Subject RE: [firebird-support] *** possible bug in FB 2.5.2 supperclassic with UDF *** solved
Author ICAMSoft

Thanks for anybody who replied and

again my apology for the easiness i charged firebird for the problem...


The problem's reason and the solution for any who may concern:


As some of repliers said the problem was in memory management of delphi under concurrent threads.

After  15 years using delphi,  i discovered by googling the variable IsMultiThread


Adding in initialization section the following line

IsMultiThread :=true;

everything is ok, also using superclassic (at least in my machine).


PS1: <IsMultiThread :=true> is silently done by Delphi itself, if threads exist in the uses list. Bad for me, my functions where pretty simple and so threads unit was not declared in uses.

PS2:  I think that this could be a major trap for many delphi programmers and that a relative note in documentation about UDF with Delphi in should be added


Best Regards



Athens, Greece