An environment for dataflow program development of parallel processing system-harray

Abstract

This paper considers the dataflow program development environment for the system programmer who develops the compiler and proposes a method to improve the debugging efficiency. The conventional debugging methods are either: (1) to monitor the packet in the dataflow ring, or (2) to specify the function containing a bug. The former contains unsolved problems such as the determination of start timing for the data monitoring and the presentation of a large amount of information to the user. The latter contains a problem in that the debugging is impossible at the dataflow level. This paper aims at the solution of those problems, and the detailed debugging is executed on the software, not on the real machine. The information presentation on a dataflow graph is considered for systematic presentation of the debugging information. As the development environment, the parallel processing system Harray proposed by the authors is considered. In the proposed system, a two-stage process is employed in which the first step is to specify the macro-block (which is a task unit in Harray) containing the bug, and the second step is the detailed debugging of the specified macro-block. The debugging within the macroblock is executed on the software, and the debugging efficiency is improved by: (1) diagram representation for easier visual recognition, and (2) backward tracing function.