6

我在实现 TCP IOCP 客户端时遇到了一些麻烦。我已经在 Mac OSX 上实现了 kqueue,所以希望在 Windows 上做类似的事情,我的理解是 IOCP 是最接近的事情。主要问题是 GetCompetetionStatus 永远不会返回并且总是超时。我假设在创建要监视的句柄时我遗漏了一些东西,但不确定是什么。这是我到目前为止得到的地方:

我的连接例程:(为了清楚起见,删除了一些错误处理)

struct sockaddr_in server;
struct hostent *hp;
SOCKET sckfd;
WSADATA wsaData;

int iResult = WSAStartup( MAKEWORD(2,2), &wsaData );


if ((hp = gethostbyname(host)) == NULL)
    return NULL;
WSASocket(AF_INET,SOCK_STREAM,0,NULL,0,WSA_FLAG_OVERLAPPED)
if ((sckfd = WSASocket(AF_INET,SOCK_STREAM,0, NULL, 0, WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
{
    printf("Error at socket(): Socket\n");
    WSACleanup();
    return NULL;
}

server.sin_family = AF_INET;
server.sin_port = htons(port);
server.sin_addr = *((struct in_addr *)hp->h_addr);
memset(&(server.sin_zero), 0, 8);

//non zero means non blocking. 0 is blocking.
u_long iMode = -1;
iResult = ioctlsocket(sckfd, FIONBIO, &iMode);
if (iResult != NO_ERROR)
    printf("ioctlsocket failed with error: %ld\n", iResult);


HANDLE hNewIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, ulKey, 0);
CreateIoCompletionPort((HANDLE)sckfd, hNewIOCP , ulKey, 0);

connect(sckfd, (struct sockaddr *)&server, sizeof(struct sockaddr));

//WSAConnect(sckfd, (struct sockaddr *)&server, sizeof(struct sockaddr),NULL,NULL,NULL,NULL);

return sckfd;   

这是发送例程:(为了清楚起见,还删除了一些错误处理)

IOPortConnect(int ServerSocket,int timeout,string& data){

char buf[BUFSIZE];
strcpy(buf,data.c_str());
WSABUF buffer = { BUFSIZE,buf };
DWORD bytes_recvd;
int r;
ULONG_PTR ulKey = 0;
OVERLAPPED overlapped;
 OVERLAPPED* pov = NULL;
HANDLE port;

HANDLE hNewIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, ulKey, 0);
CreateIoCompletionPort((HANDLE)ServerSocket, hNewIOCP , ulKey, 0);


BOOL get = GetQueuedCompletionStatus(hNewIOCP,&bytes_recvd,&ulKey,&pov,timeout*1000);

if(!get)
    printf("waiton server failed. Error: %d\n",WSAGetLastError());
if(!pov)
    printf("waiton server failed. Error: %d\n",WSAGetLastError());

port = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, (u_long)0, 0);

SecureZeroMemory((PVOID) & overlapped, sizeof (WSAOVERLAPPED));

r = WSASend(ServerSocket, &buffer, 1, &bytes_recvd, NULL, &overlapped, NULL);
printf("WSA returned: %d WSALastError: %d\n",r,WSAGetLastError());
if(r != 0)
{
    printf("WSASend failed %d\n",GetLastError());
    printf("Bytes transfered: %d\n",bytes_recvd);
}
if (WSAGetLastError() == WSA_IO_PENDING)
    printf("we are async.\n");
CreateIoCompletionPort(port, &overlapped.hEvent,ulKey, 0);

BOOL test = GetQueuedCompletionStatus(port,&bytes_recvd,&ulKey,&pov,timeout*1000); 

CloseHandle(port);
return true;

}

任何见解将不胜感激。

4

2 回答 2

5

您正在将同一个套接字与多个 IOCompletionPorts 相关联。我确定那是无效的。在您的 IOPortConnect 函数(您在哪里进行写入)中,您调用 CreateIOCompletionPort 4 次,传入一个镜头句柄。

我的建议:

  • 创建一个 IOCompletion 端口(最终,您可以将多个套接字与之关联)。
  • 创建一个工作线程池(通过调用 CreateThread),每个工作线程通过在循环中调用 GetQueuedCompletionStatus 阻塞 IOCompletionPort 句柄。
  • 创建一个或多个 WSA_OVERLAPPED 套接字,并将每个套接字与 IOCompletionPort 相关联。
  • 使用采用 OVERLAPPED* 的 WSA 套接字函数来触发重叠操作。
  • 当工作线程从 GetQueuedCompletionStatus 返回时处理已发出请求的完成,并带有您传入的 OVERLAPPED* 以启动操作。

注意:WSASend 返回 0 和 SOCKET_ERROR,其中 WSAGetLastError() 作为 WSA_IO_PENDING 作为代码指示您将获得到达 GetQueuedCompletionStatus 的 IO 完成数据包。任何其他错误代码意味着您应该立即处理错误,因为 IO 操作没有排队,因此不会有进一步的回调。

注意 2:传递给 WSASend(或其他)函数的 OVERLAPPED* 是从 GetQueuedCompletionStatus 返回的 OVERLAPPED*。您可以使用此事实通过调用传递更多上下文信息:

struct MYOVERLAPPED {
  OVERLAPPED ovl;
};
MYOVERLAPPED ctx;
WSASend(...,&ctx.ovl);
...
OVERLAPPED* pov;
if(GetQueuedCompletionStatus(...,&pov,...)){
  MYOVERLAPPED* pCtx = (MYOVERLAPPED*)pov;
于 2011-04-19T16:07:29.893 回答
1

Chris 已经处理了大部分问题,您可能已经查看了大量示例代码,但是......

我在这里有一些免费的 IOCP 代码:http ://www.serverframework.com/products---the-free-framework.html

There are also several of my CodeProject articles on the subject linked from that page.

于 2011-04-19T21:00:09.180 回答