Vfrdtyky

So I am writing a hotel reservation system where I have hotel rooms stored in shared memory and will have an x number of customers reserve, cancel, pay, etc the rooms. Each customer will be a child process and they should all be running concurrently, trying to do the stated transactions to the rooms.

Here is my code for forking the child processes:

int pid[10];

for(int i = 0; i < numOfCustomers; i++) {

    pid[i] = fork();

    if(pid[i] < 0) {

        perror("Bad fork");

    }

    else if(pid[i] == 0) { //is child i (Each customer is a child process)

        cout << "CUSTOMER: " << i << endl;

        while(!customers[i].transactions.empty()) { //runs until customer finishes all transactions

            string op = customers[i].transactions.front();

            if(op == "reserve") {

                if(sem_wait(semid, 0))

                    exit(1);

                Reserve tempq = customers[i].reservequeue.front();

                for(int i = 0; i < tempq.roomcounter; i++) {

                    int roomnum = tempq.roomqueue.front();

                    if(shared_memory[roomnum-1].isavailable == true) {

                        shared_memory[roomnum-1].isavailable = false;

                        shared_memory[roomnum-1].day = tempq.day;

                        shared_memory[roomnum-1].month = tempq.month;

                        shared_memory[roomnum-1].year = tempq.year;

                        shared_memory[roomnum-1].customer = cust;

                    }

                    else {

                        cout << "Room " << roomnum << " already taken." << endl;

                    }

                    tempq.roomqueue.pop();

                }

                customers[i].reservequeue.pop();

                if(sem_signal(semid, 0))

                    exit(1);

            }

            else if(op == "cancel") { //not done yet

                cout << "cancel" << endl; 

            }

            else if(op == "check") { //not done yet

                cout << "check" << endl;

            }

            else if(op == "pay") { //not done yet

                cout << "pay" << endl;

            }

            customers[i].transactions.pop();

        }

        exit(0);

    }

    else { //is parent



    }

}



//waits for each process to finish

for (int i = 0; i < numOfCustomers; i++) {

    wait(NULL);

}

The problem is that it does everything in child one first, finishes, then does everything in child 2. Processes aren't running concurrently which defeats the whole purpose of having shared memory and using semaphores.

Any help would be greatly appreciated, thanks.