Answer the priority for system high-priority I/O processes,
such as a process handling input from a network.
highestPriority
Answer the highest valid priority
lowIOPriority
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.
lowestPriority
Answer the lowest valid priority
priorityName: priority
Private - Answer a name for the given process priority
rockBottomPriority
Answer the lowest valid priority
systemBackgroundPriority
Answer the priority for system background-priority processes.
Examples are an incremental garbage collector or status checker.
timingPriority
Answer the priority for system real-time processes.
unpreemptedPriority
Answer the highest priority avilable in the system; never
create a process with this priority, instead use
BlockClosure>>#valueWithoutPreemption.
userBackgroundPriority
Answer the priority for user background-priority processes
userInterruptPriority
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.
userSchedulingPriority
Answer the priority for user standard-priority processes