Re: Patch to make powerd(8) devd(8)-aware

On Thu, May 19, 2005 at 12:04:15PM -0700, Nate Lawson (nate_at_root.org) wrote:
> Fredrik Lindberg wrote:
> >On Wed, May 18, 2005 at 10:05:42PM -0700, Nate Lawson (nate_at_root.org) 
> >wrote:
> >
> >>I appreciate you working on a patch for this.  However, I'd prefer the 
> >>work on the devd side go into making devctl a clonable device or follow 
> >>the bpf route and hook up /dev/devctl0,1,2,...  If you start using the 
> >>/var/run/devd.pipe, it's not available for other consumers.
> >
> >Yes, devctl should probably be able to have more readers, I won't argue 
> >with that.
> >However, devd allows any number of consumers to the devd.pipe. I've had
> >upto 4 programs reading devd.pipe simultaneously and they all got the same 
> >data.
> 
> Ah, I wasn't aware of that.  I thought there might be a race for who got 
> each message.  This is fine then, and perhaps we should retire devctl as 
> a way to read messages since it is limited for that purpose and 
> duplicates the pipe.  We could keep it around for reverse signaling 
> (sending messages to the kernel, which is needed eventually).
> 
> >>Other comments:
> >>style(9) long sscanf line
> >
> >
> >I'm familiar with style(9), however I don't recall anything about sscanf, 
> >could you
> >please explain the correct behaviour in this case (except trying to 
> >reducing indent)
> 
> I just think you should wrap the lines >80 cols.  Pretty easy to do this 
> by outdenting the string.  Example:
> 
> 	printf(
> "a really long string but less than 80 cols\n");
> 
> >>extra newlines inserted into existing code
> >>change read() in devd_read() to return on error instead of running 
> >>sscanf -- this will allow the indent to be reduced.
> >
> >My mistakes, sorry.
> 
> No problems, thanks for the work.  With these changes, I'm fine with the 
> patch being committed.  I hope you can also fix the main loop soft error 
> cases as well.
> 
> -- 
> Nate

A day or two back I posted a second patch which fixed the soft error cases. I've
updated it to fix the above issues too.
It's avaiable at http://shapeshifter.se/~fli/freebsd/powerd.patch 

   Fredrik Lindberg