Object oriented distributed software system with methodology for piggybacked reflective callbacks

• US 7,353,521 B1
• Filed: 01/10/2003
• Issued: 04/01/2008
• Est. Priority Date: 10/19/2002
• Status: Expired due to Fees

• Current Assignee: Borland Software Corporation (Open Text Corporation)
• Original Assignee: Borland Software Corporation (Open Text Corporation)
• Inventors: Jin, Ke
• Primary Examiner(s): Nguyen; Van H.
• Application Number:
  US10/340,812
• Time in Patent Office: 1,908 Days
• Field of Search: 719310-316, 719/328, 719330-332, 719/312, 719/315, 709/226, 709/248, 707/10, 718/100
• US Class Current: 719/330
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449

Abstract

A distributed computing environment is described that provides an improved method for invocation of methods between remote objects. In one embodiment, the improved method comprises steps of: creating a first object having methods that may be invoked by other objects; defining a forward invocation interface for the first object, which allows the methods of the first object to be called in a forward direction; defining a callback method on the first object, for invocation of a method of the first object in a reverse direction; creating a callback handler for handling invocations of the callback method; receiving a callback invocation of the callback method by a callback caller; creating a local reflective target for each received callback; delegating the callback invocation on the callback handler with reference to the local reflective target as an input parameter; and at the first object, making a forward call on the local reflective target.

Claims

1. In a distributed computing environment, an improved method for invocation of methods between remote objects, the method comprising:

creating a first object having methods invoked by other objects, in a manner that appears as if the first object is being invoked in the other objects'"'"' address space;

defining a forward invocation interface for the first object, which allows the methods of the first object to be called in a forward direction;

defining a callback method on the first object, for invocation of a method of the first object in a reverse direction;

creating a callback handler for handling invocations of the callback method;

creating a second object having a reflective target that supports said forward invocation interface on the first object;

receiving an invocation by the second object of the callback handler, said invocation including a reference to the reflective target; and

at the first object, downcasting the reflective target so that said invocation by the second object processed through the reflective target as if it were a forward invocation.

2. The method of claim 1, wherein said reflective target supports said forward invocation interface.

3. The method of claim 1, wherein invocation of the reflective target delivers a selected one of a request or a pickup of a reply.

4. The method of claim 1, wherein said first object implements the callback handler.

5. The method of claim 1, wherein the first object downcasts the reflective target to a desired typed stub and then makes a normal forward invocation on it.

6. The method of claim 5, wherein said forward invocation made through the reflective target returns a selected one of a request to the second object or a reply from the second object.

7. The method of claim 1, wherein said first object functions as the reflective target, with its own reference being passed as a reflective target reference for invocation by a callback caller.

8. The method of claim 1, wherein the reflective target is collocated with the first object.

9. A computer-readable medium having processor-executable instructions for performing the method of claim 1.

10. A downloadable set of processor-executable instructions for performing the method of claim 1.

11. A distributed computing system with improved invocation of methods between remote objects, the system comprising:

at least one processor;

a memory coupled to the at least one processor;

a first object having methods invoked by remote objects, in a manner that appears as if the first object is being invoked in the remote objects'"'"' address space;

a forward invocation interface for the first object, which allows the methods of the first object to be called in a forward direction;

a callback interface for the first object that comprises a single callback, for handling another object'"'"'s call to invoke a method of the first object in a reverse direction;

a second object having a reflective target that supports said forward invocation interface on the first object and for invoking the single callback, including passing a reference that includes a signature for the reflective target; and

program logic for downcasting the reflective target so that said invocation by the second object processed through the reflective target as if it were a forward invocation.

12. The system of claim 11, wherein said reflective target supports said forward invocation interface.

13. The system of claim 11, wherein invocation of the reflective target delivers a selected one of a request or a pickup of a reply.

14. The system of claim 11, wherein said first object implements the callback interface.

15. The system of claim 11, wherein the first object downcasts the reflective target to a desired typed stub and then makes a normal forward invocation on it.

16. The system of claim 15, wherein said forward invocation made through the reflective target returns a selected one of a request to the second object or a reply from the second object.

17. The system of claim 11, wherein said first object functions as the reflective target, with its own reference being passed as a reflective target reference for invocation by a callback caller.

18. The system of claim 11, wherein the reflective target is collocated with the first object.