Shared closure eviction implementation

• US 7,840,760 B2
• Filed: 05/26/2009
• Issued: 11/23/2010
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Wintergerst, Michael, Petev, Petio G.
• Primary Examiner(s): RUTZ, JARED IAN
• Application Number:
  US12/472,256
• Publication Number:
  US 20090282196A1
• Time in Patent Office: 546 Days
• Field of Search: 711/130, 711/133
• US Class Current: 711/133
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/123 with age lists, e.g. queue, most recently used [MRU] list or least recently used [LRU] list

Abstract

Methods for a treatment of cached objects are described. In one embodiment, management of a region of a cache is configured with an eviction policy plug-in. The eviction policy plug-in includes an eviction timing component and a sorting component, with the eviction timing component including code to implement an eviction timing method, and the eviction timing method to trigger eviction of an object from the region of cache. The sorting component includes code to implement a sorting method to identify an object that is eligible for eviction in the region of cache. The sorting method involves identifying an object that has been cached in the region of cache for a longer time period than other objects that are cached in the cache region.

Claims

1. A computer-implemented method, comprising:

storing a plurality of objects into memory, the storing including forming a shared closure using a group of one or more of the plurality of objects based on a determination that every reference stemming from the one or more objects in the group stays within the group;

identifying from the memory an object from the plurality of objects that is eligible for eviction; and

evicting the shared closure from the memory based on a determination that the object identified as eligible for eviction is a member of the shared closure.

2. The computer-implemented method of claim 1, wherein the memory comprises a cache.

3. The computer-implemented method of claim 1, wherein the evicting is performed on a timed basis.

4. The computer-implemented method of claim 1, wherein the evicting is performed in response to another object being newly entered into the memory.

5. The method of claim 1, wherein the evicting is performed until a usage of the memory drops below a specific level.

6. The method of claim 1, wherein

the memory includes a plurality of shared closures, the method further comprising merging at least two of the plurality of shared closures.

7. A computer-implemented system, comprising;

memory to store a plurality of objects, the storing including forming a shared closure using a group of one or more of the objects from the plurality of objects based on a determination that every reference stemming from the one or more objects in the group stays within the group; and

an eviction controller operatively coupled to the memory, the eviction controller configured to;

identify from the memory an object from the plurality of objects that is eligible for eviction; and

evict the shared closure from the memory based on a determination that the object identified as eligible for eviction is a member of the shared closure.

8. The computer-implemented system of claim 7, wherein the memory comprises a cache.

9. The computer-implemented system of claim 7, wherein the eviction controller is configured to perform the evicting on a timed basis.

10. The computer-implemented system of claim 7, wherein the eviction controller is configured to perform the evicting in response to another object being newly entered into the memory.

11. The computer-implemented system of claim 7, wherein the eviction controller is configured to perform the evicting until a usage of the memory drops below a specific level.

12. The computer-implemented system of claim 7, wherein

the memory includes two or more shared closures, wherein the eviction controller is configured to merge at least two of the two or more shared closures.

13. The computer-implemented system of claim 7, wherein the memory includes two or more shared closures, wherein the eviction controller is configured to sort the two or more shared closures.

14. The computer-implemented system of claim 7, wherein the eviction controller comprises a plug-in module.

15. A non-transitory computer-readable storage medium storing instructions which, when executed by a processor, cause the processor to perform a method, the method comprising:

storing a plurality of objects into memory, the storing including forming a shared closure using a group of one or more of the plurality of objects based on a determination that every reference stemming from the one or more objects in the group stays within the group;

identifying from the memory an object from the plurality of objects that is eligible for eviction; and

evicting the shared closure from the memory based on a determination that the object identified as eligible for eviction is a member of the shared closure.

16. The non-transitory computer-readable storage medium of claim 15, wherein the memory comprises a cache.

17. The non-transitory computer-readable storage medium of claim 15, wherein the evicting is performed on a timed basis.

18. The non-transitory computer-readable storage medium of claim 15, wherein the evicting is performed in response to another object being newly entered into the memory.

19. The non-transitory computer-readable storage medium of claim 15, wherein the evicting is performed until a usage of the memory drops below a specific level.

20. The non-transitory computer-readable storage medium of claim 15, wherein

the memory includes two or more shared closures, the method further comprising merging at least two of the two or more shared closures.