Re: how to convert code that uses cmp to python3

From	Terry Reedy <tjreedy@udel.edu>
Newsgroups	comp.lang.python
Subject	Re: how to convert code that uses cmp to python3
Date	2016-04-08 02:12 -0400
Message-ID	<mailman.64.1460095944.2253.python-list@python.org> (permalink)
References	(1 earlier) <CAPTjJmrGiQS9uhFU-+TQ4nUWQ2p4gmJoQitMotS0Ob--qm1iWg@mail.gmail.com> <mailman.22.1460031736.2253.python-list@python.org> <87a8l5p6ek.fsf@nightsong.com> <874mbdi5ai.fsf@elektro.pacujo.net> <ne7i3s$sra$1@ger.gmane.org>

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On 4/7/2016 3:32 PM, Marko Rauhamaa wrote:

> I use AVL trees to implement timers. You need to be able to insert
> elements in a sorted order and remove them quickly.
>
> Guido chose a different method to implement timers for asyncio. He
> decided to never remove canceled timers.

In 3.5.1, asyncio.base_events.BaseEventLoop._run_once
has this code to remove cancelled timers when they become too numerous.

         if (sched_count > _MIN_SCHEDULED_TIMER_HANDLES and
             self._timer_cancelled_count / sched_count >
                 _MIN_CANCELLED_TIMER_HANDLES_FRACTION):
             # Remove delayed calls that were cancelled if their number
             # is too high
             new_scheduled = []
             for handle in self._scheduled:
                 if handle._cancelled:
                     handle._scheduled = False
                 else:
                     new_scheduled.append(handle)

             heapq.heapify(new_scheduled)
             self._scheduled = new_scheduled
             self._timer_cancelled_count = 0


-- 
Terry Jan Reedy

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Re: how to convert code that uses cmp to python3 Paul Rubin <no.email@nospam.invalid> - 2016-04-07 12:26 -0700
  Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-07 22:32 +0300
    Re: how to convert code that uses cmp to python3 Paul Rubin <no.email@nospam.invalid> - 2016-04-07 14:15 -0700
      Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-08 07:22 +0300
        Re: how to convert code that uses cmp to python3 Terry Reedy <tjreedy@udel.edu> - 2016-04-08 02:20 -0400
          Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-08 09:53 +0300
            Re: how to convert code that uses cmp to python3 Paul Rubin <no.email@nospam.invalid> - 2016-04-08 00:03 -0700
              Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-08 10:40 +0300
                Re: how to convert code that uses cmp to python3 Paul Rubin <no.email@nospam.invalid> - 2016-04-08 01:43 -0700
    Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-08 07:17 +0300
      Re: how to convert code that uses cmp to python3 Ian Kelly <ian.g.kelly@gmail.com> - 2016-04-07 22:37 -0600
        Re: how to convert code that uses cmp to python3 Marko Rauhamaa <marko@pacujo.net> - 2016-04-08 08:00 +0300
    Re: how to convert code that uses cmp to python3 Terry Reedy <tjreedy@udel.edu> - 2016-04-08 02:12 -0400

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