Abstract: A testing apparatus designed to check the completion of a command issued earlier in a multiprocessing system having a plurality of nodes. During an initialization phase, each command has been identified by a handle and a record containing the task to be performed asynchronously had been established. When a request for checking the completion of a command is issued, the pre-established record is simply checked for location of last task executed and completed. If the last or most current task is not the last task before the completion of the total command, the user application can choose to either continue the operation of command processing or permanently or temporarily abandon it.