[Varriount]

Hello, my team has just started programming in java, and we've studied the documentation of WPILib, however some of us still have questions regarding thread safety and thread usage of WPILib's components.
What, if any, components of WPILib use threads? (Not including java's native thread library)
Does the VM on the cRio do any sort of automatic background threading or threading without the explicit usage of thread objects, in such a way that we would need to ensure the thread safety of our code?