# New Ticket Created by Elizabeth Mattijsen # Please include the string: [perl #127968] # in the subject line of all future correspondence about this issue. # <URL: https://rt.perl.org/Ticket/Display.html?id=127968 >
[2016-04-22T16:08:20+0100] <marcusramberg> Listening to Damian talk about concurrency in Oslo, and I tried one of his examples, but it seems to crash perl6 when you try to run it for some iterations - https://gist.github.com/marcusramberg/f789306f4f580c6cf1270ca12a333391 [2016-04-22T16:08:30+0100] <marcusramberg> gives me [1] 33874 abort perl6 channel.p6 [2016-04-22T16:11:44+0100] <RabidGravy> marcusramberg, so it does [2016-04-22T16:12:23+0100] <lizmat> marcusramberg: crash confirmed :-( [2016-04-22T16:12:34+0100] <marcusramberg> :-/ [2016-04-22T16:13:29+0100] <lizmat> marcusramberg: the good news is that it fails consistently after a fixed number of iterations [2016-04-22T16:13:31+0100] <perlpilot> marcusramberg: Did Damian actually run it ? [2016-04-22T16:13:41+0100] <marcusramberg> perlpilot: only once [2016-04-22T16:13:50+0100] <RabidGravy> lizmat, marcusramberg it appears to be associated with garbage collection looking at the backtrace [2016-04-22T16:13:55+0100] <lizmat> marcusramberg: and that number actually differs with different settings of MVM_SPESH_DISABLE and --optimize [2016-04-22T16:13:59+0100] <perlpilot> marcusramberg: do you happen to know what rakudo version he was using? [2016-04-22T16:14:53+0100] <lizmat> if I add an "nqp::force_gc" to the sleep_sort sub, it doesn't fail [2016-04-22T16:15:11+0100] <marcusramberg> perlpilot: no. he's still talking :) [2016-04-22T16:15:29+0100] <lizmat> RabidGravy: so indeed GC related [2016-04-22T16:15:41+0100] <perlpilot> marcusramberg: well ask him about it! See if he admits to shenanigans ;) [2016-04-22T16:18:26+0100] <lizmat> marcusramberg: care to submit a rakudobug ? [2016-04-22T16:18:57+0100] <marcusramberg> lizmat: I can try [2016-04-22T16:19:18+0100] <lizmat> copy this discussion to an email and send it to rakudo...@perl.org The code in question: ====================================================== sub sleep_sort (*@list where .all >= 0) { my $channel = Channel.new; await @list.map: -> $delay { Promise.start({ sleep $delay / 1000; $channel.send($delay); }); }; $channel.close; return $channel.list; } say sleep_sort(3,2,1,5,4) for (1 ... 10000); ======================================================
