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

Obtain Thread IDs: id_nearest System Call

• Returns the ID of the thread which would really receive a message sent to a specified destination thread.
• Also returns a type field, indicating the direction of the IPC with respect to the clan boundary.

• If destination is:

  inside own clan:

  returns destination thread ID, type = same;

  outside own clan:

  returns own chief's ID, type = outer;

  in subclan of own clan:

  returns ID of chief (within own clan) of subclan, type = inner;

  nil:

  returns own thread ID.