void acc_right(void* p)
{
 DWORD m_delay;
 int m_serial;
 int tmp1 , tmp2, rand_num;
 int counter = 0;

//get info from para

 m_serial = ((ThreadInfo*) (p)) -> serial;
 m_delay  = (DWORD) (((ThreadInfo*)(p)) -> delay*INTE_PER_SEC);

 do
 {

  flag[m_serial]=true;
  turn=1-m_serial;
  while (flag[1-m_serial] && turn==1-m_serial);

//begin critical_section

  printf("I am thread  %d , I am doing  %05dth step\n",m_serial,counter);
  tmp1 = accnt1;
  tmp2 = accnt2;
  rand_num = rand();

  accnt1 = tmp1 - rand_num;
  Sleep(m_delay);
  accnt2 = tmp2 + rand_num;
  accnt = accnt1 + accnt2;
//critical_section  end

  flag[m_serial]=false;

  counter++;
  printf("Now the random number is %d ; and accnt1+accnt2 =  %05d\n\n",rand_num,accnt);
 } while (counter<10); 
 printf("At last of thread %d accnt1+accnt2 =  %05d\n",m_serial,accnt);
} //end acc_right

void acc_wrong(void* p)
{
 DWORD m_delay;
 int m_serial;
 int tmp1 , tmp2, rand_num;
 int counter = 0;

//get info from para

 m_serial = ((ThreadInfo*) (p)) -> serial;
 m_delay  = (DWORD) (((ThreadInfo*)(p)) -> delay*INTE_PER_SEC);

 do
 {

//begin critical_section

  printf("I am thread  %d , I am doing  %05dth step\n",m_serial,counter);
  tmp1 = accnt1;
  tmp2 = accnt2;
  rand_num = rand();

  accnt1 = tmp1 - rand_num;
  Sleep(m_delay);
  accnt2 = tmp2 + rand_num;
  accnt = accnt1 + accnt2;
//critical_section  end

  counter++;
  printf("Now the random number is %d ; and accnt1+accnt2 =  %05d\n\n",rand_num,accnt);
 } while (counter<10); 
 printf("At last of thread %d accnt1+accnt2 =  %05d\n",m_serial,accnt);
} //end acc_wrong

任務三  同步對象解決臨界區問題
一、基本信息
實踐題目：同步對象解決臨界區問題－兄弟問題
二、實踐內容簡要描述
實踐目標：
學會使用Win32同步對象（臨界區內核對象、信號量內核對象等）；
用同步對象解決臨界區問題－兄弟問題。
實踐內容：
設置競爭條件：
定義兩個全局變量：accnt1和accnt2，初值都為零；
創建兩個線程acc1和acc2；
（1）獲得一個隨機數
（2）從accnt1減去這個隨機數；
（3）將這個隨機數加到accnt2中；
（4）正確的話，accnt1+accnt2=0。
設置條件使其不正確。
用Win32提供的同步對象實現兩個線程的協作，以解決以上臨界區問題，即兄弟問題。
三、實踐報告主要內容
設計思路：
用一個臨界區變量可以實現兩個線程對臨界區的訪問，在每個線程進入臨界區前調用EnterCriticalSection函數申請權限，離開臨界區后調用LeaveCriticalSection函數釋放資源從而讓其他線程可以訪問，這樣可以阻止兩個線程同時處于臨界區。
主要數據結構：
struct ThreadInfo
{
 int serial;
 double delay;
};//存放線程的ID及其執行延時（模擬兄弟在外創業的時間）

/*volatile*/  int accnt1 = 0;  //借款帳戶中金額
/*volatile*/  int accnt2 = 0;  //還款帳戶中金額
/*volatile*/  int accnt;  //借款帳戶與還款帳戶金額總和，應保持為0
CRITICAL_SECTION g_cs; //臨界區變量，用于兩個線程的互斥訪問
主要代碼結構：
do{
entry section
critical section
exit section
remainder section
}while(1);
主要代碼分析：
1．entry section用于在進入臨界區時的等待
EnterCriticalSection(&my_section); 
2．exit section用于離開臨界區后的發送信號的工作，通知另外的線程可以進入臨界區
 LeaveCriticalSection(&my_section);
四、實踐結果
基本數據：
 
