Virtual resource ID mapping

• US 7,415,709 B2
• Filed: 08/06/2004
• Issued: 08/19/2008
• Est. Priority Date: 10/05/1999
• Status: Expired due to Fees

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Operating Corporation (NortonLifeLock Inc.)
• Inventors: Bharadhwaj, Rajeev, Hipp, Burton A., Romans, William C., Yeh, Yuh-yen
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): Truong; Camquy
• Application Number:
  US10/912,828
• Publication Number:
  US 20050010924A1
• Time in Patent Office: 1,474 Days
• Field of Search: 718/104, 718/1
• 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 specfic RID have been given up.

Claims

1. A computer system comprising hardware adapted to execute program instructions from a computer readable storage 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, when executed on the computer system:

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 and identifies the application to the software module;

responsive to 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 by invoking a resource-specific allocator;

the software module is operable to retrieve the application identifier from a process state corresponding to the application;

responsive to 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 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.

2. The computer system as recited in claim 1 wherein:

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

responsive to 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.

3. The computer system as recited in claim 1 wherein:

the application is operable to generate a second resource request;

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

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

responsive to 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.

4. The computer system as recited in claim 1 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.

5. A computer readable storage medium storing a plurality of instructions which, when executed:

generate a corresponding resource request to an 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 by invoking a resource-specific allocator;

retrieve the application identifier from a process state corresponding to the application; 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 and identifying the application to the plurality of instructions, the virtual resource identifier, and the system resource identifier, and return the virtual resource identifier to the application.

6. The computer readable storage medium as recited in claim 5 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.

7. The computer readable storage medium as recited in claim 5 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.

8. The computer readable storage medium as recited in claim 5 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.

9. A method comprising:

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

assigning a virtual resource identifier to the resource wherein assigning the virtual resource identifier includes invoking a resource-specific allocator;

retrieving the application identifier from a process state corresponding to the application; 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 and identifying the application, the virtual resource identifier, and the system resource identifier, and returning the virtual resource identifier to the application.

10. The method as recited in claim 9 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.

11. The method as recited in claim 9 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.

12. The method as recited in claim 9 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.