s.c

这是我自己写的用c语言的聊天室

/*
	s.c A chat server by Ze Zhang and Johannes Detlefsen
	compile: gcc -o s s.c list.c -lpthread
*/

#include <stdio.h>
#include <stdlib.h>		// for atoi() function
#include <sys/socket.h>
#include <sys/types.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
#include <sys/wait.h>
#include <pthread.h>		// for the cosy POSIX threads
#include <arpa/inet.h>		// for inet_ntoa() function
#include <fcntl.h>
#include <unistd.h>
#include <sys/msg.h>
#include "list.h"		// linked list to save socket file descriptors in it

#define BACKLOG 10		// connections on the queue
#define MAXDATALEN 1024
#define PORT 9034

/*initialize list*/
	List L;
    //Position P; //better declare local
	pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void * server(void * arg);

int main( int argc, char *argv[] ) {
	int sockfd,new_fd; // listen on sock_fd, new connection on new_fd
	int portnum;
	struct sockaddr_in server_addr;
	struct sockaddr_in client_addr;
	int sin_size;
	pthread_t thread_id;
	int sfd; /* socket file descriptor in the linked list*/
	Position P;

	/*check if portnumber is received by argument, if not use defined */
	if( argc == 2 )	portnum = atoi(argv[1]);
	 else portnum = PORT;

	/*set up linked list to store the socket file descriptors */
	L = MakeEmpty( NULL );
	P = Header( L );

	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(1);
	}

	/* initialize the server_addr */
	server_addr.sin_family=AF_INET;
	server_addr.sin_addr.s_addr = INADDR_ANY; // here we get our IP address of www.tec.hkr.se
	server_addr.sin_port=htons(portnum);
	memset(&(server_addr.sin_zero), '\0', 8); // zero the rest of the struct

	/* bind the port to the socket */
	if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr))== -1) {
		perror("bind");
		exit(1);
	}

	/* listen if anyone connecting to the port*/
	if (listen(sockfd, BACKLOG) == -1) {
            perror("listen");
            exit(1);
        }
 	else printf("server is running now!\nPlease exit after all connections closed with Ctrl-c \n");

	while(1){
		sin_size=sizeof(struct sockaddr_in);

		if ((new_fd = accept(sockfd, (struct sockaddr *)&client_addr,&sin_size)) == -1) {
			perror("accept");
			continue;
		}
	printf("new connection accepted\n");
	  /* store new file descriptors in linked list */
		//sfd=new_fd;
		pthread_mutex_lock(&mutex);
		printf("mutex lock aquired for INSERT\n");
		P = Header( L );
		Insert( new_fd, L, P );	//printf("Inserted sfd -%d- on the list\n",sfd);
	  	P = Advance( P );		//go to next one
		PrintList( L );
		pthread_mutex_unlock(&mutex);
		printf("mutex INSERT unlock\n");

	  printf("server got connection from %s\n",inet_ntoa(client_addr.sin_addr));
	  pthread_create(&thread_id,NULL,server,(void*)&new_fd);

	  // pthread_join(thread_id,NULL); say: thread attribute is detached!!!
	  pthread_detach(thread_id); /* now we never ever have to wait for this one anymore
	  it's easier (less code) do change a joinable thread into detached state than creating
	  a detached thread... */
  	}

  DeleteList( L );	// clean up linked list
  close(sockfd);	// close Socket
}

/*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
** Server function starts for every connected Client
**xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/

void * server(void * arg){
  int msglen;
  char	*buffer =(char *) malloc(MAXDATALEN),
  	*msg    =(char *) malloc(MAXDATALEN),
	*termmsg=(char *) malloc(30);
  char	dpchar[]=": ", *strp;
  char usrname[10];
  int ts_fd,termlen;
  ts_fd = * (int *) arg; 	/* get thread-socket file descriptor*/
  int sfd; 			/* socket file descriptor in the linked list*/
	Position P;

  if(recv(ts_fd,usrname,MAXDATALEN,0) == -1){
      printf("error: could not recv usrname!\n");
	  exit(1);
  }
	else printf("%s connected to the server\n",usrname);

	while(1){
	 recv(ts_fd,buffer,MAXDATALEN,0);

	 /* termination control */
	 if ( strncmp( buffer, "/q", 2) == 0 ){
		printf("%s has left the chat\n",usrname);
		strcpy(termmsg,usrname);
		strp=termmsg;
		strp=strp+(strlen(termmsg));
		strcpy(strp," has left the chat");
		termlen=strlen(termmsg);
		pthread_mutex_lock(&mutex);
		printf("mutex lock aquired for DELETE\n");
		Position P = Header( L );
        	do{	// delete socket file descriptor from linked list
            		P = Advance( P );
            		sfd = Retrieve( P ); //read from list!
			if(sfd == ts_fd) Delete( sfd, L );
			if(sfd != ts_fd) send(sfd,termmsg,termlen,0);
        	} while( !IsLast( P, L ) );
		PrintList( L );
		/*if( IsEmpty( L ) ){
			L = MakeEmpty( NULL );
			P = Header( L );
		}*/
		pthread_mutex_unlock(&mutex);
		printf("mutex DELETE unlock \n");
		close(ts_fd);
		 break;
	 }

	strcpy(msg,usrname);
	strp=msg;
	strp=strp+(strlen(msg));
	strcpy(strp,dpchar);
	strp+=2; // move pointer 2 forward because dpchar contains ": "
	strcpy(strp,buffer);
	msglen=strlen(msg);
	//if(send(ts_fd,msg,msglen,0)>0) 	printf("msg -%s- send\n",msg);

	/* send msg to all clients: */
	pthread_mutex_lock(&mutex);
	printf("mutex lock aquired for SEND\n");
	Position P = Header( L );
        do{
            P = Advance( P );
            sfd = Retrieve( P ); //read from list!
			//if(sfd != ts_fd)
			send(sfd,msg,msglen,0);
        } while( !IsLast( P, L ) );
	PrintList( L );
	pthread_mutex_unlock(&mutex);
	printf("mutex SEND unlock\n");
   };
     return 0;
}

/*	Is the linked list a CRITICAL SECTION indeed?
	Do we need to protect the linked list with MUTEX, CONDVAR or Semaphores ?
*/