Patent · US Expired

Garbage collection system and method for locating root set pointers in method activation records

US5848423A · kind A · utility

66Cited by
15References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 23, 1997
Grant dateDec 8, 1998
Priority date
Expiry dateApr 23, 2017

Classification

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

Abstract

In an object oriented computer system, a root set of object references includes object references stored in the computer system's registers, as well as object references stored in activation records in the program stack. Whenever a method is invoked, a corresponding activation record is stored on the program stack. The activation record includes the invocation address for the method called as well as parameters passed to the called method. A class loader, which loads object classes into memory, determines the locations of the object references in the activation records associated with each method in a loaded object class. A list of offset values for each method activation record is stored by the class loader in a hash table data structure at a location in the hash table data structure determined by hashing the unique invocation address assigned to the method. At the beginning of each garbage collection cycle, a root set locator procedure processes each activation record in the program stack by applying a hash function to the invocation address in the activation record to determine where in the hash table data structure to locate the object reference offsets for that activation reco…

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