System and method for shared memory based IPC queue template having event based notification

• US 7,308,688 B2
• Filed: 08/19/2004
• Issued: 12/11/2007
• Est. Priority Date: 08/19/2003
• Status: Expired due to Fees

• Current Assignee: Toshiba Corporation, Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: Sodhi, Ajit S.
• Primary Examiner(s): Thomson; William
• Assistant Examiner(s): Pantoliano, Jr.; Richard
• Application Number:
  US10/921,530
• Publication Number:
  US 20050044551A1
• Time in Patent Office: 1,209 Days
• Field of Search: 719/312, 370412-429
• US Class Current: 719/312
• CPC Class Codes: G06F 2209/548 Queue
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

This invention is directed to a system and method for using a template that allows a user to define a specific message format for use in a shared memory queue in the inter-process communication environment. A shared segment of the size needed to hold the supplied number of elements and a queue header are created. The system then unmaps the queue from the user'"'"'s address space. The queue contents are reset to initialize the state. The supplied element in the queue is Pushed. The element for the queue First-In/First-Out (FIFO) is Popped. An element from the queue may be returned, without affecting queue status. The element content in the queue is then updated. The queue is subsequently locked for exclusive access. The lock may be released, enabling changes to the queue. The system also provides the element count in the queue and the logical name of the inter-process communication queue. The shared memory based header maintained by each inter-process communication queue allows all the clients of the queue to access queue information from a single source.

Claims

1. A system for peer-based inter-process communication comprising:

a plurality of peer processes, each process including

a bus system for selectively communicating data between first and second processes of the plurality thereof;

means adapted for generating, via the first process, a shared memory message template in accordance with a format acceptable to each of a plurality of peer processes thereto;

means adapted for setting an initialization process identification value to the first process;

means adapted for communicating a generated shared memory message template to each of the plurality of peer processes; and

a shared memory for selectively storing shared data in accordance with the generated shared memory message template such that shared data associated therewith is accessible by each of the plurality of processes;

wherein each process includes notification means adapted for notifying at least one of the plurality of processes when a modification is made to content of the shared memory; and

wherein each process includes a locking mechanism for selectively locking the shared memory from access by at least one other process.

2. The system for peer-based inter-process communication of claim 1, wherein the shared memory message template further comprises a header component.

3. The system for peer-based inter-process communication of claim 2, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

4. The system for peer-based inter-process communication of claim 2, wherein the header component further comprises information representative of a next element used when adding an element to the shared memory.

5. The system for peer-based inter-process communication of claim 2, wherein the header component further comprises information representative of a next element used when retrieving an element from the shared memory.

6. The system for peer-based inter-process communication of claim 2, wherein the header component further comprises information representative of a number of used elements in the shared memory.

7. The system for peer-based inter-process communications of claim 1 further comprising means adapted for determining a number of the plurality of processes accessing the shared memory.

8. The system for peer-based inter-process communications of claim 1 further comprising means adapted for resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.

9. A method for peer-based inter-process communication performed in a system comprising a plurality of peer processes, wherein the method comprises the steps of:

selectively communicating data between a first and a second process of the plurality of peer processes;

generating, via the first process, a shared memory message template in accordance with a format acceptable to each of a plurality of peer processes thereto;

setting an initialization process identification value to the first process;

communicating a generated shared memory message template to each of the plurality of peer processes;

selectively storing shared data in accordance with the generated shared memory message template such that shared data associated therewith is in a shared memory accessible by each of the plurality of processes;

notifying at least one of the plurality of processes when a modification is made to content of the shared memory; and

selectively locking the shared memory from access by at least one other process.

10. The method for peer-based inter-process communication of claim 9, wherein the shared memory message template further comprises a header component.

11. The method for peer-based inter-process communication of claim 10, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

12. The method for peer-based inter-process communication of claim 10, wherein the header component further comprises information representative of a next element used when adding an element to the shared memory.

13. The method for peer-based inter-process communication of claim 10, wherein the header component further comprises information representative of a next element used when retrieving an element from the shared memory.

14. The method for peer-based inter-process communication of claim 10, wherein the header component further comprises information representative of a number of used elements in the shared memory.

15. The method for peer-based inter-process communications of claim 9 further comprising the step of determining a number of the plurality of processes accessing the shared memory.

16. The method for peer-based inter-process communications of claim 9 further comprising the step of resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.

17. A computer implemented method for peer-based inter-process communication performed in a system comprising a plurality of peer processes, wherein the method comprises the steps of:

selectively communicating data between a first and a second process of the plurality of peer processes;

generating, via the first process, a shared memory message template in accordance with a format acceptable to each of a plurality of peer processes thereto;

setting an initialization process identification value to the first process;

communicating a generated shared memory message template to each of the plurality of peer processes;

selectively storing shared data in accordance with the generated shared memory message template such that shared data associated therewith is in a shared memory accessible by each of the plurality of processes;

notifying at least one of the plurality of processes when a modification is made to content of the shared memory; and

selectively locking the shared memory from access by at least one other process.

18. The computer implemented method for peer-based inter-process communication of claim 17, wherein the shared memory message template further comprises a header component.

19. The computer implemented method for peer-based inter-process communication of claim 18, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

20. The computer implemented method for peer-based inter-process communication of claim 18, wherein the header component further comprises means adapted for designating a next element used when adding an element to the shared memory.

21. The computer implemented method for peer-based inter-process communication of claim 18, wherein the header component further comprises means adapted for designating a next element used when retrieving an element from the shared memory.

22. The computer implemented method for peer-based inter-process communication of claim 18, wherein the header component further comprises means adapted for indicating a number of used elements in the shared memory.

23. The computer implemented method for peer-based inter-process communications of claim 17 further comprising the step of determining a number of the plurality of processes accessing the shared memory.

24. The computer implemented method for peer-based inter-process communications of claim 17 further comprising the step of resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.