Several questions (language comparison)

[Radical Pi]

Originally Posted by flameout

In the C++ WPILib, is there a way to set thread priorities? I believe it can be done in both LabVIEW and Java.

Use the class Task. In the constructor: Task("myTask", function, priority), where function is a pointer to the thread's main and priority is thread priority (100 is default). Call Start with any arguments to the main function to start the task.

Originally Posted by flameout

What about UDP communication? I know LabVIEW contains primitives, but is this doable in Java and C++?

vxWorks implements the socket system in C++. You can see how it's used in the CANJaguar SpeedControl example or in Vision/PCVideoServer.cpp (the former copy-pasted the latter)

Originally Posted by flameout

Is there some sort of event handling available? Could I, for example, run a section of code whenever a new image is available from the camera, or run a section of code when a digital input changes without polling?

I don't have the exact code in front of me, but I can push you in the right direction on how to do this. Team 639 used a rotating kicker and had a IR sensor that pulsed a Digital Line whenever the kicker reached a certain angle.
Any class that inherits from InterruptableSensorBase (That means DigitalInput, but not AnalogChannel) can interrupt the code. I think the code was somewhere along the lines of this:

DigitalInput *sensor;

void InterruptFunction() {
//do stuff here
}

Init() {
//blah
sensor = new DigitalInput(1);
sensor->RequestInterrupts( (tInterruptHandler)InterruptFunction);
sensor->EnableInterrupts();
//blah
}

I'm unsure of the line with the RequestInterrupts function, other than that I'm sure of everything.

No idea if an equivalent exists in Java