Method for detecting infinite loops by setting a flag indicating execution of an idle task having lower priority than executing application tasks
US5278976A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 1990 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Apr 16, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/0715
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for detecting infinite tight loops and infinite inter-task loops in applications tasks in multi-task, real-time systems. In accordance with the inventive method, a low priority task, the idle task, is executed whenever no other task is ready to execute. Further, when the idle task executes it sets a flag. A higher priority, watch dog task executes and tests the flag. If the flag has been set, the watch dog task resets the flag and sends a signal to reset a watch dog timer, however, if the flag has not been set by the idle task for a predetermined time period, the watch dog task will stop resetting the watch dog timer. As a result, this will cause the watch dog timer to trigger and reset the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.