ReadFile(客户端命名管道)挂起 - Win32 VC ++

时间:2015-02-19 07:23:49

标签: c++ client named-pipes createfile

我将以下代码作为另一个向客户端发送消息的模块的一部分。这是针对IPC的。两个dll由exe加载,这两个需要通信

在DLL-1中,我将以下代码行作为名为pipe的服务器。

pipe = CreateNamedPipe("\\\\.\\pipe\\S2D8",PIPE_ACCESS_OUTBOUND | FILE_FLAG_OVERLAPPED /**1-way, send only with overlapped IO*/,
        PIPE_TYPE_MESSAGE,1,0,0, 0, NULL);
    if( INVALID_HANDLE_VALUE != pipe )
    {
        log("Created Named Pipe as Serverl\n");     
    }
    else 
    {
        log("Cannot create Named Pipe as Server\n");        
    }

在DLL-1的其他地方,我有以下服务器

bool result = ConnectNamedPipe(pipe, NULL);
            if (!result)
            {
                CloseHandle(pipe); // close the pipe

            }
            else
            {
                DWORD numWritten;
                WriteFile(pipe,KeyBoardBuffer,strlen(KeyBoardBuffer) * sizeof(char),&numWritten,0);
                log("Bytes writtern to pipe:%d\n",numWritten);
            }

当我查看日志时,我可以看到那个命名管道。好到目前为止。

在DLL-2中,我将以下内容作为客户端部分

log("Connecting to named pipe at client\n");
        if(pipe2 == NULL || pipe2 == INVALID_HANDLE_VALUE)
        {

            pipe2 = CreateFile("\\\\.\\pipe\\S2D8", GENERIC_READ , 
                FILE_SHARE_READ | FILE_SHARE_WRITE,NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,NULL);

            if (pipe2 == INVALID_HANDLE_VALUE)
            {
                log("Cannot connect to named pipe at client%x\n", GetLastError());
                CloseHandle(pipe2);
            }
            else
            {
                log("Connected to named pipe at client! Going to read!!!\n");
                char buffer[256] = {'\0'};
                DWORD numBytesRead = 0;
                BOOL result = ReadFile(
                    pipe2,
                    buffer, // the data from the pipe will be put here
                    sizeof(buffer) * sizeof(char), // number of bytes allocated
                    &numBytesRead, // this will store number of bytes actually read
                    NULL // not using overlapped IO
                    );
                if (result) 
                {
                    kbBuffer[numBytesRead / sizeof(char)] = '\0'; // null terminate the string
                    log( "Number of bytes read: %d\n",numBytesRead);
                    log(kbBuffer );
                }
                else 
                {
                    log("Failed to read data from the pipe.\n");                
                }
            }
        }

在我的日志中,我可以看到“连接到客户端的命名管道”行,然后“连接到客户端的命名管道!去阅读!!!”,之后日志中没有任何内容,一切似乎卡住。

管道的命名约定是否正确?或者我必须定义任何安全设置吗?

我正在使用VS2010,Win7 x64。

非常感谢任何指导。

2 个答案:

答案 0 :(得分:0)

您正在调用错误的方法。管道应该预先存在,因此您应该调用OpenFile(),而不是CreateFile()

答案 1 :(得分:0)

啊,我找到了挂起的答案,我必须做一个PeekNamedPipe(pipe2, NULL, 0, NULL, &bytesAvailable, NULL);,然后在我做ReadFile()之前检查bytesAvailable是否大于零