Do recursive coroutines leak memory?

Questions & Answers
1

I’ve got a function that needs to run roughly every half second, so naturally I’m looking at a coroutine.

I’m just curious, is this sufficient, or will this cause the stack frame associated with this coroutine to get bigger and bigger over time?

void Start ()
{
	StartCoroutine(LookForSquidward());
}

IEnumerator LookForSquidward()
{
	yield return new WaitForSeconds(0.5f);
	if (IsThisPatrick()) {
		Debug.Log("Yes, this is Squidward.");
	} else {
		Debug.Log ("No, this is Patrick.");
	}
	StartCoroutine(LookForSquidward());
}

I know the approach of using a while loop instead of a recursive StartCoroutine would unambiguously not grow the stack frame, but I’d like to know the specifics of how this approach works (or doesn’t).

2

This way this will work because the coroutine is not stricly recursive: each coroutine overlaps the next one for one frame. To be recursive, and hence have possible issues, you would need to do that instead:

// FAULTY CODE. DON'T DO THIS. 
void Start ()
{
    StartCoroutine(LookForSquidward());
}

IEnumerator LookForSquidward()
{
    yield return new WaitForSeconds(0.5f);
    if (IsThisPatrick()) {
       Debug.Log("Yes, this is Squidward.");
    } else {
       Debug.Log ("No, this is Patrick.");
    }
    yield return StartCoroutine(LookForSquidward());
}

But IMHO, using loops is a better approach. Still, your code works and doesn’t raise any recursive issue.