[BRLTTY] lock on device

[Samuel Thibault]

Hi,

Raoul MEGELAS, le Wed 04 Apr 2007 07:58:38 +0200, a écrit :
> > Why should another program be started?
> 
> 1. i don't realized that brltty retry the device connection if lost:
> 
> brltty -b ts -d /dev/cuaU0
> 	brltty start fine!
> 
> stty -f /dev/cuaU0 whatever_speed_you want, or minicom... from another user 
> in multi user as normal...
> 
> 	braille lost!

Yes. If you're connected to the Internet and suddenly use the stty
command above, you'd lose the connection too. This may happen on Linux
too and never posed a problem. Should we really care ?

> perhaps (???) a lock on the device would help for this purpose; but,

Well, there are two kinds of problems. The parameters of the port, for
which BSD provides a solution as you suggested but other OSes don't ;
and the access to the port itself (sending/receiving), for which there
is usually only a cooperative lock-based solution, hence not really safe
by design.

Samuel