Thank you infinitely for all this information.
It will take me a while to absorb and poke around in the right places but this is
definitely extremely useful, thank you.
I will most probably come back to you with more questions, in a near future
time...
bruno
Terry Lambert wrote:
> > > To add t
> > To add to this, the close calls can be forces; there is a flag
> > in the device structure wich can force notification. I'm not
> > sure what it does over a fork(), though: I think you really want
> > open notification.
>
> You mean that when I register my device/kernel module, I can
> expli
Julian Elischer wrote:
> the problem here can be solved by using Poul's 'cloning device'
> interface in the driver.
> I don't think he has it quite completed but it is partly there.. maybe
> enough..
>
this seems very promising. Any pointers toward more info on this ?
Thanks
bruno
>
> only i
Terry Lambert wrote:
> > > when a process closes the device, I do not get a "close" call for each
> > > process closing the device. I instead get a close only on the last
> > > process closing the device.
> >
> > devices in a similar way as the one is used for scanning pty's).
>
> To add to this,
Terry Lambert wrote:
>
> > If I understand you correctly, you have multiple processes all of which
> > are going to try to open /dev/foo, and you want them to behave as though
> > they have each opened a unique device?
> >
> > You can't do this with FreeBSD, or with many other Unixes.
>
> Any SV
> If I understand you correctly, you have multiple processes all of which
> are going to try to open /dev/foo, and you want them to behave as though
> they have each opened a unique device?
>
> You can't do this with FreeBSD, or with many other Unixes.
Any SVR4 system can support this. So can
> > when a process closes the device, I do not get a "close" call for each
> > process closing the device. I instead get a close only on the last
> > process closing the device.
>
> the reason for this is that you might have a process fork() after
> it has opened the device, and you do not want t
Hello,
Luigi Rizzo wrote:
> you could do something like this:
> + open allocates a descriptor which stores the PID of the process requesting
> access to the "device"
>
doing that now
> + each I/O operation uses the descriptor matching the PID passed to the
> read/write/ioctl
that too
>
>
> Hi,
>
> The reason I am doing this, is precisely because I need to virtualize accesses
> from several processes to _one_ _predefined_ device. I have no control over that
> device name from the client process point of view, so I can not have multiple
> devices. I pretty much need to be able to
> The reason I am doing this, is precisely because I need to virtualize
> accesses from several processes to _one_ _predefined_ device. I have no
> control over that device name from the client process point of view, so I
> can not have multiple devices. I pretty much need to be able to lie to
Hi,
The reason I am doing this, is precisely because I need to virtualize accesses
from several processes to _one_ _predefined_ device. I have no control over that
device name from the client process point of view, so I can not have multiple
devices. I pretty much need to be able to lie to the
> when a process closes the device, I do not get a "close" call for each
> process closing the device. I instead get a close only on the last
> process closing the device.
the reason for this is that you might have a process fork() after
it has opened the device, and you do not want to get to the
Hello everybody,
I am writing a pseudo-device driver (as a kernel module) that needs to
be opened in write mode by several processes. The problem I am having is
that I do get all the "open" calls when a process opens the device, and
I am able to process data written, etc. on a per-process basis;
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