[zeromq-dev] What's a tickless timer?

[Pieter Hintjens]

This is pretty much the reactor pattern we use in CZMQ. You set-up
timers and then handle them by e.g. sending messages.

-Pieter

On Tue, Feb 5, 2013 at 8:40 PM, Apostolis Xekoukoulotakis
<xekoukou at gmail.com> wrote:
> Those delayed msgs are used to wake up the actor.
>
>
> 2013/2/5 Apostolis Xekoukoulotakis <xekoukou at gmail.com>
>>
>> Let me say one of my use cases that, i think cant be handled by timers.
>> This is WIP.
>>
>> I have in each thread multiple actors. Each such actor might want to ask
>> for a service (like a database).
>> It sends a message and then work passes to other actors. Since there is a
>> chance that the response from the service is lost,
>> I want to use the lazy pirate pattern per actor. So what I did was add a
>> tickless service with poll
>>  that sends msgs to a socket (or directly to the same thread that has the
>> poll ) after a specific delay.
>>
>> I think that having payloads on timers is a useful pattern in general.
>>
>> 2013/2/5 Pieter Hintjens <ph at imatix.com>
>>>
>>> On Tue, Feb 5, 2013 at 5:35 PM, Apostolis Xekoukoulotakis
>>> <xekoukou at gmail.com> wrote:
>>>
>>> > If you have a timer to expire after 1m , you dont check every 20 ms if
>>> > it
>>> > expired, you use poll() that wakes after 1m if no other event happens.
>>>
>>> Right. The original goal is to reduce CPU wakeups, so tickless code
>>> will work nicely on low power devices. The concept comes from the
>>> Linux kernel: https://lesswatts.org/projects/tickless/
>>>
>>> As well as reducing CPU wakeups it makes it easier to schedule precise
>>> events, e.g. send PING once per second, even if there was some other
>>> activity in the meantime. You need this when you are doing anything
>>> complex.
>>>
>>> zmq_poll should IMO have tickless timers built in, and it's something
>>> I'd like to add to CZMQ (poll class with tickless timers).
>>>
>>> -Pieter
>>> _______________________________________________
>>> zeromq-dev mailing list
>>> zeromq-dev at lists.zeromq.org
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>>
>>
>>
>>
>> --
>>
>>
>>
>> Sincerely yours,
>>
>>      Apostolis Xekoukoulotakis
>
>
>
>
> --
>
>
> Sincerely yours,
>
>      Apostolis Xekoukoulotakis
>
>
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