Virtual resource ID mapping

• US 20050010924A1
• Filed: 08/06/2004
• Published: 01/13/2005
• Est. Priority Date: 10/05/1999
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Corporation (NortonLifeLock Inc.)
• Inventors: Bharadhwaj, Rajeev, Romans, William C., Hipp, Burton A., Yeh, Yuh-yen
• Granted Patent: US 7,415,709 B2
• Time in Patent Office: Days
• US Class Current: 718/104
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]
• CPC Class Codes: Y10S 707/99931 Database or file accessing

Abstract

The present invention provides virtual mapping of system resource identifiers in use by a software application for the purpose of making the running state of an application node independent. By adding a layer of indirection between the application and the resource, new system resources are reallocated and then can be mapped to the application'"'"'s existing resource requirements while it is running, without the application detecting a failure or change in resource handles. This layer of indirection makes the application'"'"'s system resource identifier (system RID) transparent to the application. RID'"'"'s are usually numeric in form, but can also be alphanumeric. RID'"'"'s are unique to a machine, and can be reused once all claims to a specific RID have been given up.

Claims

1-2. -2. (Cancelled)

3. A computer system comprising hardware adapted to execute program instructions from a computer readable medium, the program instructions including an application, an operating system and a software module between the operating system and the application for resource requests, wherein:

the application is operable to generate a first resource request for a resource for use by the application, wherein an application identifier is assigned to the application;

responsive to receiving the first resource request from the application, the software module is operable to generate a corresponding resource request to the operating system;

the software module is operable to assign a virtual resource identifier to the resource;

responsive to receiving the corresponding resource request, the operating system is operable to allocate the resource and to return a system resource identifier corresponding to the resource to the software module; and

responsive to receiving the system resource identifier from the operating system, the software module is operable to record a mapping of the application identifier, the virtual resource identifier, and the system resource identifier, and the software module is operable to return the virtual resource identifier to the application.

4. The computer system as recited in claim 3 wherein the software module is operable to assign the virtual resource identifier by invoking a resource-specific allocator.

5. The computer system as recited in claim 3 wherein:

the application is operable to generate a second resource request that uses the virtual resource identifier; and

responsive to receiving the second resource request, the software module is operable to translate the virtual resource identifier and the application identifier of the application to the system resource identifier using the mapping, and the software module is operable to provide the system resource identifier to the operating system.

6. The computer system as recited in claim 5 wherein the software module is operable to retrieve the application identifier from a process state corresponding to the application.

7. The computer system as recited in claim 3 wherein:

the application is operable to generate a second resource request;

responsive to receiving the second resource request, the software module is operable to generate a corresponding second resource request to the operating system;

responsive to receiving the corresponding second resource request, the operating system is operable to return the system resource identifier to the software module; and

responsive to receiving the system resource identifier from the operating system, the software module is operable to translate the system resource identifier and the application identifier to the virtual resource identifier using the mapping, and the software module is operable to return the virtual resource identifier to the application.

8. The computer system as recited in claim 7 wherein the software module is operable to retrieve the application identifier from a process state corresponding to the application.

9. The computer system as recited in claim 3 wherein, responsive to a restore of the application from a snapshot, the software module is operable to record a mapping of the application identifier, the virtual resource identifier, and a different system resource identifier corresponding to a different resource allocated by the operating system.

10. A computer readable medium comprising a plurality of instructions which, when executed:

generate a corresponding resource request to the operating system responsive to receiving a first resource request from an application for a resource to be used by the application;

assign a virtual resource identifier to the resource; and

responsive to receiving a system resource identifier corresponding to the resource from the operating system, record a mapping of an application identifier assigned to the application, the virtual resource identifier, and the system resource identifier, and return the virtual resource identifier to the application.

11. The computer readable medium as recited in claim 10 wherein the plurality of instructions, when executed, assign the virtual resource identifier by invoking a resource-specific allocator.

12. The computer readable medium as recited in claim 10 wherein the plurality of instructions, when executed responsive to receiving a second resource request from the application that uses the virtual resource identifier, translate the virtual resource identifier and the application identifier of the application to the system resource identifier using the mapping, and wherein the plurality of instructions, when executed, provide the system resource identifier to the operating system.

13. The computer readable medium as recited in claim 12 wherein the plurality of instructions, when executed, retrieve the application identifier from a process state corresponding to the application.

14. The computer readable medium as recited in claim 10 wherein the plurality of instructions, when executed:

responsive to receiving a second resource request from the application, generate a corresponding second resource request to the operating system; and

responsive to receiving the system resource identifier from the operating system in response to the corresponding second request, translate the system resource identifier and the application identifier to the virtual resource identifier using the mapping, and return the virtual resource identifier to the application.

15. The computer readable medium as recited in claim 14 wherein the plurality of instructions, when executed, retrieve the application identifier from a process state corresponding to the application.

16. The computer readable medium as recited in claim 10 wherein the plurality of instructions, when executed responsive to a restore of the application from a snapshot, map the application identifier and virtual resource identifier to a different system resource identifier corresponding to a different resource allocated by the operating system.

17. A method comprising:

generating a corresponding resource request to the operating system responsive to receiving a first resource request from an application for a resource to be used by the application;

assigning a virtual resource identifier to the resource; and

responsive to receiving a system resource identifier corresponding to the resource from the operating system, recording a mapping of an application identifier assigned to the application, the virtual resource identifier, and the system resource identifier, and returning the virtual resource identifier to the application.

18. The method as recited in claim 17 wherein assigning the virtual resource identifier includes invoking a resource-specific allocator.

19. The method as recited in claim 17 further comprising:

responsive to receiving a second resource request from the application that uses the virtual resource identifier, translating the virtual resource identifier and the application identifier of the application to the system resource identifier using the mapping; and

providing the system resource identifier to the operating system.

20. The method as recited in claim 19 further comprising retrieving the application identifier from a process state corresponding to the application.

21. The method as recited in claim 17 further comprising:

generating a corresponding second resource request to the operating system responsive to receiving a second resource request from the application;

responsive to receiving the system resource identifier from the operating system in response to the corresponding second request, translating the system resource identifier and the application identifier to the virtual resource identifier using the mapping, and returning the virtual resource identifier to the application.

22. The method as recited in claim 21 further comprising retrieving the application identifier from a process state corresponding to the application.

23. The method as recited in claim 17 further comprising mapping the application identifier and virtual resource identifier to a different system resource identifier corresponding to a different resource allocated by the operating system responsive to a restore of the application from a snapshot.