Taskflow-San: Sanitizing Erroneous Control Flow in Taskflow Graphs

Taskflow is a general-purpose parallel and heterogeneous task graph programming system that enables in-graph control flow to express end-to-end parallelism. By integrating control-flow decisions into condition tasks, developers can efficiently overlap CPU-GPU dependent tasks both inside and outside control flow, largely enhancing the capability of task graph parallelism. Condition tasks are powerful but also mistake-prone. For large task graphs, users can easily encounter erroneous control-flow tasks that cannot be correctly scheduled by the Taskflow runtime. To overcome this challenge, this paper introduces a new instrumentation module, Taskflow-San, to assist users to detect erroneous control-flow tasks in Taskflow graphs.