Apparatus and method for assisting exact garbage collection by using a stack cache of tag bits
US6101580A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1997 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Apr 23, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99957
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In computer systems which do not inherently distinguish between references and primitive values within a program stack a method and apparatus to assist exact garbage collection techniques utilizes a stack tag cache which operates in conjunction with a program stack and supplies a tag item for every entry in the process stack. The value of a tag item indicates whether the stack entry is either a reference to another memory location or a primitive value, i.e. integer or floating point number. The arrangements and values of the tag items are correlated with changes to the program stack. The stack tag cache includes facilities for swapping the contents of the cache in the event of a trap or context switch, as well as means for redundantly verifying the tag value with intended instruction operand types.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.