源程序代碼行數 完成實踐投入的總時間 資料查閱時間 編程調試時間 源程序文件    
193 0.2小時 0.1小時 0.1小時 ex3.cpp  
測試數據設計：
“ex3.dat”文件內容如下：
 0  1
1  1
2  1
3  1
4  1
測試結果分析：
運行結果圖如下所示：
Now, We begin to read thread Information to thread_info array
I am thread  0 , I am doing  00000th step
I am thread  1 , I am doing  00000th step
Now the random number is 22413 ; and accnt1+accnt2 =  00000
I am thread  2 , I am doing  00000th step
Now the random number is 17802 ; and accnt1+accnt2 =  00000
I am thread  3 , I am doing  00000th step
Now the random number is 5286 ; and accnt1+accnt2 =  00000
I am thread  4 , I am doing  00000th step
Now the random number is 23304 ; and accnt1+accnt2 =  00000
I am thread  0 , I am doing  00001th step
Now the random number is 12270 ; and accnt1+accnt2 =  00000
I am thread  1 , I am doing  00001th step
Now the random number is 12170 ; and accnt1+accnt2 =  00000
I am thread  2 , I am doing  00001th step
Now the random number is 4729 ; and accnt1+accnt2 =  00000
I am thread  3 , I am doing  00001th step
Now the random number is 28247 ; and accnt1+accnt2 =  00000
I am thread  4 , I am doing  00001th step
Now the random number is 3819 ; and accnt1+accnt2 =  00000
I am thread  0 , I am doing  00002th step
Now the random number is 2578 ; and accnt1+accnt2 =  00000
I am thread  1 , I am doing  00002th step
Now the random number is 21931 ; and accnt1+accnt2 =  00000
I am thread  2 , I am doing  00002th step
Now the random number is 170 ; and accnt1+accnt2 =  00000
I am thread  3 , I am doing  00002th step
Now the random number is 18300 ; and accnt1+accnt2 =  00000
I am thread  4 , I am doing  00002th step
Now the random number is 2054 ; and accnt1+accnt2 =  00000
I am thread  0 , I am doing  00003th step
Now the random number is 538 ; and accnt1+accnt2 =  00000
I am thread  1 , I am doing  00003th step
Now the random number is 12469 ; and accnt1+accnt2 =  00000
I am thread  2 , I am doing  00003th step
Now the random number is 7825 ; and accnt1+accnt2 =  00000
I am thread  3 , I am doing  00003th step
Now the random number is 14181 ; and accnt1+accnt2 =  00000
I am thread  4 , I am doing  00003th step
Now the random number is 5984 ; and accnt1+accnt2 =  00000
I am thread  0 , I am doing  00004th step
Now the random number is 17150 ; and accnt1+accnt2 =  00000
I am thread  1 , I am doing  00004th step
Now the random number is 15529 ; and accnt1+accnt2 =  00000
At last of thread 0 accnt1+accnt2 =  00000
I am thread  2 , I am doing  00004th step
Now the random number is 31878 ; and accnt1+accnt2 =  00000
At last of thread 1 accnt1+accnt2 =  00000
I am thread  3 , I am doing  00004th step
Now the random number is 3842 ; and accnt1+accnt2 =  00000
At last of thread 2 accnt1+accnt2 =  00000
I am thread  4 , I am doing  00004th step
Now the random number is 5953 ; and accnt1+accnt2 =  00000
At last of thread 3 accnt1+accnt2 =  00000
Now the random number is 23968 ; and accnt1+accnt2 =  00000
At last of thread 4 accnt1+accnt2 =  00000
All threads have finished Operating.
Press any key to finish this Program.
程序運行過程中，線程1或線程2向accnt1中借款，一定延時后向accnt2中還款，總額accnt均為0，程序運行結果完全正確。
五、實踐體會
 使用臨界區變量解決臨界區問題實現起來比軟件方法簡單明了，并且可以應用到多進程的情況之中，通過這次實驗我基本了解了臨界區變量的使用方法和作用，其實，解決臨界區問題的方法相當的多，從中選取一種合適的是要很多經驗積累的。

六、參考文獻
1、MSDN

附：源程序代碼
#include <windows.h>
#include <conio.h>
#include <stdlib.h>
#include <fstream.h>
#include <stdio.h>
#include <time.h>
#define INTE_PER_SEC  500
#define MAX_THREAD_NUM  64
#define RIGHT_VERSION TRUE
#define WRONG_VERSION FALSE

CRITICAL_SECTION  my_section;

struct ThreadInfo
{
 int serial;
 double  delay;
};

/*volatile*/  int accnt1 = 0; 
/*volatile*/  int accnt2 = 0;
/*volatile*/  int accnt;

void account( char* file,BOOL version);
void acc_right(void* p);
void acc_wrong(void* p);

////////////////////////////////////////////////////////
// main function
////////////////////////////////////////////////////////

int main( int agrc, char* argv[] )
{
 char ch;

 while ( TRUE )
 {
  // Clear screen
  system( "cls" );

