BLACS -- Advanced Topics
The BLACS provide “globally-blocking” point-to-point receive, broadcasts and combines. The BLACS point-to-point send is “locally-blocking”.
- Globally blocking: The return from the operation implies that the buffer is available for re-use. The operation may not complete unless the complement of the operation is called.
- Locally blocking: The return from the send implies that the buffer is available for re-use. The send will complete regardless of whether the corresponding receive is posted.