Dynamic generation of wrapper classes to implement call-by-value semantics

• US 8,881,099 B2
• Filed: 09/10/2004
• Issued: 11/04/2014
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Gallagher, William John
• Primary Examiner(s): Zhen, Li B
• Assistant Examiner(s): BODDEN, EVRAL E
• Application Number:
  US10/938,963
• Publication Number:
  US 20060107222A1
• Time in Patent Office: 3,707 Days
• Field of Search: None
• US Class Current: 717/108
• CPC Class Codes: G06F 9/541 via adapters, e.g. between incompatible applications
• CPC Class Codes: G06F 9/548 Object oriented; Remote method invocation [RMI] non-remote method invocation G06F9/449

Abstract

A system and method for dynamically generating proxy classes in order to enforce call-by-value semantics between clients and EJBs collocated with a virtual machine. The virtual machine can be a Java virtual machine (JVM) or some other type of virtual machine. The proxy classes are dynamically generated at runtime using dynamic byte code generation. Generated proxies are then interposed between a client and an EJB. The interposition of the generated proxies allows the proxies to intercept communication between the client and the EJB. The dynamically generated wrapper classes may be used in any system wherein a first entity invokes a second entity, wherein the second entity has an interface that can be retrieved or introspected and utilizes call-by-value semantics.

Claims

1. A method for supporting method invoking between software objects, comprising:

receiving a request, from a first software object in a first software module on a virtual machine, to access a second software object in a second software module on the virtual machine, wherein the request contains a method invocation using a parameter object and call-by-value semantics, wherein the parameter object is located in the first software module in the virtual machine;

performing introspection on the second software object to identify one or more interfaces for communicating therewith;

dynamically generating a wrapper object for the second software object on the virtual machine where the first software module and the second software module are collocated, wherein the wrapper object is configured to communicate with the second software object based on the one or more identified interfaces, wherein the dynamically generated wrapper object operates to

intercept communication between the first and second software objects, and

optimize the parameter object based on the type thereof, wherein the optimization includes

determining if the parameter object is immutable, and if it is, passing a reference of the parameter object to the second software object, so that the second software object can access the parameter object in the software module,

determining if the parameter object is mutable and can be cloned, and if it is, creating a clone thereof and passing the clone to the second software object, and

determining if the parameter object is mutable but cannot be cloned, and if it cannot be cloned, serializing the parameter object and passing the serialized object to the second software object; and

providing the first software object with a reference to the wrapper object, instead of a direct reference to the second software object, so that the first software object accesses the second software object using the wrapper object.

2. The method of claim 1, wherein the wrapper object is generated using dynamic bytecode generation as a proxy at runtime.

3. The method of claim 1, further comprising:

retrieving information about the second software object contained in a deployment descriptor associated with the second software object.

4. The method of claim 1, wherein the reference to the wrapper object is provided to the first software object, upon invocation by the first software object of a method in the second software object to which the wrapper object references.

5. The method of claim 1, further comprising:

receiving identification information of the second software object.

6. A non-transitory computer-readable storage medium, storing instructions for supporting communication between objects, the instructions comprising:

receiving a request, from a first software object in a first software module on a virtual machine, to access a second software object in a second software module on the virtual machine, wherein the request contains a method invocation using a parameter object and call-by-value semantics, wherein the parameter object is located in the first software module in the virtual machine;

performing introspection on the second software object to identify one or more interfaces for communicating therewith;

dynamically generating a wrapper object for the second software object on the virtual machine where the first software module and the second software module are collocated, wherein the wrapper object is configured to communicate with the second software object based on the one or more identified interfaces, wherein the dynamically generated wrapper object operates to

intercept communication between the first and second software objects, and

optimize the parameter object based on the type thereof, wherein the optimization includes

determining if the parameter object is immutable, and if it is, passing a reference of the parameter object to the second software object, so that the second software object can access the parameter object in the first software module,

determining if the parameter object is mutable and can be cloned, and if it is, creating a clone thereof and passing the clone to the second software object, and

determining if the parameter object is mutable but cannot be cloned, and if it cannot be cloned, serializing the parameter object and passing the serialized object to the second software object; and

providing the first software object with a reference to the wrapper object, instead of a direct reference to the second software object, so that the first software object accesses the second software object using the wrapper object.

7. The non-transitory computer-readable storage medium of claim 6, further comprising

receiving information about the second software object contained in a deployment descriptor associated with the second software object.

8. The non-transitory computer-readable storage medium of claim 6, wherein the reference to the wrapper object is provided to the first software object upon invocation by the first software object of a method in the second software object to which the wrapper object references.

9. The non-transitory computer-readable storage medium of claim 6, further comprising:

receiving identification information of the second software object.

15. The non-transitory computer-readable storage medium of claim 6, wherein the wrapper object is generated using dynamic bytecode generation as a proxy at runtime.

10. A system to support invoking between software objects, comprising:

one or more microprocessors; and

a virtual machine running on the one or more microprocessors, wherein a container on the virtual machine is configured to perform a method to;

receive request, from a first software object in a first software module on a virtual machine, to access a second software object in a second software module on the virtual machine, wherein the request contains a method invocation using a parameter object and call-by-value semantics, and wherein the parameter object is located in the first software module on the virtual machine,

perform introspection on the second software object to identify one or more interfaces for communicating therewith,

dynamically generate a wrapper object for the second software object on the virtual machine where the first software module and the second software module are collocated, wherein the wrapper object is configured to communicate with the second software object based on the one or more identified interfaces, wherein the dynamically generated wrapper object operates to

intercept communication between the first software object and the second software object, and

optimize the parameter object based on the type thereof, wherein the optimization includes

determining if the parameter object is immutable, and if it is, passing a reference of the parameter object to the second software object, so that the second software object can access the parameter object in the first software module,

determining if the parameter object is mutable and can be cloned, and if it is, creating a clone thereof and passing the clone to the another software object, and

determining if the parameter object is mutable but cannot be cloned, and if it cannot be cloned, serializing the parameter object and passing the serialized object to the another software object, and

provide the first software object with a reference to the wrapper object, instead of a direct reference to the second software object, so that the first software object accesses the second software object using the wrapper object.

11. The system of claim 10, further comprising, wherein the wrapper object is generated using dynamic bytecode generation as a proxy at runtime.

12. The system of claim 10, wherein the container on the virtual machine further operates to receive information about the second software object contained in a deployment descriptor associated with the second software object.

13. The system of claim 10, wherein the reference to the wrapper object is provided to the first software object upon invocation by the first software object of a method in the second software object to which the wrapper object references.

14. The system of claim 10, the container on the virtual machine further operates to receive identification information of the second software object.