Patent · US Expired

Method and apparatus for performing generational garbage collection using remembered set counter

US6226653A · kind A · utility

78Cited by
5References
27Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 10, 2000
Grant dateMay 1, 2001
Priority date
Expiry dateJan 10, 2020

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S707/99957
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus are provided for the efficient management of remembered sets in a generational garbage collection scheme. In order to manage the remembered set, the present invention provides a first mechanism for detecting when an old object has a pointer to a young object, and needs to be added to the remembered set, and a second mechanism for detecting when an object already in the remembered set no longer contains a pointer to a young object, so that the object can be removed from the remembered set. Entries in the remembered set have an associated counter, C, identifying the garbage collection cycle during which the object was placed in the remembered set. Objects inserted into the remembered set are assumed to point to the youngest possible object. Entries automatically expire from the remembered set when the garbage collection counter reaches C+N, since the objects pointed to by the object in the remembered set must now themselves be old objects. If an old object (one that has survived at least N garbage collections) is identified during a minor garbage collection, the old object is scanned normally, and is placed into the remembered set, with a counter C identifying …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.