Each Subproceso de Arbortext PE has a flag which is set any time it returns a fatal error. When a work thread detects an unusable Subproceso de Arbortext PE, it sets a flag that records the state of the Subproceso de Arbortext PE. At a later time, the work thread scans all running Subprocesos de Arbortext PE and requests the operating system to terminate any with the hung or fatal flag set to true.