lkml.org 
[lkml]   [2003]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Synchronous signal delivery..
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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:33    [W:0.162 / U:0.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site