Abstract: A process for maintaining synchronization of processors that are executing a same plurality of applications in parallel includes interrupting a current task between processing two successive instructions of an application being processed when an interrupt request occurs to process another application. An intermediate state reached by the current task is saved when the interrupt request occurs, and a counter for each of the processors indicating a number of instructions processed by each of the processors is maintained. A processor is caused to issue a synchronization confirmation in response to a comparison result that the numbers of instructions processed are identical. The processor is caused to enter a wait state when its number of processed-instructions is the largest among the processors or to execute a procedure for processing the instructions until its processed-instruction counter reaches the largest number.

Abstract: This process for maintaining synchronization applies to processors of redundant parallel processing units of a computer running, in parallel and under the control of the same multi-tasking time-sharing operating system (30) and independent clocks of the same speed, with the same applications with the same parameterizations. It consists on the one hand of including in the operating system (30) a synchronization service (303) called by a synchronization interrupt request and applying a correction of synchronization based on comparing the contents of the processed-instruction counters belonging to the various processors (1, 2) and the utilisation of the lockstep operating mode and on the other hand of inserting a synchronization interrupt request when commencing the processing of timing interrupts generated by the scheduler (301) of the operating system in order to terminate a time slice allocated to processing an application.