关于windows线程同步的四种方法

#include "stdafx.h"
#include "iostream"
#include "list"
#include "windows.h"
#include "process.h"

using namespace std;
/*
线程同步
1.临界区
2.信号量
3.事件对象
4.互斥量
*/

/************************************************************************/
/* 临界区    单进程内线程同步                                   */
/************************************************************************/
CRITICAL_SECTION g_cri;   //临界区
list<int> g_list2;
unsigned int __stdcall threadRead(LPVOID param)
{
while(true)
{
EnterCriticalSection(&g_cri);
for (list<int>::iterator it = g_list2.begin(); it != g_list2.end();it++)
{
cout << "元素为:"<<*it << endl;
}
LeaveCriticalSection(&g_cri);
Sleep(100);
}
return 0;
}

unsigned int __stdcall threadWrite(LPVOID param)
{
srand(GetTickCount());
while (true)
{
EnterCriticalSection(&g_cri);
if (g_list2.size()>0)
{
if (rand() % 100 > 50)
{
g_list2.push_back(rand());
}
else
{
g_list2.erase(g_list2.begin());
}
}
else
{
g_list2.push_back(rand());
}
LeaveCriticalSection(&g_cri);
Sleep(100);
}
return 0;
}

HANDLE g_mutex;  //互斥量

unsigned int times = 0;
/************************************************************************/
/*   互斥量                                                              */
/************************************************************************/
unsigned int __stdcall firstThread(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_mutex, INFINITE);
if (times <=20)
{
cout << "线程1的第" << times++ << "次.." << endl;
}
else
{
break;
}
ReleaseMutex(g_mutex);
}
return 0;
}

unsigned int __stdcall secondThread(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_mutex, INFINITE);
if (times <= 20)
{
Sleep(1);
cout << "线程2的第" << times++ << "次.." << endl;
}
else
{
break;
}
ReleaseMutex(g_mutex);
}
return 0;
}

/************************************************************************/
/* 事件对象     可对进程外的线程同步
CreateEvent(NULL, false, false, NULL);
setEvent(g_event);
*/
/************************************************************************/

HANDLE g_event;
unsigned int __stdcall firstThread2(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_event, INFINITE);
if (times <= 20)
{
cout << "线程1的第" << times++ << "次.." << endl;
}
else
{
break;
}
SetEvent(g_event);

}
return 0;
}

unsigned int __stdcall secondThread2(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_event, INFINITE);
if (times <= 20)
{
Sleep(1);
cout << "线程2的第" << times++ << "次.." << endl;
}
else
{
break;
}
SetEvent(g_event);
}
return 0;
}

/************************************************************************/
/* 信号量   主要是可以指定个数
允许多个线程同一时刻访问同一资源，我们可以指定允许个数
*/
/************************************************************************/
HANDLE g_semaphore;

unsigned int __stdcall firstThread3(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_semaphore, INFINITE);
if (times <= 20)
{
cout << "线程1的第" << times++ << "次.." << endl;
}
else
{
break;
}
ReleaseSemaphore(g_semaphore, 1, NULL);

}
return 0;
}

unsigned int __stdcall secondThread3(LPVOID param)
{
while (true)
{
WaitForSingleObject(g_semaphore, INFINITE);
if (times <= 20)
{
Sleep(1);
cout << "线程2的第" << times++ << "次.." << endl;
}
else
{
break;
}
ReleaseSemaphore(g_semaphore, 1, NULL);

}
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
//InitializeCriticalSection(&g_cri);  //初始化临界区
//g_mutex = CreateMutex(NULL, false, NULL);  //创建互斥量

//g_event = CreateEvent(NULL, false, false, NULL); //可以根据第四个参数(线程名称)进行，不同进程的线程同步
//SetEvent(g_event);

g_semaphore = CreateSemaphore(NULL, 1, 1, NULL);   //信号量
HANDLE g_thread1 = (HANDLE)_beginthreadex(NULL, 0, firstThread3, NULL, 0, NULL);
HANDLE g_thread2 = (HANDLE)_beginthreadex(NULL, 0, secondThread3, NULL, 0, NULL);

CloseHandle(g_thread1);
CloseHandle(g_thread2);

cout << "主线程..\n";
Sleep(400000);

system("pause");
return 0;
}