进程间通讯demo

// 使用Memory Mapping file共享数据，使用一个Event作为并发控制。
// 仅为练习使用。





#define BUFFER_SIZE (100*1024)
#define BUFSIZE 1024

struct BufferStruct
{
    BOOL hasRead;
    TCHAR buf[512];
};

void CEDSInstallMain1Dlg::OnBnClickedButton1()
{    
    TCHAR szMapFileName[] = _T("Local\\TestHelloWorld");

    // Create the file mapping object
    HANDLE hMapFile = CreateFileMapping(
        INVALID_HANDLE_VALUE,	// Use paging file instead of existing file. // Pass file handle to share in a file.
        NULL,					// Default security 
        PAGE_READWRITE,			// Read/write access
        0,						// Max. object size 
        BUFFER_SIZE,			// Buffer size  
        szMapFileName			// Name of mapping object
        );

    if (hMapFile == NULL) 
        return;

    // Create file view from the file mapping object.
    BufferStruct* pBuf = (BufferStruct*) MapViewOfFile(
        hMapFile,				// Handle of the map object
        FILE_MAP_ALL_ACCESS,	// Read/write permission
        0,						// A high-order DWORD of the file offset where the view begins.
        0,						// A low-order DWORD of the file offset where the view is to begin. 
        BUFFER_SIZE				// The number of bytes of a file mapping to map to the view.
        );

    if (pBuf == NULL)
    { 
        CloseHandle(hMapFile);
        return;
    }

    pBuf->hasRead = TRUE;

    PROCESS_INFORMATION pi[3];


    for (int i = 0; i< 3; i++)
    {
        STARTUPINFO si;

        ZeroMemory( &si, sizeof(si) );
        si.cb = sizeof(si);
        //si.dwFlags = STARTF_USESHOWWINDOW;
        //si.wShowWindow = SW_HIDE;

        ZeroMemory(&pi, sizeof(pi));
        CString cmdstr;
        cmdstr.Format("C:\\Work\\EDSInstall\\Release\\EDSInstall.exe");

        // Start the child process. 
        if(!CreateProcess(NULL,   // No module name (use command line)
            cmdstr.GetBuffer(0),        // Command line
            NULL,           // Process handle not inheritable
            NULL,           // Thread handle not inheritable
            FALSE,          // Set handle inheritance to FALSE
            0,              // No creation flags
            NULL,           // Use parent's environment block
            NULL,           // Use parent's starting directory 
            &si,            // Pointer to STARTUPINFO structure
            &pi[i] )           // Pointer to PROCESS_INFORMATION structure
            ) 
        {
            AfxMessageBox("CreateProcess failed (%d).");
            return;
        }

    }    

    HANDLE globalEvent = CreateEvent(0, TRUE, FALSE, TEXT("GlobalTestEvent"));
    SetEvent(globalEvent);

    Sleep(2000);

    do 
    {
        DWORD dwRet = WaitForSingleObject(globalEvent, 100);
        if (dwRet == WAIT_OBJECT_0)
        {
            if (pBuf && !pBuf->hasRead)
            {
                CString msgFromGlobal = pBuf->buf;

                // *********************william test*************12/23/2009 1:40:44 PM
                TCHAR bufferWill[512];
                _stprintf(bufferWill, TEXT(" [%s] BEGIN read: %s ##[%p]L%d\n"), __FUNCTION__,
                    msgFromGlobal, this, __LINE__); 
                ::OutputDebugString(bufferWill); 
                // **********************************************/

                memset(pBuf->buf, 0, sizeof(TCHAR) * 512);
                
                pBuf->hasRead = TRUE; 

                SetEvent(globalEvent);

                // it is equal to do something.
                Sleep(500);
            }
            else
            {
                SetEvent(globalEvent);
                // wait the data written.
                Sleep(500);
            }            
        }
        else
        {
            Sleep(500);
        }

