How can I give the "user interface thread" higher priority?

Question

We do alot of activex calls to front panels. We need to increase/decrease the priority of the user interface thread to resolve our thread problem. Anyone know how to do this?
Chuck

Answer 1

Hello,
As P.M. was saying, you can adjust the thread priorities
through the VI Properties dialogue. 
Another place to modify the multithreading system in LabVIEW is a VI
located at: [LabVIEW Directory]\vi.lib\Utility\sysinfo.llb\threadconfig.vi.  However I do not think this will remedy any
problems you are having.
From a Multithreading in LabVIEW tutorial (http://zone.ni.com/devzone/conceptd.nsf/webmain/d2e196c7416f373a862568690074c759)
Priorities in the User Interface and
Single-Threaded Applications
Within the User Interface execution
system, priority levels are handled in the same way for single-threaded and
multithreaded applications.
In single-threaded applications and
in the User Interface execution system of multithreaded applications, the
execution system queue has multiple entry points. The execution system places
higher priority VIs on the queue in front of lower priority VIs.
If a high-priority task is running and the queue contains only lower priority
tasks, the high-priority VI continues to run. For example, if the execution
queue contains two VIs of each priority level, the time-critical VIs share execution time exclusively until both finish.
Then, the high priority VIs share execution
time exclusively until both finish, and so on. However, if the higher priority
VIs call a function that waits, the execution system removes higher priority
VIs from the queue until the wait or I/O completes, assigning other tasks
(possibly with lower priority) to run. When the wait or I/O completes, the
execution system reinserts the pending task on the queue in front of lower
priority tasks. Refer to the Synchronous/Blocking Nodes section for a list of
asynchronous functions that wait.
Also, if a high priority VI calls a lower priority subVI,
that subVI is raised to the same priority level as the caller for the duration
of that call. Consequently, you do not need to modify the priority levels of
the subVIs that a VI calls to raise the priority level of the subVI.
Thus changing the priority of your VI will change the
priority of UI calls for that particular VI. 
Again, I caution you because I suspect that if you are having problems
with your application not running correctly, I do not believe that manipulating
the thread priorities will resolve these issues.
Hope this helps,
Travis M
LabVIEW R&D
National Instruments