System and method for performing context checks

• US 20020194252A1
• Filed: 06/26/2002
• Published: 12/19/2002
• Est. Priority Date: 05/06/1994
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Powers, John Richard III
• Granted Patent: US 7,016,891 B2
• Time in Patent Office: Days
• US Class Current: 718/108
• CPC Class Codes: G06F 9/44589 Program code verification, e.g. Java bytecode verification, proof-carrying code high-level semantic checks G06F8/43; testing and debugging software G06F11/36
• CPC Class Codes: G06F 9/468 Specific access rights for resources, e.g. using capability register
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99937 Sorting
• CPC Class Codes: Y10S 707/99939 Privileged access

Abstract

A system and method is described which provides for context checking of an operating environment. A context manager controls the execution of context checks requested by applications or processes. In one embodiment, the context check modules are defined as self-contained modules located in a database. When the data base is opened, these modules are loaded and registered with the context manager. Upon occurrence of certain user actions, the context manager will issue an event to cause the appropriate modules to perform a context check of certain context of the environment. The resulting context information is stored in memory by the context manager and provided to the applications by the context manager when needed. One advantage is that the context checks performed can be changed simply by adding or deleting modules from the database. In other embodiments, context checking functions can also be provided by providing context files, which are loaded at initiation of the context manager and are independent of the database utilized, and by providing certain highly repeatable functions within the function of the context manager itself.

Claims

1. In a computer system comprising a processing unit executing at least one process, said computer system operating in a context, a context checking mechanism for evaluating context comprising:

a database comprising a plurality of database modules;

a delivery engine which retrieves database modules and executes instructions in accordance with database modules when said database is opened;

at least one context module stored in the database, said context module, when executed, performing a context check and providing a result;

a memory for storage of the result;

a context manager which manages the checking of context, said context manager retrieving said context module when said database is opened, said context manager causing the execution of the said context module upon occurrence of a specified event and providing the result of the context when requested by a process.

2. The context checking mechanism as set forth in claim 1, wherein upon occurrence of the specified event a request to perform a context check is communicated to the context manager, said context check identified by a context identification.

3. The context checking mechanism as set forth in claim 2, further comprising a context specification, said context specification specifying the context identification and a name of a corresponding context module, which when executed, performs the requested context check;

said context manager receiving the request to perform a context check and retrieving the name of the corresponding context module from the context specification to cause execution of the corresponding context module.

4. The context checking mechanism as set forth in claim 1, further comprising a registered module list each element in the list comprising an identification of each context module (“

module ID”

) and a pointer to the location of the context module.

5. The context checking mechanism as set forth in claim 4 wherein said registered module list is a linked list, each element in the list further comprising a linked list pointer pointing to the location of the next element in the list.

6. The context checking mechanism as set forth in claim 4, wherein if a first element in the list identifies a first context module having a first module ID and a second context module to be loaded has the first module ID, said context manager causing the first element to be removed from the list and a second element to be added to the list thereby overriding the first context module, said second element further comprising an identification of the location of the overriden first context module.

7. The context checking mechanism as set forth in claim 6, wherein when the second context module is unloaded and the second element of the registered module list is to be removed, said context manager re-loading the first context module, the location of which is identified in the second element of the registered module list.

8. The context checking mechanism as set forth in claim 1, wherein the delivery engine executing a database module requests the result of the context.

9. The context checking mechanism as set forth in claim 8, wherein the database module identifies a next database module the delivery engine is to retrieve and execute based upon the result of the context.

10. The context checking mechanism as set forth in claim 1, wherein a process executing requests the result of the context.

11. The context checking mechanism as set forth in claim 1, wherein the specified event comprises a user action.

12. The context checking mechanism as set forth in claim 1, wherein the specified event comprises a lapse of a predetermined amount of time.

13. The context checking mechanism as set forth in claim 11, wherein said computer system further comprises at least one user data entry device, said user action comprising the entry of data by said user data entry device.

14. The context checking mechanism as set forth in claim 1, wherein said context manager retrieves and loads a copy of the context module when the database is opened, said context manager further unloading the context module when the database is closed, wherein the context modules are executed when the database is opened.

15. The context checking mechanism as set forth in claim 1, wherein the context manager allocates a portion of memory for storage of context results when the database is opened and de-allocates the portion of memory when the database is closed.

