| 摘要 |
Software duplication system (100) having an active processing system (104a) comprising a processor (112) and a memory system (108) having at least one memory area (120a-y), a duplication system (128) and a standby processing system (104b-n) operable to perform the functions of the active processing system (104a). The duplication system (128) is operable to set a number of memory areas (120a-y) to a read-only state. In response to an attempt to write to these memory areas (120a-y) a notification that a write fault has occurred is produced. The state of the selected memory areas (120a-y) is changed to a writeable state and at least some of the alterations to the selected memory areas (120a-y) are provided to the standby processing system (120a-y) which then replicates the changes in appropriate locations in its memory. This way write faults are used to track memory areas that have been changed by an application processes (116a-y) in the active processor (104a) during a selected interval. |
