[Windows c++] CRITACAL_SECTION 和 Mutex 的安全性对比

原创

obentul 2022-09-23 13:37:23 博主文章分类：C/C++ ©著作权

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例子代码：

// ConsoleApplication1.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <Windows.h>
#include <process.h>
#include <string>
#include <iostream>

using namespace std;

CRITICAL_SECTION protector;
int a = [](CRITICAL_SECTION& cs){
  InitializeCriticalSection(&cs);
  return 0;
}(protector);

int cnt_1 = 0;
int cnt_2 = 0;

HANDLE mutex= CreateMutex(NULL,FALSE,NULL);

unsigned int __stdcall thread1(void* ptr)
{
  while (1){
    //EnterCriticalSection(&protector); //进入临界区
    WaitForSingleObject(mutex,INFINITE);
    cout << "thread 1 进入临界区" << endl;     //输出
    if (cnt_1 == 5) return 0;     //30秒后直接退出,同时不离开临界区,这会导致thread2锁住,因此2号线程将不再输出内容
    Sleep(3000);            //等待
    //LeaveCriticalSection(&protector); //离开临界区
    ReleaseMutex(mutex);
    cout << "thread 1 离开临界区" << endl;     //输出
    cnt_1++;
    Sleep(10);              //让另外一个线程抢临界区
  }
  return 0;
}

unsigned int __stdcall thread2(void* ptr)
{
  while (1){
    //EnterCriticalSection(&protector); //进入临界区
    WaitForSingleObject(mutex, INFINITE);
    cout << "thread 2 进入临界区" << endl;
    Sleep(3000);
    //LeaveCriticalSection(&protector); //离开临界区
    ReleaseMutex(mutex);
    cout << "thread 2 离开临界区" << endl;
    Sleep(10);              //让另外一个线程抢临界区
  }
  return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
  int step1;

  unsigned int i, j;
  _beginthreadex(NULL, 0, thread1, NULL, 0, &i);
  _beginthreadex(NULL, 0, thread2, NULL, 0, &j);

  cin >> step1;

  return 0;
}