16. The context checking mechanism as set forth in claim 1, further comprising at least one context file, each context file comprising instructions, when executed, perform a context check, each context file loaded into memory during startup of the computer system.

17. The context checking mechanism as set forth in claim 4, further comprising at least one context file, each context file comprising instructions, when executed, perform a context check, each context file loaded into memory during startup of the computer system, said registered module list further comprising identification of context files loaded and a pointer to the location of the context file.

18. The context checking mechanism as set forth in claim 17, wherein if a context file is loaded having an identification of a first name and a context module has an identification of the first name, said context manager causing the context file to be unloaded when the database is opened and reloaded after the database is closed.

19. The context checking mechanism as set forth in claim 1, said context manager further comprising instructions to perform a context check.

20. The context checking mechanism as set forth in claim 4, further comprising an application process executing on the computer system, said application process comprising instructions which, when executed, perform a context check, said registered module list further comprising identification of the application process.

21. The context checking mechanism as set forth in claim 1, said context manager further loading an event handler for each context module retrieved, wherein the context module is executed by issuing an event to the event handler.

22. The context checking mechanism as set forth in claim 4, wherein said context manager causes execution of a context module by referencing the registered module list to identify the location of the context module to execute and causing code at that location of the context module to be executed.

23. The context checking mechanism as set forth in claim 22, wherein upon occurrence of the specified event a request to perform a context check is communicated to the context manager, said context check identified by a context identification;

said mechanism further comprising a context specification, said context specification specifying the context identification and a name of a corresponding context module, which when executed, performs the requested context check;

said context manager receiving the request to perform a context check and retrieving the name of the corresponding context module from ii the context specification to cause execution of the corresponding context module.

25. The method as set forth in claim 24, said database further comprising at least one database module comprising instructions, and said process executing instructions from the database module.

26. The method as set forth in claim 24, wherein the specified event comprises a request by the process for context information.

27. The method as set forth in claim 24, wherein the specified event comprises the occurrence of a user action;

said method further comprising the step of storing the result in memory and providing the result from memory when requested by the process.

28. The method as set forth in claim 24, further comprising the step of generating a registered module list comprising identification of each loaded context module and a pointer to the location of the context module.

29. The method as set forth in claim 25, further comprising the step of retrieving additional database modules for execution based upon the result of the context.

30. The method as set forth in claim 24, further comprising the step of generating a context specification, said context specification specifying the context identification and a name of a corresponding context module, which when executed, performs the requested context check;

said context manager receiving the request to perform a context check and retrieving the name of the corresponding context module from the context specification to cause execution of the corresponding context module.

31. The method as set forth in claim 30, further comprising the step of generating a registered module list, each element in the list comprising an identification of each context module (“

module ID”

) and a pointer to the location of the context module.

32. The method as set forth in claim 24, further comprising the steps of:

providing at least one context file, each context file comprising instructions, when executed, perform a context check; and

during startup of the computer system, loading each context file into memory.

33. The method as set forth in claim 32, further comprising the step of generating a registered module list comprising the steps of:

generating an entry identifying each context file and a pointer to the location of the context file;

generating an entry identifying of each loaded context module and a pointer to the location of the context module; and

if the identification of a context file and context module are the same,

removing the context file from the registered module list, and

generating an entry identifying the context file removed once the database is closed.

34. The method as set forth in claim 24, further comprising the steps of:

executing an application process comprising context check instructions, which, when executed, perform a context check; and

generating a registered module list comprising the steps of;

generating an entry identifying each context file and a pointer to the location of the context file, and

generating an entry identifying of each application process requesting to be registered in the registered module list.

35. The method as set forth in claim 24, wherein said step of loading the context module for execution comprises the step of loading an event handler associated with the context module, said step of executing a context module to perform a context check comprises the step of issuing an event to the event handler instruction the context module to be executed and said step of providing the result comprises the step of generating an event providing the result of the context check.

24. In a computer system comprising a processing executing at least one process, said computer system operating in a context, a method for evaluating context comprising the steps of:

providing a database comprising at least one context module;

opening the database;

retrieving the context module from the database and loading the context module for execution;

executing instructions as a process;

upon occurrence of a specified event, executing the context module to perform a context check to generate a context check result;

providing the result of the context check when requested by the process.