MPI_Request* requests = new MPI_Request[expected_recv_count];
for (k = 0; k < expected_recv_count; k++) {
tmp_buf[k] = smpi_get_tmp_sendbuffer(count * std::max(extent, true_extent));
MPI_Request* requests = new MPI_Request[expected_recv_count];
for (k = 0; k < expected_recv_count; k++) {
tmp_buf[k] = smpi_get_tmp_sendbuffer(count * std::max(extent, true_extent));