System and method for communication between windowing environments

• US 5,313,581 A
• Filed: 09/28/1993
• Issued: 05/17/1994
• Est. Priority Date: 09/14/1990
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Giokas, Dennis G., Leskowitz, Andrew T.
• Primary Examiner(s): Shaw, Dale M.
• Assistant Examiner(s): DINH, DUNG C
• Application Number:
  US08/128,031
• Time in Patent Office: 231 Days
• Field of Search: 395/200, 395/500, 395/157, 395/650, 395/700, 340/706
• US Class Current: 719/329
• CPC Class Codes: G06F 9/452 Remote windowing, e.g. X-Window System, desktop virtualisation protocols for virtual reality H04L67/131
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06F 9/543 User-generated data transfer, e.g. clipboards, dynamic data exchange [DDE], object linking and embedding [OLE]
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A communication client is connected to multiple display servers. When a client of one of the display servers issues a communication, the communication client notes the communication in the display server coupled to the client and relays the communication to the other servers for use by clients of the other servers.

Claims

1. In a computer system having a display server connected to a first server and a second server, said first server with a first communications facility for providing communication between clients of the first server, and said second server with a second communication facility for providing communication between clients of the second server, a method of operating said display server, comprising the steps of:

providing a shared communication client of both the first and second servers;

receiving, by the shared communication client, a first communication transmitted by the first client to the first communication facility of the first server;

sending, to the second communication facility of the second server, a notification for the second client of the first communication from the first client;

detecting said notification by said display server to confirm that said second client has received said first communication from said first client;

the first server having a first communication data base which may be controlled at each instance by only one of the clients of the first server, and the method further includes the steps of

taking control of the first communication data base by the shared communication client, and wherein the step of receiving the first communication transmitted by the first client includes the substeps of

receiving a first server event indicating that the first client has taken control of the first communication data base and that the shared communication client no longer has control;

requesting, in response to the receipt of the first server event, the contents of the first communication data base from the first client;

receiving from the first client, after the request of the contents of the first communication data base, the contents of the first communication data base; and

recovering control of the first communication data base by the shared communication client.

2. A method according to claim 1, wherein the second server has a second communication data base for which one of the clients of the second server may be sent an event when the contents of the second communication data base changes, wherein the method further includes the step of

designating the shared communication client as the client of the second server to be sent an event when the contents of the second communication data base changes;

and

wherein the step of receiving notification of the second communication transmitted by the second client includes the substep of

receiving a second server event indicating that the second client has changed the second communication data base.

3. A method according to claim 1, wherein the second server has a second communication data base, and wherein the step of sending notification of the first communication transmitted by the first client includes the substeps of

writing data into the second communication data base in accordance with the contents of the first communication data base received from the first client.

4. A method according to claim 3, wherein the step of sending notification of the second communication transmitted by the second client includes the substeps of

receiving a first server event originating from the first client requesting the contents of the first communication data base;

and

sending the contents of the first communication data base to the first client.

5. A method according to claim 3, wherein the step of ending notification of the second communication transmitted by the second client includes the substeps of

receiving an first server event originating from the first client requesting that the contents of the first communication data base be stored in a buffer accessible to the first client;

storing, in response to the receipt of the first server event, the contents of the first communication data base in the buffer;

sending a request to the first server to notify the first client of the completion of the storage of the first communication data base contents in the buffer.

6. A method according to either of claims 1 or 2, further including the steps, performed by the first server, of

emulating the shared communication client in a process in which the facilities of the first server are implemented;

sending the emulated shared communication client a first server vent by calling a first entry point of the shared communication client.

7. The method according to either of claims 1 or 2, further including the steps, performed by the first server, of:

generating a first server event in response to a change in the status of the first server;

determining a set of clients to receive the first server event; and

calling, in response to receiving a first server event, a first entry point to emulate the shared communication client if the shared communication client is a member of the set of determined clients.

8. A method according to either of claims 1 or 2, wherein the second server provides centralized graphics functions to the second server clients through a second server protocol and wherein the method further includes the steps, performed by the first server, of:

providing centralized graphics functions to first server clients through a first protocol including the substep of

executing the protocol of the second server to function as one of the clients of the second server;

emulating the shared communication client in a process in which the graphics functions provided by the first server are implemented;

sending the emulated shared communication client a first server event by passing control to a first entry point; and

sending the emulated shared communication client a second server event by passing control to a second entry point to the shared communication client.

