Answer the priority for system high-priority I/O processes, such as a process handling input from a network.
Answer the highest valid priority
Answer the priority of idle processes.
Answer the priority for system low-priority I/O processes. Examples are the process handling input from the user (keyboard, pointing device, etc.) and the process distributing input from a network.
Answer the lowest valid priority
Private - Answer a name for the given process priority
Answer the priority for system background-priority processes. An incremental garbage collector could run at this level but now it runs at idlePriority instead.
Answer the priority for system real-time processes.
Answer the highest priority avilable in the system; never create a process with this priority, instead use BlockClosure>>#valueWithoutPreemption.
Answer the priority for user background-priority processes
Answer the priority for user interrupt-priority processes. Processes run at this level will preempt the window scheduler and should, therefore, not consume the processor forever.
Answer the priority for user standard-priority processes