Synchronization with partial memory replication

• US 20080126322A1
• Filed: 10/05/2007
• Published: 05/29/2008
• 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:
  US11/973,330
• Publication Number:
  US 20080126322A1
• Time in Patent Office: Days
• US Class Current: 707/3
• CPC Class Codes: G06F 2209/522 Manager
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A multiple computer system is disclosed in which the local memory of each computer (M1, M2, . . . Mn) can be different having some memory locations (A, B) which are replicated in other computers and other memory locations (E) which are not. When any computer seeks to acquire or release a synchronizing lock a check (171, 181) is made to see if the relevant memory location is present on any other machine. If yes, synchronization is carried out. However, if no, then no synchronization is required and the synchronizing procedures are by-passed

Claims

1. In a multiple computer environment in which a plurality of computers are all interconnected via a communications network and substantially simultaneously execute corresponding different portions of an application program written to be executed only on a single computer, and in which each of said plurality of computers has an independent local memory which is not necessarily identical, the improvement comprising a particular method of controlling the acquiring and/or releasing of a synchronizing lock comprising the steps of:

(i) prior to acquiring or releasing a synchronizing lock on a specific local memory location checking to determine if that memory location is replicated in the local memory of any other computer; and

(ii) by-passing acquiring or releasing said synchronizing lock only if said specific memory location is not replicated on at least one other computer.

2. The method as in claim 1, including the further step of:

(iii) carrying out step (i) including by consulting a look-up table listing said memory locations and said computers.

3. The method as in claim 2, including the further step of:

(iv) maintaining said look-up table in a server computer.

8. At least one computer configured to carry out the method as in claim 1.

9. The at least one computer as defined in claim 8, wherein said at least one computer comprises a plurality of interconnected computers.

4. A computer program stored in a computer readable media, the computer program including executable computer program instructions and 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 in a single computer for use in cooperation with at least one other computer in a multiple computer environment in which a plurality of computers are all interconnected via a communications network and substantially simultaneously execute corresponding different portions of an application program written to be executed only on a single computer, and in which each of said plurality of computers has an independent local memory which is not necessarily identical;

the modification of operation including performing a method of controlling the acquiring and/or releasing of a synchronizing lock, said method comprising;

(i) prior to acquiring or releasing a synchronizing lock on a specific local memory location checking to determine if that memory location is replicated in the local memory of any other computer; and

(ii) by-passing acquiring or releasing said lock only if said specific memory location is not replicated on at least one other computer.

5. The computer program product as in claim 4, wherein the method including the further step of:

(iii) carrying out step (i) including by consulting a look-up table listing said memory locations and said computers.

6. The computer program product as in claim 5, wherein the method including the further step of:

(iv) maintaining said look-up table in a server computer.

7. A synchronizing lock data structure for use in a multiple computer system having a plurality of network interconnected computers, the synchronizing lock data structure comprising:

a look-up table storing a plurality of memory location identifiers for independent local memory locations in each of a plurality of computers; and

a replication indicator for indicating if a memory location for which it is desired to acquire or release a synchronizing lock is then currently replicated in the local memory of any other one of the plurality of computers.