CODEWITHSUNDEEP
csocketssocketserver
user3751012
user3751012

Reputation: 551

Multiple client not getting connected and cannot communicate at the same time

Below is the server code which I have written for multiple clients. But if I want to connect it with the second client, I am not able to connect it at the same time. At first I need to close the first client and then only I can connect and communicate with the second client. I think I have some problem while using the pthread_join. Not sure what is the exact problem. I want to make the server work for multiple clients at the same time. 

#include<stdio.h>
#include<string.h>    //strlen
#include<stdlib.h>    //strlen
#include<sys/socket.h>
#include<arpa/inet.h> //inet_addr
#include<unistd.h>    //write
#include<pthread.h> //for thread


 #define MAX_CLIENTS 5


//the thread function
void *new_connection_handler(void *);

int main(int argc , char *argv[])
{
    int socket_desc , client_sock , c , *new_sock;
    struct sockaddr_in server , client;


    //Create socket
    socket_desc = socket(AF_INET , SOCK_STREAM , 0);
    if (socket_desc == -1)
    {
        printf("Could not create socket");
    }


    //Prepare the sockaddr_in structure
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
    server.sin_port = htons( 8888 );
    bzero (&server.sin_zero, 8);



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


    //Listen
    listen(socket_desc , MAX_CLIENTS);



    //Accept and incoming connection
    printf("Waiting for incoming connections\n");




    c = sizeof(struct sockaddr_in);
    while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c)) )
    {
        printf("Connection accepted");



        pthread_t thread_id;
        new_sock = malloc(1);
        *new_sock = client_sock;



        if( pthread_create( &thread_id , NULL ,  new_connection_handler , (void*) new_sock) < 0)
        {
            perror("could not create thread");
            return 1;
        }



     printf("Handler assigned\n");
    }


    if (client_sock < 0)
    {
        perror("accept failed");
        return 1;
    }

    return 0;
}


void *new_connection_handler(void *socket_desc)
{
    //Get the socket descriptor
    int sock = *(int*)socket_desc;
    int read_size;
    char *message , client_message[2000];



    //Send some messages to the client
    message = "This is connection handler\n";
    write(sock , message , strlen(message));


    message = "Type something \n";
    write(sock , message , strlen(message));


    //Receive a message from client
    while( (read_size = recv(sock , client_message , 2000 , 0)) > 0 )
    {
        //Send the message back to client
        write(sock , client_message , strlen(client_message));
    }



    if(read_size == 0)
    {
        printf("Client disconnected\n");
        fflush(stdout);
    }
    else if(read_size == -1)
    {
        perror("recv failed");
    }

    //Free the socket pointer
    free(socket_desc);

    return 0;
}

Upvotes: 0

Views: 270

Answers (1)

n. m. could be an AI
n. m. could be an AI

Reputation: 119877

There is no need to join all threads. Detached threads are appropriate for this task.

I assume you are really calling pthread_join inside the while (accept(..)) loop, otherwise your description doesn't make much sense. If this is the case, just replace it with pthread_detach.

If you want to wait for all the threads to terminate before exiting, use a pthreads condition variable to count active threads. In your case the main program never exits so you can simply ignore the issue.

Upvotes: 2

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