Concurrent and Parallel Programming

Given the following java class called Parcel_Delivery,

class Parcel_Delivery {

private int[] b;

public Parcel_Delivery(int n) {

b = new int[n];

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

b[i] = 0;

}

}

public void deliver(int i, int parcels) {

b[i] = b[i] + parcels;

}

public int empty(int i) {

int result = b[i];

box = 0;

return result;

}

}

1. Make a thread safe version of class Parcel_Delivery in such a way that delivery deliver parcels at same time and do not block each other.

2. Add a transfer function, which transfer parcels from one box to another that is thread safe.

3. Give a lock-free thread safe version of Parcel_Delivery.