Context switching with reader-writer locks

• US 9,798,585 B2
• Filed: 05/19/2015
• Issued: 10/24/2017
• Est. Priority Date: 05/19/2015
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Nanduri, Keshav Sai
• Primary Examiner(s): Chen, Qing
• Assistant Examiner(s): THATCHER, CLINT A
• Application Number:
  US14/716,833
• Publication Number:
  US 20160342444A1
• Time in Patent Office: 889 Days
• Field of Search: 718102
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/5038 considering the execution order of a plurality of tasks, e.g. taking priority or time dependency constraints into consideration scheduling strategies G06F9/4881 and subgroups
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A method for scheduling threads for a software application. The method may include obtaining a thread from a thread queue. The thread may be a program segment of a software process. The method may include determining that the thread is for reading data from a program resource. The method may include, in response to determining that the thread is for reading the program resource, designating an exclusion lock on the program resource to various reader threads. The reader threads may include the thread from the thread queue. The method may include retrieving, by the reader threads, data from the program resource.

Claims

1. A method for scheduling threads for a software application, comprising:

terminating, to a first writer thread, an exclusion lock on a program resource;

activating, in response to terminating the exclusion lock to the writer thread, a plurality of reader threads and a second writer thread from suspension in a thread queue, wherein the thread queue comprises a plurality of suspended threads;

designating the exclusion lock on the program resource to the plurality of reader threads;

inserting the second writer thread in a writer queue, wherein the second writer thread automatically obtains the exclusion lock in response to a termination of the exclusion lock to the plurality of reader threads; and

retrieving, by the plurality of reader threads, first data from the program resource.

2. The method of claim 1, further comprising:

obtaining a suspended thread;

sorting the plurality of suspended threads within the thread queue according to a plurality of priority scores associated with the plurality of suspended threads,

wherein the suspended thread is inserted into a location in the thread queue based on a priority score of the suspended thread.

3. The method of claim 1,

wherein the plurality of reader threads retrieve the first data from the program resource substantially simultaneously.

4. The method of claim 1,

wherein the plurality of reader threads are located at consecutive positions in the thread queue.

5. The method of claim 1,

wherein the program resource is a portion of memory configured to be accessed by the software process.

6. A system for scheduling threads for a software application, comprising:

a processor;

a memory executable by the processor, the memory comprising functionality for;

terminating, to a first writer thread, an exclusion lock on a program resource;

activating, in response to terminating the exclusion lock to the writer thread, a plurality of reader threads and a second writer thread from suspension in a thread queue, wherein the thread queue comprises a plurality of suspended threads;

designating the exclusion lock on the program resource to the plurality of reader threads;

inserting the second writer thread in a writer queue, wherein the second writer threads automatically obtains the exclusion lock in response to a termination of the exclusion lock to the plurality of reader threads; and

retrieving, by the plurality of reader threads, first data from the program resource.

7. The system of claim 6, wherein the memory further comprises functionality for:

obtaining a suspended thread;

sorting the plurality of suspended threads within the thread queue according to a plurality of priority scores associated with the plurality of suspended threads, wherein the second suspended thread is inserted into a location in the thread queue based on a priority score of the second suspended thread.

8. The system of claim 6,

wherein the plurality of reader threads retrieve the first data from the program resource substantially simultaneously.

10. The non-transitory computer readable medium of claim 6, wherein the instructions further comprise functionality for:

obtaining a suspended thread;

sorting the plurality of suspended threads within the thread queue according to a plurality of priority scores associated with the plurality of suspended threads, wherein the second suspended thread is inserted into a location in the thread queue based on a priority score of the second suspended thread.

9. A non-transitory computer readable medium storing instructions for scheduling threads for a software application, the instructions comprising functionality for:

terminating, to a first writer thread, an exclusion lock on a program resource;

activating, in response to terminating the exclusion lock to the writer thread, a plurality of reader threads and a second writer thread from suspension in a thread queue, wherein the thread queue comprises a plurality of suspended threads;

designating the exclusion lock on the program resource to the plurality of reader threads;

inserting the second writer thread in the writer queue, wherein the second writer thread automatically obtains the exclusion lock in response to termination of the exclusion lock to the plurality of reader threads; and

retrieving, by the plurality of reader threads, first data from the program resource.

11. The non-transitory computer readable medium of claim 9,

wherein the plurality of reader threads retrieve the first data from the program resource substantially simultaneously.