iocp进行SOCKET通信(转载)
当然TCP方式的模型还有事件选择模型。
就是把所有的网络事件和我们的一个程序里定义的事件梆定。
这个有它的好处，可能可以让我们更好的写一个线程来管理
接收与发送。
现在来讲一下一个完成端口模型。
完成端口
一个完成端口其实就是一个通知队列，由操作系统把已经完成的重叠I/O请求的通知
放入其中。当某项I/O操作一旦完成，某个可以对该操作结果进行处理的工作者线程
就会收到一则通知。而套接字在被创建后，可以在任何时候与某个完成端口进行关
联。
步骤:
1、创建一个空的完成端口；
2、得到本地机器的CPU个数；
3、开启CPU*2个工作线程(又名线程池),全部都在等待完成端口的完成包;
4、创建TCP的监听socket，使用事件邦定，创建监听线程;
5、当有人连接进入的时候，将Client socket保存到一个我们自己定义的关键键，
并把它与我们创建的完成端口关联；
6、使用WSARecv和WSASend函数投递一些请求，这是使用重叠I/O的方式;
7、重复5~6;
注：1、重叠I/O的方式中，接收与发送数据包的时候，一定要进行投递请求这是
它们这个体系结构的特点
当然，在完成端口方式中，不是直接使用的WSARecv和WSASend函数进行请求
的投递的。而是使用的ReadFile,Write的方式
2、完成端口使用了系统内部的一些模型，所以我们只要按照一定的顺序调用就
可以完成了。
3、完成端口是使用在这样的情况下，有成千上万的用户连接的时候，它能够
保证性能不会降低。
#include < winsock2.h > #include < windows.h > #include < stdio.h > #define PORT 5150 #define DATA_BUFSIZE 8192 // 关键项 typedef struct 
{
OVERLAPPED Overlapped; WSABUF DataBuf; CHAR Buffer[DATA_BUFSIZE]; DWORD BytesSEND; DWORD BytesRECV;
} PER_IO_OPERATION_DATA, * LPPER_IO_OPERATION_DATA;typedef struct { SOCKET Socket;} PER_HANDLE_DATA, * LPPER_HANDLE_DATA;DWORD WINAPI ServerWorkerThread(LPVOID CompletionPortID); void main( void ) { SOCKADDR_IN InternetAddr; SOCKET Listen; SOCKET Accept; HANDLE CompletionPort; SYSTEM_INFO SystemInfo; LPPER_HANDLE_DATA PerHandleData; LPPER_IO_OPERATION_DATA PerIoData; int i; DWORD RecvBytes; DWORD Flags; DWORD ThreadID; WSADATA wsaData; DWORD Ret; if ((Ret = WSAStartup( 0x0202 , & wsaData)) != 0 )
{
printf( " WSAStartup failed with error %d\n " , Ret); return ;
} // 打开一个空的完成端口 if ((CompletionPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0 , 0 )) == NULL) { printf( " CreateIoCompletionPort failed with error: %d\n " , GetLastError()); return ; } // Determine how many processors are on the system. GetSystemInfo( & SystemInfo); // 开启cpu个数的2倍个的线程 for (i = 0 ; i < SystemInfo.dwNumberOfProcessors * 2 ; i ++ ) { HANDLE ThreadHandle; // Create a server worker thread and pass the completion port to the thread. if ((ThreadHandle = CreateThread(NULL, 0 , ServerWorkerThread, CompletionPort, 0 , & ThreadID)) == NULL) { printf( " CreateThread() failed with error %d\n " , GetLastError()); return ; } // Close the thread handle CloseHandle(ThreadHandle); } // 打开一个服务器socket if ((Listen = WSASocket(AF_INET, SOCK_STREAM, 0 , NULL, 0 , WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET) { printf( " WSASocket() failed with error %d\n " , WSAGetLastError()); return ; } InternetAddr.sin_family = AF_INET; InternetAddr.sin_addr.s_addr = htonl(INADDR_ANY); InternetAddr.sin_port = htons(PORT); if (bind(Listen, (PSOCKADDR) & InternetAddr, sizeof (InternetAddr)) == SOCKET_ERROR) { printf( " bind() failed with error %d\n " , WSAGetLastError()); return ; } if (listen(Listen, 5 ) == SOCKET_ERROR) { printf( " listen() failed with error %d\n " , WSAGetLastError()); return ; } // 开始接收从客户端来的连接 while (TRUE) { if ((Accept = WSAAccept(Listen, NULL, NULL, NULL, 0 )) == SOCKET_ERROR) { printf( " WSAAccept() failed with error %d\n " , WSAGetLastError()); return ; } // 创建一个关键项用于保存这个客户端的信息，用户接收发送的重叠结构， // 还有使用到的缓冲区 if ((PerHandleData = (LPPER_HANDLE_DATA) GlobalAlloc(GPTR, sizeof (PER_HANDLE_DATA))) == NULL) { printf( " GlobalAlloc() failed with error %d\n " , GetLastError()); return ; } // Associate the accepted socket with the original completion port. printf( " Socket