Screen Version

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

L4 Threads

• A thread is the basic active entity (unit of execution and scheduling).

• Threads communicate via message-passing IPC.

• Each thread has
  • a register set (IP, SP, user-visible registers, processor state)
  • an associated task/address space
  • a page fault handler (pager)
    this is a thread which receives page faults (via IPC)
  • an exception handler (dependent on architecture)
    this is a thread which receives exceptions (via IPC)
  • preempters (not implemented)
    tread which receives preemption messages
  • scheduling parameters (priority, time slice)

.