多线程的同一个功能使用哪个线程

Posted 2023-02-16

【中文标题】多线程的同一个功能使用哪个线程

【英文标题】：Which thread is used in the same function of multithread

【发布时间】：2017-12-27 06:22:11

【问题描述】：

在 mfc 代码中，

声明如下

CWinThread* _pThread[5];
DWORD _ThreadArg[5] =  HIGHEST_THREAD, // 0x00
                    ABOVE_AVE_THREAD, // 0x3F
                    NORMAL_THREAD, // 0x7F
                    BELOW_AVE_THREAD, // 0xBF
                    LOWEST_THREAD // 0xFF
                    ; 

int i;
for (i= 0; i< 5; i++)

    _pThread[i] = AfxBeginThread(ThreadFunc,
                                &_ThreadArg[i],
                                THREAD_PRIORITY_NORMAL,
                                0,
                                //CREATE_SUSPENDED,
                                NULL,
                                NULL);
    //_pThread[i]->ResumeThread();

// setup relative priority of threads
_pThread[0]->SetThreadPriority(THREAD_PRIORITY_HIGHEST);
_pThread[1]->SetThreadPriority(THREAD_PRIORITY_ABOVE_NORMAL);
_pThread[2]->SetThreadPriority(THREAD_PRIORITY_NORMAL);
_pThread[3]->SetThreadPriority(THREAD_PRIORITY_BELOW_NORMAL);
_pThread[4]->SetThreadPriority(THREAD_PRIORITY_LOWEST);

使用相同的线程函数

UINT CThreadPoolDlg::ThreadFuncTh1(LPVOID ThreadArg)

    DWORD dwArg = *(DWORD*)ThreadArg;
    //txtTh[0].SetWindowTextW(_T("23"));
    AfxGetMainWnd()->GetDlgItem(IDC_THD1)->SetWindowText(_T("1"));
    return 0;

如何检查同一函数中正在使用哪个线程？

【问题讨论】：

呃，每个线程都有自己的本地dwArg，明确标识线程。您要解决的真正问题是什么？

此外，从拥有线程以外的线程更新窗口肯定会导致灾难。当您连 Windows GUI 编程的基础知识都无法理解时，您确定要使用 MFC 吗？

【参考方案1】：

我得到如下答案

_pThread[0] = AfxBeginThread(ThreadFunc,this,
                            THREAD_PRIORITY_NORMAL,
                            0,
                            NULL,
                            NULL);

_pThread[1] = AfxBeginThread(ThreadFunc,this,
                            THREAD_PRIORITY_NORMAL,
                            0,
                            CREATE_SUSPENDED,
                            NULL);

_pThread[2] = AfxBeginThread(ThreadFunc,this,
                            THREAD_PRIORITY_NORMAL,
                            0,
                            CREATE_SUSPENDED,
                            NULL);

线程函数声明如下

UINT CThreadPoolDlg::ThreadFunc(LPVOID ThreadArg)

    CThreadPoolDlg* dwArg = (CThreadPoolDlg*)ThreadArg;
    DWORD dThread = GetCurrentThreadId();

    //txtTh[0].SetWindowTextW(_T("23"));
    while(1)
       
        CString strTemp;

        if(dThread == dwArg->_pThread[0]->m_nThreadID)
                   
            AfxGetMainWnd()->GetDlgItem(IDC_THD1)->GetWindowText(strTemp);      
            int n = _wtoi(strTemp);
            strTemp.Format(_T("%d"), ++n);      
            AfxGetMainWnd()->GetDlgItem(IDC_THD1)->SetWindowText(strTemp);

            if(n > 5)
            
                ::SendMessage(dwArg->GetSafeHwnd(), OWM_MYMETHOD, 0, 0);
                //dwArg->_pThread[1]->ResumeThread();
            
        

        if(dThread == dwArg->_pThread[1]->m_nThreadID)
                   
            AfxGetMainWnd()->GetDlgItem(IDC_THD2)->GetWindowText(strTemp);      
            int n = _wtoi(strTemp);
            strTemp.Format(_T("%d"), ++n);      
            AfxGetMainWnd()->GetDlgItem(IDC_THD2)->SetWindowText(strTemp);

            if(n > 5)
            
                dwArg->_pThread[2]->ResumeThread();
            
        

        if(dThread == dwArg->_pThread[2]->m_nThreadID)
        
            AfxGetMainWnd()->GetDlgItem(IDC_THD3)->GetWindowText(strTemp);
            int n = _wtoi(strTemp);
            strTemp.Format(_T("%d"), ++n);
            AfxGetMainWnd()->GetDlgItem(IDC_THD3)->SetWindowText(strTemp);
        

        Sleep(500);
    
    return 0;

看看就知道了

DWORD dThread = GetCurrentThreadId();
dThread == dwArg->_pThread[1]->m_nThreadID

然后我会得到当前线程ID...