Subversion Repositories f9daq

/*

    C socket server example, handles multiple clients using threads */

#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 threading , link with lpthread

#define PORT 3210

//the thread function 

void *connection_handler(void *);

int is_connected = 0;

int ncalls=0;

int writesock(int sock, char *msg, int len ){

    int hdr[2];

    hdr[0]=ncalls++;

    hdr[1]= len + 8;

    write(sock , hdr , 8);

    return write(sock , msg , len);

}

int main(int argc , char *argv[]) {

    int socket_desc , client_sock , c , *new_sock=NULL;

    struct sockaddr_in server , client;

    //Create socket

    socket_desc = socket(AF_INET , SOCK_STREAM , 0);

    if (socket_desc == -1)

    {

        printf("Could not create socket");

    }

    puts("Socket created");

    //Prepare the sockaddr_in structure

    server.sin_family = AF_INET;

    server.sin_addr.s_addr = 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 , 3);

    //Accept and incoming connection

    puts("Waiting for incoming connections...");

    c = sizeof(struct sockaddr_in);

    //Accept and incoming connection

    puts("Waiting for incoming connections...");

    c = sizeof(struct sockaddr_in);

    while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c)) )

    {

        puts("Connection accepted");

        pthread_t sniffer_thread;

        if (is_connected){

            char message[0xFF]="Only one client can connect. Disconnect it first!";

            perror(message);

            writesock(client_sock , message , strlen(message));

            close (client_sock);

            continue;

        }

        new_sock = (int *) malloc(1);

        *new_sock = client_sock;

        if( pthread_create( &sniffer_thread , NULL , connection_handler , (void*) new_sock) < 0)

        {

            perror("could not create thread");

            return 1;

        }

        //Now join the thread , so that we dont terminate before the thread

        //pthread_join( sniffer_thread , NULL);

        puts("Handler assigned");

    }

    if (client_sock < 0)

    {

        perror("accept failed");

        return 1;

    }

    return 0;

}

void *daq_handler(void *data){

 int s = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

 //Get the socket descriptor

 int sock = *(int*)data;

 char msg[0xFF];

 int cnt=0;

 while (1){

    sprintf(msg, "daq_handler %d %d", sock, cnt++);

    int error = 0;

    socklen_t len = sizeof (error);

    int retval = getsockopt (sock, SOL_SOCKET, SO_ERROR, &error, &len);

    if (retval!=0 || error!=0) break;

    writesock(sock , msg , strlen(msg));

    sleep(5);

 }

 printf("Exiting thread %d", sock ) ;

}

/*

 * This will handle connection for each client

 * */

void *connection_handler(void *socket_desc) {

    //Get the socket descriptor

    int sock = *(int*)socket_desc;

    int read_size;

    char *message , client_message[2000];

    is_connected = 1;

    //Send some messages to the client

    message = "Info from connection handler\n";

    writesock(sock , message , strlen(message));

    //Receive a message from client

    pthread_t daq_thread = 0;

    while( (read_size = recv(sock , client_message , 2000 , 0)) > 0 )

    {

        //Send the message back to client

        int * hdr = (int *) client_message;

        char *msg = &client_message[8];

        printf("Received %d bytes RECID = %d LEN %d\n",read_size, hdr[0], hdr[1]);

        switch (hdr[0]){

           case 0:

           hdr[0]= sock;

           if( pthread_create( &daq_thread , NULL , daq_handler , (void*) &client_message) < 0)

        {

            perror("could not create daq thread");

            break ;

        }

break;

           case 3:

         if (daq_thread) {

            pthread_cancel(daq_thread);

            daq_thread = 0;

         }

break;

           default: break;

        }

        writesock(sock , msg , strlen(msg));

    }

    if(read_size == 0)

    {

        puts("Client disconnected");

        fflush(stdout);

    }

    else if(read_size == -1)

    {

        perror("recv failed");

    }

    if (daq_thread) {

      pthread_cancel(daq_thread);

      daq_thread = 0;

    }

    //Free the socket pointer

    free(socket_desc);

    socket_desc = 0;

    is_connected = 0;

    return 0;

}