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Date:      Fri, 27 Oct 2000 15:08:34 +0200
From:      Poul-Henning Kamp <phk@critter.freebsd.dk>
To:        Alexander Maret <maret@atrada.net>
Cc:        "'freebsd-hackers@freebsd.org'" <freebsd-hackers@FreeBSD.ORG>
Subject:   Re: AW: AW: Accessing the tty structure of an opened device 
Message-ID:  <10553.972652114@critter>
In-Reply-To: Your message of "Fri, 27 Oct 2000 15:05:29 %2B0200." <58A002A02C5ED311812E0050044517F00D2613@erlangen01.atrada.de> 

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In message <58A002A02C5ED311812E0050044517F00D2613@erlangen01.atrada.de>, Alexa
nder Maret writes:
>> From: Poul-Henning Kamp [mailto:phk@critter.freebsd.dk]
>> Subject: Re: AW: Accessing the tty structure of an opened device 
>> 
>> 
>> How fast do these pulses arrive ?  Consider using the
>> PPS-API for that: <sys/timepps.h>
>> 
>
>the time between a pulse and a space often only takes
>a few milliseconds. I have to meassure that with
>gettimeofday().

You will need to do this in a device driver, there is no way you
can reliably measure that from userland.

Trust me on this: I've tried.

--
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


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