number %d connected\n " , Accept); PerHandleData -> Socket = Accept; // 与我们的创建的那个完成端口关联起来,将关键项也与指定的一个完成端口关联 if (CreateIoCompletionPort((HANDLE) Accept, CompletionPort, (DWORD) PerHandleData, 0 ) == NULL) { printf( " CreateIoCompletionPort failed with error %d\n " , GetLastError()); return ; } // 投递一次接收，由于接收都需要使用这个函数来投递一个接收的准备 if ((PerIoData = (LPPER_IO_OPERATION_DATA) GlobalAlloc(GPTR, sizeof (PER_IO_OPERATION_DATA))) == NULL) { printf( " GlobalAlloc() failed with error %d\n " , GetLastError()); return ; } ZeroMemory( & (PerIoData -> Overlapped), sizeof (OVERLAPPED)); PerIoData -> BytesSEND = 0 ; PerIoData -> BytesRECV = 0 ; PerIoData -> DataBuf.len = DATA_BUFSIZE; PerIoData -> DataBuf.buf = PerIoData -> Buffer; Flags = 0 ; if (WSARecv(Accept, & (PerIoData -> DataBuf), 1 , & RecvBytes, & Flags, & (PerIoData -> Overlapped), NULL) == SOCKET_ERROR) { if (WSAGetLastError() != ERROR_IO_PENDING) { printf( " WSARecv() failed with error %d\n " , WSAGetLastError()); return ; } } } } // 工作线程 DWORD WINAPI ServerWorkerThread(LPVOID CompletionPortID) { HANDLE CompletionPort = (HANDLE) CompletionPortID; DWORD BytesTransferred; LPOVERLAPPED Overlapped; LPPER_HANDLE_DATA PerHandleData; LPPER_IO_OPERATION_DATA PerIoData; DWORD SendBytes, RecvBytes; DWORD Flags; while (TRUE) { // 完成端口有消息来了 if (GetQueuedCompletionStatus(CompletionPort, & BytesTransferred, (LPDWORD) & PerHandleData, (LPOVERLAPPED * ) & PerIoData, INFINITE) == 0 ) { printf( " GetQueuedCompletionStatus failed with error %d\n " , GetLastError()); return 0 ; } // 是不是有人退出了 if (BytesTransferred == 0 ) { printf( " Closing socket %d\n " , PerHandleData -> Socket); if (closesocket(PerHandleData -> Socket) == SOCKET_ERROR) { printf( " closesocket() failed with error %d\n " , WSAGetLastError()); return 0 ; } GlobalFree(PerHandleData); GlobalFree(PerIoData); continue ; } // if (PerIoData -> BytesRECV == 0 ) { PerIoData -> BytesRECV = BytesTransferred; PerIoData -> BytesSEND = 0 ; } else { PerIoData -> BytesSEND += BytesTransferred; } if (PerIoData -> BytesRECV > PerIoData -> BytesSEND) { // Post another WSASend() request. // Since WSASend() is not gauranteed to send all of the bytes requested, // continue posting WSASend() calls until all received bytes are sent. ZeroMemory( & (PerIoData -> Overlapped), sizeof (OVERLAPPED)); PerIoData -> DataBuf.buf = PerIoData -> Buffer + PerIoData -> BytesSEND; PerIoData -> DataBuf.len = PerIoData -> BytesRECV - PerIoData -> BytesSEND; if (WSASend(PerHandleData -> Socket, & (PerIoData -> DataBuf), 1 , & SendBytes, 0 , & (PerIoData -> Overlapped), NULL) == SOCKET_ERROR) { if (WSAGetLastError() != ERROR_IO_PENDING) { printf( " WSASend() failed with error %d\n " , WSAGetLastError()); return 0 ; } } } else { PerIoData -> BytesRECV = 0 ; // Now that there are no more bytes to send post another WSARecv() request. Flags = 0 ; ZeroMemory( & (PerIoData -> Overlapped), sizeof (OVERLAPPED)); PerIoData -> DataBuf.len = DATA_BUFSIZE; PerIoData -> DataBuf.buf = PerIoData -> Buffer; if (WSARecv(PerHandleData -> Socket, & (PerIoData -> DataBuf), 1 , & RecvBytes, & Flags, & (PerIoData -> Overlapped), NULL) == SOCKET_ERROR) { if (WSAGetLastError() != ERROR_IO_PENDING) { printf( " WSARecv() failed with error %d\n " , WSAGetLastError()); return 0 ; } } } } } 
