Mutex

// Mutex.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <windows.h>
#include <assert.h>


//Mutex的OpenMutex()与ReleaseMutex()必须线程配对的.不配对线程的操作会报错(Attempt Release Mutex not owner by caller).
//Mutex对象的句柄所在线程退出,会自动释放&关闭句柄,且Mutex对象会置为有信号
LONG g_i0{};
LONG g_i1{};
DWORD WINAPI ThreadProc1(LPVOID lpThreadParameter);
DWORD WINAPI ThreadProc2(LPVOID lpThreadParameter);

int main()
{
    HANDLE hMutex = CreateMutexA(0, 0, "Mutex0");        // Mutex创建出来就是有信号的
    if (!hMutex) { assert(0); }

    HANDLE hThread[2]{};
    hThread[0] = CreateThread(0, 0, ThreadProc1, 0, 0, 0);
    hThread[1] = CreateThread(0, 0, ThreadProc2, 0, 0, 0);

    WaitForMultipleObjects(2, hThread, TRUE, INFINITE);
    CloseHandle(hThread[0]);
    CloseHandle(hThread[1]);
    CloseHandle(hMutex);

    printf("%d\n", g_i0);
    printf("%d\n", g_i1);
    system("pause");

    return 0;
}


DWORD WINAPI ThreadProc1(LPVOID lpThreadParameter)
{
    HANDLE hMutex = OpenMutexA(MUTEX_ALL_ACCESS, 0, "Mutex0");        // 不对信号产生影响
    if (!hMutex) { assert(0); }
    WaitForSingleObject(hMutex, INFINITE);                            // 有信号变无信号,没信号阻塞
    for (int i = 0; i < 1000000; i++)
    {
        g_i0++;
        g_i1++;
    }
    //ReleaseMutex(hMutex);                                            // 无信号变为有信号
    //CloseHandle(hMutex);

    return 0;
}

DWORD WINAPI ThreadProc2(LPVOID lpThreadParameter)
{
    HANDLE hMutex = OpenMutexA(MUTEX_ALL_ACCESS, 0, "Mutex0");
    if (!hMutex) { assert(0); }
    WaitForSingleObject(hMutex, INFINITE);
    for (int i = 0; i < 1000000; i++)
    {
        g_i0++;
        g_i1++;
    }        
    ReleaseMutex(hMutex);
    CloseHandle(hMutex);

    return 0;
}