Did you mean it's not atomic across different metrics? That I think should be acceptable. A single metric however should get swapped losslessly with atomic-swap. Either an increment of m should be applied before swap (making the reading n + m, or after it leaving the accumulator at m and reading at n). But it should not be lost.
Am I misunderstanding something? -- Regards, Janmejay PS: Please blame the typos in this mail on my phone's uncivilized soft keyboard sporting it's not-so-smart-assist technology. On Oct 8, 2015 12:33 PM, "Rainer Gerhards" <[email protected]> wrote: > 2015-10-08 8:30 GMT+02:00 singh.janmejay <[email protected]>: > >> Similarly, when one thread goes to output the stats, you need to lock > > them so that there isn't a lost increment between the time that you read > > the stat and the time you zero it. > > > > No, this involves the same shared (uncontended) lock, except > > atomic-increment is replaced by atomic-swap with 0. > > > > Just FYI: this is what the current stats system also does. It is also > where some inaccuracy stems from. Reporting stats is not atomic > without looks, so a stats counter may be read with value n, then m > atomic increments happen to it on another thread, then value n is > being reported (but we are really at n+m) and then the stats counter > is reset to 0 via an atomic swap. So m updates are lost. IMHO this is > perfectly acceptable, because otherwise we would lose almost all > concurrency. > > Rainer > _______________________________________________ > rsyslog mailing list > http://lists.adiscon.net/mailman/listinfo/rsyslog > http://www.rsyslog.com/professional-services/ > What's up with rsyslog? Follow https://twitter.com/rgerhards > NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad > of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you > DON'T LIKE THAT. > _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com/professional-services/ What's up with rsyslog? Follow https://twitter.com/rgerhards NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT.
