Lennart Poettering
56c5959202
So far StopWhenUnneeded= handling and UpheldBy= handling was already processed by a queue that is dispatched in a deferred mode of operation instead of instantly. This changes BoundBy= handling to be processed the same way. This should ensure that all *event*-to-job propagation is done directly from unit_notify(), while all *state*-to-job propagation is done from a deferred work queue, quite systematically. The work queue is submitted to by unit_notify() too. Key really is the difference between event and state: some jobs shall be queued one-time on events (think: OnFailure= + OnSuccess= and similar), others shall be queued continuously when a specific state is in effect (think: UpheldBy=). The latter cases are usually effect of the combination of states of a few units (e.g. StopWhenUnneeded= checks wether any of the Wants=/Requires=/… deps are still up before acting), and hence it makes sense to trigger them to be run after an individual unit's state changed, but process them on a queue that runs whenever there's nothing else to do that ensures the decision on them is only taken after all jobs/queued IO events are dispatched, and things settled, so that it makes sense to come to a combined conclusion. If we'd dispatch this work immediately inside of unit_notify() we'd always act instantly, even though another event from another unit that is already queued might make the work unnecessary or invalid. This is mostly a commit to make things philosophically clean. It does not add features, but it should make corner cases more robust.
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