자바 스레드 풀을 사용하여 동기화된 간단한 인출, 입금 구현하고 있는데 자꾸 결과값이 안나오네요

Question

제목 그대로입니다. balance값이 자꾸 동기화가 되질 않고 엉뚱한 값이 나와요. 뭐가 문제일까요? 동기화 부분은 다 한것 같은데 다른데에서 문제가 있는걸까요.. 고수님들 도와주세요..import java.security.SecureRandom; public class Transaction implements Runnable { private static final SecureRandom generator = new SecureRandom(); private final int sleepTime; // random sleep time for thread private String transaction; private int amount; private int balance; private Account account; public Transaction (String transaction, int amount, Account account) { this.transaction = transaction; this.amount = amount; this.account = account; sleepTime = generator.nextInt(2000); } @Override public void run() { // TODO Auto-generated method stub try { if(transaction == "deposit") { balance = account.deposit(amount); } else if (transaction == "withdraw") { balance = account.withdraw(amount); } System.out.println("[" + transaction + "] amount : " + amount +" balance : " + balance); Thread.sleep(sleepTime); }catch (InterruptedException e) { e.printStackTrace(); Thread.currentThread().interrupt(); // re-interrupt the thread } } } public class Account { private static int balance; public synchronized int deposit(int amount) { balance += amount; return balance; } public synchronized int withdraw(int amount) { balance -= amount; return balance; } } public class AccountTest { public static void main(String[] args) { // TODO Auto-generated method stub List john = Collections.synchronizedList(new ArrayList<>()); Account account = new Account(); // add Transaction objects john.add(new Transaction("deposit", 1000, account)); john.add(new Transaction("withdraw", 500, account)); john.add(new Transaction("withdraw", 200, account)); john.add(new Transaction("deposit", 3000, account)); ExecutorService executorService = Executors.newCachedThreadPool(); for(int i=0; i

자바 스레드 풀을 사용하여 동기화된 간단한 인출, 입금 구현하고 있는데 자꾸 결과값이 안나오네요

0개의 답변

#synchronized 목록