On Fri, 16 Dec 2011 08:00:03 +0100
Andreas Raab <andreas.raab at gmx.de> wrote:

> [*] A more radical version would suspend *all* user processes and let 
> the user decide which of the suspended processes to inspect. This might 
> have some interesting side effects though...

This is somewhat similar to tty group handling under UNIX derived systems.  This would also
be fairly trivial to implement.  Processes could be flagged as system or non-system, and
on user interrupt, all non-system process would be suspended and debuggers would raise
on all.  The user could decide which to resume.  This would be painful only if there were
many user threads running, and that's another unusual use case.  Typically, we're running
stuff under UIProcess.  Or alternatively, suspend and debug all if there are fewer processes
than some configurable limit (possibly zero), and otherwise, suspend all and bring up a
dialog for choosing debug, suspend, terminate, or resume on each (system processes
excluded).

I think quantum counting is expensive, a heuristic, and thus potentially wrong.

-- 
Christopher Oliver <current.input.port at gmail.com>