用IO完成例程写服务器，如何用WSASend发送数据给客户端?

[gdlk159]

怎么我看的例子都是怎么WSARecv,我不需要接受,我要发送数据给客户端,咋弄啊?

[赵4老师]

参考Microsoft SDK\samples\netds\WinSock\iocp\IocpServer.Cpp ?

[氰客]

MSDN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#define DATA_BUFSIZE 4096
#define SEND_COUNT   10

int __cdecl main()
{
    WSADATA wsd;
    struct addrinfo *result = NULL;
    struct addrinfo hints = { 0 };
    WSAOVERLAPPED SendOverlapped = { 0 };
    SOCKET ListenSocket = INVALID_SOCKET;
    SOCKET AcceptSocket = INVALID_SOCKET;
    WSABUF DataBuf;
    DWORD SendBytes;
    DWORD Flags;
    char buffer[DATA_BUFSIZE];
    int err, rc, i;

    // Load Winsock
    rc = WSAStartup(MAKEWORD(2, 2), &wsd);
    if (rc != 0) {
        fprintf(stderr, "Unable to load Winsock: %d\n", rc);
        return 1;
    }
    // Initialize the hints to obtain the 
    // wildcard bind address for IPv4
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;
    hints.ai_flags = AI_PASSIVE;

    rc = getaddrinfo(NULL, "27015", &hints, &result);
    if (rc != 0) {
        fprintf(stderr, "getaddrinfo failed: %d\n", rc);
        return 1;
    }

    ListenSocket = socket(result->ai_family,
                          result->ai_socktype, result->ai_protocol);
    if (ListenSocket == INVALID_SOCKET) {
        fprintf(stderr, "socket failed: %d\n", WSAGetLastError());
        freeaddrinfo(result);
        return 1;
    }

    rc = bind(ListenSocket, result->ai_addr, (int) result->ai_addrlen);
    if (rc == SOCKET_ERROR) {
        fprintf(stderr, "bind failed: %d\n", WSAGetLastError());
        freeaddrinfo(result);
        closesocket(ListenSocket);
        return 1;
    }

    rc = listen(ListenSocket, 1);
    if (rc == SOCKET_ERROR) {
        fprintf(stderr, "listen failed: %d\n", WSAGetLastError());
        freeaddrinfo(result);
        closesocket(ListenSocket);
        return 1;
    }
    // Accept an incoming connection request
    AcceptSocket = accept(ListenSocket, NULL, NULL);
    if (AcceptSocket == INVALID_SOCKET) {
        fprintf(stderr, "accept failed: %d\n", WSAGetLastError());
        freeaddrinfo(result);
        closesocket(ListenSocket);
        return 1;
    }

    printf("Client Accepted...\n");

    // Create an event handle and setup an overlapped structure.
    SendOverlapped.hEvent = WSACreateEvent();
    if (SendOverlapped.hEvent == NULL) {
        fprintf(stderr, "WSACreateEvent failed: %d\n", WSAGetLastError());
        freeaddrinfo(result);
        closesocket(ListenSocket);
        closesocket(AcceptSocket);
        return 1;
    }

    DataBuf.len = DATA_BUFSIZE;
    DataBuf.buf = buffer;

    for (i = 0; i < SEND_COUNT; i++) {

        rc = WSASend(AcceptSocket, &DataBuf, 1,
                     &SendBytes, 0, &SendOverlapped, NULL);
        if ((rc == SOCKET_ERROR) &&
            (WSA_IO_PENDING != (err = WSAGetLastError()))) {
            fprintf(stderr, "WSASend failed: %d\n", err);
            break;
        }

        rc = WSAWaitForMultipleEvents(1, &SendOverlapped.hEvent, TRUE, INFINITE,
                                      TRUE);
        if (rc == WSA_WAIT_FAILED) {
            fprintf(stderr, "WSAWaitForMultipleEvents failed: %d\n",
                    WSAGetLastError());
            break;
        }

        rc = WSAGetOverlappedResult(AcceptSocket, &SendOverlapped, &SendBytes,
                                    FALSE, &Flags);
        if (rc == FALSE) {
            fprintf(stderr, "WSASend operation failed: %d\n",
                    WSAGetLastError());
            break;
        }

        printf("Wrote %d bytes\n", SendBytes);

        WSAResetEvent(SendOverlapped.hEvent);

    }

    WSACloseEvent(SendOverlapped.hEvent);
    closesocket(AcceptSocket);
    closesocket(ListenSocket);
    freeaddrinfo(result);

    WSACleanup();

    return 0;
}