Nested locks to avoid mutex parking

• US 20050050257A1
• Filed: 07/07/2004
• Published: 03/03/2005
• Est. Priority Date: 08/25/2003
• Status: Abandoned Application

• Current Assignee: OPNET Technologies Incorporated (Riverbed Technology Incorporated)
• Original Assignee: OPNET Technologies Incorporated (Riverbed Technology Incorporated)
• Inventors: Shakula, Alexey
• Application Number:
  US10/886,448
• Publication Number:
  US 20050050257A1
• Time in Patent Office: Days
• US Class Current: 711/1
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance

Abstract

A native mutex lock of an operating system is embedded within an application-controlled spinlock. Each of these locks are applied to the same resource, in such a manner that, in select applications, and particularly in parallel processed applications, the adverse side-effects of the inner native mutex lock are avoided. In a preferred embodiment, each call to a system routine that is known to invoke a native mutex is replaced by a call to a corresponding routine that spinlocks the resource before calling the system routine that invokes the native mutex, then releases the spinlock when the system call is completed. By locking the resource before the native mutex is invoked, the calling task is assured that the resource is currently available to the task when the native mutex is invoked, and therefore the task will not be parked/deactivated by the native mutex.

Claims

1. A method of controlling access to a resource, comprising:

acquiring a spinlock on the resource,

acquiring a native mutex lock on the resource,

accessing the resource,

releasing the native mutex lock, and

releasing the spinlock.

2. The method of claim 1, further including:

invoking a system routine after acquiring, and before releasing, the spinlock,

wherein

the system routine is configured to acquire, and release, the native mutex lock.

3. The method of claim 2, wherein

the native mutex lock is configured to selectively deactivate a process when the resource is unavailable for access, and

the spinlock prevents the native mutex lock from deactivating the process by assuring that the resource is available for access.

4. The method of claim 3, wherein

the spinlock is configured to maintain the process in an active state until the resource is available for access.

5. The method of claim 4, wherein

the acquiring and releasing of the native mutex lock is automatically performed by an operating system of a computing system that is executing this method.

6. The method of claim 1, wherein

the native mutex lock is configured to selectively deactivate a process when the resource is unavailable for access, and

the spinlock prevents the native mutex lock from deactivating the process by assuring that the resource is available for access.

7. The method of claim 6, wherein

the spinlock is configured to maintain the process in an active state until the resource is available for access.

8. The method of claim 7, wherein

the acquiring and releasing of the native mutex lock is automatically performed by an operating system of a computing system that is executing this method.

9. The method of claim 1, wherein

the acquiring and releasing of the native mutex lock is automatically performed by an operating system of a computing system that is executing this method.

10. A method of improving performance of an application program, comprising:

creating an encapsulating function that includes a target function within a spinlock for a resource, and

replacing each reference to the target function in the application program with a reference to the encapsulating function, so that the application program invokes the spinlock before invoking the target function,

wherein

the target function is configured to invoke a native mutex lock for the resource.

11. The method of claim 10, further including

identifying the target function by assessing a likelihood of degradation of the performance of the application program caused by deactivation of a task of the application program during execution of the native mutex lock.

12. The method of claim 11, wherein

the target function is included in an operating system that is not modifiable by a user of the operating system.

13. The method of claim 12, wherein

replacing each reference to the target function includes editing a source of the application program to replace each occurrence of a name of the target function with a name of the encapsulating function.

14. The method of claim 10, wherein

replacing each reference to the target function includes editing a source of the application program to replace each occurrence of a name of the target function with a name of the encapsulating function.

15. The method of claim 10, wherein

replacing each reference to the target function includes editing code of the application program to replace each occurrence of an address of the target function with an address of the encapsulating function.

16. The method of claim 10, wherein

replacing each reference to the target function includes a mapping of a symbolic name of the target function to an address of the encapsulating function.

17. An application program, comprising:

an encapsulating routine that encapsulates a target routine within a spinlock for a resource, and

a plurality of calls to the encapsulating routine,

wherein

the target routine is configured to invoke a native mutex lock for the resource.

18. The application program of claim 17, wherein

the target routine includes a system routine that is provided by an operating system.

19. The application program of claim 17, wherein

the native mutex lock is configured to selectively deactivate a process of the application program when the resource is unavailable for access, and

the spinlock prevents the native mutex lock from deactivating the process by assuring that the resource is available for access before the native mutex lock is invoked.

20. The application program of claim 19, wherein

the spinlock is configured to maintain the process in an active state until the resource is available for access.