[boomergeek]

My understanding is that in a realtime operating system (such as VXWorks), a particular task runs until the system tick is complete or a system call is made that allows preemption (to allow a higher priority task to run). Lower priority tasks can run if the task gives up the processor (e.g,. taskdelay system call).
This is a function of the realtime OS and not whether Java or C++ is the programming language.