Distributed processing in a system of computers at terminals connected by a communication network

• US 5,555,427 A
• Filed: 08/19/1991
• Issued: 09/10/1996
• Est. Priority Date: 12/26/1989
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ryu, Tadamitsu, Kakehi, Gen, Aoe, Shigeru
• Primary Examiner(s): Bowler, Alyssa H.
• Assistant Examiner(s): Nguyen, Dzung C.
• Application Number:
  US07/743,390
• Time in Patent Office: 1,849 Days
• Field of Search: 395/800, 395/400, 395/425, 395/375, 395/600, 395/650, 395/725, 395/200, 364/DIG. 1, 364/DIG. 2
• US Class Current: 709/201
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548

Abstract

A system for distributing processing between terminals (T₁ ˜T_n) connected via a communication network (30). Each terminal (T_i) is provided with at least one method group (32) and a memory unit (34) to store data files. An originating terminal, e.g., terminal (T₁) accesses data elsewhere in the distributed system by generating a message. The message includes a terminal code identifying an object to access a terminal (T₂) to execute an object, a method code identifying a method for accessing the data and a command name containing or identifying the desired data. The terminal, e.g., terminal (T₂), containing the desired data, decodes the message and accesses a data file in the memory unit (34) containing the desired data identified by the command name. The message may also include a selector and reset conditions which control the sequence of data processing in the terminals (T₀ and T_n) so that the processing of the originating (T₁) and data accessing (T₂) terminals can be coordinated. When the processing identified by the method code is completed in the data accessing terminal (T₂), a message including the resulting data is sent from the data accessing terminal (T₂) to the originating terminal (T₁). Objects according to the present invention may contain a method without data and may be transmitted from one terminal to another as data. Thus, any application or operating system program can be replaced or added by transmitting an object containing that program as data.

Claims

1. A distributed processing system, comprising:

a communication network to transmit messages, including data; and

a plurality of terminals connected together by said communication network, each of said terminals capable of generating the messages, each of the messages having a terminal number for identifying one of said terminals to receive the message, a method code identifying processing of data and a command for identifying data to be processed, each of said terminals including

a memory unit to store objects, including methods, at least one of the objects including a learning method for learning the data and the methods of the objects;

a processor, operatively connected to said communication network, to execute the methods stored in said memory unit; and

a system table to store identifying information on the location and execution sequence of the methods stored in said memory unit, said processor updating said system table and the contents of said memory unit upon receipt of one of the messages from another terminal instructing said processor to execute the learning method stored in said memory unit.

2. A terminal in a distributed processing system, comprising:

object storage means for storing objects, including at least one object including a method;

system table means for storing identifying information on location and execution sequence of the objects stored in said object storage means; and

decomposing means for decomposing the method in one of the objects into byte data in response to a transfer request;

transfer means for transferring the byte data decomposed by said decomposing means to another terminal upon completion of the decomposing and for receiving an updated object requested to be transferred to said terminal; and

installation means for storing the updated object into said object storage means and for updating said system table means with an object name corresponding to the updated object.

3. A method for transferring programs in a distributed processing system executing objects in terminals, the objects inclusive of objects including a method, said method comprising:

(a) receiving a transfer request at a first terminal to transfer a selected object from the first terminal to a second terminal;

(b) decomposing the selected object into byte data in response to the transfer request;

(c) transferring the byte data decomposed in step (b) to the second terminal upon completion of said decomposing;

(d) receiving the byte data at the second terminal;

(e) composing the byte data to produce an updated object corresponding to the selected object requested to be transferred to the second terminal; and

(f) storing the updated object and an object name, corresponding to the updated object, in the second terminal.

4. A method as recited in claim 3, wherein said decomposing in step (b) comprises the step of selecting one of the method and data in the selected object for said transferring in step (c).

5. A message transmitted between objects in a distributed processing system having a plurality of terminals connected by a communication network, said message comprising:

a terminal number for identifying one of the terminals to receive said message;

a method code identifying processing of data; and

a command for identifying data to be processed, said command including a sequence file identifier identifying a sequence defined in a sequence file for executing objects, triggered by said message, in a defined order at a plurality of the terminals, said command including a selector condition and a reset condition when said method code identifies a common object, the selector condition determining how the common object executes and the reset condition determining how execution of the common object and any subsequent additional common objects ends.

