[e-lang] Draft "Causeway: A message-oriented distributed debugger" -- please comment

[David-Sarah Hopwood]

Terry Stanley wrote:
> Tyler Close, Mark Miller, and I are writing a paper on Causeway. Our
> current draft is at
> <http://erights.org/elang/tools/causeway/cw-paper09.pdf>.

In the example of section 2.2:

# In the worst case, potential causality -- the happened-before relation --
# must be considered. You must examine q2, q3, q4 and q5, although you know
# know that you can safely ignore q6.

The potential causality could be automatically narrowed further than implied
by the happened-before relation. In the example, suppose that the bug that
manifests at q5 involves a particular subset S of q's state. We can ask
whether any state change made in q4 could have influenced (in an
information/control flow sense, based on the semantics of the language
in which the buggy program is written) any state in S. If not, then q4 can't
be relevant to the bug.

This requires much more information than is in a Causeway trace file,
though.

-- 
David-Sarah Hopwood ⚥