@InProceedings{RitsonSimpson08,
  title =        "{V}irtual {M}achine {B}ased {D}ebugging for occam-\π",
  author=        "Ritson,  Carl G. and Simpson,  Jonathan",
  editor=        "Welch, Peter H. and Stepney,  S. and Polack,  F.A.C and Barnes,  Frederick R. M. and McEwan,  Alistair A. and Stiles,  G. S. and Broenink,  Jan F. and Sampson,  Adam T.",
  pages =        "293--307",
  booktitle=     "{C}ommunicating {P}rocess {A}rchitectures 2008",
  isbn=          "978-1-58603-907-3",
  year=          "2008",
  month=         "sep",
  abstract=      "While we strive to create robust language constructs and
     design
patterns which prevent the introduction of faults
     during software
development, an inevitable element of human
     error still remains.We
must therefore endeavor to ease and
     accelerate the process of
diagnosing and fixing software
     faults, commonly known as debugging.

Current support for
     debugging occam-\π programs is fairly limited.
     At
best the developer is presented with a reference to the
     last known
code line executed before their program
     abnormally terminated. This
assumes the program does in fact
     terminate, and does not instead
live-lock. In cases where
     this support is not sufficient, developers
must instrument
     their own tracing support,
     \textlessq\textgreater\textlesscode\textgreaterprintf\textless/code\textgreater
style\textless/q\textgreater.
     An exercise which typically enlightens one as to the
     true
meaning of concurrency ...  

In this paper we explore
     previous work in the field of debugging
occam programs and
     introduce a new method for run-time monitoring
     of
occam-\π applications, based on the Transterpreter
     virtual machine
interpreter. By adding a set of extensions
     to the Transterpreter,
we give occam-\π processes the
     ability to interact with their
execution environment. Use of
     a virtual machine allows us to
expose program execution
     state which would otherwise require
non-portable or
     specialised hardware support. Using a model which
bears
     similarities to that applied when debugging embedded
     systems
with a JTAG connection, we describe debugging
     occam-\π by mediating
the execution of one execution
     process from another."
}