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POJava synchronization not working as (I) expected
 

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    <p>programmer mates. I was testing java threading capabilities with a very simple code (or at least it <em>seemed</em> simple). I have this class Account:</p> <pre><code>public class Account { protected double balance; public synchronized void withdraw(double value) { this.balance = this.balance - value; } public synchronized void deposit(double value) { this.balance = this.balance + value; } public synchronized double getBalance() { return this.balance; } } </code></pre> <p>And I have two threads: <code>Depositer</code>, that deposits $10 a thousand times:</p> <pre><code>public class Depositer extends Thread { protected Account account; public Depositer(Account a) { account = a; } @Override public void run() { for(int i = 0; i &lt; 1000; i++) { this.account.deposit(10); } } } </code></pre> <p>And <code>Withdrawer</code>, that withdraws $10 a thousand times:</p> <pre><code>public class Withdrawer extends Thread { protected Account account; public Withdrawer(Account a) { account = a; } @Override public void run() { for(int i = 0; i &lt; 1000; i++) { this.account.withdraw(10); } } } </code></pre> <p>This arrangement is executed by:</p> <pre><code>public class Main { public static void main(String[] args) { Account account = new Account(); Thread c1 = new Depositer(account); Thread c2 = new Withdrawer(account); c2.start(); c1.start(); System.out.println(account.getBalance()); } } </code></pre> <p>As the methods are sychronized, I just expected that the balance was always 0 at the end, but this not happens sometimes. And I sincerely cannot figure out why. Can someone see where is my fault?</p>
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    1. USLailson Bandeira
    1. USLailson Bandeira
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      1. VTUpMod
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      1. VTUpMod
    1. COCan you perhaps tell us what results you are getting?
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      1. USmnuzzo
    2. COI was getting all sorts of value, but my error was not waiting for the threads to finish. With join, it always display zero, as it should.
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      1. USLailson Bandeira
 

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