System and method for retrieving values of captured local variables for lambda functions in Java

Patent metadata

Field	Value
Publication number	US-9798569-B2
Application number	US-201615043695-A
Country	US
Kind code	B2
Filing date	Feb 15, 2016
Priority date	Feb 15, 2016
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A system for and method of retrieving values of captured local variables for a lambda function in Java. In one embodiment, the system includes: (1) a Java virtual machine and (2) a captured variable retriever that interacts with the Java virtual machine and configured to retrieve a signature of the lambda function from a classfile of a Java class containing the lambda function, compare the signature with a declaration of the lambda function to identify arguments corresponding to the captured local variables, modify the lambda function and cause the Java virtual machine to execute the modified lambda function.

First claim

What is claimed is:

1. A system for retrieving a value of a captured local variable for a lambda function in Java, comprising:
a Java virtual machine executed on a host processor; and
a captured variable retriever that interacts with said Java virtual machine and configured to retrieve a signature of said lambda function from a classfile of a Java class containing said lambda function, compare said signature with a declaration of said lambda function to identify an argument corresponding to said captured local variable, modify said lambda function using said argument and cause said Java virtual machine to execute said modified lambda function with a null value passed to each corresponding formal parameter of said lambda function.

2. The system as recited in claim 1 wherein said captured variable retriever is further configured to retrieve and return a value of said argument when said Java virtual machine executes said modified lambda function and set said captured local variable to said value.

3. The system as recited in claim 1 wherein said captured variable retriever is further configured to pass said lambda function along with value of said captured local variable to a compiler that compiles said lambda function into an intermediate representation.

4. The system as recited in claim 3 wherein said captured variable retriever is further configured to invoke an optimizer that optimizes said intermediate representation and generates code that can execute on a device.

5. The system as recited in claim 4 wherein said device is a graphics processing unit.

6. The system as recited in claim 1 wherein said lambda function includes multiple captured local variables and said captured variable retriever is configured to retrieve values of all said multiple captured local variables.

7. A method of retrieving a value of a captured local variable for a lambda function in Java, comprising:
retrieving a signature of said lambda function from a classfile of a Java class containing said lambda function;
comparing said signature with a declaration of said lambda function to identify an argument corresponding to said captured local variable;
modify said lambda function using said argument; and
causing a Java virtual machine to execute said modified lambda function with a null value passed to each corresponding formal parameter of said lambda function.

8. The method as recited in claim 7 wherein said causing comprises:
retrieving and returning a value of said argument; and
setting said captured local variable to said value.

9. The method as recited in claim 7 further comprising passing said lambda function along with value of said captured local variable to a compiler that compiles said lambda function into an intermediate representation.

10. The method as recited in claim 9 further comprising invoking an optimizer to optimize said intermediate representation and generate code that can execute on a device.

11. The method as recited in claim 10 wherein said device is a graphics processing unit.

12. The method as recited in claim 7 wherein said lambda function includes multiple captured local variables and said method further comprises retrieving values of all said multiple captured local variables.

Assignees

• Nvidia Corp

Inventors

• Lai Michael
• Grover Vinod
• Lee Sean
• Marathe Jaydeep

Classifications

• G06F9/45516 Primary

  Runtime code conversion or optimisation · CPC title

• G06F9/44521

  Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading · CPC title

• G06F2009/45562

  Creating, deleting, cloning virtual machine instances · CPC title

• G06F9/45558 Primary

  Hypervisor-specific management and integration aspects · CPC title