| 摘要 |
Two sets of areas are respectively composed of an original information area (A1, A2) that stores information that is transmitted from an actual process (11) to a back-up process (12) and a difference area (B1, B2, B3) that memorizes the information related to the change when the actual process changes the original information area and are set in a shared memory (10). The back-up process (12) reads out information related to the pass-through information stored in the difference area (B1, B2, B3) of one of two sets and passes through (13) the information related to the change. The actual process (11) stores the changed information that is transmitted to the back-up process (12) to said original information area (A1, A2) of the back-up process and the information related to the change to the difference area (B1, B2, B3) the back-up process. The original information memorized in the original information area (A1, A2) of said other set by at least one of the criteria of a preset time interval or a preset volume stored in said difference area (B1, B2, B3) is copied and two sets of areas (A, B) are switched. |
