Description. A party sends a message to another party.
Case 1:
Non-blocking send
The task that sends the message
is completed after handing the message to the underlying communication
infrastructure
Case 2: Blocking send
The task that sends waits
until the message has reached its destination as indicated by an
acknowledgment.
Case 3: Blocking send
with fault
Same as previous case but a fault occurs and is propagated
back to the sender. The case of "non-blocking send with fault" is
similar to this one except that the execution does not block at the
task where the message is emitted.