    } while (1);

    AfxMessageBox("finished");

    for (int i = 0; i< 3; i++)
    {    
        // Close process and thread handles. 
        CloseHandle( pi[i].hProcess );
        CloseHandle( pi[i].hThread );
    }

    UnmapViewOfFile(pBuf);

    CloseHandle(hMapFile);
    CloseHandle(globalEvent);
}

 

In the client side:

 

        // *********************william test*************12/23/2009 2:24:20 PM
        TCHAR bufferWill[512];
        _stprintf(bufferWill, TEXT(" [%s] BEGIN  ##L%d\n"), __FUNCTION__,
             __LINE__); 
        ::OutputDebugString(bufferWill); 
        // **********************************************/

        TCHAR szMapFileName[] = _T("Local\\TestHelloWorld");

        // Create the file mapping object
        HANDLE hMapFile = CreateFileMapping(
            INVALID_HANDLE_VALUE,	// Use paging file instead of existing file. // Pass file handle to share in a file.
            NULL,					// Default security 
            PAGE_READWRITE,			// Read/write access
            0,						// Max. object size 
            BUFFER_SIZE,			// Buffer size  
            szMapFileName			// Name of mapping object
            );

        if (hMapFile == NULL) 
            return nRetCode;

        // Create file view from the file mapping object.
        BufferStruct* pBuf = (BufferStruct*) MapViewOfFile(
            hMapFile,				// Handle of the map object
            FILE_MAP_ALL_ACCESS,	// Read/write permission
            0,						// A high-order DWORD of the file offset where the view begins.
            0,						// A low-order DWORD of the file offset where the view is to begin. 
            BUFFER_SIZE				// The number of bytes of a file mapping to map to the view.
            );

        if (pBuf == NULL)
        { 
            CloseHandle(hMapFile);
            return nRetCode;
        }

        // *********************william test*************12/23/2009 2:24:20 PM
        _stprintf(bufferWill, TEXT(" [%s] step1  ##L%d\n"), __FUNCTION__,
            __LINE__); 
        ::OutputDebugString(bufferWill); 
        // **********************************************/


        HANDLE globalEvent = CreateEvent(0, TRUE, FALSE, TEXT("GlobalTestEvent"));

        // *********************william test*************12/23/2009 2:24:20 PM
        _stprintf(bufferWill, TEXT(" [%s] step2 %X %X ##L%d\n"), __FUNCTION__,
            GetCurrentProcessId(), globalEvent, __LINE__); 
        ::OutputDebugString(bufferWill); 
        // **********************************************/

        do 
        {
            DWORD dwRet = WaitForSingleObject(globalEvent, 200);
 
            if (dwRet == WAIT_OBJECT_0)
            {
                if (pBuf && pBuf->hasRead)
                {
                    CString str;
                    str.Format("String from sub %X", GetCurrentProcessId());

                    // Write the message to the file view.
                    int cbMessageBytes = (str.GetLength() + 1 /* NULL */) * sizeof(TCHAR);

                    CopyMemory((PVOID)pBuf->buf, str.GetBuffer(0), cbMessageBytes);

                    // *********************william test*************12/23/2009 2:24:20 PM
                    _stprintf(bufferWill, TEXT(" [%s] step-loop2 Write: %X  ##L%d\n"), __FUNCTION__,
                        GetCurrentProcessId(),   __LINE__); 
                    ::OutputDebugString(bufferWill); 
                    // **********************************************/

                    pBuf->hasRead = FALSE;

                    SetEvent(globalEvent);

                    // it is equal to do something.
                    Sleep(800);
                }
                else
                {
                    SetEvent(globalEvent);
                    // wait the data written.
                    Sleep(500);
                }
            }
            else
            {
                Sleep(500);
            }

        } while (1);


        UnmapViewOfFile(pBuf);

        CloseHandle(hMapFile);
        CloseHandle(globalEvent);