Method for an interpreter to control a native function call based on a signature of the native function

• US 7,360,206 B1
• Filed: 03/13/2003
• Issued: 04/15/2008
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Hatcher, Andrew J.
• Primary Examiner(s): CHAVIS, JOHN Q
• Application Number:
  US10/388,988
• Time in Patent Office: 1,860 Days
• Field of Search: 717/139
• US Class Current: 717/139
• CPC Class Codes: G06F 9/45508 Runtime interpretation or emulation, e g. emulator loops, bytecode interpretation

Abstract

A method for implementing an interpreter comprises determining if a signature of a native function declared in code for an interpreted application matches a signature of the native function stored in a linking mechanism to link a function call to the native function in the interpreted application to native code implementing the native function; and invoking the native code only if the signatures match.

Claims

1. A method of implementing an interpreter, the method comprising:

determining, during runtime of an interpreted application, whether a signature of a native function declared in the interpreted application matches a signature of the native function stored in a linking mechanism which links a function call to the native function in the interpreted application to native code implementing the native function; and

invoking the native code in response to the function call in the interpreted application if the signatures match.

2. The method of claim 1, wherein the linking mechanism comprises a table which includes a mapping of a name of the native function to a signature of the native function, and to a pointer to the native code.

3. The method of claim 2, wherein the determining comprises performing a look-up of the signature of the native function as declared in the code for the interpreted application, and comparing the looked-up signature against a corresponding signature in the table.

4. The method of claim 3, wherein the look-up is performed at a time when the code for the interpreted application is being run.

5. The method of claim 2, wherein the table is constructed at a time when the interpreter is compiled.

6. The method of claim 1, wherein the interpreter is a Java interpreter within a Java Virtual Machine.

7. The method of claim 1, further comprising executing an error routine if the signatures do not match.

8. The method of claim 7, wherein the error routine comprises a function that generates an exception.

9. The method of claim 7, wherein the error routine comprises a routine to notify a user to update the linking mechanism so that the signature of the native function stored in the linking mechanism matches the signature of the native method as declared in the code for the interpreted application.

10. The method of claim 7, wherein the error routine comprises code to cause the interpreter to search for alternative code for the interpreted application in which a signature of the native function as declared in the alternative code matches the signature of the native function stored in the linking mechanism.

11. The method of claim 10, wherein the search for the alternative code comprises downloading the alternative code over a network connection.

12. A method of implementing an interpreter, the method comprising:

building a table of native functions, each implemented in a native language, wherein the table includes a mapping of a name for a native function, to a signature for the native function, and to a pointer to native code implementing the native function; and

defining a control mechanism to control, during runtime of an interpreted application, calls to the native function by the interpreted application, based on the table.

13. The method of claim 12, wherein the control mechanism performs a look-up of a signature of the native function based on a declaration of the native function in code for the interpreted application when a function call instruction to the native function is encountered;

compares the looked-up signature with a corresponding signature in the table of native functions; and

executes the function call instruction if the signatures match.

14. The method of claim 13, wherein the control mechanism executes an error routine if the signatures do not match.

15. The method of claim 14, wherein the error routine comprises code to cause the interpreter to search for alternative code for the interpreted application in which a signature of the native function as declared matches a signature of the native function stored in a table.

16. The method of claim 15, wherein the search for the alternative code comprises downloading alternative code over a network connection.

17. The method of claim 14, wherein the error routine comprises a routine to notify a user to update the table so that the signature of the native function stored in the table matches the signature of the native function as declared in the interpreted application.

18. The method of claim 12, wherein the interpreter comprises a Java interpreter within a Java Virtual Machine.

19. The method of claim 18, wherein the interpreted code comprises a Java class file.

20. An interpreter, comprising:

a mechanism to determine, during runtime of an interpreted application, if a signature of a native function declared in the interpreted application matches a signature of the native function stored in a linking mechanism which links a function call to the native function in the interpreted application to the native code implementing the native function;

a mechanism to invoke the native function in response to the function call in the interpreted application if the signatures match; and

a mechanism to display a notification to a user if the declared signature does not match the implemented signature.

21. The interpreter of claim 20, wherein the linking mechanism comprises a table which includes a mapping of a name of the native function to a signature of the native function, and to a pointer to the native code.

22. A machine-accessible medium, having stored thereon a sequence of instructions, which if executed by a processing system causes the processing system to perform a process comprising:

determining, during runtime of an interpreted application, if a signature of a native function declared in the interpreted application matches the signature of the native function stored in a linking mechanism which links a function call to the native function in the interpreted application to native code implementing the native function; and

invoking the native code in response to the function call in the interpreted application if the signatures match.

23. The machine-accessible medium of claim 22, wherein the linking mechanism comprises a table which includes a mapping of a name of the native function to a signature of the native function, and to a pointer to the native code.

24. A computer system, comprising:

a processor; and

a memory coupled to the processor, the memory storing instructions which when executed by the processor cause the processor to perform a method comprising

determining, during runtime of an interpreted application, if a signature of the native function declared in the interpreted application matches a signature of the native function stored in a linking mechanism which links a function call to the native function in the interpreted application to native code implementing the native function; and

invoking the native code in response to the function call in the interpreted application if the signatures match.

25. The computer system of claim 24, wherein the linking mechanism comprises a table which includes a mapping of a name of the native function to a signature of the native function, and to a pointer to the native code.

26. A method for implementing an interpreter, comprising:

encountering, during runtime of an interpreted application, a native function call instruction in the interpreted program;

copying parameters for the native function to a machine stack;

performing a look-up of a signature of the native function in a class file containing a declaration of the native function;

comparing the looked-up native function signature with a signature of the native function in a table of native functions which was built when the interpreter was compiled;

executing native code comprising the native function if the signatures match; and

executing an error routine if the signatures do not match.

27. An interpreter, which upon encountering a native function call instruction in an interpreted program, during runtime of an interpreted application, performs a method comprising:

copying parameters for the native function to a machine stack;

performing a look-up of a signature of the native function in a class file containing a declaration of the native function;

comparing the looked-up native function signature with a signature of the native function in a table of native functions which was built when the interpreter was compiled;

executing native code comprising the native function if the signatures match; and

executing an error routine if the signatures do not match; and

displaying a notification to a user if the declared signature does not match the implemented signature.

28. A machine-accessible medium, having stored thereon a sequence of instructions which if executed by a processing system, cause the processing system to perform a process comprising:

encountering, during runtime of an interpreted application, a native function call instruction in the interpreted program;

copying parameters for the native function to a machine stack;

performing a look-up of a signature of the native function in a class file containing a declaration of the native function;

comparing the looked-up native function signature with a signature of the native function in a table of native functions which was built when the interpreter was compiled;

executing native code comprising the native function if the signatures match; and

executing an error routine if the signatures do not match.

29. A computer system, comprising:

a processor;

a memory coupled to the processor, the memory storing instructions which when executed by the processor cause the processor to perform a method comprising

encountering, during runtime of an interpreted application, a native function call instruction in the interpreted program;

copying parameters for the native function to a machine stack;

performing a look-up of a signature of the native function in a class file containing a declaration of the native function;

comparing the looked-up native function signature with a signature of the native function in a table of native functions which was built when the interpreter was compiled;

executing native code comprising the native function if the signatures match; and

executing an error routine if the signatures do not match.