//latency time per message
#define COST_LATENCY (1.e-6)
//memory bandwidth: time per per byte
#define COST_MEMBW (1.e-9)
//network bandwidth: time per byte
#define COST_NETWBW (5.e-10)
//flop cost: time per flop
#define COST_FLOP (2.e-11)
//flop cost: time per flop
#define COST_OFFLOADBW (5.e-10)


CommData::CommData(){
  ...
}