linux-kernel - Re: Real time clock update notification

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Sat, 28 Jan 2012 09:26:54 -0500
From:	Colin Walters <walters@...bum.org>
To:	Bob Richmond <bob@...ez.org>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Real time clock update notification

On Fri, 2012-01-27 at 14:52 -0800, Bob Richmond wrote:
> Is there any kind of facility for a process that is blocking in any one 
> of the event notification system calls (select/poll/epoll_wait) to be 
> unblocked in the event that the realtime clock has been updated? For 
> instance, say I want to fire off an event at the exact moment that the 
> realtime clock flips to 2pm. I first query the realtime clock via 
> clock_gettime(CLOCK_REALTIME), and know that in 3 hours, it will be 2pm 
> and I want to unblock at that moment. So I block in epoll_wait for 3 hours.

You're looking for "timerfd".  Our use in GNOME is here:

http://git.gnome.org/browse/gnome-desktop/tree/libgnome-desktop/gnome-datetime-source.c

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