事實上Java實現並沒有成功，不知為何總會有似乎是死鎖的情況發生，任務並不能執行結束。

我已經再三檢查了我的程式碼實現，也邀請朋友來檢查我的程式碼，但朋友同樣也遇到了跟我一樣的問題。

Java實現：

 1 public class Solution{
 2 
 3     static int balance = 5000;      // 嘗試用兩個執行緒來對餘額進行修改
 4     static int trade_amount = 12;   // 一個執行緒充值，一個執行緒取錢，每次操作的額度和操作的次數相同
 5                                     // 在併發情況下，最後的金額應該還保持原來的數目
 

 6     static boolean[] WhoIsRuning = new boolean[] {false, false};
 7     static int turn = 0;
 8 
 9     public static void main(String[] args) throws InterruptedException {
10         long delay = 2; // 控制執行緒的速度，讓執行緒跑的慢一點
11 
12         Thread one = new Thread(new Runnable(){
13             @Override
 
14             public void run() {
15                 int me      = 0;
16                 int other   = 1;
17                 for( int i = 0; i < 100; i++ ){
18                     /* 進入臨界區 */
19                     WhoIsRuning[me] = true; turn = other;
20                     while( WhoIsRuning[other] && turn == other ) ;
 
21                     /* 訪問敏感資源 */
22                     balance += trade_amount;
23                     System.out.println("#" + i + " one(0) top up 13 yuan.");
24                     /* 退出臨界區 */
25                     WhoIsRuning[me] = false;
26                     /* 為了更容易觸發似乎是死鎖的情形，讓執行緒跑的慢一點*/
27                     try{
28                         Thread.sleep(delay);
29                     }catch( InterruptedException e ){
30                         e.printStackTrace();
31                     }
32                 }
33             }
34         });
35         Thread another = new Thread(new Runnable(){
36             @Override
37             public void run() {
38                 /* 與執行緒1相似的程式碼，但改變了身份和行為 */
39                 int me      = 1;
40                 int other   = 0;
41 
42                 for( int i = 0; i < 100; i++ ){
43                     WhoIsRuning[me] = true; turn = other;
44                     while( WhoIsRuning[other] && turn == other ) ;
45 
46                     balance -= trade_amount;
47                     System.out.println("#" + i + " another(1) withdraw up 13 yuan.");
48 
49                     WhoIsRuning[me] = false;
50 
51                     try{
52                         Thread.sleep(delay);
53                     }catch( InterruptedException e ){
54                         e.printStackTrace();
55                     }
56                 }
57             }
58         });
59         one.start();    another.start();
60         another.join(); one.join();
61 
62         System.out.println("\nthe balance now is " + balance);
63     }
64 }

C++實現得到了預期的效果：

// PetersonsAlgorithm.cpp : 此檔案包含 "main" 函式。程式執行將在此處開始並結束。
//

#include <iostream>
#include <thread>
#include <stdio.h>
#include <Windows.h>

int balance         = 5000;
int trade_amount    = 13;
int delay           = 0;

/* mutual exclusion contorls */ 
int wantsToAccessBalance[]  = { 0, 0 };
int turn                    = 0;

void TopUpBalance() {

    int me = 0, another = 1;
    for (size_t i = 0; i < 100; i++)
    {
        wantsToAccessBalance[me] = true; turn = another;
        while (wantsToAccessBalance[another] && turn == another);

        balance += trade_amount;
        printf("#%d. top up %d amount, the balance now left %d.\n",
            i, trade_amount, balance);
        Sleep(delay);
        wantsToAccessBalance[me] = false;
    }

}

void WithdrawMoney() {

    int me = 1, another = 0;
    for (size_t i = 0; i < 100; i++)
    {
        wantsToAccessBalance[me] = true; turn = another;
        while (wantsToAccessBalance[another] && turn == another);

        balance -= trade_amount;
        printf("#%d. withdraw %d amount, the balance now left %d.\n",
            i, trade_amount, balance);
        Sleep(delay);
        wantsToAccessBalance[me] = false;
    }
}

int main()
{
    std::thread     topup{ TopUpBalance };
    std::thread     withdraw{ WithdrawMoney };

    topup.join(); withdraw.join();

    printf("\nthe final balance now left %d.\n", balance);
}