Question

我正在尝试使用在线教程学习winsock编程。此示例来自MSDN库，尽管已修改。我编译了它，似乎只对一个请求工作正常。处理单个请求后，服务器退出。我已阅读处理多个请求并使服务器持久化可以通过线程完成，但不知道如何做到这一点，并没有在互联网上找到有用的例子。请帮忙。

#undef UNICODE

#define WIN32_LEAN_AND_MEAN

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

// Need to link with Ws2_32.lib
#pragma comment (lib, "Ws2_32.lib")
// #pragma comment (lib, "Mswsock.lib")

#define DEFAULT_BUFLEN 4096
#define DEFAULT_PORT "27015"
char recvbuf[DEFAULT_BUFLEN];

void handleBuffer()
{
recvbuf[DEFAULT_BUFLEN-1]='\0';
printf("\n************The server has received the following request***************\n");
printf("%s",recvbuf);
}

int __cdecl main(void)
{
WSADATA wsaData;
SOCKET ListenSocket = INVALID_SOCKET,
       ClientSocket = INVALID_SOCKET;
struct addrinfo *result = NULL,hints;
char* sendbuf = "HTTP/1.0 200 OK\r\nServer: Test\r\nContent-Type: text/HTML\r\n\r\n<html><title>Test Server</title><body><span style=\"color:#2032DC; font-family:arial; font-size:large; position:absolute; left:4%;\">This is test server responding.</span></body></html>";
int iResult, iSendResult;
int recvbuflen = DEFAULT_BUFLEN;
char e;

// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != 0) {
    printf("WSAStartup failed with error: %d\n", iResult);
    return 1;
}
else
    printf("\nInitialising winsock...done");

ZeroMemory(&hints, sizeof(hints));
hints.ai_family = AF_INET;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
hints.ai_flags = AI_PASSIVE;
printf("\n");

// Resolve the server address and port
iResult = getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);
if ( iResult != 0 ) {
    printf("getaddrinfo failed with error: %d\n", iResult);
    WSACleanup();
    return 1;
}
else
    printf("\nResolving server address...done");
//localhost:27015/
// Create a SOCKET for connecting to server

ListenSocket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
if (ListenSocket == INVALID_SOCKET) {
    printf("socket failed with error: %ld\n", WSAGetLastError());
    freeaddrinfo(result);
    WSACleanup();
    return 1;
}
else
    printf("\nCreating connection socket...done");

// Setup the TCP listening socket
iResult = bind( ListenSocket, result->ai_addr, (int)result->ai_addrlen);
if (iResult == SOCKET_ERROR) {
    printf("bind failed with error: %d\n", WSAGetLastError());
    freeaddrinfo(result);
    closesocket(ListenSocket);
    WSACleanup();
    return 1;
}
else
    printf("\nCreating listening socket...done");
    printf("\nWaiting for connection... ");

freeaddrinfo(result);

iResult = listen(ListenSocket, SOMAXCONN);

if (iResult == SOCKET_ERROR) {
    printf("listen failed with error: %d\n", WSAGetLastError());
    closesocket(ListenSocket);
    WSACleanup();
    return 1;
}

    // Accept a client socket
    ClientSocket = accept(ListenSocket, NULL, NULL);
    if (ClientSocket == INVALID_SOCKET) {
        printf("accept failed with error: %d\n", WSAGetLastError());
        closesocket(ListenSocket);
        WSACleanup();
        return 1;
    }

    // No longer need server socket
    closesocket(ListenSocket);

    iResult = recv(ClientSocket, recvbuf, recvbuflen,0);
    if (iResult > 0)
    {
        printf("Bytes received: %d\n", iResult);
    }
    else if (iResult == 0)
        printf("Connection closing...\n");
    else
    {
        printf("recv failed with error: %d\n", WSAGetLastError());
        closesocket(ClientSocket);
        WSACleanup();
        return 1;
    }


    iSendResult = send(ClientSocket,sendbuf,(int)strlen(sendbuf), 0 );
        if (iSendResult == SOCKET_ERROR)
        {
            printf("send failed with error: %d\n", WSAGetLastError());
            closesocket(ClientSocket);
            WSACleanup();
            return 1;
        }
    printf("Bytes sent: %d\n", iSendResult);
    handleBuffer();

    // shutdown the connection since we're done
    iResult = shutdown(ClientSocket, SD_SEND);
    if (iResult == SOCKET_ERROR) {
        printf("shutdown failed with error: %d\n", WSAGetLastError());
        closesocket(ClientSocket);
        WSACleanup();
        return 1;
    }
// cleanup
closesocket(ClientSocket);
WSACleanup();
printf("\n\nPress any key to quit.");

getch();
return 0;
}

Answer 1

直截了当。

  ClientSocket = accept(ListenSocket, NULL, NULL);

这将返回用于与连接的客户端通信的套接字，您所要做的就是为此套接字执行读/写循环并将其粘贴到新的线程中。同时，将主循环保持在accept（）。

你没得到什么？

修改

假设您要使用Posix线程，请看一下 http://www.yolinux.com/TUTORIALS/LinuxTutorialPosixThreads.html

掌握了这一点后，您可能需要更多的力量和灵活性：请查看http://www.lowtek.com/sockets/select.html

您可以使用select来避免使用线程，您可以使用它来通过线程分发您的客户端（例如1..N客户端由1个线程管理）

<强>备注

等待代码中有漏洞：

int recvbuflen = DEFAULT_BUFLEN;

然后你将它用于接收..这很糟糕，这可能会产生溢出，为了解决这个问题，请将缓冲区声明为： char recvbuf [DEFAULT_BUFLEN + 1];

C Prog - 保持Web服务器不断收听

1 个答案: