Contention detection with modified message format

• US 20080130631A1
• Filed: 10/05/2007
• Published: 06/05/2008
• Est. Priority Date: 10/05/2006
• Status: Abandoned Application

• Current Assignee: John M. Holt
• Original Assignee: John M. Holt
• Inventors: Holt, John M.
• Application Number:
  US11/973,392
• Publication Number:
  US 20080130631A1
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

A multiple computer system is disclosed in which n computers (M1, M2 . . . Mn) each run a different portion of a single application program written to execute only on a single computer. The local memory of each computer is maintained substantially the same by updating all computers with every change made to addressed memory locations. Contention can arise when the same memory location is substantially simultaneously updated by two or more machines because of transmission delays and latency of the communications network interconnecting all the computers. In particular a method of broadcast memory updating with contention detection and resolution is disclosed which utilizes either a single or plural count value(s) and/or single or plural resolution value(s) for multiple memory locations. The count value is indicative of the number of the sequence of occasions on which a memory location has been updated. Contention is indicated if the currently stored count value and the incoming updating count value are the same.

Claims

1. A system for broadcasting an addressed memory updating signal or packet over a communications network interconnecting a plurality of computers, each said computer executing a different portion of an applications program written to execute on a single computer, and each having an independent local memory with at least one memory location being replicated in each said local memory said system comprising:

at least one replicated memory location being replicated in each said local memory having a specific location identifier in each said computer;

a plurality of sources each of which can update said replicated memory location(s) and each of which utilizes an updating format for the signal or packet carrying out the updating;

said updating format comprising;

(i) the specific identifier of each replicated memory location to be updated, (ii) the content with which said each replicated memory location is to be updated, and (iii) at least one updating count of the updating source, the or each said updating count comprising a number indicative of the sequence of occasions on which the updating source has been updated inclusive of the current updating, and (iv) at least one resolution value of the updating source, each said resolution value comprising a unique value of the updating source.

2. A method of broadcasting a memory updating signal or packet over a communications network interconnecting a plurality of computers each executing a different portion of an application program written to execute on a single computer, and each having an independent local memory with at least one addressed memory location being replicated in each said local memory, each of which has a specific location identifier and can be updated substantially simultaneously from a plurality of sources, said method of broadcasting a memory updating signal or packet comprising:

utilizing an updating format for the signal or packet carrying out the updating; and

said updating format comprising;

(i) the specific identifier of each memory location to be updated, (ii) the content with which said each memory location is to be updated, and (iii) at least one updating count of the updating source;

each said updating count comprising a number indicative of the sequence of occasions on which the updating source has been updated inclusive of the current updating; and

at least one resolution value of the updating source, each said resolution value comprising a unique value of the updating source.

3. The method of broadcasting a memory updating signal or packet as in claim 2, wherein:

the specific identifier of each memory location to be updated comprises the specific identifier of at least two replicated memory locations to be updated;

the content with which said each memory location is to be updated comprises the content with which said each replicated memory location is to be updated;

the at least one updating count of the updating source comprises one updating count of the updating source for all said replicated memory locations; and

the number indicative of the sequence of occasions on which the updating source has been updated comprises a number indicative of the highest magnitude sequence of occasions on which all said replicated memory locations have been updated inclusive of the current updating.

4. A computer program stored in a computer readable media, the computer program adapted for execution in a processor within a computer or information appliance and a memory coupled with the processor to modify the operation of the computer or information appliance, for modifying the operation of the computer or information appliance that is operating to send or receive a broadcast of a memory updating signal or packet over a communications network interconnecting a plurality of computers each executing a different portion of an application program written to execute on a single computer, and each having an independent local memory with at least one addressed memory location being replicated in each said local memory, each of which has a specific location identifier and can be updated substantially simultaneously from a plurality of sources, said modification including performing a method of broadcasting a memory updating signal or packet comprising

utilizing an updating format for the signal or packet carrying out the updating;

said updating format comprising;

(i) the specific identifier of each memory location to be updated, (ii) the content with which said each memory location is to be updated, and (iii) at least one updating count of the updating source;

each said updating count comprising a number indicative of the sequence of occasions on which the updating source has been updated inclusive of the current updating; and

at least one resolution value of the updating source, each said resolution value comprising a unique value of the updating source.

5. A method of broadcasting a memory updating signal or packet over a communications network interconnecting a plurality of computers each executing a different portion of an application program written to execute on a single computer, and each having an independent local memory with at least one addressed memory location being replicated in each said local memory, each of which has a specific location identifier and can be updated substantially simultaneously from a plurality of sources, said method of broadcasting a memory updating signal or packet comprising:

utilizing an updating format for the signal or packet carrying out the updating;

said format comprising;

(i) the specific identifier of at least two replicated memory locations to be updated, (ii) the content with which said each replicated memory location is to be updated, and (iii) one updating count of the updating source for all said replicated memory locations;

said one updating count comprising a number indicative of the highest magnitude sequence of occasions on which all said replicated memory locations have been updated inclusive of the current updating, and at least one resolution value of the updating source; and

said resolution value comprising a unique value of the updating source.

6. An updating data structure format of a signal or packet of information for carrying out a memory updating process among a plurality of computers, the updating format for a signal or packet comprising:

(i) the specific identifier of each memory location to be updated;

(ii) the content with which said each memory location is to be updated; and

(iii) at least one updating count of the updating source;

each said updating count comprising a number indicative of the sequence of occasions on which the updating source has been updated inclusive of the current updating, and at least one resolution value of the updating source, each said resolution value comprising a unique value of the updating source.

7. The format for a signal or packet carrying out a memory updating process amount a plurality of computers as in claim 6, wherein:

a specific identifier of each memory location to be updated comprises the specific identifier of at least two replicated memory locations to be updated;

a content with which said each memory location is to be updated comprises the content with which said each replicated memory location is to be updated;

at least one updating count of the updating source comprises one updating count of the updating source for all said replicated memory locations; and

a number indicative of the sequence of occasions on which the updating source has been updated comprises a number indicative of the highest magnitude sequence of occasions on which all said replicated memory locations have been updated inclusive of the current updating.