/dev/dsp exclusive open?

/dev/dsp exclusive open?

[Steve Finney]

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In various docs, I thought I had seen references to the fact that
only one process should be able to open /dev/dsp (OSS). I'm running ALSA 1.0.10rc1
(Linux kernel 2.6.14.3), and it appears as if it is possible to open
/dev/dsp twice (two separate processes), but the _third_ open will
return EBUSY. Is this a bug or a feature?

Thanks,
sf

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Re: /dev/dsp exclusive open?

[Lee Revell]

On Wed, 2006-04-19 at 12:06 -0600, Steve Finney wrote:
> In various docs, I thought I had seen references to the fact that
> only one process should be able to open /dev/dsp (OSS). I'm running
> ALSA 1.0.10rc1
> (Linux kernel 2.6.14.3), and it appears as if it is possible to open
> /dev/dsp twice (two separate processes), but the _third_ open will
> return EBUSY. Is this a bug or a feature?
> 
It depends on the hardware.  If the device does hardware mixing like
emu10k1 or some VIA chips then multiple open will be possible.  If the
hardware only handles a single stereo stream like most new devices then
only one process can open it.

Since your hardware supports two streams I am guessing this is a VIA
chipset?

Lee



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