UNIX for Advanced & Expert Users

static void *server(void *arg)                  
struct sigaction sa;    
int i, num_fd, client_fd;    
struct sockaddr_in client_addr;    
 
socklen_t len = sizeof(client_addr);                
if (listen(s_sock_debugsvr, s_backlog) == -1) {            
         log("Debug Server: cannot listen");            
         pthread_exit(NULL);        
}       
sa.sa_handler = sigchld_handler; // reap all dead processes       
sigemptyset(&sa.sa_mask);        
sa.sa_flags = SA_RESTART;        
if (sigaction(SIGCHLD, &sa, NULL) == -1) {            
         log("Debug Server: Error in sigaction");            
         pthread_exit(NULL);        
}    
 
epfd = epoll_create(EPOLL_INIT_SIZE);    
if (epfd < 0) {        
         log("Exiting debug server worker thread...");        
         pthread_exit(NULL);    
}    
 
ev.events = EPOLLIN | EPOLLET;    
ev.data.fd = s_sock_debugsvr;    // add server socket to epoll    
epoll_ctl(epfd, EPOLL_CTL_ADD, s_sock_debugsvr, &ev);    
 
while (1) {        
         num_fd = epoll_wait(epfd, events, MAXEVENTS, 500);                
         for (i=0; i<num_fd; i++) {            
               if(events[i].data.fd == s_sock_debugsvr) {               
               /* New connection. Add it to list of epoll. Will allow notification when                   
                  data is received on this connection later. */                                
                      client_fd = accept(s_sock_debugsvr,(struct sockaddr *) &client_addr,&len);                
                      set_nonblocking(client_fd);                
                      ev.data.fd = client_fd;                
                      ev.events = EPOLLIN | EPOLLET;                
                      epoll_ctl(epfd, EPOLL_CTL_ADD, client_fd, &ev);                
                      printf("Added: %d\n", client_fd);           
               }            
               else if(events[i].events & EPOLLIN) {                
                      /* A request has come from a connected client. */                
                     client_fd = events[i].data.fd;               
                     /* Now dispatch the function to read from client socket */                
                    dispatch(io_thread_pool, read_socket, (void *)client_fd);           
               }       
        }    
}    
close(epfd);   
 return NULL;
}

static voidread_socket(void *arg) {    
      struct debug_query *client_debug_query;    
      int num_bytes, client_fd;        
      client_fd = (int)arg;    
      num_bytes = recv(client_fd, request, MAX_BUF_SZ-1, 0);        
      if (num_bytes < 0) {        /* An error has occured */                     
           close_proper(client_fd);        /* Delete from epoll */
           io_thread_cleaner_fn((void *)client_debug_query);        
           return;    
      }    
      if (num_bytes == 0) {        /* Client has closed connection */        
           close_proper(client_fd);        
           io_thread_cleaner_fn((void *) client_debug_query);        
           return;   
       }       
        /* If I have come here, it means there is data fom client that I need to act on. */        
      dispatch_with_cleanup(worker_thread_pool, on_debugquery, (void*)client_debug_query, io_thread_cleaner_fn, (void*)client_debug_query);    }

  static voidon_debugquery(void *arg){                  
            /* Do some processing */               
           ev.data.fd = client_fd;               
           epoll_ctl(epfd, EPOLL_CTL_DEL, client_fd, &ev);               
          close(client_fd);}