> http://firebird.sourceforge.net/index.php?op=useful&id=deatz_udf#left
>
> both from the "really useful" section -- the name says it all! <g>

Thanks. I've read those.

Now I have changed cdecl; export; to stdcall; but there is not change.

>
> you can also download http://www.cvalde.com/utilities/FreeUDFLib.zip,
> it includes Delphi sources so you can see how it's done.

I've read the source to that in entirety, so I'm ready to understand any explanations
given to me.

Also, where is IB_Util.PAS and is it relevant to FB?

TIA.

Raymond.

>
> regards & hth,
> fingerman
>
> Senthil Palanisamy wrote:
> > Hi Raymond,
> >
> > This problem occurs due to access violation in the Usage of pointer
> > variable.
> > im not aware of delphi.
> > in C and C++ if we try like "copying a string to a pointer variable without
> > allocating the memory", then an access violation will take place and it will
> > kill the IB/firebird service.
> >
> > regards,
> > senthil.
> >
> > ----- Original Message -----
> > From: "Raymond Kennington" <progsol@...>
> > Newsgroups: egroups.ib-support
> > To: <ib-support@yahoogroups.com>
> > Sent: Thursday, November 07, 2002 10:05 PM
> > Subject: [ib-support] Using UDF: "Connection Lost to Database"
> >
> >
> >
> >>Using a UDF causes the error message: "Connection Lost to Database" to
> >
> > appear.
> >
> >>All the relevant code is below. What is causing this?
> >>
> >>Is all memory correctly allocated and destroyed by the following?
> >>
> >>How to make the following thread-safe?
> >>
> >>Any other suggestions to improve the following?
> >>
> >>TIA.
> >>
> >>Raymond.
> >>--------
> >>
> >>library Algorithms;
> >>
> >>uses
> >> SysUtils,
> >> Classes,
> >> ConfNum in 'ConfNum.pas';
> >>
> >>{$R *.res}
> >>
> >>exports
> >> CalcCheckDigit;
> >>
> >>begin
> >>end.
> >>
> >>unit ConfNum;
> >>
> >>interface
> >>
> >>function CalcCheckDigit(var TheConfNum : PChar; ResultBuffer : PChar) :
> >
> > PChar; cdecl;
> >
> >>export;
> >>
> >>implementation
> >>
> >>uses
> >> SysUtils;
> >>
> >>function CalcCheckDigit(var TheConfNum : PChar; ResultBuffer : PChar) :
> >
> > PChar; cdecl;
> >
> >>export;
> >>var
> >> c : array[0..1] of Char;
> >>
> >> i : Integer;
> >>begin
> >> Result := ResultBuffer;
> >>
> >> c[0] := 'A';
> >> c[1] := #0;
> >>
> >> StrCopy(Result, c);
> >>end;
> >>
> >>initialization
> >> IsMultiThread := True;
> >>
> >>end.
> >>
> >>DECLARE EXTERNAL FUNCTION CalcCheckDigit
> >>CSTRING(11) CHARACTER SET NONE,
> >>CSTRING(2) CHARACTER SET NONE
> >>RETURNS PARAMETER 2
> >>ENTRY_POINT 'CalcCheckDigit' MODULE_NAME 'Algorithms';
> >>
> >>SELECT CalcCheckDigit('0000111111') FROM RDB$DATABASE;
> >>
> >>--
> >>Raymond Kennington
> >>Programming Solutions
> >>W2W Team B
> >>

--
Raymond Kennington
Programming Solutions
W2W Team B