PDG: a portable process-level debugger for CSP-style parallel programs

We present PDG, a debugger that allows one to identify erroneous processes without examining the source-level. Instead the interactions between processes are examined by animating program behaviour. For this, we use hierarchical graphical representations that are constructed during top-down program development. During animation, a debugging kernel implementing a record-replay mechanism guarantees reproducible program behaviour. To minimise interference, we are developing a tracing mechanism that decides at run-time which messages are to be traced to guarantee reproducibility. The run-time debugging kernel provides portability by supporting standard portable communication calls. In addition, the kernel itself is easy to port, since all architecture and communication-protocol dependent functionality is clearly separated from the generic debugging functionality.<>