Row corresponds to ranks, and columns corresponds to data.
Input:
Output:
126127128129130131132133134135136
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.gather(send[rank], recv, 0); } }); t[i].start(); }