These messages must be called on main.

[garrettmoon]

Resolves #2813

[garrettmoon]

@nguyenhuy does this look right to you?

[nguyenhuy]

Yes, these methods should be called on main. I'm down for this approach. But I have one question: Should we capture strong self in these new blocks?

[garrettmoon]

@nguyenhuy it should be fine because nothing is retaining the block itself?

[nguyenhuy]

@garrettmoon I was just worrying that in rare cases, we might end up keeping these nodes around for a bit longer than needed. But this is definitely an improvement.

[garrettmoon]

@nguyenhuy oh good point! I wonder if they should be though?

[nguyenhuy]

@garrettmoon Thinking more about it, I think we actually want them to be around. For example, an image node should be kept alive until it clears its contents (i.e cache entry, placeholder image, etc).

[appleguy]

@nguyenhuy could you share with me (maybe in an email, once you're up tomorrow) what changed in this area to cause off-main thread calls to occur? This didn't occur in practice before 2.0, right?

[nguyenhuy]

@appleguy it's an external cause actually (#2813). Developers can call -[ASNetworkImageNode setURL:] in background which then triggers -setNeeedPreload. Since it's a legitimate use case to call -setURL: off main, I think this is necessary.