Object lifetime control in an object-oriented memory protection mechanism
US5075848A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1989 |
| Grant date | Dec 24, 1991 |
| Priority date | — |
| Expiry date | Dec 22, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2216/09
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An object-oriented computer architecture in which access descriptors include an object index for selecting an object in the address space, and a rights field specifying the permissible operations on a bi-paged object selected by the access descriptor. A local object lifetime bit is provided in the encoded fields portion of access descriptors, object descriptors, and page table entries to determine the lifetime of an object. The AD lifetime bit in the encoded fields of AD is compared in OTE Lifetime Check Logic with the destination object lifetime, the OTE local bit in the encoded fields of the OTE access descriptor. The OTE local bit in the encoded fields of the OTE is compared in PDTE Lifetime Check Logic with the destination object lifetime, the PDTE local bit in the encoded fields of the PDTE access descriptor. The PDTE local bit in the encoded fields of the PDTE is compared in PTE Lifetime Check Logic with the destination object lifetime, the PTE local bit in the encoded fields of the PTE access descriptor. If any of these checks fails, a protection lifetime fault is asserted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.