[Mono-list] Threading ThreadPriority under Mono/Linux vs Windows

[Chris Howie]

On Fri, Jun 26, 2009 at 5:43 AM, Oenren<r.oenema at idento.eu> wrote:
> So does this means Mono hasn't implement the option ThreadPriority or the
> combination Slackware and Mono doesn't support the option ThreadPriority? If
> the combination Slackware/Mono doesn't support the option ThreadPriority,
> are there any other Linux distributions which supports the ThreadPriority
> option?

Let me further clarify Robert's response and explain why this is.

On Linux, processes (and threads, since in most cases they are
implemented as processes) have a "nice" value that is analogous to the
task priority value in Windows.  The higher the nice value, the lower
the priority of the process.  The range of values goes from -20 (high
priority) to 20 (lowest priority).  Processes inherit the nice value
of their parent, which in most cases is 0, the base or "normal" value.

The trick is that root is the only one allowed to alter the nice value
by decreasing it -- all other users can increase the value on their
processes, but cannot later decrease it.  So if I "renice" a process
or thread to 10 I cannot later set it back to 0.  This makes
implementing ThreadPriority problematic, since you would be able to
use the low/lowest priorities but you would not later be able to set
it back to normal.

-- 
Chris Howie
http://www.chrishowie.com
http://en.wikipedia.org/wiki/User:Crazycomputers