Modified machine architecture with advanced synchronization

• US 20070101057A1
• Filed: 10/18/2006
• Published: 05/03/2007
• Est. Priority Date: 10/25/2005
• Status: Active Grant

• Current Assignee: Waratek Limited (Waratek Holdings Ltd.)
• Original Assignee: Waratek Pty Limited
• Inventors: Holt, John
• Granted Patent: US 7,761,670 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A multiple computer environment is disclosed in which an application program executes simultaneously on a plurality of computers (M1, M2, . . . Mn) interconnected by a communications network (53) and in which the local memory of each computer is maintained substantially the same by updating in due course. A lock mechanism is provided to permit exclusive access to an asset, object, or structure (ie memory location) by acquisition and release of the lock. In particular, before a new lock can be acquired by any other computer on a memory location previously locked by one computer, any re-written content(s) for the previously locked memory location are transmitted to all the other computers and their corresponding memory locations (before the in due course updating). Thus when the new lock is acquired all the corresponding memory locations of all computers have been updated.

Claims

1. In a multiple computer environment in which different portions of at least one application program each written to execute on only a single computer, each execute substantially simultaneously on a corresponding one of a plurality of computers, each having a local memory and each being interconnected via a communications network, and in which at least one memory location is replicated in the memory of each said plurality of computers, and after each occasion at which each said memory location has its contents written to, or re-written, with a new content, all said corresponding memory locations of said computers are in due course updated via said communications network with said new content, the further improvement comprising the steps of:

(i) prior to initially writing said new content, acquiring a lock on an object, asset or resource,

(ii) recording the name and updated content of said local memory locations written to prior to releasing said lock,

(iii) releasing said lock, and

(iv) prior to permitting the acquisition of the same lock by another one of said computers, transmitting said updated memory location(s) and updated content(s) to said another one computer, whereby any said computer on acquiring said lock has acquired said previously updated contents without needing to wait for said in due course updating of all said computers.

2. The improved method as claimed in claim 1 in which each said computer has an independent local memory accessible only by the corresponding portion of said application program.

3. The improved method as claimed in claim 1 in which the object, asset or resource locked is the object, asset or resource to which said new content is to be written.

4. The improved method as claimed in claim 3 including the further step of:

(v) transmitting in step (iv) all memory locations and contents updated in step (ii).

5. The improved method as claimed in claim 3 including the further step of:

(vi) transmitting in step (iv) all memory locations and only their final contents as updated in step (ii).

6. The improved method as claimed in claim 3 including the further steps of:

(vii) prior to acquiring said lock, detecting all applications program steps which potentially write to listed memory location(s), and

(viii) recording the name of said listed memory location(s) prior to releasing said lock.

7. The improved method as claimed claim 6 wherein said detecting all application program steps takes place either before loading, or during loading, or after loading but before execution of the relevant code.

8. The improved method as claimed in claim 6 wherein said recording of the name of said listed memory locations takes place either at the time of detection or at the time of execution of an detected program step.

9. The improved method as claimed in claim 6 including the further step of:

(ix) for each recorded memory location recording all contents updated in step (ii).

10. The improved method as claimed in claim 6 including the further step of:

(x) for each recorded memory location recording only the final contents as updated in step (ii).

19. A plurality of computers interconnected via a communications network and operable to ensure carrying out of the method as claimed in claim 1.

20. A computer program product comprising a set of program instructions stored in a storage medium and operable to permit a plurality of computers to carry out the method as claimed in claim 1.

11. A computer system comprising a plurality of computers each having a local memory and each being interconnected via a communications network wherein different portions of at least one application program each written to execute on only a single computer, each execute substantially simultaneously on a corresponding one of said plurality of computers, at least one memory location is replicated in the local memory of each said computer, said system further comprising updating means associated with each said computer to in due course update each said memory location via said communications network after each occasion at which each said memory location has its content written to, or re-written, with a new content, and lock means associated with each said computer to acquire a lock on an object, asset or resource, said lock means including a recording means in which is recorded the name and updated content of all said local memory locations written to prior to releasing said lock, and said lock means after releasing said lock and prior to permitting the acquisition of the same lock by another one of said computers transmitting said updated memory location(s) and updated content(s) to said another one computer, whereby any said computer on acquiring said lock has acquired said previously updated contents without needing to wait for said in due course updating of all said computers.

12. The computer system as claimed in claim 11 wherein each said computer has an independent local memory accessible only by the corresponding portion of said application program.

13. The system as claimed in claim 11 wherein the object, asset or resource locked is the object asset or resource to which said new content is written.

14. The computer system as claimed in claim 11 wherein said lock means comprises a lock server computer in addition to said plurality of computers, and also connected to said plurality of computers via said communications network.

15. The computer system as claimed in claim 11 wherein said recording means comprises a look up table.

16. The computer system as claimed in claim 14 wherein said look up table includes all contents updated for each recorded memory location.

