Method and apparatus for dynamically optimizing byte-coded programs

• US 6,237,141 B1
• Filed: 08/02/1999
• Issued: 05/22/2001
• Est. Priority Date: 10/06/1997
• Status: Expired due to Fees

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Griswold, David, Griesemer, Robert, Hölzle, Urs
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): NGUYEN BA, HOANG VU A
• Application Number:
  US09/365,706
• Time in Patent Office: 659 Days
• Field of Search: 717/9, 717/5, 717/1
• US Class Current: 717/153
• CPC Class Codes: G06F 8/48 Incremental compilation software reuse G06F8/36
• CPC Class Codes: G06F 9/4552 Involving translation to a different instruction set architecture, e.g. just-in-time translation in a JVM

Abstract

Methods and apparatus for dynamically determining whether portions of code should be interpreted or compiled in order to optimize a software application during run-time are disclosed. According to one aspect of the present invention, computer-implemented method for run-time processing of a computer program which includes byte-codes arranged as a plurality of methods includes invoking a first method selected from the plurality of methods. Invoking the first selected method involves interpreting the first selected method. An invocation tracker which is arranged to track the number of invocations of the first selected method is updated, and a determination is made regarding when the invocation tracker indicates that the number of invocations of the first selected method exceeds a threshold value. The first selected method is compiled when it is determined that the invocation tracker indicates that the number of invocations of the first selected method exceeds a threshold value. This threshold value is periodically adjusted to keep the compilation and the interpretation overheads within acceptable ranges.

Claims

1. A computer-implemented method for processing a computer program during run-time, the computer program including byte codes, the byte codes being arranged as a plurality of methods, the computer-implemented method comprising:

invoking a first method selected from the plurality of methods, wherein invoking the first selected method includes interpreting the first selected method;

determining when it is suitable to compile the first selected method; and

compiling the first selected method when it is determined that compiling the first selected method is suitable.

2. A computer-implemented method as recited in claim 1 wherein determining when it is suitable to compile the first selected method includes determining when a counter arranged to track a number of invocation of the first selected method indicates that the number of invocations of the first selected method exceeds a given value.

3. A computer-implemented method as recited in claim 1 wherein determining when it is suitable to compile the first selected method includes monitoring the clock ticks of a timer and determining an overall amount of time associated with interpreting the first selected method.

4. A computer-implemented method as recited in claim 3 wherein the timer is an operating system timer.

5. A computer-implemented method as recited in claim 3 wherein the clock ticks of the timer are monitored to determine when a number of clock ticks exceeds a threshold value.

6. A computer-implemented method as recited in claim 5 wherein when it is determined that the number of clock ticks exceeds the threshold value, the first selected method is compiled.

7. A computer-implemented method as recited in claim 5 further including:

measuring a compilation overhead associated with compiling the first selected method;

determining when the compilation overhead is within an acceptable range; and

adjusting the threshold value when it is determined that the compilation overhead is not within the acceptable range.

8. A computer-implemented method as recited in claim 1 wherein determining when it is suitable to compile the first selected method includes monitoring an amount of time elapsed while interpreting the first selected method, wherein when the amount of time elapsed exceeds a threshold value, the first selected method is compiled.

9. A computer-implemented method as recited in claim 8 further including:

measuring a compilation overhead associated with compiling the first selected method;

determining when the compilation overhead is within an acceptable range; and

adjusting the threshold value when it is determined that the compilation overhead is not within the acceptable range.

10. A computer-implemented method as recited in claim 1 further including:

determining when to compile the first selected method when it is determined that compiling the first selected method is suitable; and

scheduling a compilation of the first selected method when it is determined that compiling the first selected method is suitable.

11. A computer-implemented method as recited in claim 10 wherein scheduling the compilation of the first selected method includes delaying the compilation of the first selected method before compiling the first selected method.

12. A computer-implemented method for processing a computer program during run-time, the program including byte codes, the byte codes being arranged as a plurality of methods, the computer-implemented method comprising:

invoking a first method selected from the plurality of methods, wherein invoking the first selected method includes calling a second method selected from the plurality of methods;

invoking the second selected method in response to calling the second selected method, the second selected method being invoked using the first selected method, wherein invoking the second selected method includes interpreting the second selected method;

tracking a number of invocations of the second selected method;

determining when the number of invocations of the second selected method exceeds a threshold value; and

compiling the first selected method when it is determined that the number of invocations of the second selected method exceeds the threshold value.

13. A computer-implemented method as recited in claim 12 wherein compiling the first selected method includes inlining the second selected method into the first selected method.

14. A computer-implemented method as recited in claim 12 wherein compiling the first selected method includes recompiling the first selected method.

15. A computer-implemented method as recited in claim 12 further including delaying compilation of the first selected method.

16. A computer program product according to claim 15 further including computer code for delaying compilation of the first selected method.

17. A computer-implemented method for processing a computer program during run-time, the program including byte codes, the byte codes being arranged as a plurality of methods, the computer-implemented method comprising:

invoking a first method selected from the plurality of methods, wherein invoking the first selected method includes calling a second method selected from the plurality of methods;

invoking the second selected method in response to calling the second selected method, the second selected method being invoked using the first selected method, wherein invoking the second selected method includes interpreting the second selected method;

determining when time associated with interpreting the second selected method exceeds a threshold value; and

compiling the first selected method when it is determined that the time associated with interpreting the second selected method exceeds the threshold value.

18. A computer-implemented method as recited in claim 17 wherein compiling the first selected method includes inlining the second selected method into the first selected method.

19. A computer-implemented method as recited in claim 17 further including delaying compilation of the first selected method.

20. A computer program product for causing a computer to process byte codes during runtime, the byte codes being arranged as a plurality of methods, the computer program product comprising:

computer code for invoking a first method selected from the plurality of methods, wherein invoking the first selected method includes interpreting the first selected method;

computer code for determining when it is desirable to compile the first selected method;

computer code for compiling the first selected method when it is determined that compiling the first selected method is desirable; and

a computer-readable medium that stores the computer codes.

21. A computer program product according to claim 20 further including computer code for delaying a compilation of the first method when it is determined that compiling the first selected method is desirable.

22. A computer system for executing byte codes, the byte codes being arranged as a plurality of methods, the computer system comprising:

an interpreter arranged to interpret a first method selected from the plurality of methods;

a mechanism for determining when it is beneficial to compile the first selected method; and

a compiler arranged to compile the first selected method when compiling the first selected method is determined to be beneficial.

23. A computer system according to claim 22 wherein the mechanism is one selected from a group consisting of an invocation tracking mechanism and a timer.

24. A computer system according to claim 23 wherein the timer is a computer system timer.

25. A computer system according to claim 22 further including a delaying mechanism arranged to delay a compilation of the first selected method when compiling the first selected method is determined to be beneficial.

26. A computer program product for processing byte codes during run-time, the byte codes being arranged as a plurality of methods, the computer program product comprising:

computer code for invoking a first method selected from the plurality of methods, wherein invoking the first selected method includes calling a second method selected from the plurality of methods;

computer code for invoking the second selected method in response to calling the second selected method, the second selected method being invoked using the first selected method, wherein invoking the second selected method includes interpreting the second selected method;

computer code for tracking a number of invocations of the second selected method;

computer code for determining when the number of invocations of the second selected method exceeds a threshold value;

computer code for compiling the first selected method when it is determined that the number of invocations of the second selected method exceeds the threshold value; and

a computer-readable medium that stores the computer codes.

27. A computer-program product according to claim 26 wherein computer code for compiling the first selected method includes computer code for inlining the second selected method into the first selected method.