Java 我的同步不起作用
我尝试在Bank.transfer中使用synchronized和ReentrantLock,但得到的输出如下: 从7岁到3岁转为82.0岁。总计918人,从0人到4人,共计27.0人。总数973 而总数必须等于1000。告诉我我怎么了Java 我的同步不起作用,java,synchronization,Java,Synchronization,我尝试在Bank.transfer中使用synchronized和ReentrantLock,但得到的输出如下: 从7岁到3岁转为82.0岁。总计918人,从0人到4人,共计27.0人。总数973 而总数必须等于1000。告诉我我怎么了 public class expr { public static Bank b = new Bank(); public static void main(String[] args) throws IOException, Interrupt
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;
}
}
在完成变压器两端后,计算总流量。。。i、 e.将System.println移到accounts[到]+=amount.在完成transfier的两端后计算总数。。。i、 e.将System.println移到accounts[到]+=金额之后。这部分看起来很奇怪:
accounts[from] -= amount;
System.out.println("From " + from + " to " + to + " transfered " + amount + ". Total " + getTotal());
accounts[to] += amount;
您正在传输完成前打印总数。此部分看起来很奇怪:
accounts[from] -= amount;
System.out.println("From " + from + " to " + to + " transfered " + amount + ". Total " + getTotal());
accounts[to] += amount;
您正在打印转账完成前的总额。您在从一个帐户扣除款项后,但在将其添加到另一个帐户之前,调用getTotal。根据转账金额,它将始终显示小于100。您在从一个帐户扣除款项后,但在将其添加到另一个帐户之前,调用getTotal。根据传输的金额,它将始终显示小于100。选择未中断。记住这句话,意思是,如果一种成熟语言的一个基本部分不能正常工作,那可能就是你正在做的事情。看看你打印输出的地方。我会觉得这是一个奇怪的“巧合”,转移的金额和总数达到1000;选择没有被破坏。记住这句话,意思是,如果一种成熟语言的一个基本部分不能正常工作,那可能就是你正在做的事情。看看你打印输出的地方。我会觉得这是一个奇怪的“巧合”,转移的金额和总数达到1000;