Re: [asio-users] Do idle timers affect performance?

[Bob P. <gra...@gm...>]

On Thu, Sep 23, 2010 at 12:45 PM, Igor R <boo...@gm...> wrote:
>> Presumably if you have a lot of timers set to expire very close to each other you may see some sort of pseudo thundering herd effect. A possible solution would be to provide the io_service with more thread resources, though that itself has the obvious flaw that there may be a greater amount of overhead due to synchronisation techniques and servicing of threads. If you're working in the ultra high frequency domains of computing you'll quickly learn that it is a very delicate balancing act.
>
> Thanks for your answer. I understand that simultaneous "waking" of
> many timers might be problematic.

You might be interested in this old article:

Gene Tucciarone, "Constant Time Software Interval Timers"
Embedded System Design Vol. 9 No. 6, June 1996
http://leadingedgeinnovations.biz/EmbeddedSystemProgramming/files/96/9606/f-tuccia.pdf

A phone system might have tens of thousands of timers running at any
given time, as an example. [At which point I'd use Erlang for a phone
system.]
In light of that article how does ASIO handle timers?  There are many
variation such as constant time to set regardless of the number
running etc.


> My question, however, related to some other issue: if I create
> thousands of deadline_timer's (on the same io_service), and never
> start them, will they affect somehow the performance of that
> io_service?