gnus-atomic-setq
gnus-atomic-setq is a Lisp macro in `gnus-util.el
'.
(gnus-atomic-setq &rest PAIRS)
Similar to setq, except that the real symbols are only assigned when
there are no errors. And when the real symbols are assigned, they are
done so atomically. If other variables might be changed via side-effect,
see gnus-atomic-progn-assign. It is safe to use gnus-atomic-setq
with potentially long computations.