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

IPC System Call Overview

One system call, variants accessible via separate C library entry points

Client functions

• send() send a message (blocking) to a specific thread
• receive() ``closed'' receive from specific sender (might be interrupt)--
  includes sleeping (if specify invalid sender)
• wait() ``open'' receive from any thread (incl. interrupt)
• call() send and wait for reply (usual ``RPC'' operation)
• reply_and_wait() send message and wait for any new message
  typical server operation
• send_deceiving() like send() but substituting sender ID
• reply_deceiving_and_wait() 
  like reply_and_wait() but substituting sender ID

C bindings for chiefs

Alternative bindings which return the ID of the intended destination in the case of redirection:

• chief_send() 
  identical to send_deceiving
• chief_wait() 
  like wait() but returns ID of intended destination
• chief_receive() 
  like receive() but returns ID of intended destination
• chief_call() 
  like call() but substitutes sender ID and returns ID of intended destination
• chief_reply_and_wait() 
  like reply_deceiving_and_wait() but returns ID of intended destination

The ID of the intended destination supports transparent forwarding by chief.