-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathBank.java
More file actions
75 lines (60 loc) · 1.74 KB
/
Bank.java
File metadata and controls
75 lines (60 loc) · 1.74 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
package Chapter14Thread.synchronize;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class Bank {
private final double[] accounts;//只能初始化一次
//保证同步的锁
private Lock bankLock;
//条件对象
private Condition sufficientFunds;
//初始化每个账户中的钱
public Bank(int n,double initalBallBounce){
accounts=new double[n];
for(int i=0;i<accounts.length;i++){
accounts[i]=initalBallBounce;
}
//初始化银行锁
bankLock=new ReentrantLock();
//银行锁的条件对象
sufficientFunds=bankLock.newCondition();
}
//可以用synchronize关键字
public void transfer(int from ,int to,double amount){
//线程封锁封锁锁对象
bankLock.lock();
try {
while(accounts[from]<amount)
//余额不足，--调用await(),当前线程阻塞，并放弃了锁
//进入该条件的等待集，当锁可用时，不能立即解除阻塞，相反，一直处于阻塞知道另一个线程调用singalAll()
sufficientFunds.await();
//返回正在执行的线程对象
System.out.println(Thread.currentThread());
accounts[from]-=amount;
System.out.printf("%10.2f from %d to %d",amount,from ,to);
accounts[to]+=amount;
System.out.printf("Total balance is %10.2f%n",getTotalBalance());
//唤醒所有等待线程(只是通知正在等待的线程，此时可能满足条件，值得再次去检测条件)
//WARNNNING-------当一个线程拥有条件锁时，只能调用await,singalAll,singal
sufficientFunds.signalAll();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public double getTotalBalance(){
bankLock.lock();
try{
double sum=0;
for(double a:accounts){
sum+=a;
}
return sum;
}finally{
bankLock.unlock();
}
}
public int size(){
return accounts.length;
}
}