System and method for mapping driver level event function calls from a process-based driver level program to a session-based instrumentation control driver level system

• US 5,771,388 A
• Filed: 05/06/1997
• Issued: 06/23/1998
• Est. Priority Date: 05/04/1994
• Status: Expired due to Term

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Mondrik, Dan, Andrade, Hugo, DeKey, Samson
• Primary Examiner(s): Auve, Glenn A.
• Application Number:
  US08/851,834
• Time in Patent Office: 413 Days
• Field of Search: 395/735, 395/651, 395/500, 395/733, 395/739, 395/741, 395/742
• US Class Current: 710/262
• CPC Class Codes: G06F 13/105 where the programme performs an input/output emulation function
• CPC Class Codes: G06F 8/20 Software design
• CPC Class Codes: G06F 8/24 Object-oriented
• CPC Class Codes: G06F 9/45537 Provision of facilities of other operating environments, e.g. WINE I/O emulation G06F13/105

Abstract

A system and method for enabling applications written for SICL driver level software to operate with a VISA system. The present invention maps driver level event function calls from the SICL driver level library to VISA resource operations. This enables a VISA system to operate in conjunction with applications written for the SICL I/O library. The SICL Driver level library provides a completely different methodology for enabling and handling events than does a VISA system. According to the present invention, the method verifies and translate session identifier parameters from SICL functions to corresponding session identifiers in a VISA system. The method also verifies and translates interrupt condition parameters from SICL to corresponding event types in VISA for numerous event functions. Further, the method examines parameters in various SICL event functions and invokes the appropriate VISA operations to perform the indicated functions. In many instances, the method of the present invention is required to invoke multiple VISA operations to perform the desired functions indicated by a single SICL function. The method of the present invention performs many other operations necessary to map SICL event commands to the appropriate VISA operations.

Claims

1. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call from an application to a function in said first driver level library which enables interrupts, wherein said function in said first driver level library which enables interrupts includes one or more parameters, including a first parameter that determines whether interrupts should be enabled or disabled for a session to said first driver level library;

examining said first parameter of said function in said first driver level library which enables interrupts;

invoking an operation in said second driver level library which disables events if said first parameter indicates that interrupts should be disabled; and

invoking an operation in said second driver level library which enables events if said first parameter indicates that interrupts should be enabled.

2. The computer-readable storage media of claim 1, wherein the program instructions further implement the step of:

determining if a function in said first driver level library which installs an interrupt handler has already been called;

wherein said step of invoking said operation in said second driver level library which enables events includes setting a parameter indicating that a handler should be called immediately if said function in said first driver level library which installs an interrupt handler has already been called;

wherein said step of invoking said operation in said second driver level library which enables events includes setting a parameter indicating that information about an event should be placed on a suspend queue if said function in said first driver level library which installs an interrupt handler has not been called.

3. The computer-readable storage media of claim 1, wherein the program instructions further implement the steps of:

the second driver level library saving information in a data structure regarding a state of events which are enabled and disabled for said session to said first driver level library.

4. The computer-readable storage media of claim 1, wherein said function in said first driver level library which enables interrupts includes a parameter which identifies a session to said first driver level library, wherein the program instructions further implement the step of:

translating said session identifier parameter to a value which corresponds to a session to said second driver level library.

5. The computer-readable storage media of claim 1, wherein said function in said first driver level library which enables interrupts includes a second parameter that determines which interrupt condition to enable or disable for a session to said first driver level library, wherein the program instructions further implement the step of:

mapping said second parameter to an event type in said second driver level library.

6. The computer-readable storage media of claim 1, wherein said function in said first driver level library which enables interrupts includes a second parameter that determines which interrupt condition to enable or disable for a session to said first driver level library, wherein the program instructions further implement the steps of:

determining if said second parameter references a value which disables all interrupts for a session; and

invoking an operation in said second driver level library which disables events for the session if said second parameter references a value which disables all interrupts for the session.

7. The computer-readable storage media of claim 1, wherein said first driver level library is the Standard Instrument Control Library (SICL) and wherein said second driver level library is the Virtual Instrument Software Architecture (VISA);

wherein said function in said first driver level library which enables interrupts is an isetintr function in said SICL library.

8. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function in said first driver level library which disables execution of interrupt handlers for a plurality of sessions in a first process;

maintaining a data structure comprising sessions to said second driver level library which correspond to said first process;

examining said data structure to determine which sessions are enabled for said first process in response to receiving said call to said function in said first driver level library which disables execution of interrupt handlers; and

invoking an operation in said second driver level library which suspends execution for all enabled events in each of said sessions to said second driver level library which correspond to said first process after said step of examining.

9. The computer-readable storage media of claim 8, wherein the program instructions further implement the steps of:

performing said operation in said second driver level library which suspends execution for all enabled events in said sessions to said second driver level library corresponding to said first process, wherein said step of performing comprises;

determining which events are enabled in one of said sessions to said second driver level library corresponding to said first process;

suspending execution of said events enabled in said one of said sessions to said second driver level library corresponding to said first process; and

performing said steps of determining and suspending for each of said sessions to said second driver level library corresponding to said first process.

10. The computer-readable storage media of claim 8, wherein said first driver level library further includes a function which enables execution of interrupt handlers, wherein said function in said first driver level library which disables execution of interrupt handlers and said function in said first driver level library which enables execution of interrupt handlers can be nested, wherein the program instructions further implement the steps of:

determining if said function in said first driver level library which disables execution of said interrupt handlers has been called without a corresponding call to said function in said first driver level library which enables execution of said interrupt handlers; and

performing said steps of examining and invoking only if said function in said first driver level library which disables execution of said interrupt handlers has not been called without a corresponding call to said function in said first driver level library which enables execution of said interrupt handlers.

11. The computer-readable storage media of claim 8, wherein said first driver level library further includes a function which enables execution of interrupt handlers, wherein said function in said first driver level library which disables execution of interrupt handlers and said function in said first driver level library which enables execution of interrupt handlers can be nested, wherein the program instructions further implement the steps of:

determining if said function in said first, driver level library which disables execution of said interrupt handlers has been called once without a corresponding call to said function in said first driver level library which enables execution of said interrupt handlers;

setting a count variable equal to one if said function which disables execution of interrupt handlers has not been called without an accompanying call to said function in said first driver level library which enables execution of interrupt handlers;

incrementing said count variable if said function in said first driver level library which disables execution of said interrupt handlers has already been called without an accompanying call to said function which enables execution of said interrupt handlers.

12. The computer-readable storage media of claim 8, wherein said first driver level library is the Standard Instrument Control Library and said second driver level library is the Virtual Instrument Software Architecture Library.

13. The computer-readable storage media of claim 12, wherein said function in said first driver level library which disables execution of interrupt handlers is an iintroff function.

14. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function in said first driver level library which enables execution of interrupt handlers for a plurality of sessions in a first process;

maintaining a data structure comprising sessions to said second driver level library which correspond to said first process;

examining said data structure to determine which sessions are enabled for said first process in response to receiving said call to said function in said first driver level library which enables execution of interrupt handlers; and

invoking an operation in said second driver level library which enables execution of all enabled events in each of said sessions to said second driver level library which correspond to said first process after said step of examining.

15. The computer-readable storage media of claim 14, wherein the program instructions further implement the steps of:

performing said operation in said second driver level library which enables execution of all enabled events in said sessions to said second driver level library corresponding to said first process, wherein said step of performing comprises;

determining which events are enabled in one of said sessions to said second driver level library corresponding to said first process;

enabling execution of said events enabled in said one of said sessions to said second driver level library corresponding to said first process; and

performing said steps of determining and enabling for each of said sessions to said second driver level library corresponding to said first process.

16. The computer-readable storage media of claim 14, wherein said first driver level library further includes a function which disables execution of interrupt handlers, wherein said function in said first driver level library which disables execution of interrupt handlers and said function in said first driver level library which enables execution of interrupt handlers can be nested, wherein the program instructions further implement the steps of:

determining if said function in said first driver level library which disables execution of said interrupt handlers has been called once without a corresponding call to said function in said first driver level library which enables execution of said interrupt handlers; and

performing said steps of examining and invoking in response to said step of receiving said call to said function in said first driver level library which enables execution of interrupt handlers, wherein said step of performing is performed only if said function in said first driver level library which disables execution of said interrupt handlers has been called once without a corresponding call to said function in said first driver level library which enables execution of interrupt handlers.

