Signals in C++

[bronze sequoia]

Are there any resources that are especially good if you wanna learn more about how signals work, etc? Especially in the context of game development. I'm not sure where they are best used etc, or if they always require macros like in Qt. I guess some sort of introduction would be good.

[raw glacier]

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[bronze sequoia]

Are signals ever used to delay some function calls?

[gritty knoll]

You pretty much never need signals unless you're doing systems programming stuff

[gritty knoll]

In theory you could use a timer_create/SIGALRM sigaction but that's really limited and hacky

there are better ways to go about doing that

keep in mind in signal handlers you're extremely restricted in what functionality you can use

you can't do anything that might take a lock or call malloc, or interact with global state (without proper lock-free approaches)

[bronze sequoia]

But godot has signals.

[gritty knoll]

I'm guessing they're talking about a different kind of signal

If you want to learn about godot's signal system you'd have to read their docs

[bronze sequoia]

There are docs for how they are used but right now if I have to look around in the godot source code, I'd probably need to schedule that for another time.

There seem to be docs for how they are used, but not for how they are implemeneted.

[gritty knoll]

It's likely jsut a matter of signal emit calling all registered signal handlers

There are concurrency implications here, e.g. if you take a lock then emit a signal and a handler tries to take the same lock

Alternatively this could be implemented as part of an engine's event loop

[bronze sequoia]

Would there be one signal handler for every signal?

[gritty knoll]

Not necessarily

But I can't speak to godot in particular