thrdcore.cpp

MFC的线程局部存储的源代码,主要讲述MFC的线程局部存储。需要的可以下载。

#include "_afxwin.h"
#include "_afxtls_.h"
#include <process.h>
#include <stdio.h>

struct _AFX_THREAD_STARTUP
{
	CWinThread* pThread;	// 控制新线程的CWinThread对象的指针
	HANDLE hEvent;		// 此事件在线程初始化完毕后将被触发
	HANDLE hEvent2;		// 此事件在创建线程从CreateThread函数返回时将被触发
	
	BOOL bError;		// 指示线程是否初始化成功
};

UINT __stdcall _AfxThreadEntry(void* pParam)
{
	_AFX_THREAD_STARTUP* pStartup = (_AFX_THREAD_STARTUP*)pParam;
	CWinThread* pThread = pStartup->pThread;
	try
	{	
		// 设置新线程的状态
		AFX_MODULE_THREAD_STATE* pState = AfxGetModuleThreadState();
		pState->m_pCurrentWinThread = pThread;
	}
	catch(...)
	{
		// 如果try块有异常抛出，此处的代码将被执行
		pStartup->bError = TRUE;
		::SetEvent(pStartup->hEvent);
		AfxEndThread((UINT)-1, FALSE);
	}

	// 调用下面的SetEvent函数后，pStartup所指向的内存空间就有可能被父线程销毁，
	// 所以要保存hEvent2的值
	HANDLE hEvent2 = pStartup->hEvent2;

	// 允许父线程从CWinThread::CreateThread函数返回
	::SetEvent(pStartup->hEvent);

	// 等待父线程中CWinThread::CreateThread函数的代码执行完毕
	::WaitForSingleObject(hEvent2, INFINITE);
	::CloseHandle(hEvent2);

	// 调用用户指定的线程函数
	DWORD nResult = 0;
	if(pThread->m_pfnThreadProc)
		nResult = (*pThread->m_pfnThreadProc)(pThread->m_pThreadParams);

	// 结束线程
	AfxEndThread(nResult);
	return 0;
}


CWinThread* AfxGetThread()
{
	// 返回当前线程CWinThread对象的指针
	AFX_MODULE_THREAD_STATE* pState = AfxGetModuleThreadState();
	return pState->m_pCurrentWinThread;
}

void AfxEndThread(UINT nExitCode, BOOL bDelete)
{
	// 释放当前CWinThread对象占用的内存
	AFX_MODULE_THREAD_STATE* pState = AfxGetModuleThreadState();
	CWinThread* pThread = pState->m_pCurrentWinThread;
	if (pThread != NULL)
	{
		if (bDelete)
			pThread->Delete();
		pState->m_pCurrentWinThread = NULL;
	}

	// 释放线程局部存储占用的内存
	if (_afxThreadData != NULL)
		_afxThreadData->DeleteValues(NULL, FALSE);

	// 结束此线程的运行
	_endthreadex(nExitCode);
}

CWinThread* AfxBeginThread(AFX_THREADPROC pfnThreadProc, LPVOID pParam,
	int nPriority, UINT nStackSize, DWORD dwCreateFlags,
	LPSECURITY_ATTRIBUTES lpSecurityAttrs)
{
	// 为新线程创建一个CWinThead类的对象
	CWinThread* pThread = new CWinThread(pfnThreadProc, pParam);

	// 创建线程，并挂起
	if (!pThread->CreateThread(dwCreateFlags|CREATE_SUSPENDED, nStackSize,
		lpSecurityAttrs))
	{
		pThread->Delete();
		return NULL;
	}

	// 设置新线程的优先级
	pThread->SetThreadPriority(nPriority);

	// 如果没有指定CREATE_SUSPENDED标记，则唤醒线程
	if (!(dwCreateFlags & CREATE_SUSPENDED))
		pThread->ResumeThread();

	return pThread;
}

//----------------- CWinThread类--------------------//

void CWinThread::CommonConstruct ()
{
	m_hThread = NULL;
	m_nThreadID = 0;
	m_bAutoDelete = TRUE;
}

CWinThread::CWinThread(AFX_THREADPROC pfnThreadProc, LPVOID pParam)
{
	m_pfnThreadProc = pfnThreadProc;
	m_pThreadParams = pParam;

	CommonConstruct();
}

CWinThread::CWinThread()
{
	m_pThreadParams = NULL;
	m_pfnThreadProc = NULL;

	CommonConstruct();
}

CWinThread::~CWinThread()
{
	// 释放线程内核对象句柄
	if (m_hThread != NULL)
		CloseHandle(m_hThread);

	// 清除线程的状态
	AFX_MODULE_THREAD_STATE* pState = AfxGetModuleThreadState();
	if (pState->m_pCurrentWinThread == this)
		pState->m_pCurrentWinThread = NULL;
}

BOOL CWinThread::CreateThread(DWORD dwCreateFlags, UINT nStackSize,
	LPSECURITY_ATTRIBUTES lpSecurityAttrs)
{
	// 为线程的初始化定义变量startup
	_AFX_THREAD_STARTUP startup; memset(&startup, 0, sizeof(startup));
	startup.pThread = this;
	startup.hEvent = ::CreateEvent(NULL, TRUE, FALSE, NULL);
	startup.hEvent2 = ::CreateEvent(NULL, TRUE, FALSE, NULL);

	// 创建一个初始状态为不可调度的线程（挂起）
	m_hThread = (HANDLE)_beginthreadex(lpSecurityAttrs, nStackSize,
		&_AfxThreadEntry, &startup, dwCreateFlags | CREATE_SUSPENDED, (UINT*)&m_nThreadID);
	if (m_hThread == NULL)
		return FALSE;

	// 恢复线程的执行，并等待线程初始化完毕
	ResumeThread();
	::WaitForSingleObject(startup.hEvent, INFINITE);
	::CloseHandle(startup.hEvent);

	// 如果用户创建的是一个挂起的线程，我们就暂停线程的运行
	if (dwCreateFlags & CREATE_SUSPENDED)
		::SuspendThread(m_hThread);

	// 如果线程在初始化时出错，释放所有资源
	if (startup.bError)
	{
		::WaitForSingleObject(m_hThread, INFINITE);
		::CloseHandle(m_hThread);
		m_hThread = NULL;
		::CloseHandle(startup.hEvent2);
		return FALSE;
	}

	// 通知线程继续运行
	::SetEvent(startup.hEvent2);

	return TRUE;
}

void CWinThread::Delete()
{
	// 如果指定了自动清除的话，删除this指针
	if (m_bAutoDelete)
		delete this;
}



UINT MyFunc(LPVOID lpParam)
{
	printf(" Thread Identify: %d \n", AfxGetThread()->m_nThreadID);
	return 0;
}

void main()
{
	for(int i=0; i<10; i++)
	{
		AfxBeginThread(MyFunc, NULL);
	}
	system("pause");
}