17. The computer-readable storage media of claim 14, wherein said first driver level library further includes a function which disables execution of interrupt handlers, wherein said function in said first driver level library which disables execution of interrupt handlers and said function in said first driver level library which enables execution of interrupt handlers can be nested, wherein the program instructions further implement the steps of:

determining if said function in said first driver level library which disables execution of said interrupt handlers has been called once without a corresponding call to said function in said first driver level library which enables execution of said interrupt handlers; and

setting a count variable equal to one if said function which disables execution of interrupt handlers has not been called without an accompanying call to said function in said first driver level library which enables execution of interrupt handlers;

incrementing said count variable if said function in said first driver level library which disables execution of said interrupt handlers has already been called without an accompanying call to said function which enables execution of said interrupt handlers.

18. The computer-readable storage media of claim 17, wherein the program instructions further implement the steps of:

determining a value of said count variable after said step of receiving said call to said function in said first driver level library which enables execution of interrupt handlers;

decrementing said count variable if said count value is greater than one; and

returning a success value after said step of decrementing if said count value is determined to be greater than one.

19. The computer-readable storage media of claim 14, wherein said first driver level library is the Standard Instrument Control Library and said second driver level library is the Virtual Instrument Software Architecture library.

20. The computer-readable storage media of claim 19, wherein said function in said first driver level library which enables execution of interrupt handlers is an iintron function.

21. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function from an application, wherein said function is comprised in said first driver level library and operates to install a first interrupt handler for use by said application, wherein said second driver level library cannot call said first interrupt handler in said application, wherein said first driver level library further includes a function which enables interrupt conditions, wherein said function which enables interrupt conditions and said function which installs said first interrupt handler may be called in any order in said first driver level library;

determining if said function in said first driver level library which enables interrupt conditions has already been called;

invoking an operation in said second driver level library which enables interrupt conditions only if said function in said first driver level library which enables interrupt conditions has already been called

installing a second handler in said application which is callable by said second driver level library, wherein said second handler calls said first interrupt handler.

22. The computer-readable storage media of claim 21, wherein said function in said first driver level library which installs said first interrupt handler includes a parameter which references a procedure to be installed as said first interrupt handler, wherein the program instructions further implement the steps of:

determining if said parameter references a valid procedure to be installed as said first interrupt handler;

invoking an operation in said second driver level library which installs an interrupt handler if said parameter references a valid procedure to be installed as said first interrupt handler;

invoking an operation in said second driver level library which uninstalls an interrupt handler if said parameter does not reference a valid procedure to be installed as said first interrupt handler.

23. The computer-readable storage media of claim 22, wherein the program instructions further implement the step of:

invoking an operation in said second driver level library which disables interrupt conditions after said step of invoking an operation in said second driver level library which uninstalls an interrupt handler if said parameter does not reference a valid procedure to be installed as said first interrupt handler.

24. The computer-readable storage media of claim 22, wherein the program instructions further implement the step of saving a value of said parameter in a data structure.

25. The computer-readable storage media of claim 21, wherein said function in said first driver level library which installs an interrupt handler includes a parameter which identifies a session to said first driver level library, wherein the program instructions further implement the step of:

translating said session identifier parameter to a value which corresponds to a session to said second driver level library.

26. The computer-readable storage media of claim 21, wherein said first driver level library is the Standard Instrument Control Library and wherein said second driver level library is the Virtual Instrument Software Architecture.

27. The computer-readable storage media of claim 26, wherein said function in said first driver level library which installs an interrupt handler is an ionintr function call in said SICL library.

28. The computer-readable storage media of claim 21, wherein the program instructions further implement the steps of:

examining said parameter which references said procedure to be installed as said first interrupt handler in said first driver level library session data structure in response to an interrupt occurring in said application;

calling said second handler in response to said examining, wherein said second handler calls said first handler.

29. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function from an application, wherein said function is comprised in said first driver level library and operates to install a first interrupt handler for use by said application for service requests (SRQs), wherein said second driver level library cannot call said first interrupt handler in said application, wherein said function in said first driver level library which installs an interrupt handler includes a parameter which references a procedure to be installed as said interrupt handler;

determining if said parameter references a valid procedure to be installed as said first interrupt handler;

invoking an operation in said second driver level library which installs a second interrupt handler if said parameter references a valid procedure to be installed as said first interrupt handler, wherein said second interrupt handler is callable by said second driver level library, wherein said second interrupt handler calls said first interrupt handler; and

invoking an operation in said second driver level library which uninstalls an interrupt handler if said procedure does not reference a valid procedure to be installed as said interrupt handler;

invoking an operation in said second driver level library which enables interrupt conditions for service requests (SRQs) if said parameter references a valid procedure to be installed as said first interrupt handler; and

invoking an operation in said second driver level library which disables interrupt conditions for service requests (SRQs) if said parameter does not reference a valid procedure to be installed as said first interrupt handler.

