[英]can i make this class thread safe via immutable object?
我有一堂課,我有2個人檢查余額並從一個普通帳戶中提取資金。.我已通過synchronized
關鍵字使交易線程變得安全,但是它有很多開銷,我了解了不可變對象和線程安全性他們提供 。 但是我無法通過不可變對象使此類線程安全
代碼:
final class bank implements Runnable
{
private final int balance,min_balance;
bank(int bal,int mbal)
{
this.balance=bal;
this.min_balance=mbal;
}
@Override
public void run()
{
transaction();
}
public void transaction()
{
if(checkBalance()> min_balance)
{
System.out.println("checkin is done by : "+Thread.currentThread().getName()
+" and Balance left in the account is : "+checkBalance());
System.out.println(Thread.currentThread().getName()+" is going to sleep ...");
try{
Thread.currentThread().sleep(2000); }
catch(Exception e){
}
System.out.println(Thread.currentThread().getName()+" Woke up ..");
withdraw();
System.out.println(Thread.currentThread().getName()+" has made the withdrawl ..");
}
else{
lowBalance();
}
}
int checkBalance()
{
return balance;
}
void lowBalance()
{
System.out.println("balance is not adequate");
}
void withdraw()
{
balance=balance-20; //this wont work as balance is private
}
}
public class ryanmonica {
public static void main(String args[])
{
bank obj=new bank(100,20);
Thread t1=new Thread(obj);
Thread t2=new Thread(obj);
t1.setName("Ryan");
t2.setName("Monica");
t1.start();
t2.start();
}
}
不可變對象的狀態永遠不會改變。 由於您需要在實例中更改狀態( balance
和minBalance
正在更改),因此需要使用同步機制。
不可變對象是線程安全的,因為它們不允許在實例中更改狀態。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.