C++ winsock服务器同时发送和接收
我是WinSock的新手,我正在尝试一些东西。我有客户机和服务器程序,它们相互通信。如果客户机键入某些内容,服务器只会回显它。我希望它们能够同时接收和发送,所以我将客户端设置为非阻塞模式,工作正常。但是,当我试图将服务器置于非阻塞状态时,它崩溃了,因为recv==SOCKET\u错误 所以问题是:为什么客户端可以在非阻塞模式下工作,而服务器不能?我怎样才能解决这个问题 TCP_服务器: TCP_客户端:C++ winsock服务器同时发送和接收,c++,winsock,C++,Winsock,我是WinSock的新手,我正在尝试一些东西。我有客户机和服务器程序,它们相互通信。如果客户机键入某些内容,服务器只会回显它。我希望它们能够同时接收和发送,所以我将客户端设置为非阻塞模式,工作正常。但是,当我试图将服务器置于非阻塞状态时,它崩溃了,因为recv==SOCKET\u错误 所以问题是:为什么客户端可以在非阻塞模式下工作,而服务器不能?我怎样才能解决这个问题 TCP_服务器: TCP_客户端: 您没有处理由于WSAEWOULDBLOCK错误(这不是致命错误)导致发送/接收失败的情况。这
您没有处理由于WSAEWOULDBLOCK错误(这不是致命错误)导致发送/接收失败的情况。这只是意味着此时没有工作要做,请稍后再试 对于recv,这意味着没有可从套接字的接收缓冲区读取的字节。当有字节可从套接字读取,或者对等方执行了正常断开连接时,套接字将处于可读状态 对于发送,这意味着对等方的接收缓冲区已满,在对等方读取一些字节以清除缓冲区空间之前,无法接收新字节。任何未发送的字节都必须传递,以便稍后再次发送。当可以向对等方发送新字节时,套接字将处于可写状态,而当对等方的缓冲区已满时,套接字将不处于可写状态 当您的服务器接受客户机并尝试从其接收时,recv将继续使用WSAEWOULDBLOCK失败,直到客户机实际发送某些内容 因此,您需要正确地处理WSAEWOULDBLOCK,并根据需要重试。或者更好的方法是,使用select或WSAAsyncSelect、WSAEventSelect或重叠I/O来检测套接字的实际状态,以了解何时可以安全地调用send/recv,而不会导致WSAEWOULDBLOCK错误
#include <iostream>
#include <WS2tcpip.h>
#include <Windows.h>
#pragma comment (lib,"ws2_32.lib")
using namespace std;
string receive(SOCKET clientSocket, char* buf)
{
ZeroMemory(buf, 4096);
int bytesReceived = recv(clientSocket, buf, 4096, 0);
string bufStr = buf;
cout << "bytes received: " << bytesReceived << endl;
if (bytesReceived == SOCKET_ERROR)
{
cerr << "error met recv() in de reciev() functie" << endl;
exit(EXIT_FAILURE);
}
if (bytesReceived == 0)
{
cout << "client disconnected" << endl;
exit(EXIT_FAILURE);
}
return bufStr;
}
void main()
{
//initialize winsock
WSADATA wsData;
WORD ver = MAKEWORD(2, 2);
int wsOk = WSAStartup(ver, &wsData);
if (wsOk != 0) {
cerr << "can't initialize winsock ABORT";
return;
}
//create socket
SOCKET listening = socket(AF_INET, SOCK_STREAM, 0);
if (listening == INVALID_SOCKET) {
cerr << "cant create socket ABORT" << std::endl;
}
//bind IP adress and port to socket
sockaddr_in hint;
hint.sin_family = AF_INET;
hint.sin_port = htons(54000);
hint.sin_addr.S_un.S_addr = INADDR_ANY; //could also inet_pton
bind(listening, (sockaddr*)&hint, sizeof(hint));
//tell winsock the socket is for listening
listen(listening, SOMAXCONN);
//wait for connection
sockaddr_in client;
int clientSize = sizeof(client);
SOCKET clientSocket = accept(listening, (sockaddr*)&client, &clientSize);
if (clientSocket == INVALID_SOCKET) {
cerr << "somthing went wrong with client socket accept ABORT";
exit(EXIT_FAILURE);
}
char host[NI_MAXHOST]; //client remote name
char service[NI_MAXSERV]; //service (i.e port) the client is connected on
ZeroMemory(host, NI_MAXHOST);
ZeroMemory(service, NI_MAXSERV);
if (getnameinfo((sockaddr*)&client, sizeof(client), host, NI_MAXHOST, service, NI_MAXSERV, 0) == 0)
{
cout << host << " connected on port " << service << endl;
}
else {
inet_ntop(AF_INET, &client.sin_addr, host, NI_MAXHOST);
