METHOD OR SYSTEM FOR ACCESS TO SHARED RESOURCE

• US 20150149737A1
• Filed: 11/22/2013
• Published: 05/28/2015
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: R2 Solutions LLC (Acacia Research Corporation)
• Original Assignee: Yahoo! Inc. (Apollo Global Management, Inc.)
• Inventors: Hobson, Jay, Wang, Derek
• Granted Patent: US 10,203,995 B2
• Time in Patent Office: Days
• US Class Current: 711/152
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

Methods and/or systems are provided that may be utilized to read from or write to a resource, such as a shared memory, for example.

Claims

1. A method of permitting a particular task access to a sharable resource capable of being accessed by multiple tasks executing concurrently with respect to the sharable resource, the method comprising:

determining the state of a flag for the sharable resource;

executing the following for a default state;

incrementing a counter tracking the number of concurrent tasks accessing the sharable resource;

accessing the sharable resource to execute the portion of the particular task involving access to the sharable resource; and

decrementing the counter tracking the number of concurrent tasks accessing the sharable resource after completion of the portion of the particular task involving access to the sharable resource; and

executing the following for a non-default state;

waiting until the state of the flag comprises a default state by re-toggling.

2. The method of claim 1, wherein the resource comprises a memory;

and wherein the accessing the sharable resource comprises reading state information stored in memory locations of the memory.

3. The method of claim 2, after the flag comprises a default state by re-toggling,

incrementing a counter tracking the number of concurrent tasks reading the sharable memory;

accessing the sharable memory to execute the portion of the particular task involving reading; and

decrementing the counter tracking the number of concurrent tasks reading the sharable memory after completion.

4. The method of claim 1, wherein the resource comprises a memory;

and further comprising;

toggling the flag so that it is no longer a default state;

determining the state of a counter tracking the number of concurrent tasks accessing the sharable memory;

writing state information to memory locations of the sharable memory if the state of the counter comprises a zero value; and

otherwise waiting until the state of the counter comprises a zero value and then writing to the sharable memory.

5. The method of claim 1, wherein counter comprises an integer counter.

6. The method of claim 1, wherein the counter comprises a floating point counter.

7. The method of claim 1, further comprising issuing an application programming interface (API) call to determine the state of the flag.

8. The method of claim 1, wherein the resource comprises a memory;

and wherein the accessing is capable of being performed over a network by a device located remote from the memory.

9. A system, comprising:

one or more shared memories, a write flag, a read task counter; and

a processor;

the processor to toggle the state of the write flag, increment or decrement the task counter, and read to or write from the one or more shared memories in accordance with executing one or more threads concurrently.

10. The system of claim 9, wherein multiple concurrent threads are capable of being executed to read from the one or more shared memories concurrently if the state of the write flag comprises a default state indicating no threads are writing to the one or more shared memories.

11. The system of claim 10, one thread is capable of being executed to write to the one or more shared memories if the state of the write flag comprises a non-default state and the state of the read task counter comprises zero.

12. The system of claim 9, wherein the processor is capable of issuing an application programming interface (API) call to determine the state of the write flag.

13. The system of claim 9, wherein the resource is located local to the processor.

14. The system of claim 9, wherein the resource is located remote from the processor and is accessible via a network.

15. An article, comprising:

a storage medium comprising machine-readable instructions executable by a special purpose apparatus to permit a particular task access to a sharable resource capable of being accessed by multiple tasks capable of executing concurrently with respect to the sharable resource,

the instructions further executable to;

determine the state of a flag for the sharable resource;

execute the following for a default state;

increment a counter to track the number of concurrent tasks to access the sharable resource;

access the sharable resource to execute the portion of the particular task that includes access to the sharable resource; and

decrement the counter after completion of the portion of the particular task; and

execute the following for a non-default state;

wait until the state of the flag comprises a default state as a result of a re-toggle.

16. The article of claim 15, wherein the resource comprises a memory;

and wherein the instructions, to access the resource, are further executable to read state information stored in memory locations of the memory.

17. The article of claim 16, wherein the instructions, further executable to re-toggle the state of the flag so that the flag comprises a default state;

and further executable to;

increment a counter to track the number of concurrent tasks to read the sharable memory;

read the sharable memory; and

decrement the counter after completion of the read operation.

18. The article of claim 15, wherein the resource comprises a memory;

and wherein the instructions are further executable to;

toggle the state of the flag so that it is no longer a default state;

determine the state of a counter to track the number of concurrent tasks to access the sharable memory;

write state information to memory locations of the sharable memory if the state of the counter comprises a zero value; and

otherwise wait until the state of the counter comprises a zero value and then write to the sharable memory.

19. The article of claim 15, wherein the instructions are further executable to issue an application programming interface (API) call to determine the state of the flag.

20. The article of claim 15, wherein the instructions are further executable to access the sharable memory over a network remote from the special purpose apparatus.