1 Reply
      Latest reply on Sep 5, 2016 1:25 AM by eskimo
      horpse Level 1 Level 1 (0 points)

        Hi Apple,


        I happened to encounter this crash today. It gave " dispatch_queue_wakeup_with_qos_slow ". Unfortunately, there is no information on this issue elsewhere on the internet. So what exactly does it mean by " slow quality of service " during the waking up of a thread in the dispatch queue?



        • Re: Dispatch queue wakeup slow quality of service
          eskimo Apple Staff Apple Staff (13,905 points)

          I suspect that you’re misreading this identifier.  You should read it as “dispatch queue wakeup with QoS, taking the slow path”.  Many algorithms within Dispatch have a fast path, which is the typical case when things go well (no lock contention and so on).  Clearly the existence of a fast path implies that there also exists a slow path, and that’s what this routine implements.

          If you want to see this in context you can look at the Dispatch source code for this routine.

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