9. A method according to claim 8, further including the step, performed by the emulated shared communication client, of receiving an event by returning control to the first server.

10. A method according to either of claims 1 or 2, wherein the first server provides centralized graphics functions to the first server clients through a first server protocol, and further including the steps, performed by the second server, of

providing centralized graphics functions to second server clients through a second protocol including the substep of executing the protocol of the first server to function as one of the clients of the first server;

emulating the shared communication client in a process in which the graphics functions provided by the second server are implemented;

sending the shared communication client a first server event by setting the execution path to a first entry point to the shared communication client; and

sending the shared communication client a second server event by setting the execution path to a second entry point to the shared communication client.

11. A method according to claim 10, further including the step, performed by the emulated shared communication client, of receiving an event by returning control to the second server.

19. The method according to either of claims 1 or 2, further including the step of providing graphics wherein the step of providing graphics functions includes the substeps of

receiving a request for a graphics operation from the selected first server client, and

executing the graphics operation request;

wherein an emulation of the shared communication client is interleaved with the performance of the step of the execution of the graphics operation request.

12. In a computer system having a display server connected to a first server and a second server, said first server with a first communications facility for providing communication between clients of the first server, and said second server with a second communication facility for providing communication between clients of the second server, a method of operating said display server, comprising the steps of:

providing a shared communication client of both the first and second servers;

receiving, by the shared communication client, a first communication transmitted by the first client to the first communication facility of the first server;

sending, to the second communication facility of the second server, a notification for the second client of the first communication from the first client;

detecting said notification by said display server to confirm that said second client has received said first communication from said first client;

the first server having a first communication data base which may be controlled at each instance by only one of the clients of the first server, and the wherein the method further includes the steps, performed by the first server, of

emulating the shared communication client in a process in which the facilities of the first server are implemented; and

sending a first server event to the shared communication client by calling a first entry point to the shared communication client, thereby indicating that the first client has asserted control of the first communication data base, and wherein the method further includes the steps, performed by the shared communication client, of

receiving the first server event indicating that the first client has asserted control of the first communication data base;

requesting, in response to the receipt of the first server sent, the contents of the first communication data base from the first client; and

receiving from the first client, after the request of the contents of the first communication data base, the contents of the first communication data base.

13. A method according to claim 12, wherein the second server has a second communication data base for which one of the clients of the second server may be sent an event when the contents of the second communication data base changes, wherein the method further includes the step, performed by the shared communication client, of

designating the shared communication client as the client of the second server to be sent an event when the contents of the second communication data base changes, and

wherein the step of receiving notification of the second communication transmitted by the second client includes the substep of

receiving a second server event indicating that the second client has changed the second communication data base.

14. The method according to either of claims 12 or 13, further including the steps, performed by the first server, of

generating a first server event in response to a change in the status of the first server;

determining a set of clients to receive the first server event; and

calling, in response to the receiving step, a first entry point to emulate the shared communication client if the shared communication client is a member of the set of determined clients.

15. A method according to either of claims 12 or 13, wherein the second server provides centralized graphics functions the second server clients through a second server protocol, and wherein the method further includes the steps, performed by the first server, of

providing centralized graphics functions to first server clients through a first protocol including the substep of

executing the protocol of the second server to function as one of the clients of the second server;

emulating the shared communication client in a process in which the graphics functions provided by the first server are implemented;

sending the emulated shared communication client a first server event by passing control to a first entry point; and

sending the emulated shared communication client a second server event by passing control to a second entry point to the shared communication client.

16. A method according to claim 15, further including the step, performed by the emulated shared communication client, of receiving an event by returning control to the first server.

17. A method according to either of claims 12 or 13, wherein the first server provides centralized graphics functions to the first server clients through a first server protocol, and further including the steps, performed by the second server, of:

providing centralized graphics functions to second server clients through a second protocol including the substep of executing the protocol of the first server to function as one of the clients of the first server;

emulating the shared communication client in a process in which the graphics functions provided by the second server are implemented;

sending the shared communication client a first server event by setting the execution path to a first entry point to the shared communication point; and

sending the emulated shared communication client a second server event by setting the execution path to a second entry point to the shared communication client.

