| 摘要 |
PROBLEM TO BE SOLVED: To provide a concentrated cache updated without overhead of a lock. SOLUTION: Update is primitive on the point that it can not be interrupted on the way. An application accesses data through a reference table to always freely read the data into a concentrated cache. The application transmits an update request to a service routine instead of directly updating the cache. In order to update the cache, the service routine proceeds in two steps. In the first step, the service routine prepares new data without updating the reference table, and adds them in the cache. The application accessing the cache during the first step can not see the new data because the reference table is not updated yet. After the first step is completed, the service routine executes the second step of the update process, that is, automatic update of the reference table. In the two-step update process, the cache is always kept in a consistent state. COPYRIGHT: (C)2004,JPO&NCIPI
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