Efficient class memory management

• US 7,337,298 B2
• Filed: 10/05/2005
• Issued: 02/26/2008
• Est. Priority Date: 10/05/2005
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Kawachiya, Kiyokuni, Onodera, Tamiya, Gray-Donald, Trent A., Ogata, Kazunori
• Primary Examiner(s): Verbrugge; Kevin
• Application Number:
  US11/244,905
• Publication Number:
  US 20070078916A1
• Time in Patent Office: 874 Days
• Field of Search: None
• US Class Current: 711/170
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing

Abstract

Memory segments are allocated for a classloader to store class information, such as by selecting an allocation approach based on classloader type. In a first approach, in response to each request, a segment having a fixed size is allocated. In a second approach, in response to a first request, a first segment having a size equal to an amount of memory needed to store information related to the request is allocated. In response to a second request, a second segment having a second size is allocated, and in response to a third request, a third segment having a third size greater than the second size is allocated. In a third approach, in response to the first request, a first segment having a first size is allocated. In response to a second request, a second segment having a second size greater than the first size is allocated.

Claims

1. A method for managing class memory in which memory segments are allocated for a classloader to store information for classes loaded by the classloader, comprising:

in response to a first request received from the classloader, allocating a first memory segment having a first size;

in response to a second request received from the classloader, allocating a second memory segment having a second size greater than the first size; and

,

in response to a third request received from the classloader, allocating a third memory segment having a third size greater than the second size.

2. The method of claim 1, further comprising, for each additional request received from the classloader, allocating an additional memory segment having a size greater than a size of a memory segment allocated in response to an immediately previously request received from the classloader.

3. The method of claim 2, wherein the size of the additional memory segment is twice the size of the memory segment allocated in response to the immediately previously request.

4. The method of claim 2, wherein the size of the additional memory segment is no greater than 128 kilobytes.

5. The method of claim 1, wherein the first size is four kilobytes, the second size is eight kilobytes, and the third size is sixteen kilobytes.

6. The method of claim 1, wherein each of the first size, the second size, and the third size is potentially greater than an amount of memory needed by the classloader to store information in conjunction with a corresponding one of the first request, the second request, and the third request.

7. The method of claim 1, wherein the method is for managing class memory in relation to a virtual machine.

8. The method of claim 7, wherein the method is for managing class memory in relation to a Java®

virtual machine.

9. A method for managing class memory in which memory segments are allocated for a classloader to store information for classes loaded by the classloader, comprising:

in response to a first request received from the classloader, allocating a first memory segment having a first size equal to an amount of memory needed by the classloader to store information in conjunction with the first request;

in response to a second request received from the classloader, allocating a second memory segment having a second size; and

,

in response to a third request received from the classloader, allocating a third memory segment having a third size greater than the second size.

10. The method of claim 9, further comprising, for each additional request received from the classloader, allocating an additional memory segment having a size greater than a size of a memory segment allocated in response to an immediately previously request received from the classloader.

11. The method of claim 10, wherein the size of the additional memory segment is twice the size of the memory segment allocated in response to the immediately previously request.

12. The method of claim 9, wherein the second size is four kilobytes, and the third size is eight kilobytes.

13. The method of claim 9, wherein each of the second size and the third size is potentially greater than an amount of memory needed by the classloader to store information in conjunction with a corresponding one of the second request and the third request.

14. The method of claim 9, wherein the method is for managing class memory in relation to at least one of:

a virtual machine, and a Java®

virtual machine.

15. A method for managing class memory in which memory segments are allocated for a classloader to store information for classes loaded by the classloader, comprising:

determining a type of the classloader;

performing an allocation approach to allocate memory segments for the classloader based on the type of classloader, the allocation approach selected from a group of allocation approaches comprising;

a first allocation approach comprising;

in response to each request received from the classloader, allocating a memory segment having a fixed size;

a second allocation approach comprising;

in response to a first request received from the classloader, allocating a first memory segment having a size equal to an amount of memory needed by the classloader to store information in conjunction with the first request;

in response to a second request received from the classloader, allocating a second memory segment having a second size; and

,

in response to a third request received from the classloader, allocating a third memory segment having a third size greater than the second size;

a third allocation approach comprising;

in response to the first request received from the classloader, allocating a first memory segment having a first size;

in response to the second request received from the classloader, allocating the second memory segment having the second size greater than the first size; and

,

in response to the third request received from the classloader, allocating the third memory segment having the third size greater than the second size.

16. The method of claim 15, wherein the first allocation approach is employed for a type of classloader that loads many classes.

17. The method of claim 16, wherein the second allocation approach is employed for a type of classloader that loads a single class.

18. The method of claim 17, wherein the third allocation approach is employed for all other types of classloaders.

19. The method of claim 15, wherein each of the first size, the second size, and the third size is potentially greater than an amount of memory needed by the classloader to store information in conjunction with a corresponding one of the first request, the second request, and the third request.

20. The method of claim 15, wherein the type of classloader is determined by the class of the classloader object.