17. The computer system as claimed in claim 14 wherein said look up table includes only the final content of each updated content for each recorded memory location.

18. The computer system as claimed in claim 14 wherein the contents of said look up table comprises the address of a memory location at which said updated content is stored.

21. A single computer intended to operate in a multiple computer system which comprises a plurality of computers each having a local memory and each being interconnected via a communications network wherein different portions of at least one application program each written to execute on only a single computer, each execute substantially simultaneously on a corresponding one of said plurality of computers, and at least one memory location is replicated in the local memory of each said computer, said system further comprising updating means associated with each said computer to in due course update each said memory location via said communications network after each occasion at which each said memory location has its content written to, or re-written, with a new content,

said single computer comprising:

a local memory having at least one memory location intended to be updated via a communications port connectable to said communications network,

updating means to in due course update the memory locations of other substantially similar computers via said communications port;

lock means associated with said local memory to acquire a lock on an object, asset or resource of said local memory, said lock means including a recording means in which is recorded the name and updated content of said local memory locations written to prior to releasing said lock, and

said lock means after releasing said lock and prior to permitting the acquisition of the same lock by another one of said computers, transferring said updated memory location(s) and updated content(s) to said communications port for transmittal to said another one computer whereby any said another one computer on acquiring said lock has acquired said previously updated contents without needing to wait for said in due course updating of all said computers.

22. The computer as claimed in claim 21 wherein said local memory is an independent local memory accessible only by the corresponding portion of said application program executing on said computer.

23. The computer as claimed in claim 21 wherein the object, asset or resource locked is the object, asset or resource to which said new content is written.

24. The computer as claimed in claim 21 wherein said lock means further includes a lock server computer connectable to said single computer via said communications network.

25. The computer as claimed in claim 21 wherein said recording means comprises a look up table.

26. The computer as defined in claim 25 wherein said look up table includes all contents updated for each recorded memory location.

27. The computer as claimed in claim 25 wherein said look up table includes only the final content of each updated content for each recorded memory location.

28. The computer as claimed in claim 25 wherein the contents of said look up table comprises the address of a memory location at which said updated content is stored.

29. In a single computer, adapted to interoperate with a plurality of other external computers as a multiple computer system wherein said computer has a local processor and a local memory coupled to the local processor and said computers are at least intermittently interconnected via a communications network, and wherein different portions of an application program written to execute on only a one computer are modified to execute substantially simultaneously on said single computer and said plurality of computers, and wherein at least one memory location is replicated in the local memory of each said computer, each said computer including memory location updating means to in due course update each said memory location via said communications network after each occasion at which each said memory location has its content written to, or re-written, with a new content;

a method comprising;

acquiring a lock on an object, asset, or resource of said local memory of said single computer prior to initially writing said new content;

recording the name and updated content of said at least one local memory location of said single computer written to prior to releasing said lock;

releasing said lock on said object, asset, or resource of said local memory of said single computer; and

sending a communication of said updated memory location(s) and updated content(s) to other of said plurality of computers by said single computer over said communications network.

30. The method as claimed in claim 29, further comprising:

permitting but not requiring the acquisition of a new lock on the same object, asset, or resource by another one of said computers;

wherein any said another one of said plurality of computers on acquiring said new lock has acquired said previously updated memory location contents without needing to wait for said in due course updating of the updated contents of all said plurality of computers.

31. The method as claimed in claim 30, further comprising:

updating the local memory locations of other of the plurality of computers via said communications network in due course.

32. The method as claimed in claim 29, further comprising:

generating a memory update message that includes said updated memory locations(s) and updated content(s) that are to be updated in due course in other of the computers, prior to sending said communication and sending said generated memory update message with said communication.

33. A computer program product comprising a set of program instructions stored in a storage medium and operable to permit a computer to carry out the method as claimed in claim 29.

34. In a single computer, adapted to interoperate with a plurality of other external computers as a multiple computer system wherein said computer has a local processor and a local memory coupled to the local processor and said computers are at least intermittently interconnected via a communications network, and wherein different portions of an application program written to execute on only a one computer are modified to execute substantially simultaneously on said single computer and said plurality of computers, and wherein at least one memory location is replicated in the local memory of each said computer, each said computer including memory location updating means to in due course update each said memory location via said communications network after each occasion at which each said memory location has its content written to, or re-written, with a new content;

a method comprising;

receiving a communication of updated memory location(s) and updated content(s) to send by a different one of said plurality of computers by said single computer over said communications network; and

updating the local memory locations of said single computer in response to said received communication.

35. The method of claim 34, wherein the communication received includes a memory update message that includes said updated memory locations(s) and updated content(s) that are to be updated in due course in the receiving computer.

36. A computer program product comprising a set of program instructions stored in a storage medium and operable to permit a computer to carry out the method as claimed in claim 34.