METHODS AND APPARATUS TO MANAGE OBJECT LOCKS

• US 20110153992A1
• Filed: 12/23/2009
• Published: 06/23/2011
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Sun, Mingqiu, Dohrmann, Stephen H., Lai, Konrad K., Srinivas, Suresh, Srinivasan, Uma, Rajwar, Ravi
• Granted Patent: US 8,972,994 B2
• Time in Patent Office: Days
• US Class Current: 712/220
• CPC Class Codes: G06F 16/1767 Concurrency control, e.g. optimistic or pessimistic approaches
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: G06F 8/458 Synchronisation, e.g. post-wait, barriers, locks synchronisation among tasks G06F9/52
• CPC Class Codes: G06F 9/3842 Speculative instruction execution
• CPC Class Codes: G06F 9/45516 Runtime code conversion or optimisation
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: G06F 9/528 by using speculative mechanisms
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

Example methods and apparatus to manage object locks are disclosed. A disclosed example method includes receiving an object lock request from a processor, the lock request associated with object lock code to lock an object, and generating object lock-bypass code based on a type of the processor, the object lock-bypass code to execute in a managed runtime in response to receiving the object lock request. The example method also includes identifying a type of instruction set architecture (ISA) associated with the processor, invoking a checkpoint instruction for the processor based on the identified ISA, suspending the object lock code from executing and executing target code when the object is uncontended, and allowing the object lock code to execute when the object is contended.

Claims

1. A method to bypass an object lock, comprising:

receiving an object lock request from a processor, the lock request associated with object lock code to lock an object;

generating object lock-bypass code based on a type of the processor, the object lock-bypass code to execute in a managed runtime in response to receiving the object lock request;

identifying a type of instruction set architecture (ISA) associated with the processor;

invoking a checkpoint instruction for the processor based on the identified ISA;

suspending the object lock code from executing and executing target code when the object is uncontended; and

allowing the object lock code to execute when the object is contended.

2. A method as defined in claim 1, wherein generating the object lock-bypass code comprises generating a code shell.

3. A method as defined in claim 2, further comprising populating the code shell with instructions based on the identified type of ISA.

4. A method as defined in claim 1, further comprising executing a critical section of code without the object lock.

5. A method as defined in claim 1, further comprising invoking an ISA-specific status register query in response to an indication of contention for the object, the status register to identify a cause for the object contention.

6. A method as defined in claim 5, further comprising counting a number of instances of contention for the object.

7. A method as defined in claim 6, further comprising flagging the object when the number of instances of contention exceeds a threshold value.

8. A method as defined in claim 7, further comprising adding the object name to an object forecaster to prevent subsequent lock-bypass code generation associated with the object.

9. A method as defined in claim 8, further comprising executing the object lock code when the object name is in the object forecaster.

10. A method as defined in claim 1, further comprising adding a name associated with the object to an object forecaster data store when the object is contended.

11. A method as defined in claim 10, further comprising querying the object forecaster data store in response to receiving the object lock request, and bypassing generating the object lock-bypass code when the object forecaster contains the object name.

12. An apparatus to bypass an object lock, comprising:

an exception handler monitor to receive an object lock request from a runtime environment, the lock request associated with object lock code to lock an object;

a bypass code shell builder to generate object lock-bypass code;

an instruction set architecture (ISA) identifier to identify a type of ISA associated with a processor executing the runtime environment, the bypass code shell builder to populate the object lock-bypass code with instructions based on the identified type of ISA; and

an object lock tester to invoke a checkpoint instruction and suspend the object lock code when the object is uncontended, and to allow the object lock code when the object is contended.

13. An apparatus as defined in claim 12, further comprising a speculative code manager to allow a critical section of code to execute without the object lock when the object is uncontended.

14. An apparatus as defined in claim 12, further comprising an ISA data store to store a plurality of ISA-specific instructions, the ISA identifier to query the ISA data store to retrieve the ISA-specific instructions for the object lock-bypass code.

15. A tangible article of manufacture storing machine accessible instructions that, when executed, cause a machine to:

receive an object lock request from a processor, the lock request associated with object lock code to lock an object;

generate object lock-bypass code based on a type of the processor, the object lock-bypass code to execute in a managed runtime in response to receiving the object lock request;

identify a type of instruction set architecture (ISA) associated with the processor;

invoke a checkpoint instruction for the processor based on the identified ISA;

suspend the object lock code from executing and executing target code when the object is uncontended; and

allow the object lock code to execute when the object is contended.

16. An article of manufacture as defined in claim 15 wherein the machine accessible instructions, when executed, cause the machine to generate a code shell.

17. An article of manufacture as defined in claim 16 wherein the machine accessible instructions, when executed, cause the machine to populate the code shell with instructions based on the identified type of ISA.

18. An article of manufacture as defined in claim 15 wherein the machine accessible instructions, when executed, cause the machine to execute a critical section of code without the object lock.

19. An article of manufacture as defined in claim 15 wherein the machine accessible instructions, when executed, cause the machine to invoke an ISA-specific status register query in response to an indication of contention for the object, the status register to identify a cause for the object contention.

20. An article of manufacture as defined in claim 19 wherein the machine accessible instructions, when executed, cause the machine to count a number of instances of contention for the object.

21. (canceled)