High-level debugging in parasight

Abstract

Debugging parallel programs with time critical dependencies is difficult due to subtle race conditions that may cause deadlock, starvation, and other errors. These errors can be detected by multiple instrumentation points triggered by logical assertions. Although some advanced debuggers provide a programmer with the ability to define complex logical assertions, they are inadequate for debugging parallel programs due to the high overhead of monitoring these assertions. This paper describes the facilities for high-level debugging in Parasight™ a parallel programming environment. In Parasight, high-level debugging facilities are implemented as separate programs that are linked dynamically to a target program. The target program is controlled by attaching these debugging programs to light-weight instrumentation points that are dynamically inserted and deleted. Different facilities of arbitrary complexity may be created to support high-level debugging. Parasight has been implemented on Multimax™ a shared-memory multiprocessor. It has been used for debugging and profiling “C” programs.