Dual process display server

• US 5,321,808 A
• Filed: 03/20/1992
• Issued: 06/14/1994
• Est. Priority Date: 03/20/1992
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Company (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Rupp, Lawrence E.
• Primary Examiner(s): RICHARDSON, ROBERT
• Application Number:
  US07/855,188
• Time in Patent Office: 816 Days
• Field of Search: 395/162-166, 340/721, 340/723, 340/747
• US Class Current: 345/502
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

A dual process display server comprising a first memory; a second memory; a first process for receiving requests from a client program, dispatching client requests falling within a first prescribed category of requests, storing in the first memory requests falling within a second prescribed category of requests and storing in the second memory messages associated with requests stored in the first memory; and a second process for retrieving messages from the second memory, retrieving client requests from the first memory, and dispatching requests retrieved from the first memory in accordance with messages retrieved from the second memory.

Claims

1. A dual process display server, comprising:

(a) a first memory;

(b) a second memory;

(c) a first process comprising means for

receiving requests from a client program, first request dispatcher means for dispatching client requests falling within a first prescribed category of requests, and second request dispatcher means for storing in said first memory requests falling within a second prescribed category of requests and for storing in said second memory messages associated with requests stored in said first memory; and

(d) a second process comprising means for retrieving messages from said second memory, means for retrieving client requests from said first memory, and message dispatcher means for dispatching requests retrieved from said first memory in accordance with messages retrieved from said second memory.

2. A dual process display server as recited in claim 1, further comprising a third memory, means associated with said second process for storing messages in said third memory, and second message dispatcher means associated with said first process for retrieving messages from said third memory and dispatching said messages.

3. A dual process display server as recited in claim 2, wherein said second request dispatching means comprises means for carrying out the following steps in response to the receipt of a request from a client:

(1) determining whether said second process is idle;

(2) enqueueing said request if said second process is not idle;

(3) if said second process is idle, storing said request in said first memory and storing in said second memory a message indicating that said request has been stored in said first memory; and

(4) blocking further requests from that client.

4. A dual process display server as recited in claim 3, wherein said server is adapted to operate in an X Window environment, said first category encompasses core X Window requests and said second category encompasses PEX requests.

5. A dual process display server as recited in claim 4, further comprising means for unblocking a client that has issued a PEX request upon said second process completing the servicing of that PEX request.

6. A computer graphics system, comprising:

(a) a local area network bus;

(b) a plurality of computers each of which is coupled to said bus and programmed to operate as an X Window System client program;

(c) a raster display; and

(d) a dual process display server coupled to said bus and said raster display, said dual process display server comprising;

(1) a first memory;

(2) a second memory;

(3) a first process comprising means

for receiving requests from said client programs, first request dispatcher means for dispatching client requests falling within a first prescribed category of requests, and second request dispatcher means for storing in said first memory requests falling within a second prescribed category of requests and storing in said second memory messages associated with requests stored in said first memory; and

(4) a second process comprising means for retrieving messages from said second memory, means for retrieving client requests from said first memory, and message dispatcher means for dispatching requests retrieved from said first memory in accordance with messages retrieved from said second memory.

7. A computer graphics system as recited in claim 6, further comprising a third memory, means associated with said second process for storing messages in said third memory, and second message dispatcher means associated with said first process for retrieving messages from said third memory and dispatching said messages.

8. A computer graphics system as recited in claim 7, wherein said second request dispatching means comprises means for carrying out the following steps in response to the receipt of a request from a client:

(1) determining whether said second process is idle;

(2) enqueueing said request if said second process is not idle;

(3) if said second process is idle, storing said request in said first memory and storing in said second memory a message indicating that said request has been stored in said first memory; and

(4) blocking further requests from that client.

9. A computer graphics system as recited in claim 8, wherein said first category encompasses core X Window requests and said second category encompasses PEX requests.

10. A computer graphics system as recited in claim 9, further comprising means for unblocking a client that has issued a PEX request upon said second process completing the servicing of that PEX request.

11. A method for servicing client requests in a computer graphics system operating in accordance with an X Window protocol, comprising the steps of:

(a) receiving requests from a client program into a first process;

(b) dispatching via said first process client requests falling within a first prescribed category of requests;

(c) storing in a first memory, via said first process, requests falling within a second prescribed category of requests;

(d) storing in a second memory, via said first process, messages associated with requests stored in said first memory;

(e) retrieving messages from said second memory into a second process;

(f) retrieving client requests from said first memory into said second process; and

(g) dispatching, via said second process, requests retrieved from said first memory in accordance with messages retrieved from said second memory.

12. A method as described in claim 11, further comprising the steps of storing messages from said second process in a third memory, and retrieving messages from said third memory into said first process and dispatching said messages via said first process.

13. A method as described in claim 12, further comprising carrying out the following steps in response to the receipt from a client of a message falling within said second category:

(1) determining whether said second process is idle;

(2) enqueueing said request if said second process is not idle;

(3) if said second process is idle, storing said request in said first memory and storing in said second memory a message indicating that said request has been stored in said first memory; and

(4) blocking further requests from that client.

14. A method as described in claim 13, wherein said first category encompasses core X Window requests and said second category encompasses PEX requests.

15. A method as described in claim 14, further comprising the step of unblocking a client that has issued a PEX request upon said second process completing the servicing of that PEX request.