>> Assuming that your question targets Delphi case, the answer is:
>>
>> Otherwise you have to require each procedure written in Delphi to take
>> two additional parameters - current DB handle and current TR handle, and
>> require Delphi code to pass them somehow into isc_XXX calls when
>> callback mechanism should be used (btw, will IBO or FIB+ allow such
>> things?).
>
> IBO doesn't currently use anything like the TLS (that I understand) when establishing callback channels. I thought TLS was about securing connections across networks (Transport-level Security). You seem to be talking about isolating invocations of a procedure from one another, threads actually (for which IBO has a robust mechanism and I can't comment about FIB+).
>
> Are you talking about a different thing for which TLS is an acronym? I suspect so...maybe "thread-local storage" or something along those lines?

Yes, that is Thread-Local-Storage in this context, not the Transport
Layer Security. Also the callback in this context has an opposite
meaning - in our case ESP (read "application") calls the engine back
(i.e. the ESP executes some statement), while in other contexts the
engine calls the application back (like AFAIK in the current
Windows-based authentication). :)

Roman