Using devices

["Kiran Kumar Immidi" <kimmidi novell com>]

Hi,
  This is with reference to the "Using devices" section of the HAL
specification. In the "Out-of-process D-BUS service", it says - "The
volume manager could offer an operation for writing ISO images... A
desktop file manager would use the HAL daemon to query for the HAL
device object that is a CD recorder and pass the object reference to the
D-BUS service offered by the volume manager."

  According to this, the object reference should be passed to the the
D-BUS service offered by the volume manager. Would it not be more
intutive if an interface to the device were available ( or a provision
to make that available be available) for accessing the device. For
instance if I get the object reference
/org/freedesktop/Hal/devices/block_3_0 to a CDROM, it would be nice if
it offered an "interface" to open/close/play, rather than having to pass
the object reference to a third component (the D-BUS service like the
volume manager). 

  The approach described currently also means (perhaps) that there
would a daemon sort of entity to handle requests for a particular set of
devices, which would mean a lot of daemons if there a good number of
devices. If there would be a defined central way to handle each of the
devices, it would possibly rule out such proliferation of daemons.

  It also refers to other ways of dealing with device-specific
operations. Could any one enlighten me on these?


Regards,
Kiran Kumar Immidi