File content as of revision 1:35d97f58d4d9:

#include "mbed.h"
#include "EthernetInterface.h"

#define SERVER_PORT   7
#define BUFFLEN 100

int bufsize=1024;      //Size of the shared memory
char *buffer;   //This is the shared memory between the child threads

void Debug(void const *data)
{
    TCPSocketServer server;
    server.bind(SERVER_PORT);
    server.listen();
    
    while (true) {
        printf("\nWait for new connection...\n");
        TCPSocketConnection client;
        server.accept(client);
        client.set_blocking(false, 1500); // Timeout after (1.5)s
        
        printf("Connection from: %s\n", client.get_address());
        char buffer[256];
        while (true) {
            int n = client.receive(buffer, sizeof(buffer));
            if (n <= 0) break;
            
            client.send_all(buffer, n);
            if (n <= 0) break;
        }
        
        client.close();
    }
}
void Handle_client(void const *socket_data) {
   int socket; 
   socket = (int)socket_data;
   //pc.printf("Socket connected #%d\n",socket); 
 
   //pc.printf("Shared memory message is %s\n",buffer); 
   lwip_recv(socket,buffer,bufsize,0); 


   if (lwip_send(socket,buffer,strlen(buffer),0)!=strlen(buffer)) //send the content of the shared memory back to the socket 
   {
   //     pc.printf("failed send\n");
 
   }
  
  // pc.printf("Message sent successfully to socket %d\n",socket);

}

int main (void) {

    EthernetInterface eth;
    eth.init(); //Use DHCP
    eth.connect();
    Thread t1(Debug, (void *) 1);
    while(1)
    {
    
    }
   // pc.printf("IP Address is %s\n", eth.getIPAddress());
    /*int socket_server;
    struct sockaddr_in localHost;
    memset(&localHost, 0, sizeof(localHost));
    int new_socket;
    
    if( (socket_server= lwip_socket(AF_INET, SOCK_STREAM, 0))<0)
    {
   //     pc.printf("failed socket init\n");
        return -1;
    }
    localHost.sin_family = AF_INET;
    localHost.sin_port = htons(SERVER_PORT);
    localHost.sin_addr.s_addr = INADDR_ANY;
    
    if (lwip_bind(socket_server, (const struct sockaddr *) &localHost, sizeof(localHost)) < 0) {
   //     pc.printf("failed socket bind init\n");
        return -1;
    }
      if (lwip_listen(socket_server,3)<0)
  {
    perror("listen");
    exit(EXIT_FAILURE);
  }
  socklen_t newSockRemoteHostLen = sizeof(localHost);
  int tid;
  
  for(tid=0;tid<=2;tid++) 
  {
    new_socket = lwip_accept(socket_server, (struct sockaddr*) &localHost, &newSockRemoteHostLen);
    if (new_socket < 0)
    {
   // pc.printf("failed socket accept\n");
        return -1;
     }

       Thread t(Handle_client, (void *) new_socket);
   }*/
 
}