18. A method according to claim 17, further including the step, performed by the emulated shared communication client, of receiving an event by returning control to the second server.

20. A computer system for providing communication mechanisms to clients comprising:

a display server;

a first server processor, connected to said display server, for responding to communication operations requests generated by a first one of the clients of the first server processor, the first server processor including

a first communication facility for communicating between clients of the first server;

a second server processor, connected to said display server, for responding to the communication operations requests generated by a second one of the clients of the second server processor, the second server processor including

a second communication facility for communication between clients of the second server; and

a shared communication client, coupled to the first server processor as a client and to the second server processor as a client, including

means for receiving a first communication transmitted by the first client to the first communication facility of the first server; and

means, coupled to the receiving means, for sending to the second communication facility of the second server a notification for the second client of the first communication from the first client; and

means to detect in said display server said notification to confirm receipt of said notification from said first server to said second server;

wherein the first server processor includes

a first communication data base which may be controlled at each instance by only one of the clients of the first server processor, wherein the shared communication client further includes

means for taking control of the first communication data base by the shared communication client, and wherein the means for receiving the first communication transmitted by the first client includes

means for receiving a first server processor event indicating that the first client has taken control of the first communication data base and that the shared communication client no longer has control;

means for requesting, responsive to the means for receiving the first server processor event, the contents of the first communication data base from the first client;

means for receiving from the first client, after the request of the contents of the first communication data base, the contents of the first communication data base; and

means for recovering control of the first communication data bases by the shared communication client.

21. A system according to claim 20, wherein the second server processor includes

a second communication data base for which one of the clients of the second server processor may be sent an event when the contents of the second communication data base changes, wherein the shared communication client further includes

means for designating the shared communication client as the client of the second server processor to be sent an event when the contents of the second communication data base changes, and wherein the means for receiving notification of the second communication transmitted by the second client includes

means for receiving a second server processor event indicating that the second client has changed the second communication data base.

22. A system according to claim 20, wherein the second server processor includes

a second communication data base, and wherein the means for sending notification of the first communication transmitted by the first client includes

means for writing data into the second communication data base in accordance with the contents of the first communication data base received from the first client.

23. A system according to claim 22, wherein the means for sending notification of the second communication transmitted by the second client includes

means for receiving a first server processor event originating from the first client requesting the contents of the first communication data base;

and

means for sending the contents of the first communication data base to the first client.

24. A system according to claim 22, wherein the means for sending notification of the second communication transmitted by the second client includes

means for receiving an first server processor event originating from the first client requesting that the contents of the first communication data base be stored in a buffer accessible to the first client;

means, responsive to the means for receiving the first server processor event, for storing the contents of the first communication data base in the buffer;

means for sending a request to the first server processor to notify the first client of the completion of the storage of the first communication data base contents in the buffer.

25. A system according to either of claims 20 or 21, wherein the first server processor includes

means for emulating the shared communication client in a process in which other facilities of the first server processor are implemented;

and

means for sending the emulated shared communication client a first server processor event by calling a first entry point of the shared communication client.

26. The system according to either of claims 20 or 21, wherein the first server processor includes

means for generating a first server processor event in response to a change in the status of the first server processor;

means for determining a set of clients to receive the first server processor event; and

means for calling, responsive to the means for determining, first entry point to emulate the shared communication client if the shared communication client is a member of the set of determined clients.

27. A system according to either of claims 20 or 21, wherein the second server processor includes

means for providing centralized graphics functions to the second server processor clients through a second server processor protocol including

means for providing centralized graphics functions to first server processor clients through a first protocol including

means for executing the protocol of the second server processor to function as one of the clients of the second server processor;

means for emulating the shared communication client in a process in;

which the graphics functions provided by the first server processor are implemented;

means for sending the emulated shared communication client a first server processor event by passing control to a first entry point; and

means for sending the emulated shared communication client a second server processor event by passing control to a second entry point of the shared communication client.

28. A system according to claim 27, wherein the emulated shared communication client further includes means for receiving an event by returning control to the first server processor.

