bit_map
memset(&softs->bit_map, SLOT_AVAILABLE, sizeof(softs->bit_map));
softs->bit_map.bit_vector[target] = SLOT_AVAILABLE;
if(softs->bit_map.bit_vector[avail_target] == SLOT_AVAILABLE){
softs->bit_map.bit_vector[avail_target] = SLOT_TAKEN;
bit_map_t bit_map;