c - c linux中客户端服务器聊天应用程序中的多线程

Question

我想使用 linux 在 c 中创建一个客户端服务器聊天应用程序。我想在客户端和服务器程序中创建两个线程。一个用于发送，另一个用于接收 .. 我是线程的新手 .. 请让我知道我应该如何创建它？这是我的服务器代码..

#include <stdlib.h>
#include <stdio.h>
#include <string.h>    //strlen
#include <sys/socket.h>
#include <arpa/inet.h> //inet_addr
#include <unistd.h>    //write
#define port 8877


int main(int argc , char *argv[])
{
    int socket_desc , client_sock , c , client_reply;
    struct sockaddr_in server , client;
    char client_message[5000];
    char repltocli[6000];
    //Create socket
    socket_desc = socket(AF_INET , SOCK_STREAM , 0);

    //Prepare the sockaddr_in structure
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = htonl(INADDR_ANY);
    server.sin_port = htons( port);

    //Bind
    if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
    {
        //print the error message
        perror("bind failed. Error");
        return 1;
    }
    puts("bind done");

    //Listen
    listen(socket_desc , 9);

    //Accept and incoming connection
    puts("Waiting for incoming connections...");
    c = sizeof(struct sockaddr_in);

    //accept connection from an incoming client
    client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c);
    if (client_sock < 0)
    {
        perror("accept failed");
        return 1;
    }
    puts("Connection accepted");

    puts("press ctrl+c to terminate the application");

    while(1)
    {
        //Receive a message from client
        recv(client_sock , client_message , 5000 , 0);

        puts("messege recived from client :");
        puts(client_message);

        memset(client_message, 0, sizeof(client_message));

        printf("enter your message : ");
        fgets(repltocli, 6000,stdin);

        //Send some data
        send(client_sock, repltocli , strlen(repltocli) , 0) ;

        memset(repltocli, 0, sizeof(repltocli));


    }

    return 0;
}

Answer 1

为了处理线程你需要创建thread functions ，返回类型应该是 void * 并且有/没有参数。但是如果你使用参数，参数应该是 void *

接收消息的线程-

void *receive_message(){
            while(1){
                    //Receive a message from client
                    recv(client_sock , client_message , 5000 , 0);
                    //puts("messege recived from client :"); // Comment this line out. Else it will annoye the user by printing every time
                    puts(client_message);

                    memset(client_message, 0, sizeof(client_message));
            }
}

发送消息的线程-

void *send_message(){
            while(1){       
                    // printf("enter your message : "); // Comment this line out. Else it will annoye the user by printing every time
                    fgets(repltocli, 6000,stdin);
                    //Send some data
                    send(client_sock, repltocli , strlen(repltocli) , 0) ;

                    memset(repltocli, 0, sizeof(repltocli));
            }
}

并全局声明repltocli数组，client_sock和client_message数组，因为你的线程也需要它!

在您的 main() 中为线程声明两个 pthread_d 变量-

int main(){

pthread_d thread_send, thread_recv;

// Do your stuff like socket, bind, listen and accept!

// Create these two threads and make sure that your main program should be alive-

pthread_create(&thread_send, NULL, send_message, NULL);
pthread_create(&thread_recv, NULL, receive_message, NULL);

while(1); // Press ctrl + C to terminate!
return 0;
}

对另一边也做同样的事情。