30. The computer-readable storage media of claim 29, wherein the program instructions further implement the step of saving a value of said parameter in a data structure.

31. The computer-readable, storage media of claim 29, wherein said first driver level library is the Standard Instrument Control Library and wherein said second driver level library is the Virtual Instrument Software Architecture.

32. The computer-readable storage media of claim 31, wherein said function in said first driver level library which installs said first interrupt handler for service requests is an ionsrq function in said SICL library.

33. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call from an application to a function in said first driver level library which installs an error handler in said application for sessions which correspond to a first process;

determining which sessions to said second driver level library corresponding to said first process are opened;

examining a parameter in said function which references said error handler to determine if said parameter references a valid error handler;

invoking an operation in said second driver level library which uninstalls an error handler from said sessions to said second driver level library if said parameter does not reference a valid error handler;

invoking an operation in said second driver level library which installs said error handler for said sessions in said process if said parameter references a valid error handler.

34. The computer-readable storage media of claim 33, wherein said parameter comprises a pointer to an error handler and wherein said step of determining if said parameter which references said error handler is valid comprises determining if said parameter is zero.

35. The computer-readable storage media of claim 33, wherein the program instructions further implement the steps of:

examining said parameter in said function which references said error handler to determine if said parameter is a special value;

changing said parameter to point to a handler in said first driver level library if said parameter is a special value.

36. The computer-readable storage media of claim 33, wherein the program instructions further implement the step of saving a value of said parameter in a data structure.

37. The computer-readable storage media of claim 33, wherein said first driver level library is the Standard Instrument Control Library and said second driver level library is the Virtual Instrument Software Architecture library.

38. The computer-readable storage media of claim 37, wherein said function in said first driver level library which installs an error handler is an ionerror function in said SICL library.

39. The computer-readable storage media of claim 33, wherein the program instructions further implement the steps of:

determining if a new session to said first driver level library has been opened;

determining if said function which installs an error handler has already been called after said step of said new session opening to said first driver level library;

installing an error handler on said new session if said function in said first driver level library which installs an error handler has already been called.

40. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function in said first driver level library which enables execution of interrupt handlers for a plurality of sessions in a first process;

maintaining a data structure comprising sessions to said second driver level library which correspond to said first process;

examining said data structure to determine which sessions are enabled for said first process; and

invoking a plurality of operations in said second driver level library which enable execution of all enabled events in each of said sessions to said second driver level library which correspond to said first process.

41. The computer-readable storage media of claim 40, wherein the program instructions further implement the steps of:

performing said plurality of operations in said second driver level library which enable execution of all enabled events in said sessions to said second driver level library corresponding to said first process, wherein said step of performing comprises;

determining which events are enabled in one of said sessions to said second driver level library corresponding to said first process;

performing an operation to enable execution of an event for each of said events enabled in said one of said sessions to said second driver level library corresponding to said first process; and

performing said steps of determining and performing an operation for each of said sessions to said second driver level library corresponding to said first process.

42. A computer-readable storage media which stores program instructions for mapping driver level event function calls from a first driver level library to a second driver level library in an instrumentation system including a computer system, wherein the program instructions implement the steps of:

receiving a call to a function in said first driver level library which disables execution of interrupt handlers for a plurality of sessions in a first process;

maintaining a data structure comprising sessions to said second driver level library which correspond to said first process;

examining said data structure to determine which sessions are enabled for said first process; and

invoking a plurality of operations in said second driver level library which suspend execution for all enabled events in each of said sessions to said second driver level library which correspond to said first process.

43. The computer-readable storage media of claim 42, wherein the program instructions further implement the steps of:

performing said plurality of operations in said second driver level library which suspend execution for all enabled events in said sessions to said second driver level library corresponding to said first process, wherein said step of performing comprises;

determining which events are enabled in one of said sessions to said second driver level library corresponding to said first process;

performing an operation to suspend execution of an event for each of said events enabled in said one of said sessions to said second driver level library corresponding to said first process; and

performing said steps of determining and performing an operation for each of said sessions to said second driver level library corresponding to said first process.