  // display prompt info
  printf("*********************************************\n");
  printf("       1.Start the right version(with the using of CRITICAL_SECTION)\n");
  printf("       2.Start the wrong version(without any algorithm of synchronization)\n");
  printf("       3.Exit to Windows\n");
  printf("*********************************************\n");
  printf("Input your choice(1 、2 or 3): ");

  // if the number inputed is error, retry!
  do
  {
   ch = (char)_getch(); 
  }while ( ch != '1' && ch != '2'&& ch != '3');

  system ( "cls" );
  if ( ch == '1')
   account("ex3.dat",RIGHT_VERSION);
  else if (ch =='2')
   account("ex3.dat",WRONG_VERSION);
  else if ( ch == '3')
   return 0;
  printf("\nPress any key to finish this Program. \n");
  _getch();
 } //end while
} //end main

void account( char* file,BOOL version)
{
 DWORD n_thread = 0;
 DWORD thread_ID;
 DWORD wait_for_all;
// Tread Object Array

 HANDLE h_Thread[MAX_THREAD_NUM];
 ThreadInfo  thread_info[MAX_THREAD_NUM];

 ifstream  inFile;
 inFile.open(file);  //open file
 printf( "Now, We begin to read thread Information to thread_info array \n\n" );

 while ( inFile )
 {
  // read every thread info
  inFile>>thread_info[n_thread].serial;
  inFile>>thread_info[n_thread++].delay;
  inFile.get();
 } //end while

// initialize the data
 srand((unsigned)time(NULL));
 accnt1=0;
 accnt2=0;
// Create all thread
 if (version==RIGHT_VERSION)
 {
  InitializeCriticalSection(&my_section);  //init critical section
  for ( int i = 0; i < (int)(n_thread); i++)
  {
   // Create a thread
   h_Thread[i] = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)(acc_right), &thread_info[i], 0, &thread_ID);
  } //end for
 } else
 {
  for ( int i = 0; i < (int)(n_thread); i++)
  {
   // Create a thread
   h_Thread[i] = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)(acc_wrong), &thread_info[i], 0, &thread_ID);
  } //end for
 }
// Create thread
// waiting all thread will been finished
 wait_for_all = WaitForMultipleObjects(n_thread,h_Thread,TRUE, -1);
 printf("All threads have finished Operating.\n");
}// end account

void acc_right(void* p)
{
 DWORD m_delay;
 int m_serial;
 int tmp1 , tmp2, rand_num;
 int counter = 0;
//get info from para
 m_serial = ((ThreadInfo*) (p)) -> serial;
 m_delay  = (DWORD) (((ThreadInfo*)(p)) -> delay*INTE_PER_SEC);
 do
 {
  EnterCriticalSection(&my_section);
//begin critical_section
  printf("I am thread  %d , I am doing  %05dth step\n",m_serial,counter);
  tmp1 = accnt1;
  tmp2 = accnt2;
  rand_num = rand();
  accnt1 = tmp1 - rand_num;
  Sleep(m_delay);
  accnt2 = tmp2 + rand_num;
  accnt = accnt1 + accnt2;
//critical_section  end
  LeaveCriticalSection(&my_section);
  counter++;
  printf("Now the random number is %d ; and accnt1+accnt2 =  %05d\n\n",rand_num,accnt);
 } while (counter<5); 
 printf("At last of thread %d accnt1+accnt2 =  %05d\n",m_serial,accnt);
} //end acc_right

void acc_wrong(void* p)
{
 DWORD m_delay;
 int m_serial;
 int tmp1 , tmp2, rand_num;
 int counter = 0;
//get info from para
 m_serial = ((ThreadInfo*) (p)) -> serial;
 m_delay  = (DWORD) (((ThreadInfo*)(p)) -> delay*INTE_PER_SEC);
 do
 {
//begin critical_section
  printf("I am thread  %d , I am doing  %05dth step\n",m_serial,counter);
  tmp1 = accnt1;
  tmp2 = accnt2;
  rand_num = rand();
  accnt1 = tmp1 - rand_num;
  Sleep(m_delay);
  accnt2 = tmp2 + rand_num;
  accnt = accnt1 + accnt2;
//critical_section  end
  counter++;
  printf("Now the random number is %d ; and accnt1+accnt2 =  %05d\n\n",rand_num,accnt);
 } while (counter<5); 
 printf("At last of thread %d accnt1+accnt2 =  %05d\n",m_serial,accnt);
} //end acc_wrong

任務四  同步對象解決有限緩沖區問題
一、基本信息
實踐題目：同步對象解決有限緩沖區問題
二、實踐內容簡要描述