Screen Version

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

IPC

• Message-passing IPC provides communication between threads.

• All IPC is
  • synchronous (i.e., blocking), and
  • unbuffered
  This is key to high IPC performance

• IPC requires an agreement between sender and receiver
  (i.e., receiver must be expecting IPC, must provide buffers, etc.).
  • IPC supports in-line and out-of-line by-value data.
  • IPC supports map and grant VM operations for by-reference data.

• Blocking can be limited by timeouts.

Note the interaction between IPC and threads:

• threads need efficient IPC to talk,
• blocking IPC needs low-cost threads to be efficient.