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School of Computer Science & Engineering
University of New South Wales
 Advanced Operating Systems 
 COMP9242 2002/S2 

Tasks

• A task essentially provides an address space
  (plus a clan boundary).
• An (active) task contains one or more (active) threads.
• The number of threads in a task is fixed (128 on R4k).
  • Upon task creation, the full set of (128) threads is created with the task,
  • all but one are inactive
    (i.e., they do nothing and consume no resources).
  • further threads can be activated via a system call (lthread_ex_regs())
  • Model will change in future versions!
• Similarly, upon system initialisation, the full set of tasks (2048 on R4k)
  is created, but in an inactive state.
• A task has a chief (parent/owner).
  • Chiefs will vanish in future versions!

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