Data Locality: Reputation Example

reputation_a.cpp

// Program A: some account with associated reputation
struct Account {
  long id;
  char[64] name;
  char[300] address;
  float reputation;
}

// we want to update and add some reputation every day
void increaseReputation(){
  parallel for (int i=0; i<count; i++){
    account->reputation += 2.5;
  }
}

reputation_b.cpp

// Program B: we have a split account
struct Account {
  long id;
  AccountInfo *info;
  float reputation;
}

struct AccountInfo {
  char[64] name;
  char[300] address;
}

// we want to update and add some reputation every day
void increaseReputation(){
  parallel for (int i=0; i<count; i++){
    account->reputation += 2.5;
  }
}