Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 17 Jul 2002 12:15:45 -0700
From:      Terry Lambert <tlambert2@mindspring.com>
To:        Andrei Cojocaru <spinlock_lists@empirequest.com>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: Counting the clock cycles
Message-ID:  <3D35C261.1ED2AC46@mindspring.com>
References:  <00d501c22dc4$57d08b00$0200a8c0@twothousand>

next in thread | previous in thread | raw e-mail | index | archive | help
Andrei Cojocaru wrote:
> I was asking around in #freebsdhelp on EFNet what the equivalent of
> GetTickCount() in the Win32 API is in FreeBSD.
> 
> I need a way to properly determine passage of time that is not affected if I
> change the system clock for example. The only way I'm aware that you can do
> that is by counting the number of clock cycles since system startup. What
> function does that in FreeBSD? I'd also like a Linux way if possible. (that
> is a way that will work across all UNIX clones). Thanks and please include
> my email in the reply directly since I'm not signed up to this mailing list.

Use the Pentium Cycle Counter.

Note that power management is going to make it inaccurate as a
time base.

Give up on the idea that you will have a wall time that is more
accurate than the CMOS clock; after you've embraced that, you
can learn to stop worrying and love Intel.

-- Terry

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3D35C261.1ED2AC46>