> 2023年5月30日 08:36，Paul E. McKenney <paulmck@xxxxxxxxxx> 写道： > > On Tue, May 30, 2023 at 12:48:33AM +0800, Alan Huang wrote: >> Hi, >> >> I’m reading 14.2.1.3 Half-NBS Queue, there is one sentence says: >> >> The enqueuer might have failed between lines 9 and 10 of the listing, so that the element in question is only partially enqueued. >> >> My question is: In what circumstances would the enqueuer fail between lines 9 and 10 ? > > The following circumstances would do it: > > o Someone kills the thread at that point. > > o The CPU that the thread is running on takes an interrupt, > but there is an infinite-loop bug in the interrupt handler, > so that the thread's execution is never resumed. > > o The CPU that the thread is running on fail-stops, again > preventing that thread from resuming. (This is rare, but > does occasionally happen, especially on old or thermally > abused hardware.) > > So nothing normal, if that is what you are asking. ;-) Yeah, nothing normal. I often neglect to consider these exceptional cases. Thank you for the explanation! Thanks, Alan > > Thanx, Paul
