pub fn background_callback_stats(reset: bool) -> Option<[CallbackQueueStats; 3]>Expand description
Queue statistics for all three callback bands, or None when the
background executor has not been built yet — C callbackQueueStatus
(callback.c:115-141), whose -1 return is exactly this None and
is what callbackQueueShow turns into its “not initialized, yet”
diagnostic. reset clears every band’s high-water mark, as C’s does
for the whole array regardless of which band is being read.
Reads BACKGROUND rather than calling background(), because a
report must not be the thing that starts the facility it reports on.