Row corresponds to ranks, and columns corresponds to data.
Input:
Output:
187188189190191192193194195196197
for (int i = 0; i < t.length; ++i) { final int rank = i; t[i] = new Thread(new Runnable() { public void run() { Communicator comm = coll.createCommunicator(rank); comm.allToAll(send[rank], recv[rank]); } }); t[i].start(); }