Method and apparatus for performing byte-code optimization during pauses

• US 6,865,734 B2
• Filed: 04/17/2001
• Issued: 03/08/2005
• Est. Priority Date: 10/06/1997
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Hölzle, Urs, Bak, Lars
• Primary Examiner(s): DAS, CHAMELI
• Application Number:
  US09/836,916
• Publication Number:
  US 20010052117A1
• Time in Patent Office: 1,421 Days
• Field of Search: 717139-140, 717147-148, 717/151, 717/153, 717/136, 717/145, 717/111, 717/118, 712/216, 718/102, 719/315, 713/323
• US Class Current: 717/153
• CPC Class Codes: G06F 8/4441 Reducing the execution time required by the program code
• CPC Class Codes: G06F 8/48 Incremental compilation software reuse G06F8/36
• CPC Class Codes: G06F 9/45516 Runtime code conversion or optimisation

Abstract

Methods and apparatus for dynamically compiling byte codes associated with methods during idle periods in the execution of a computer program are disclosed. The described methods are particularly suitable for use in computer systems that are arranged to execute both interpreted and compiled byte codes. In some embodiments, methods to be dynamically compiled are referenced in one or more lists. The lists may be prioritized to facilitate the compilation of the highest priority methods first. In one embodiment, a pair of compilation lists are provided with a first one of the compilation lists being created prior to processing the computer program while the other is created during the processing of the computer program.

Claims

1. A method for dynamically performing tasks at runtime during the execution of an executable computer program, the method comprising:

determining whether there is a period which the level of activity associated with execution of the executable computer program is below a threshold level;

selecting a first task form a plurality of tasks which can be performed during the execution of the executable computer program when it is determined that there is a period which the level of activity associated with execution of the executable computer program is below a threshold level; and

initializing performance of the first task during the first period after the selecting of the first task.

2. A method as recited in claim 1, wherein the method further comprises:

determining whether an interrupt is received by the executable computer program after the initialization of the performance of the first task; and

continuing the performance of the first task for a predetermined period of time when it is determined that an interrupt has been received.

3. A method as recited in claim 2, wherein the method further comprises:

determining whether the performance of the first task is completed after the predetermined period of time; and

aborting the performance of the first task when it is determined that the first task is not completed after the predetermined period of time.

4. A method as recited in claim 1, wherein the method further comprises:

determining whether the first task is a first method;

determining whether the first method is compiled when it is determined that the first task is the first method, wherein the determination of whether the first method is compiled is made during the period of low activity;

initializing a compilation of the first method during the period when it is determined that the first method is not compiled; and

initializing a completion of the first task during the period when it is determined that the first task is not the first method.

5. A method as recited in claim 1, wherein the plurality of tasks is referenced in a first list associated with the executable computer program and the first task is a highest priority task for performance associated with the first list.

6. A method as recited in claim 1, wherein the executable computer program is compliant with the Java programming language.

7. A virtual machine for dynamically performing tasks at runtime during the execution of an executable computer program by the virtual machine, wherein the virtual machine is capable of:

determining whether there is a period which the level of activity associated with execution of the executable computer program is below a threshold level;

selecting a first task form a plurality of tasks which can be performed during the execution of the executable computer program when it is determined that there is a period which the level of activity associated with execution of the executable computer program is below a threshold level; and

initializing performance of the first task during the first period after the selecting of the first task.

8. A virtual machine as recited in claim 7, wherein the plurality of tasks is referenced in a first list associated with the executable computer program and the first task is a highest priority task for performance associated with the first list.

9. A virtual machine as recited in claim 7,

wherein a first set of tasks selected from the plurality of tasks is associated with a first list and a second set of tasks selected from the plurality of tasks is associated with a second list, the first list being created during the processing of the executable computer program the second list being created before the processing of the executable computer program, and

wherein identifying the first task includes:

selecting the first task as a highest priority task from the first list.

10. A virtual machine as recited in claim 7, wherein said virtual machine is further capable of:

determining whether an interrupt is received by the executable computer program after the initialization of the performance of the first task; and

continuing the performance of the first task for a predetermined period of time when it is determined that an interrupt has been received.

11. A virtual machine as recited in claim 10, wherein said virtual machine is further capable of:

determining whether the performance of the first task is completed after the predetermined period of time; and

aborting the performance of the first task when it is determined that the first task is not completed after the predetermined period of time.

12. A virtual machine as recited in claim 7, wherein said virtual machine is further capable of:

determining whether the first task is a first method;

determining whether the first method is compiled when it is determined that the first task is the first method, wherein the determination of whether the first method is compiled is made during the period of low activity;

initializing a compilation of the first method during the period when it is determined that the first method is not compiled; and

initializing a completion of the first task during the period when it is determined that the first task is not the first method.

13. A virtual machine as recited in claim 7, wherein the first task is compilation of a first method.

14. A virtual machine as recited in claim 7, wherein the virtual machine is a Java complaint virtual machine.

15. A computer readable medium including computer program code for dynamically performing tasks at runtime during the execution of an executable computer program, wherein the readable medium comprises:

computer program code for determining whether there is a period which the level of activity associated with execution of the executable computer program is below a threshold level;

computer program code for selecting a first task form a plurality of tasks which can be performed during the execution of the executable computer program when it is determined that there is a period which the level of activity associated with execution of the executable computer program is below a threshold level; and

computer program code for initializing performance of the first task during the first period after the selecting of the first task.

16. A computer readable medium as recited in claim 15, wherein the computer readable medium comprises:

computer program code for determining whether an interrupt is received by the executable computer program after the initialization of the performance of the first task; and

computer program code for continuing the performance of the first task for a predetermined period of time when it is determined that an interrupt has been received.

17. A computer readable medium as recited in claim 15, wherein the computer readable medium comprises:

computer program code for determining whether an interrupt is received by the executable computer program after the initialization of the performance of the first task; and

computer program code for continuing the performance of the first task for a predetermined period of time when it is determined that an interrupt has been received.

18. A computer readable medium as recited in claim 15, wherein the computer readable medium comprises:

computer program code for determining whether the performance of the first task is completed after the predetermined period of time; and

computer program code for aborting the performance of the first task when it is determined that the first task is not completed after the predetermined period of time.

19. A computer readable medium as recited in claim 15, wherein the computer readable medium comprises:

computer program code for determining whether the first task is a first method;

computer program code for determining whether the first method is compiled when it is determined that the first task is the first method, wherein the determination of whether the first method is compiled is made during the period of low activity;

computer program code for initializing a compilation of the first method during the period when it is determined that the first method is not compiled; and

computer program code for initializing a completion of the first task during the period when it is determined that the first task is not the first method.

20. A computer readable medium as recited in claim 15, wherein the executable computer program is compliant with the Java programming language.