Are delegates blocking or asynchronous?

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1

Very basic question, as the title suggests: when I subscribe to a delegate via AddDynamic() and then call Broadcast() on it, does it process the event in a blocking fashion, or is it asynchronous?

Example:

DelegatesComponent->SquadLeaderChanged.AddDynamic(this, &USquadMembershipComponent::OnSquadLeaderChanged);
DelegatesComponent->SquadLeaderChanged.Broadcast(Squad->SquadLeader);

// IS THIS GUARANTEED TO EXECUTE ONLY AFTER OnSquadLeaderChanged HAS FINISHED?
Something();

void USquadMembershipComponent::OnSquadLeaderChanged(AActor* SquadLeader)
{
	bSquadLeader = GetOwner() == SquadLeader;
}

So does Something() execute only after OnSquadLeaderChanged() has finished, or is another thread listening via Broadcast()?

I couldn’t really find anything in the source code.

2

The implementation of delegates is very complicated and is completed by UHT at compile-time.
It looks like the event is sent to the registered UObject synchronously. I can’t tell you 100% if it is complete synchronous, but it looks like that.

I also use delegates and didn’t run into async problems, the always fire at the right time.

3

Thanks and yeah, that’s also been my experience so far. Just wanted someone with more insight to confirm if it is guaranteed to be the case. I guess if I don’t get a dev to answer then I’ll just mark this as accepted in a couple of days.