Re: [Qemu-devel] Bug#758881: [bisected] VNC server can't get all sent chars correctly

[Gerd Hoffmann]

On Mo, 2014-08-25 at 21:11 -0700, Marc wrote:
> Hi,
> 
> 
> On August 25, 2014 at 3:40:01 AM, Gabriele Giacone
> (address@hidden) wrote:
> > 
> > > IMO vncdotool should be fixed to add small delays between
> > keyboard 
> > > events, as if a real person is typing, instead of sending the key
> > events 
> > > at the maximum possible speed. 
> vncdotool does have a —delay=MILLISECONDS switch that inserts a delay
> between commands.  Currently, the two behaviours causing trouble seem
> to be that delay defaults to 0 and "type insecure” is considered one
> command, so there is  no delay between key presses :(  
> 
> Is there a non-zero value for —delay that makes sense?  I’m somewhat
> hesitant to change —delay  as it would be a behavioural change for
> other users, but if the value is sufficiently small it could be a net
> usability gain.
> 
> Are you requesting that the type command be fixed to insert delays
> after every character or that default for —delay should be non-zero?

There should be a delay after every character.  It can be pretty small.
10ms should be enough (you should set TCP_NODELAY though to make sure
the key events are not buffered in the network stack).

I guess it makes sense to decouple that from the delay between commands
as the time a qemu guest needs to process a command can be much higher
than the time it needs to process a key event.

cheers,
  Gerd