Communication scope

Communication Scope

• In MPI, a process is specified by:
  • a group
  • a rank relative to the group ()
• A message label is specified by:
  • a message context
  • a message tag relative to the context
• Groups are used to partition process space
• Contexts are used to partition ``message label space''
• Groups and contexts are bound together to form a communicator object. Contexts are not visible at the application level.
• A communicator defines the scope of a communication operation