Speculative computation lock coarsening through the use of localized lock reservation

• US 7,908,256 B2
• Filed: 11/30/2007
• Issued: 03/15/2011
• Est. Priority Date: 11/30/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Burka, Peter, Grcevski, Nikola
• Primary Examiner(s): Wassum; Luke S
• Application Number:
  US11/948,154
• Publication Number:
  US 20090144281A1
• Time in Patent Office: 1,201 Days
• Field of Search: None
• US Class Current: 707/704
• CPC Class Codes: G06F 9/528 by using speculative mechanisms

Abstract

A computer-implementable method, system and computer-usable medium. One or more objects among a plurality of objects can be processed utilizing a data-processing apparatus/system. One or more lock reservations can be applied among a group of lock reservations over a multiple sequential lock operations with respect the particular object. Thereafter, the lock reservation can be cancelled with respect to the last monitor exit operation in order to eliminate lock operations where traditional lock coarsening cannot be applied.

Claims

1. A computer-implemented method, comprising:

loading, by a data processing system, a current code region and a particular object among a plurality of objects;

optimizing, by the data processing system, the current code region, wherein the optimizing includes;

speculating, by the data processing system, that a use of the particular object is exclusive with respect to a particular thread of the current code region for the duration of the current code region being optimized;

applying, by the data processing system, a lock reservation over a plurality of sequential lock operations to the particular object; and

thereafter voluntarily cancelling, by the data processing system, the lock reservation with respect to a last monitor exit operation of the plurality of sequential lock operations in order to avoid deadlock.

2. The method of claim 1 wherein the applying step and the thereafter voluntarily cancelling step are performed by a dynamic compilation component.

3. The method of claim 2 wherein the dynamic compilation component comprises a JIT (Just-in-Time) Compiler.

4. A system, comprising:

a processor;

a data bus coupled to the processor; and

a computer-usable medium embodying computer code, the computer-usable medium being coupled to the data bus, the computer program code comprising instructions executable by the processor and configured for;

loading a current code region and a particular object among a plurality of objects;

optimizing the current code region, wherein the optimizing includes;

speculating, by the data processing system, that a use of the particular object is exclusive with respect to a particular thread of the current code region for the duration of the current code region being optimized;

applying a lock reservation over a plurality of sequential lock operations to the particular object; and

thereafter voluntarily cancelling the lock reservation with respect to a last monitor exit operation of the plurality of sequential lock operations in order to avoid deadlock.

5. The system of claim 4 wherein the computer-usable medium further comprises a dynamic compilation component that performs the loading of the particular object and the applying the lock reservation over the plurality of sequential lock operations.

6. The system of claim 5 wherein the dynamic compilation component comprises a JIT (Just-in-Time) Compiler.

7. A computer-usable non-transitory medium embodying computer program code, the computer program code comprising computer executable instructions configured for:

loading a current code region and a particular object among a plurality of objects;

optimizing, by the data processing system, the current code region, wherein the optimizing includes;

speculating, by the data processing system, that a use of the particular object is exclusive with respect to a particular thread of the current code region for the duration of the current code region being optimized;

applying a lock reservation over a plurality of sequential lock operations to the particular object; and

thereafter voluntarily cancelling the lock reservation with respect to a last monitor exit operation of the plurality of sequential lock operations in order to avoid deadlock.

8. The computer-usable non-transitory medium of claim 7 wherein the applying the lock reservation and the thereafter voluntarily cancelling the lock reservation are performed by a dynamic compilation component.

9. The computer-usable non-transitory medium of claim 8, wherein the dynamic compilation component comprises a JIT (Just-in-Time) Compiler.