[BRLTTY] async(Read|Write)?

[Dave Mielke]

[quoted lines by Mario Lang on 2006/04/23 at 12:23 +0200]

>I noticed the cool new events.c file in SVN, and am wondering
>what we are going to use this for?  Can anyone enlghten me?

The main reason it's been written is to support keyboard interception via
uinput. Without it, response to keys which are passed through, i.e. 
effectively not intercepted, would be poor because brltty would have to poll
for them each time around the main loop. The mechanism can also be applied to
other things which brltty currently polls for, though, e.g. the speech FIFO,
and speech tracking input. Perhaps it'll be eventually used within braille
drivers which currently need to wait for acknowledgemnts. Once other features
(asynchronous aaccepts, asynchronous connects, alarms, and perhaps even idle
events) are added, other uses will undoubtedly capture our imaginations. It may
even be that the main loop will eventually turn into an event which is
triggered by a regularly scheduled alarm.

Regarding non-standard flow ocntrol: One of the current problems with
implementing it in user space surely is that the driver isn't immediately ready
to handle data from the display as soon as it's sent because of the delay
within the main loop. The events mechanism may solve this since a handler can
be waiting for the data.

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