Blocking behavior

Blocking Behavior

• Nonblocking send:

  returns ``immediately''

  message buffer should not be written to after return

  must check for local completion

• Blocking send:

  returns when send is locally complete

  message buffer can be written to after return

• Nonblocking receive:

  returns ``immediately''

  message buffer should not be read from after return

  must check for local completion

• Blocking receive:

  returns when receive is locally complete

  message buffer can be read from after return