National Instruments Window New Utility Library Functions, Changes and Clarifications to Existing Utility Library Functions

© National Instruments Corporation 33 LabWindows/CVI Release Notes for Windows
declaration of the function pointer. For example, if you declare the function in the external
module as
int __stdcall SetADouble (double d);
and the default calling convention is __cdecl, declare the function pointer as
int (__stdcall * SetADouble_FnPtr)(double d) = NULL;
Use the Compiler Options command in the Options menu of the Project window to
determine the default calling convention.
If you launch a 16-bit executable on Windows NT, ExecutableHasTerminated
cannotdetermine whether the executable process has terminated. The value
ExectuableHasTerminated returns is always 1. In addition, TerminateExecutable
cannot attempt to terminate the launched executable process.
New Utility Library Functions
LabWindows/CVI 5.0 adds three new functions to the Utility Library.
MapPhysicalMemory maps a physical address to a pointer that can be used in your program
like any other C pointer. For example, you can read or write an area of physical memory by
incrementing the pointer after each access.
UnMapPhysicalMemory unmaps an address that was mapped using MapPhysicalMemory.
CVIRTEHasBeenDetached indicates whether Windows 95/NT has detached the
LabWindows/CVI Run-time Engine from your standalone executable process.
Changes and Clarifications to Existing Utility Library Functions
For Delay and SyncWait on Windows 95/NT and UNIX, the respective delay and interval
parameters might now suspend the execution of the current thread while waiting for the
specified interval to expire. In previous versions of LabWindows/CVI, the functions wait
without releasing control to other threads, unnecessarily using CPU cycles. This change
should not require any modifications to your source code.
For Windows 95/NT, CheckForDuplicateAppInstance determines if another copy of the
same executable is running. This function knows if another copy of the executable is running
only if:
• The other copy has already called this function.
• The other copy of the executable was the only one running when that copy of the
executable called this function.
• The other copy of the executable has the same path as the current executable.
In previous versions of LabWindows/CVI, the Timer function returns an inv alid result if your
program runs for more than 49.71 days. At some point between 49.71 days and 99.42 days
after your first call to Timer, the function returns a value 4,294,967.297 seconds less than it