The Wiert Corner - irregular stream of stuff: jpluimers

Talking about Danny Thorpe: he also posted a nice hint on threading methods for ancient Delphi versions that equally applies to DLL exports in any Delphi version, even any programming environment.

Recently, I had to do some surgery in such a Pre-Delphi 6 application, and I was really happy to remember this answer: it instantly solved some process crashes, and the added logging allowed for investigating the actual cause.

Note that this tip isn’t just a good advice for old Delphi versions.

Even in younger Delphi versions, you have to watch methods that can be called from outside a regular Delphi context, for instance exported methods.

Heck, it applies to virtually any development environment: exceptions usually are very specific to that environment and should never cross a process boundary.

Summary

Take the approach below

• for Execute methods in your own thread classes in Delphi 5 or earlier
• for any method that can be called externally (like DLL exports)

procedure ThreadExecuteOrDllExport(...);
begin
  try
    CallInternalLogic(...parameters...);
  except
    on e: Exception do
    begin
      // output or log this error somewhere.
    end;
  end;
end;

–jeroen

via: multithreading – Program shutdown on Synchronize – Stack Overflow.