Davide Libenzi wrote:
> > Then again, it is also extremely common to write this:
> >
> > gettimeofday(...)
> > // calculate time until next application timer expires.
> > // Note also race condition here, if we're preempted.
> > read_events(..., next_app_time - timeofday)
> > // we need to know the current time.
> > gettimeofday(...)
> >
> > So perhaps the current select/poll/epoll timeout method is not
> > particularly optimal as it is?
>
> What's bad in epoll_wait() to get events from all pollable descriptors ?
Nothing wrong with that. It's the "relative to now" timeout argument
that is a bit racy, and the fact that you need a gettimeofday() system
call just before - every time - _purely_ to calculate the time until
the next application timer event.
If you must have a separate system call every time round your event
loop, it may as well set up a timerfd and let that be another pollable
descriptor.
In which case, read() is just fine for getting events :)
-- Jamie
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This archive was generated by hypermail 2b29 : Sat Feb 15 2003 - 22:01:00 EST