25bc9615b7 Document validationinterace callback blocking deadlock potential. (Matt Corallo)
Pull request description:
From the branches-I've-had-lying-around-and-forgot-to-PR department... This is a comment-only PR, but the comments point out an API quirk that isn't exactly trivial. None of our use-cases right now hit this, but if we were to call SyncWithValidationInterfaceQueue (eg to limit queue depth) in ATMP, I'm pretty sure we'd hit a deadlock there.
Backport of Core PR13402
Depends on D4138