A parallel debugger with support for distributed arrays, multiple executables and dynamic processes
In this paper we present the parallel debugger DETOP with special emphasis on new support for debugging of programs with distributed data structures such as arrays that have been partitioned over a number of processors. The new array visualizer within DETOP supports transparent browsing and visualization of distributed arrays which occur in languages such as High Performance Fortran. Visualization of sparse arrays is supported through an array mapper facility, as well as transparent visualization of arrays which have been partitioned by hand for applications in C or Fortran77. Color coding makes the visualization more expressive and easier to read.
DETOP provides a graphical user interface that is simple to use even for inexperienced users and supports not only static data parallel programs, but also dynamic programs and parallel applications based on functional decomposition. The combination of support for applications that include dynamic process creation, multiple executables, processes and threads, and distributed data structures, makes DETOP rather unique among parallel debuggers. DETOP has been implemented for Parsytec PowerPC based multicomputers with Sparcstation frontends. Ongoing efforts include portable versions of DETOP for PVM and MPI run-time environments.