Memory model for a run-time environment

• US 7,073,033 B2
• Filed: 05/08/2003
• Issued: 07/04/2006
• Est. Priority Date: 02/25/2000
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Benson, Peter, Unietis, David, Sexton, Harlan
• Primary Examiner(s): Padmanabhan, Mano
• Assistant Examiner(s): Chery, Mardochee
• Application Number:
  US10/434,483
• Publication Number:
  US 20030225740A1
• Time in Patent Office: 1,153 Days
• Field of Search: None
• US Class Current: 711/153
• CPC Class Codes: G06F 9/461 Saving or restoring of program or task context
• CPC Class Codes: G06F 9/5022 Mechanisms to release resources
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

A memory model for a run-time environment is disclosed that includes a process-specific area of memory where objects in call-specific area of memory and session-specific area of memory can be migrated to at the end of a database call. User-specific objects can be then migrated to the session-specific area of memory. In one embodiment, the process-specific area of memory can be saved in a disk file and used to hot start another instance of an application server.

Claims

1. A method of managing a memory for an application server in a run-time environment, comprising:

performing a call to a database server; and

at the end of the call, performing the steps of;

migrating, into a process-specific area of memory, objects in a call-specific area of memory and objects in a session-specific area of memory that are reachable from the objects in the process-specific area of memory, and

migrating, into the session-specific area of memory, objects in the call-specific area of memory that are reachable from objects in the session-specific area of memory but not from objects in the process-specific area of memory.

2. A method as according to claim 1, wherein the session is bounded by a period in which a client has established a connection to a database session.

3. A method as according to claim 1, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory; and

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then leaving a session of the application server that performed the call attached to a process of the application that performed the call.

4. A method as according to claim 1, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory; and

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then marking a session of the application server that performed the call as runnable only a process of the application that performed the call.

5. A method as according to claim 1, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory; and

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then cloning state in the process-specific area of memory referenced by the live reference.

6. A method as according to claim 1, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory; and

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then replacing the live reference by a symbolic reference.

7. A method as according to claim 1, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory; and

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then signaling an error.

8. A method as according to claim 1, further comprising:

saving data in the process-specific area of memory to a disk file.

9. A method as according to claim 8, further comprising:

hot-starting another process of the application based on the disk file that contains the saved data from the process-specific area of memory.

10. A computer-readable medium storage bearing instructions for managing memory for an application server in a run-time environment, said instructions being arranged to perform the method according to claim 1 upon execution by one or more processors.

11. A method of managing a memory for an application server in a run-time environment, comprising:

allocating a process-specific area of memory for holding objects used by the application server;

allocating a session-specific area of memory for holding objects used by the application server;

at a beginning of a call to a database server, allocating a call-specific area of memory;

during the call, allotting memory for objects in the call-specific area of memory; and

at an end of the call, performing the steps of;

migrating, into the process-specific area of memory, objects in the call-specific area of memory and objects in the session-specific area of memory that are reachable from the objects in the process-specific area of memory,

migrating, into the session-specific area of memory, objects in the call-specific area of memory that are reachable from the objects in the session-specific area of memory but not from the objects in the process-specific area of memory, and

releasing the call-specific area of memory.

12. A method as according to claim 11, wherein the session is bounded by a period in which a client has established a connection to a database session.

13. A method as according to claim 11, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory.

14. A method as according to claim 13, further comprising:

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then performing one of the following steps of;

leaving a session of the application server that performed the call attached to a process of the application that performed the call;

marking a session of the application server that performed the call as runnable only a process of the application that performed the call;

cloning state in the process-specific area of memory referenced by the live reference;

replacing the live reference by a symbolic reference; and

signaling an error.

15. A computer-readable medium storage bearing instructions for managing memory for an application server in a run-time environment, said instructions being arranged to perform the method according to claim 11 upon execution by one or more processors.

16. A method of managing a memory for an application server in a run-time environment, comprising:

allocating a process-specific area of memory for holding objects used by the application server;

at a beginning of a session with a database server, allocating a session-specific area of memory for holding objects used by the application server;

at a beginning of a call to a database server, allocating a call-specific area of memory;

during the call, allotting memory for objects in the call-specific area of memory;

at an end of the call, performing the steps of;

migrating, into the process-specific area of memory, objects in the call-specific area of memory and objects in the session-specific area of memory that are reachable from the objects in the process-specific area of memory,

migrating, into the session-specific area of memory, objects in the call-specific area of memory that are reachable from the objects in the session-specific area of memory but not from the objects in the process-specific area of memory, and

releasing the call-specific area of memory; and

at the end of the session, releasing the session-specific area of memory.

17. A method as according to claim 16, wherein the session is bounded by a period in which a client has established a connection to a database session.

18. A method as according to claim 16, further comprising:

determining, after said migrating into the session-specific area of memory, whether there is a live reference from the session-specific area of memory to the process-specific area of memory.

19. A method as according to claim 18, further comprising:

if there is a live reference from the session-specific area of memory to the process-specific area of memory, then performing one of the following steps of;

leaving a session of the application server that performed the call attached to a process of the application that performed the call;

marking a session of the application server that performed the call as runnable only a process of the application that performed the call;

cloning state in the process-specific area of memory referenced by the live reference;

replacing the live reference by a symbolic reference; and

signaling an error.

20. A computer-readable medium storage bearing instructions for managing memory for an application server in a run-time environment, said instructions being arranged to perform the method according to claim 16 upon execution by one or more processors.