linux socket怎么实现使用线程独立收发消息

/*tcpserver.c  2011.9.1 by yyg*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <pthread.h>

#define MYPORT 3490  //定义端口
#define BACKLOG 10
#define MAXDATASIZE 1024

int sockfd,new_fd;
pthread_t accthread,recthread;

void recmessage(void){  //接收客户端信息函数
  while(1){
    int numbytes;
    char buf[MAXDATASIZE];
    if((numbytes = recv(new_fd,buf,MAXDATASIZE,0))==-1){
      perror("recv");
      exit(1);
    }
    buf[numbytes]='\0';
    if(strcmp(buf,"exit")==0){  //若收到的是exit字符，则代表退出通信
      printf("Client is closed\n");
      close(new_fd);
      close(sockfd);
      exit(1);
    }
    printf("client:%s\n",buf);
  }/*while*/
}

void acceptconnect(void){  //接受客户端连接请求函数
  struct sockaddr_in their_addr;
  int sin_size;
  sin_size = sizeof(struct sockaddr_in);
  if((new_fd = accept(sockfd,(struct sockaddr *)&their_addr,&sin_size))==-1){
    perror("accept");
    exit(1);
  }
  printf("server:got connection from %s\n",inet_ntoa(their_addr.sin_addr));
  /*创建子线程，用于接收信息*/
  if((pthread_create(&recthread,NULL,(void*)recmessage,NULL)) != 0){
    printf("create thread error!\r\n");
    exit(1);
  }
}

int main(void){
  struct sockaddr_in my_addr;
  /*创建套接字*/
  if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){
    perror("socket");
    exit(1);
  }
  /*初始化sockaddr_in结构体相关参数*/
  my_addr.sin_family = AF_INET;
  my_addr.sin_port = htons(MYPORT);
  my_addr.sin_addr.s_addr = INADDR_ANY;
  bzero(&(my_addr.sin_zero),8);

  /*绑定端口与套接字*/
  if(bind(sockfd,(struct sockaddr*)&my_addr,sizeof(struct sockaddr)) == -1){
    perror("bind");
    exit(1);
  }
  /*监听客户端套接字*/
  if(listen(sockfd,BACKLOG)== -1){
    perror("listen");
    exit(1);
  }
  printf("listening...\n");
  /*创建子线程，用于接收信息*/
  if((pthread_create(&accthread,NULL,(void*)acceptconnect,NULL))!=0){
    printf("create thread error!\n");
    exit(1);
  }
  while(1){
    char msg[MAXDATASIZE];
    scanf("%s",msg);
    if(send(new_fd,msg,strlen(msg),0) == -1){  //发送信息，与客户端交流
      perror("send");
      exit(1);
    }
    if(strcmp(msg,"exit") ==0){
      printf("byebye\n");
      close(new_fd);
      close(sockfd);
      exit(1);
    }
  }/*while*/
  return 0;
}/*main*/