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Date:      Sat, 24 Jan 2004 14:15:14 -0500
From:      Mathew Kanner <mat@cnd.mcgill.ca>
To:        Stefan Ehmann <shoesoft@gmx.net>
Cc:        current@freebsd.org
Subject:   Re: write(2) lc_r problem
Message-ID:  <20040124191514.GO64193@cnd.mcgill.ca>
In-Reply-To: <1074937301.2959.7.camel@shoeserv.freebsd>
References:  <1074937301.2959.7.camel@shoeserv.freebsd>

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On Jan 24, Stefan Ehmann wrote:
> I'm trying to write a small sound application and run across a problem
> on CURRENT.
> 
> It's very basic at the moment. It simply reads pcm data from a file and
> uses write(2) on /dev/dsp.
> 
> But as soon as I link the program with -lc_r there's always about 1
> second delay before a write call - which makes it pretty unusable for
> playing sound.
> 
> It should be easy reproducable if you link audio/waveplay with -lc_r.
> 
> This doesn't happen in either FreeBSD 4.9, Knoppix or CURRENT if linked
> with -lkse or -lthr.
> 
> Am I'm missing something basic when using write together with lc_r or
> ist this a bug in CURRENT?

	There is definetly a bug with the sound code when using vchans
and select.  Make sure that  (using sysctl)

	hw.snd.maxautovchans=0
	hw.snd.pcmX.vchans=0

	--Mat

-- 
	In general, a standard is very useful, whether it's de facto
	or du jour.
	- Microsoft's Greg Sullivan
	as misquoted by News.Com



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