29. A system according to either of claims 20 or 21, wherein the first server processor includes

means for providing centralized graphics functions to the first server processor clients through a first server processor protocol, and wherein the second server processor further includes

means for providing centralized graphics functions to the second server processor clients through a second protocol include;

and

means for executing the protocol of the first server processor to function as one of the clients of the first server processor;

means for emulating the shared communication client in a process in;

which the graphics functions provided by the second server processor are implemented;

means for sending the shared communication client a first server processor event by setting the execution path to a first entry point to the shared communication client; and

means for sending the shared communication client a second server processor event by setting the execution path to a second entry point to the shared communication client.

30. A system according to claim 29, wherein the emulated shared communication client further includes means for receiving an event by returning control to the second server processor.

38. The system according to either of claims 20 or 21, further including

means for providing graphics functions to a selected one of the first server processor clients including

a first procedure composed of a first set of interrelated computer instructions;

wherein a means for emulating a shared communication client includes a second procedure composed of a second set of interrelated computer instructions interspersed with the first set of computer instructions.

31. A computer system for providing communication mechanisms to clients comprising:

a display server;

a first server processor, connected to said display server, for responding to communication operations requests generated by a first one of the clients of the first server processor, the first server processor including

a first communication facility for communicating between clients of the first server;

a second server processor, connected to said display server, for responding to the communication operations requests generated by a second one of the clients of the second server processor, the second server processor including

a second communication facility for communication between clients of the second server; and

a shared communication client, coupled to the first server processor as a client and to the second server processor as a client, including

means for receiving a first communication transmitted by the first client to the first communication facility of the first server; and

means, coupled to the receiving means, for sending to the second communication facility of the second server a notification for the second client of the first communication from the first client;

means to detect in said display server said notification to confirm receipt of said notification from said first server to said second server;

the first server processor including;

a first communication data base which may be controlled at each instance by only one of the clients of the first server processor, and the first server processor further includes

means for emulating the shared communication client in a process in which other facilities of the first server processor are implemented;

means for sending a first server processor event to the shared communication client, by calling a first entry point to the shared communication client, indicating that the first client has asserted control of the first communication data base, and the shared communication client further includes

means for receiving a first server processor event indicating that the first client has asserted control of the first communication data base;

means for requesting, responsive to the means for receiving the first server processor event, the contents of the first communication data base from the first client; and

means for receiving from the first client, after the request of the contents of the first communication data base, the contents of the first communication data base.

32. A system according to claim 31, wherein the second server processor includes

a second communication data base for which one of the clients of the second server processor may be sent an event when the contents of the second communication data base changes, wherein the shared communication client further includes

means for designating the shared communication client as the client of the second server processor to be sent an event when the contents of the second communication data base changes, and wherein the means for receiving notification of the second communication transmitted by the second client includes

means for receiving a second server processor event indicating that the second client has changed the second communication data base.

33. The system according to either of claims 31 or 32, wherein the first server processor further includes

means for generating a first server processor event in response to a change in the status of the first server processor;

means for determining a set of clients to receive the first ever processor event; and

means for calling, responsive to the means for determining, first entry point to emulate the shared communication client if the shared communication client is a member of the set of determined clients.

34. A system according to either of claims 31 or 32, wherein the second server processor includes

means for providing centralized graphics functions to the second server processor clients through a second server processor protocol, and

wherein the first server processor further includes means for providing centralized graphics functions to first server processor clients through a first protocol including means for executing the protocol of the second server processor to function as one of the clients of the second server processor;

means for emulating the shared communication client in a process in;

which the graphics functions provided by the first server processor are implemented;

means for sending the emulated shared communication client a first server processor event by passing control to a first entry point; and

means for sending the emulated shared communication client a second server processor event by passing control to a second entry point of the shared communication client.

35. A system according to claim 34, wherein the emulated shared communication client further includes means for receiving an event by returning control to the first server processor.

36. A system according to either of claims 31 or 32, wherein the first server processor includes

means for providing centralized graphics functions to the first server processor clients through a first server processor protocol, and

wherein the second server processor further includes

means for providing centralized graphics functions to the second server processor clients through a second protocol including

means for executing the protocol of the first server processor to function as one of the clients of the first server processor;

means for emulating the shared communication client in a process in which the graphics functions provided by the second server processor are implemented;

means for sending the shared communication client a first server processor event by setting the execution path to a first entry point to the shared communication client; and

means for sending the shared communication client a second server processor event by setting the execution path to a second entry point to the shared communication client.

37. A system according to claim 36, wherein the emulated shared communication client further includes means for receiving an event by returning control to the second server processor.