Hi Dominik,
Are you enjoying the World Cup?
> Two reasons: (1) "Schedule" is an unreliable hack and (2) this
> starts a shell every 15 seconds and my goal was to waste as little
> cpu as possible (as it interferes with certain time-critical
> applications - okay - games).
Hehe. :)
Re: (2)
>From some rudimentry tests I've performed on my Linux laptop, using
'sh' adds little overhead. Your CPU usage is going to be swamped by 'ps'.
'ps' performs ~1000 system calls [1], whereas 'sh' performs 116 system
calls [2] - an 11% overhead. Plus you've got a 'sort' in there which is
nearly another 100 system calls. 'sh' isn't going to take any longer
as the number of processes increases, but 'ps' & 'sort' will.
I realise the number of system calls isn't a direct measurement of
CPU usage, but it's a pretty good metric for the issues you're
considering here.
In short, I'm not sure adding a new builtin command to Fvwm to speedup
an arcane situation (by _at best_ 10%) is really worth it, IMHO.
I am prepared to write FvwmButtonsUpdater for you (using perllib) if you
need the extra 10% performance, but I can't promise how much faster it
will be.
Re: (1)
Having just looked into how Schedule & execute_complex_function() work,
I'm not prepared to blame Schedule just yet.
In my opinion, I don't think FVWM should grab the X server everytime it
executes a complex function. I realise it's necessary when the function
references the Motion/Click/Hold/Double modifiers but in the majority
of cases, most user functions will just use Immediate. [3]
This makes me think it would have been nice to separate AddToFunc
into 2 separate commands - AddToMouseFunc & AddToFunc. Where
AddToMouseFunc would permit modifiers, & AddToFunc would _always_
assume an Immediate modifier.
As a hack/compromise, maybe we could modify AddToFunc to keep track
of whether or not it uses a "mouse modifier" & only then grab the
X server, in execute_complex_function().
Thoughts?
SCoTT. :)
[1] strace -o /tmp/o /bin/ps -A --format "%C %P %c" >! /tmp/ps.out
wc -l /tmp/o
[2] strace -o /tmp/o sh -c : ; wc -l /tmp/o
[3] I've no data to support this, except for my own config
where I rarely use a modifier other than Immediate.