6. A method for processing messages in a distributed processing system having a plurality of terminals connected by a communication network, said method comprising the steps of:

(a) determining in a first terminal, for a first message identifying a first object, whether the first object is stored in the first terminal;

(b) triggering the first object in the first terminal when said determining in step (a) determines that the first object is stored in the first terminal; and

(c) generating a second message to a second terminal to locate the first object when said determining in step (a) determines that the first object is not stored in the first terminal.

7. A method as recited in claim 6,

wherein all messages generated in the distributed processing system, including the second message generated in step (c), include a terminal number for identifying one of the terminals to receive the message and an object code, and

wherein said method further comprises the steps of:

(d) determining whether the object code includes a sequence file identifier; and

(e) executing sequence objects in a sequence determined by entries in a sequence file when said determining in step (d) determines that the object code includes the sequence file identifier.

8. A method as recited in claim 6,

wherein all messages generated in the distributed processing system, including the second message generated in step (c), include a terminal number for identifying one of the terminals to receive the message and an object code, and

wherein said method further comprises the steps of:

(d) storing common objects in at least one of the terminals;

(e) determining whether the object code includes a common object name, a selector condition and a reset condition;

(f) triggering a corresponding common object in dependence upon the common object name and the selector condition when said determining in step (e) determines that the object code includes the common object name, the selector condition and the reset condition; and

(g) ending execution of the common objects in dependence upon the reset condition when said determining in step (e) determines that the object code includes the common object name, the selector condition and the reset condition.

9. A method as recited in claim 8, wherein said triggering in step (f) comprises the steps of:

(f1) comparing the selector condition with predetermined selector conditions in the corresponding common object; and

(f2) executing condition steps in the corresponding common object identified by one of the predetermined selector conditions in dependence upon said comparing in step (f1).

10. A method as recited in claim 8, wherein said ending in step (g) comprises the steps of:

(g1) returning to the first object when the first message was determined in step (e) to contain the common object name of one of the common objects and the reset condition is set to return;

(g2) triggering a new sequence object when the reset condition is set to trigger; and

(g3) terminating execution of the common objects without returning or triggering when the reset condition is set to terminate.

11. A method as recited in claim 6, wherein all messages generated in the distributed processing system, including the second message generated in step (c), include a terminal number for identifying one of the terminals to receive the message, a method code identifying processing of data and a command for identifying data to be processed.

12. A method as recited in claim 11, wherein said determining in step (a) comprises comparing the terminal number identifying the first terminal with the terminal number in the first message.

13. A method as recited in claim 12, wherein said generating in step (c) comprises setting the terminal number in the second message equal to the terminal number in the first message when said comparing in step (a) determines that the terminal in the first message is not equal to the terminal number of the first terminal.

14. A method as recited in claim 13, further comprising the steps of:

(d) storing method codes of each of the objects stored in each of the terminals in a command link file in each of the terminals, respectively, and all of the method codes for all of the objects stored in all of the terminals in a master system table;

(e) comparing the method code in the first message with the method codes in the command link file for the first terminal when said comparing in step (a) determines that the terminal number of the first message is unknown;

(f) executing step (b) when said comparing in step (e) determines that the method code in the first message is included in the message codes in the command link file for the first terminal; and

(g) generating a third message to access the master system table when said comparing in step (e) determines that the method code in the first message is excluded from the message codes in the command link file for the first terminal.

15. A method as recited in claim 6,

wherein said generating in step (c) comprises the step of (c1) generating the second message with a subset of a second object, and

wherein said method further comprises the steps of:

(d) storing command names associated with each of the objects stored in each of the terminals in a command link file in each of the terminals, respectively;

(e) storing the subset of the second object in the second terminal upon receipt of the second message at the second terminal; and

(f) storing a subset command name, corresponding to the subset of the second object, in the command link file of the second object.

16. A method as recited in claim 15, wherein said generating in step (c) further comprises the step of (c2) decomposing the second object into byte data prior to said generating in step (c1).

17. A method as recited in claim 16, wherein said generating in step (c2) comprises the step of transferring all of the byte data decomposed from the second object into the second message.

18. A method as recited in claim 16, wherein said generating in step (c2) comprises the step of transferring a method portion of the byte data decomposed from the second object into the second message.