mysemaphore.cpp

来自「编程实例」· C++ 代码 · 共 65 行

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

#include "stdafx.h"
#include "MySemaphore.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// The one and only application object

CWinApp theApp;

using namespace std;

DWORD threadA(void* pD)
{
	int iID=(int)pD;
	//在内部重新打开
	HANDLE hCounterIn=OpenSemaphore(SEMAPHORE_ALL_ACCESS,FALSE,"My Try");

	for(int i=0;i<3;i++)
	{
		printf("%d wait for object\n",iID);
		WaitForSingleObject(hCounterIn,INFINITE);
		printf("\t\tthread %d : do database access call\n",iID);
		Sleep(100);
		printf("\t\tthread %d : do database access call end\n",iID);
		ReleaseSemaphore(hCounterIn,1,NULL);
	}
	CloseHandle(hCounterIn);
	return 0;
}

void main()
{
	//创建信号
	HANDLE hCounter=NULL;
	if( (hCounter=OpenSemaphore(SEMAPHORE_ALL_ACCESS,FALSE,"My Try"))==NULL)
	{
		//如果没有其他进程创建这个信号，则重新创建
		hCounter = CreateSemaphore(NULL,2,2,"sam sp 44");
	}

	//创建线程
	HANDLE hThread[3];
	CWinThread* pT1=AfxBeginThread((AFX_THREADPROC)threadA,(void*)1);
	CWinThread* pT2=AfxBeginThread((AFX_THREADPROC)threadA,(void*)2);
	CWinThread* pT3=AfxBeginThread((AFX_THREADPROC)threadA,(void*)3);
	hThread[0]=pT1->m_hThread;
	hThread[1]=pT2->m_hThread;
	hThread[2]=pT3->m_hThread;
	//等待线程结束
	WaitForMultipleObjects(3,hThread,TRUE,INFINITE);

	//关闭句柄
	CloseHandle(hCounter);
}