cout << host << " connected on port " << ntohs(client.sin_port) << endl;
}
//close listening socket
closesocket(listening);
//non blocking socket leads to error
u_long mode = 1; // 1 to enable non-blocking socket
ioctlsocket(clientSocket, FIONBIO, &mode);
//non blocking socket
//while loop: accept and echo message to client
char buf[4096];
string inputTxt;
while (true)
{
inputTxt = receive(clientSocket,buf);
send(clientSocket, buf, inputTxt.size() + 1, 0);
}
closesocket(clientSocket);
WSACleanup();
}
#include <iostream>
#include <WS2tcpip.h>
#include <Windows.h>
#pragma comment (lib,"ws2_32.lib")
using namespace std;
string receive(SOCKET clientSocket, char* buf)
{
ZeroMemory(buf, 4096);
int bytesReceived = recv(clientSocket, buf, 4096, 0);
string bufStr = buf;
cout << "bytes received: " << bytesReceived << endl;
if (bytesReceived == SOCKET_ERROR)
{
cerr << "error met recv() in de reciev() functie" << endl;
exit(EXIT_FAILURE);
}
if (bytesReceived == 0)
{
cout << "client disconnected" << endl;
exit(EXIT_FAILURE);
}
return bufStr;
}
void main()
{
//initialize winsock
WSADATA wsData;
WORD ver = MAKEWORD(2, 2);
int wsOk = WSAStartup(ver, &wsData);
if (wsOk != 0) {
cerr << "can't initialize winsock ABORT";
return;
}
//create socket
SOCKET listening = socket(AF_INET, SOCK_STREAM, 0);
if (listening == INVALID_SOCKET) {
cerr << "cant create socket ABORT" << std::endl;
}
//bind IP adress and port to socket
sockaddr_in hint;
hint.sin_family = AF_INET;
hint.sin_port = htons(54000);
hint.sin_addr.S_un.S_addr = INADDR_ANY; //could also inet_pton
bind(listening, (sockaddr*)&hint, sizeof(hint));
//tell winsock the socket is for listening
listen(listening, SOMAXCONN);
//wait for connection
sockaddr_in client;
int clientSize = sizeof(client);
SOCKET clientSocket = accept(listening, (sockaddr*)&client, &clientSize);
if (clientSocket == INVALID_SOCKET) {
cerr << "somthing went wrong with client socket accept ABORT";
exit(EXIT_FAILURE);
}
char host[NI_MAXHOST]; //client remote name
char service[NI_MAXSERV]; //service (i.e port) the client is connected on
ZeroMemory(host, NI_MAXHOST);
ZeroMemory(service, NI_MAXSERV);
if (getnameinfo((sockaddr*)&client, sizeof(client), host, NI_MAXHOST, service, NI_MAXSERV, 0) == 0) {
cout << host << " connected on port " << service << endl;
}
else {
inet_ntop(AF_INET, &client.sin_addr, host, NI_MAXHOST);
cout << host << " connected on port " << ntohs(client.sin_port) << endl;
}
//close listening socket
closesocket(listening);
/*
//non blocking socket leads to error
u_long mode = 1; // 1 to enable non-blocking socket
ioctlsocket(clientSocket, FIONBIO, &mode);
//non blocking socket
*/
//while loop: accept and echo message to client
char buf[4096];
string inputTxt;
while (true)
{
inputTxt = receive(clientSocket,buf);
send(clientSocket, buf, inputTxt.size() + 1, 0);
}
closesocket(clientSocket);
WSACleanup();
}