Я пытался использовать synchronized и ReentrantLock в Bank.transfer, но я получаю вывод, подобный этому:
"От 7 до 3 передано 82,0. Всего 918", "От 0 до 4 переведено 27,0. Всего 973"
Хотя Total должен быть равен 1000. Скажите, что я не так?
public class expr {
public static Bank b = new Bank();
public static void main(String[] args) throws IOException, InterruptedException {
for (int i = 0; i < 4; i++) {
new BankTransfer();
}
}
}
public class BankTransfer implements Runnable{
public BankTransfer() {
Thread t = new Thread(this);
t.start();
}
@Override
public void run() {
while (true){
int from = (int) (expr.b.size * Math.random());
int to = (int) (expr.b.size * Math.random());
int amount = (int) (100 * Math.random());
expr.b.transfer(from, to, amount);
try {
Thread.sleep((long) (2000 * Math.random()));
} catch (InterruptedException e) {
System.out.println("Thread was interrupted!");
return;
}
}
}
}
public class Bank {
private int[] accounts;
public int size = 10;
private Lock block = new ReentrantLock();
public boolean transfer(int from, int to, double amount){
block.lock();
try{
if(accounts[from] >= amount && from != to){
accounts[from] -= amount;
System.out.println("From " + from + " to " + to + " transfered " + amount + ". Total " + getTotal());
accounts[to] += amount;
return true;
}
}finally {
block.unlock();
}
return false;
}
public Bank(){
accounts = new int[size];
for (int i = 0; i < size; ++i) {
accounts[i] = 100;
}
}
private int getTotal(){
int sum = 0;
for (int i = 0; i < size; ++i) sum += accounts[i];
return sum;
}
}