Static Data Race Detection in Multi-task Programs for Industrial Robots

An industrial robot is an automatic multi-purpose manipulator, programmable in three or more axes. A program written in a high-level programming language controls these robots, many of these programs involve multiple tasks controlling different robots. Data races are a common problem in concurrent and multi-threaded programming and they are of big concern for the multi-task industrial robotics programmers too. We present a static analysis method for detecting data races in multi-task programs for industrial robots. We propose a technique based on a relation that models when two or more statements from a task occur in between two or more statements in another task. Our static analysis is preceded by a manual, dynamic analysis step for ensuring consistency among tasks for one of the constructs which involves a task waiting for a particular duration. We define a set of not-occurs in-between rules to detect whether two statements in different tasks may race with each other. We have developed a prototype implementation of our tool for the Rapid programming language that is used to program industrial robots of ABB. Rapid has all the features of a typical programming language for industrial robots and hence our race detection framework will generalize to any programming language for industrial robots.