"Process zero executes a broadcast, followed by a blocking send operation. Pro-
cess one first executes a blocking receive that matches the send, followed by
broadcast call that matches the broadcast of process zero. This program may
deadlock. The broadcast call on process zero may block until process one ex-
ecutes the matching broadcast call, so that the send is not executed. Process
one will definitely block on the receive and so, in this case, never executes the broadcast.