JApplication::Quit exit code param

[RaiqaRasool]

In JANA2, exiting the application with a specific exit code currently requires two separate calls:

japp->SetExitCode(code);
japp->Quit(true);

This differs from JANA1, where the exit code could be passed directly to Quit(), for example:

japp->Quit(code);

It would be better if the Quit() method accepted an optional exit code parameter, such as:

void Quit(int exitCode = 0, bool skipJoin = false);

This would allow setting the exit code and quitting the application in a single call, simplifying the interface and reducing the chance of errors.

Such a change would also improve consistency with the JANA1 API, making upgrades easier and usage more intuitive.

Overall, this would enhance usability by making the shutdown process clearer and less error-prone without breaking existing code.

[DraTeots]

IDK if this all was agreed already, but what came to me, is that if to do the exactly proposed change, with this signature:

void Quit(int exitCode = 0, bool skipJoin = false);

old jana2 code having

japp->Quit(true);    // intended skipJoin = true

will be translated to

japp->Quit(exitCode = 1, skipJoin = false);

[RaiqaRasool]

Totally agree and that’s exactly why Nathan did not want to proceed with the proposed change as-is. Instead of introducing potential ambiguity or mismatches (like Quit(true) becoming Quit(1, false)), he wants to think on it more to come up with a cleaner approach. I’ve added this here as just a reminder that this might be something we’ll want to revisit to improve user experience.

[DraTeots]

As a brainstorming:

• Introduce "Exit" function and deprecate "Quit"?
• Make exitCode enum class, so that ints or bools can't be implicitly converted:

japp->Quit(1);  // Error
japp->Quit(true); // Error
japp->Quit(ExitReason.OK);  // works

but ugly...

• Introduce QuitWithCode function

It any case I remember stumbling on Quit(1) anticipating this would mean "quit with exit code 1" not "don't wait for joint".