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

• US 20050044551A1
• Filed: 08/19/2004
• Published: 02/24/2005
• Est. Priority Date: 08/19/2003
• Status: Active Grant

• Current Assignee: Toshiba Corporation, Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Corporation, Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: Sodhi, Ajit S.
• Granted Patent: US 7,308,688 B2
• Time in Patent Office: Days
• 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;

a shared memory for selectively storing shared data 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 each process further comprises a template generator, which template generator sets forth a message template specifying a format acceptable to that process;

and further comprising;

means adapted for communicating the message template to at least one other of the plurality of processes.

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

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

5. The system for peer-based inter-process communication of claim 3, wherein the header component further comprises information representative of a next element used when adding an element to the shared memory.

6. The system for peer-based inter-process communication of claim 3, wherein the header component further comprises information representative of a next element used when retrieving an element from the shared memory.

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

8. 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.

9. 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.

10. 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;

selectively storing shared data 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.

11. The method for peer-based inter-process communication of claim 10 further comprising the steps of:

generating a message template specifying a format acceptable to a process; and

communicating the message template to at least one other of the plurality of processes.

12. The method for peer-based inter-process communication of claim 11, wherein the message template further comprises a header component.

13. The method for peer-based inter-process communication of claim 12, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

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

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

16. The method for peer-based inter-process communication of claim 12, wherein the header component further comprises information representative of a number of used elements in the shared memory.

17. The method for peer-based inter-process communications of claim 10 further comprising the step of determining a number of the plurality of processes accessing the shared memory.

18. The method for peer-based inter-process communications of claim 10 further comprising the step of resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.

19. A computer readable medium of instructions for peer-based inter-process communication comprising:

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

instructions for selectively storing shared data in a shared memory accessible by each of the plurality of processes;

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

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

20. The computer readable medium of instructions for peer-based inter-process communication of claim 19 further comprising:

instructions for generating a message template specifying a format acceptable to a process; and

instructions for communicating the message template to at least one other of the plurality of processes.

21. The computer readable medium of instructions for peer-based inter-process communication of claim 20, wherein the message template further comprises a header component.

22. The computer readable medium of instructions for peer-based inter-process communication of claim 21, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

23. The computer readable medium of instructions for peer-based inter-process communication of claim 21, wherein the header component further comprises information representative of a next element used when adding an element to the shared memory.

24. The computer readable medium of instructions for peer-based inter-process communication of claim 21, wherein the header component further comprises information representative of a next element used when retrieving an element from the shared memory.

25. The computer readable medium of instructions for peer-based inter-process communication of claim 21, wherein the header component further comprises information representative of a number of used elements in the shared memory.

26. The computer readable medium of instructions for peer-based inter-process communications of claim 19 further comprising instructions for determining a number of the plurality of processes accessing the shared memory.

27. The computer readable medium of instructions for peer-based inter-process communications of claim 19 further comprising instructions for resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.

28. 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;

selectively storing shared data 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.

29. The computer implemented method for peer-based inter-process communication of claim 28 further comprising the steps of:

generating a message template specifying a format acceptable to a process; and

communicating the message template to at least one other of the plurality of processes.

30. The computer implemented method for peer-based inter-process communication of claim 29, wherein the message template further comprises a header component.

31. The computer implemented method for peer-based inter-process communication of claim 30, wherein the header component further comprises information representative of a maximum number of elements in the shared memory.

32. The computer implemented method for peer-based inter-process communication of claim 30, wherein the header component further comprises means adapted for designating a next element used when adding an element to the shared memory.

33. The computer implemented method for peer-based inter-process communication of claim 30, wherein the header component further comprises means adapted for designating a next element used when retrieving an element from the shared memory.

34. The computer implemented method for peer-based inter-process communication of claim 30, wherein the header component further comprises means adapted for indicating a number of used elements in the shared memory.

35. The computer implemented method for peer-based inter-process communications of claim 28 further comprising the step of determining a number of the plurality of processes accessing the shared memory.

36. The computer implemented method for peer-based inter-process communications of claim 28 further comprising the step of resetting the shared memory to initialize the memory, wherein the stored shared data is deleted.