Method and apparatus for checking validity of memory operations
US5613063A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1994 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Jul 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/366
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory monitoring system equips a computer program for monitoring its own memory accesses. The system employs special values, called "VALUEA" and "VALUEB," stored in the memory locations and a table of write tags, each preferably a single-bit flag corresponding to a different one of the memory's locations. If the write tag is not set for a particular memory location, VALUEA within that location indicates that it is unallocated, and VALUEB indicates that it is allocated and not initialized. The write tags can be set to indicate that the corresponding memory location contains written data. The program so equipped can monitor each memory access, including, e.g., allocation, write, read, and memory freeing operations, using the combination of the location contents and the write tag table to determine valid memory operations and to signal memory access violations. Counters can be provided to track the number of valid accesses of particular types and/or of valid accesses to particular locations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.