線程同步之互斥量

1.互斥量

採用互斥對象機制。 只有擁有互斥對象的線程纔有訪問公共資源的權限，因爲互斥對象只有一個，所以能保證公共資源不會同時被多個線程訪問。互斥不僅能實現同一應用程序的公共資源安全共享，還能實現不同應用程序的公共資源安全共享。

2.使用

HANDLE hMutex;  //定義互斥對象句柄
hMutex = CreateMutex(NULL, false, "mutex");     //創建互斥對象
WaitForSingleObject(hMutex, INFINITE);
ReleaseMutex(hMutex);

3.實例

#include<windows.h>
#include<iostream>
using namespace std;
 
int number = 1; //定義全局變量
HANDLE hMutex;  //定義互斥對象句柄
 
unsigned long __stdcall ThreadProc1(void* lp)
{
    while (number < 100)
    {
        WaitForSingleObject(hMutex, INFINITE);
        cout << "thread 1 :"<<number << endl;
        ++number;
        _sleep(100);
        ReleaseMutex(hMutex);
    }
 
    return 0;
}
 
unsigned long __stdcall ThreadProc2(void* lp)
{
    while (number < 100)
    {
        WaitForSingleObject(hMutex, INFINITE);
        cout << "thread 2 :"<<number << endl;
        ++number;
        _sleep(100);
        ReleaseMutex(hMutex);
    }
 
    return 0;
}
 
int main()
{
    hMutex = CreateMutex(NULL, false, "mutex");     //創建互斥對象
 
    CreateThread(NULL, 0, ThreadProc1, NULL, 0, NULL);
    CreateThread(NULL, 0, ThreadProc2, NULL, 0, NULL);
 
    Sleep(10*1000);
 
    system("pause");
    return 0;
}

4.結果輸出