System and method for facilitating dynamic loading of stub information to enable a program operating in one address space to invoke processing of a remote method or procedure in another address space

• US 6,654,793 B1
• Filed: 06/30/1998
• Issued: 11/25/2003
• Est. Priority Date: 04/23/1996
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Waldo, James H., Wollrath, Ann M., Riggs, Roger
• Primary Examiner(s): VU, VIET DUY
• Application Number:
  US09/107,320
• Time in Patent Office: 1,974 Days
• Field of Search: 709/201, 709/202, 709/203, 709/217, 709/313, 709/330, 709/331, 709/332, 717/116, 717/165, 717/166, 717/167
• US Class Current: 709/217
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449

Abstract

A stub retrieval and loading subsystem is disclosed for use in connection with a remote method invocation system. The stub retrieval and loading subsystem controls the retrieval and loading of a stub for a remote method, into an execution environment, to facilitate invocation of the remote method by a program executing in the execution environment. The stub retrieval subsystem includes a stub retriever for initiating a retrieval of the stub and stub loader for, when the stub is received by the stub retriever, loading the stub into the execution environment, thereby to make the stub available for use in remote invocation of the remote method. In one embodiment, the stub retrieval and loading subsystem effects the retrieval and loading for a program operating in one address space provided by one computer, of stub class instances to effect the remote invocation of methods which are provided by objects operating in another address space, which may be provided by the same computer or a different computer.

Claims

1. A method performed by a client in a data processing system, comprising:

providing to a default stub class instance a call including an identifier of a name server and a first parameter value including an identification of a class and remote method implemented by the class;

obtaining from the name server an identifier of a server that includes the class;

retrieving, during runtime, a stub class instance from the server based on the obtained identifier;

receiving a request to invoke the remote method;

providing a second parameter value for the remote method to the stub class instance;

providing, from the stub class instance, the second parameter value to the server; and

receiving by the stub class instance a result of an invocation of the remote method based on the second parameter value.

2. The method of claim 1, wherein the remote method includes a parameter of a declared type and the second parameter value includes a reference to a remote object having a specified type that is a superset of the declared type.

3. The method of claim 1, wherein the server and client are included in a single computer system.

4. The method of claim 1, wherein the server and client are located in separate remote computer systems.

5. The method of claim 1, wherein the stub class instance includes declarations for a set of one or more interfaces for the class that implements the remote method.

6. A method performed by a server in a data processing system, comprising:

providing, during runtime, an instance of a locally maintained stub class to a client;

receiving from the stub class instance a request to invoke a remote method implemented by a locally maintained class, the request including a parameter to the remote method; and

providing to the stub class instance a result of an invocation of the remote method based on the parameter.

7. The method of claim 6, wherein the remote method has a method parameter of a declared type and the parameter in the request includes a reference to an object having a specified type that is a superset of the declared type.

8. The method of claim 6, wherein the server and client are included in a single computer system.

9. The method of claim 6, wherein the server and client are located in separate remote computer systems.

10. A computer-readable medium including instructions for performing a method, when executed by a client, the method comprising:

providing to a default stub class instance a call including an identifier of a name server and a first parameter value including an identification of a class and remote method implemented by the class;

obtaining from the name server an identifier of a server that includes the class;

retrieving, during runtime, a stub class instance from the server based on the obtained identifier;

receiving a request to invoke the remote method;

providing a second parameter value for the remote method to the stub class instance;

providing, from the stub class instance, the second parameter value to the server; and

receiving by the stub class instance a result of an invocation of the remote method based on the second parameter value.

11. The computer-readable medium of claim 10, wherein the remote method includes a parameter of a declared type and the second parameter value includes a reference to a remote object having a specified type that is a superset of the declared type.

12. The computer-readable medium of claim 10, wherein the server and client are included in a single computer system.

13. The computer-readable medium of claim 10, wherein the server and client are located in separate remote computer systems.

14. The computer-readable medium of claim 10, wherein the stub class instance includes declarations for a set of one or more interfaces for the class that implements the remote method.

15. A computer-readable medium including instructions for performing a method, when executed by a server, the method comprising:

providing, during runtime, an instance of a locally maintained stub class to a client;

receiving from the stub class instance a request to invoke a remote method implemented by a locally maintained class, the request including a parameter to the remote method; and

providing to the stub class instance a result of an invocation of the remote method based on the parameter.

16. The computer-readable medium of claim 15, wherein the remote method has a method parameter of a declared type and the parameter in the request includes a reference to an object having a specified type that is a superset of the declared type.

17. The computer-readable medium of claim 15, wherein the server and client are included in a single computer system.

18. The computer-readable medium of claim 15, wherein the server and client are located in separate remote computer systems.

19. A data processing system, comprising:

means for providing to a default stub class instance a call including an identifier of a name server and a second parameter value including an identification of a class and remote method implemented by the class;

means for obtaining from the name server an identifier of a server that includes the class;

means for retrieving, during runtime, a stub class instance from the server based on the obtained identifier;

means for receiving a request to invoke the remote method;

means for providing a parameter value for the remote method to the stub class instance;

means for providing, from the stub class instance, the parameter value to the server; and

means for receiving by the stub class instance a result of an invocation of the remote method based on the parameter value.

20. A data processing system, comprising:

means for providing, during runtime, an instance of a locally maintained stub class to a client;

means for receiving from the stub class instance a request to invoke a method implemented by a locally maintained class, the request including a parameter to the method; and

means for providing to the stub class instance a result of an invocation of the method based on the parameter.