Method and device for creating an object in a non-persistent memory and/or keeping accessibility to said object

• US 6,772,171 B1
• Filed: 04/29/1999
• Issued: 08/03/2004
• Est. Priority Date: 05/04/1998
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Buhler, Peter, Baentsch, Michael, Eirich, Thomas, Hoering, Frank, Oestreicher, Marcus
• Primary Examiner(s): JUNG, DAVID YIUK
• Application Number:
  US09/302,152
• Time in Patent Office: 1,923 Days
• Field of Search: 707/1-206, 717/100-119, 711/1-6, 711/170-173, 711/100
• US Class Current: 1/1
• CPC Class Codes: G06F 9/4493 Object persistence
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method for creating an object in a non-persistent memory is proposed. From an instruction code sequence, a first instruction code is read out which effects the execution of a first function which effects the choice of a non-persistent memory as the location for the next object to be created. This object creation is effected by the execution of a second function which is effected by reading out a second instruction code. Furthermore it is proposed to store a pointer to a transient object in the stack memory and to provide a mechanism for writing this pointer to and reading it from a persistent memory.

Claims

1. A method for creating an object in a non-persistent memory, in a resource constrained system having limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, the method comprising:

reading out a first instruction code from an instruction code sequence which effects execution of a first function, and

reading out a second instruction code which effects execution of a second function which effects the creation of said object in a memory, whereby said first function effects the choice of said non-persistent memory as said memory, instead of said persistent memory.

2. A device for carrying out a method according to claim 1, further comprising a smartcard.

3. A device for carrying out a method according to claim 1, further comprising a Javacard.

4. A device for carrying out a method according to claim 1, further comprising electronic circuitry therefor.

5. A method according to claim 1, wherein the first function comprises a function of a bracket-open type.

6. A method according to claim 1, further comprising, reading a third instruction code which effects the execution of a third function which effects the choice of a persistent memory as said memory, and

reading a fourth instruction code which when read out effects the execution of a fourth function which effects the creation of another object in said persistent memory.

7. A method according to claim 6, wherein the third function comprises a function of a bracket-close type.

8. A method according to claim 1, wherein at least some of the objects in the non-persistent memory are linked, by a chain starting from a first of said objects.

9. A method according to claim 8, further comprising storing a pointer to one of the objects in the non-persistent memory, in a stack memory.

10. A method according to claim 9, wherein the pointer in the stack memory is storable in a memory location in a control means.

11. A method according to claim 10, further comprising executing a fifth function which effects that the pointer in the stack memory is stored in the memory location in the control means.

12. A method according to claim 10, further comprising executing a sixth function which effects that the pointer is written into the stack memory from the memory location in the control means.

13. A method according to one of claim 1 wherein the objects in the persistent memory are linked, by a chain starting from a first of said objects.

14. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing creation of an object in a non-persistent memory, in a resource constrained system having a limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect:

reading out a first instruction code from an instruction code sequence which effects execution of a first function, and

reading out a second instruction code which effects execution of a second function which effects the creation of said object in a memory, whereby said first function effects the choice of said non-persistent memory as said memory, instead of said persistent memory.

15. An article of manufacture as recited in claim 14, wherein the first function comprises a function of a bracket-open type.

16. An article of manufacture as recited in claim 14, the computer readable program code means in said article of manufacture further comprising computer readable program code means for causing a computer to effect reading out a third instruction code which effects the execution of a third function which effects the choice of a persistent memory as said memory for a fourth instruction code which when being read out effects the execution of a fourth function which effects the creation of another object in said persistent memory.

17. An article of manufacture as recited in claim 14, wherein the third function comprises a function of a bracket-close type.

18. An article of manufacture as recited in claim 14, wherein at least a plurality of the objects in the non-persistent memory are linked by a chain starting from a first object of said objects.

19. An article of manufacture as recited in claim 18, wherein the objects linked are linked in a form of a chain starting from a first object of said objects.

20. A device for creating an object in a non-persistent memory in a resource constrained system having a limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, comprising storing means for storing an instruction code sequence, and control means for reading instruction codes out of said instruction code sequence, and wherein a first function is executable in the case when a first instruction code is read out, and wherein a second function is executable in the case when a second instruction code is read out, which second function effects the creation of said object in a memory, whereby said first function effects the choice of said non-persistent memory as said memory, instead of said persistent memory.

21. A device according to claim 20, further comprising a third function executable in the case when a third instruction code is read out of said instruction code sequence, which third function effects the choice of a persistent memory as said memory for a fourth instruction code which when being read out effects the execution of a fourth function which effects the creation of another object in said persistent memory.

22. A device according to claim 20, wherein the objects in the non-persistent memory are linked by a chain starting from a first of said objects.

23. A device according to claim 22, further comprising a control means, a stack memory and a pointer to the first object in the non-persistent memory stored in said stack memory, said pointer being storable in a memory location in said control means.

24. A device according to claim 23, further comprising a fifth function executable to effect that the pointer in the stack memory is stored in the memory location in the control means.

25. A device according to claim 23, further comprising a sixth function executable to effect that the pointer is written into the stack memory from the memory location in the control means.

26. A device according to claim 20, wherein objects in the persistent memory are linked, by a chain starting from a first of said objects.

27. A device according to claim 20, configured as one of a smartcard, a Javacard, and electronic circuitry therefor.

28. A method for maintaining accessibility of a first object stored in a non-persistent memory of a resource constrained system having a limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein as a default, objects are created in said persistent memory, comprising:

storing a pointer to said first object in said non-persistent memory in a stack memory, said pointer in said stack memory being writable to and readable from a persistent memory location in a control means, and

executing a function to effect said storing.

29. A method according to claim 28, wherein an additional function is executed which effects that the pointer is written into the stack memory from the memory location in the control means.

30. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing accessibility of a first object stored in a limited non-persistent memory of a resource constrained system having said limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect storing a pointer to said first object in said non-persistent memory in a stack memory, wherein said pointer in said stack memory is writable to and readable from a persistent memory location in a control means.

31. A computer program product as recited in claim 30, wherein the step of storing is effectable by an execution of a fifth function.

32. A computer program product as recited in claim 30, the computer readable program code means in said computer program product further comprising computer readable program code means for causing a computer to effect executing a sixth function which effects that the pointer is written into the stack memory from the memory location in the control means.

33. A method for creating an object in a non-persistent memory, in a resource constrained system having a limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, the method comprising:

reading out a first instruction code from an instruction code sequence which effects execution of a first function, and

reading out a second instruction code which effects execution of a second function which effects the creation of said object in a memory, whereby said first function effects the choice of said non-persistent memory as said memory, instead of said persistent memory.

34. A method for maintaining accessibility of a first object stored in a limited non-persistent memory in a resource constrained system having said limited non-persistent memory and a persistent memory of greater capacity than said non-persistent memory, wherein, as a default, objects are created in said persistent memory, the method comprising storing a pointer to said first object in said non-persistent memory in a stack memory, wherein said pointer in said stack memory is writable to and readable from a persistent memory location in a control means.