comm = simcall_comm_isend(rdv, task_size, rate,
src_buff, src_buff_size, match_fun, NULL, data, 0);
simcall_comm_wait(comm, timeout);
comm = simcall_comm_isend(rdv, task_size, rate,
src_buff, src_buff_size, match_fun, NULL, data, 0);
simcall_comm_wait(comm, timeout);