Class ProcessorScheduler

Inheritance:

Object  »
  ProcessorScheduler

A single instance, named Processor, coordinates the use of the physical processor by all Processes requiring service.

In a system that is set up as a collection of cooperating processes, it is the responsibility of the processor scheduler to find ways to continue and to choose one of the found ways to continue. Process priorities are used in that choice, but most assumptions about how the scheduler has to choose the process to activate are simply wrong.

Instance Variables:

• quiescentProcessLists - Array
  A priority index array of queues that contain all processes that are ready to become the active process. The array elements are linked lists. Ready processes with priority p are stored in

  quiescentProcessLists at: p

• activeProcess - Process
  The process that is currently running.

Important Instance Methods:

• terminateActive
  Suspends the process that is currently running.

• yield
  Suspends the currently active process to give other processes of the same priority a chance to run.