Method or system for access to shared resource

• US 10,203,995 B2
• Filed: 11/22/2013
• Issued: 02/12/2019
• Est. Priority Date: 11/22/2013
• Status: Active Grant

• Current Assignee: R2 Solutions LLC (Acacia Research Corporation)
• Original Assignee: Excalibur IP, LLC (Acacia Research Corporation)
• Inventors: Hobson, Jay, Wang, Derek
• Primary Examiner(s): Abad, Farley
• Assistant Examiner(s): Yu, Henry W
• Application Number:
  US14/087,937
• Publication Number:
  US 20150149737A1
• Time in Patent Office: 1,908 Days
• Field of Search: 710 1, 710 15, 710 17, 710 19, 710 20, 710 36, 711152, 711154, 711159, 711163
• 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 comprising:

performing read and write operations on a non-locked portion of a sharable memory, the performing the read and write operations comprising;

determining a state of a flag for the non-locked portion of the sharable memory;

at least partially in response to determining that the state of the flag comprises a default state, incrementing a counter tracking a number of concurrent tasks accessing the non-locked portion of the sharable memory;

accessing the non-locked portion of the sharable memory to execute a portion of a first particular task involving reading from the non-locked portion of the sharable memory at a time at which the non-locked portion of the sharable memory is accessible to more than one of the concurrent tasks to perform one or more read operations on the non-locked portion of the sharable memory at least partially in response to evaluating whether other tasks are currently performing one or more read operations from the non-locked portion of the sharable memory based, at least in part, on a value stored in the counter;

decrementing the counter tracking the number of concurrent tasks accessing the non-locked portion of the sharable memory after completion of the portion of the first particular task;

at least partially in response to determining that the state of the flag comprises a non-default state, waiting to execute one or more portions of at least a second particular task involving access to the non-locked portion of the sharable memory until the state of the flag is changed to comprise the default state;

accessing the non-locked portion of the sharable memory location comprising a third particular task; and

wherein at least partially in response to determining that the state of the flag comprises the default state and that the third particular task involves writing to the non-locked portion of the shared memory;

toggling the state of the flag to the non-default state, and

waiting to perform the third particular task until the counter tracking the number of concurrent tasks has a value of zero.

2. The method of claim 1, the reading from the non-locked portion of the sharable memory comprises reading state information stored in memory locations of the non-locked portion of the sharable memory.

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

incrementing a counter tracking the number of concurrent tasks reading the non-locked portion of the sharable memory;

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

decrementing the counter tracking the number of concurrent tasks reading the non-locked portion of the sharable memory after completion of the number of concurrent tasks.

4. The method of claim 1, the method further comprising:

toggling the state of the flag to the non-default state;

determining a value of the counter tracking the number of concurrent tasks accessing the portion of the sharable memory; and

writing state content to memory locations of the non-locked portion of the sharable memory at least partially in response to the value of the counter comprising a zero value, or waiting until the value of the counter comprises a zero value and then writing to the non-locked portion of the sharable memory.

5. The method of claim 1, wherein the 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 accessing is capable of being performed over a network by a device located remote from the non-locked portion of the sharable memory.

9. A system, comprising:

a sharable memory, a write flag, a read task counter to track one or more concurrent tasks to access a non-locked portion of the sharable memory; and

a processor to perform read and write operations on the non-locked portion of the sharable memory, the perform of the read and write operations to comprise to toggle a state of the write flag, increment or decrement the task counter, and read from or write to the non-locked portion of the sharable memory in accordance with an execution of one or more threads concurrently;

wherein at least partially in response to a determination that the state of the write flag is to comprise a default state to permit a number of concurrent tasks to perform one or more read operations to read from the non-locked portion of the sharable memory at a particular time at least partially in response to an evaluation of an existence of a current performance of other tasks to perform one or more read operations from the non-locked portion of the sharable memory to be based, at least in part, on a value to be stored in the counter;

wherein at least partially in response to a change in the state of the write flag from a default to a non-default state while the portion of the sharable memory is to be unlocked, the processor to wait to execute one or more portions of at least a particular task in which the non-locked portion of the sharable memory is to be accessed until the state of the write flag is changed to comprise the default state; and

wherein in response to a determination that the state of the write flag is to comprise the default state and a third particular task is to involve a write operation to the non-locked portion of the shared memory, the processor to toggle the state of the flag to the non-default state and to wait to perform the third particular task until the counter tracking the number of concurrent tasks has a value of zero.

10. The system of claim 9, wherein the processor is to execute multiple concurrent threads to read from the non-locked portion of the sharable memory concurrently if the state of the write flag is to comprise the default state to indicate no threads are to be written to the sharable memory.

11. The system of claim 10, wherein the processor is to execute a thread to write to the non-locked portion of the sharable memory if the state of the write flag is to comprise the non-default state and a value of the read task counter is to comprise zero.

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

13. The system of claim 9, wherein the sharable memory is to be local to the processor.

14. The system of claim 9, wherein the sharable memory is to be remote from the processor and is to be accessible via a network.

15. An article, comprising:

a non-transitory storage medium comprising machine-readable instructions executable by a special purpose apparatus to permit a particular task access to a non-locked portion of a sharable memory to be capable of being accessed by multiple tasks concurrently with respect to the sharable memory,

wherein the instructions are further executable by the special purpose apparatus to;

determine a state of a flag for the non-locked portion of the sharable memory; and

at least partially in response to performance of read and write operations on the non-locked portion of the sharable memory and a determination that the state of the flag is to comprise a default state;

to increment a counter to track a number of concurrent tasks to access the non-locked portion of the sharable memory;

to access the non-locked portion of the sharable memory to execute a portion of a particular task to read from the non-locked portion of the sharable memory at a time at which the non-locked portion of the sharable memory is accessible by more than one of the concurrent tasks to perform one or more read operations at least partially in response to an evaluation of an existence of a current performance of other tasks to perform one or more read operations from the non-locked portion of the sharable memory to be based, at least in part, on a value to be stored in the counter;

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

at least partially in response to a determination that the state of the flag is to comprise a non-default state;

to wait until the state of the flag is to be changed to comprise the default state;

access the non-locked portion of the sharable location to comprise an additional particular task while the non-locked portion of the sharable memory is to be unlocked; and

wherein at least partially in response to a determination that the state of the flag is to comprise the default state and a determination that the additional particular task is to involve a write operation to the non-locked portion of the shared memory;

toggle the state of the flag to the non-default state, and

wait to perform the additional particular task until the counter tracking the number of concurrent tasks has a value of zero.

16. The article of claim 15, wherein the instructions, to read from the non-locked portion of the sharable memory, are further executable by the special purpose apparatus to read state content to be stored in memory locations of the sharable memory.

17. The article of claim 16, wherein the instructions are further executable by the special purpose apparatus to re-toggle the state of the flag so that the flag is to comprise the default state;

and further executable to;

increment a counter to track the number of concurrent tasks to read from the non-locked portion of the sharable memory;

read from the non-locked portion of the sharable memory; and

decrement the counter after completion of the read operation.

18. The article of claim 15, wherein the instructions are further executable by the special purpose apparatus 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 non-locked portion of the sharable memory;

write state content to memory locations of the portion of the sharable memory if a value of the counter is to comprise a zero value; and

otherwise wait until the state of the counter is to comprise a zero value and then to write to the non-locked portion of the sharable memory.

19. The article of claim 15, wherein the instructions are further executable by the special purpose apparatus 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 by the special purpose apparatus to access the non-locked portion of the sharable memory over a network remote from the special purpose apparatus.