信号量示例

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

HANDLE hSemaphore;

UINT ThreadProcFirst(LPVOID pParam);
UINT ThreadProcSecond(LPVOID pParam);
UINT ThreadProcThird(LPVOID pParam);

int main(int argc, char* argv[])
{
    hSemaphore = CreateSemaphore(NULL, 2, 2, NULL);
    AfxBeginThread(ThreadProcFirst, NULL);
    AfxBeginThread(ThreadProcSecond, NULL);
    AfxBeginThread(ThreadProcThird, NULL);
    
    /*延迟进程退出*/
    Sleep(5*1000);
//     CloseHandle(hSemaphore);

    return 0;
}

UINT ThreadProcFirst( LPVOID pParam )
{
    WaitForSingleObject(hSemaphore, INFINITE);
    AfxMessageBox("First");
    ReleaseSemaphore(hSemaphore, 1, NULL);
    return 0;
}

UINT ThreadProcSecond( LPVOID pParam )
{
    WaitForSingleObject(hSemaphore, INFINITE);
    AfxMessageBox("Second");
    ReleaseSemaphore(hSemaphore, 1, NULL);
    return 0;
}

UINT ThreadProcThird( LPVOID pParam )
{
    WaitForSingleObject(hSemaphore, INFINITE);
    AfxMessageBox("Third");
    ReleaseSemaphore(hSemaphore, 1, NULL);
    return 0;
}