linux服务器模型--select多路复用2011

最新推荐文章于 2025-06-14 00:17:57 发布

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最新推荐文章于 2025-06-14 00:17:57 发布

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本文详细介绍了一个基于TCP协议的多客户端并发服务器的实现过程。该服务器能够同时处理多个客户端的连接请求，通过使用select机制监测读写事件，并利用数组记录已连接的客户端套接字。文章深入探讨了socket编程、监听套接字设置、客户端连接接受、数据接收及发送等关键步骤。

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#include <SYS types.h>
#include <SYS ioctl.h>
#include <SYS wait.h>
#include <STDIO.H>
#include <SYS socket.h>
#include <ERRNO.H>
#include <STRING.H>
#include <STDLIB.H>
#include <SYS time.h>
#include <UNISTD.H>
#include <NETINET in.h>
#include <SYS un.h>

#define LISTEN_BACKLOGNUM 20
#define MAX_CONNECTED_NUM 20
#define NUM_SOCKFD 10
#define MAX_DATABUFFER_SIZE 200
int main(int argc, char **argv)
{
char strdatabuffer1[MAX_DATABUFFER_SIZE];
//char* strdatabuffer2;
fd_set fdset_readfd;
fd_set fdset_writefd;
fd_set fdset_errorfd;
int nmaxfds;
int hListenSocketfd;
int newclientsocketfd;
unsigned long linit = 0;

int arraysockfd[NUM_SOCKFD];
linit = init_socket_listen(atoi(argv[1]), hListenSocketfd );
if(linit < 0)
exit(0);
printf("server current states is listening...");
FD_ZERO(&fdset_readfd);
FD_ZERO(&fdset_writefd);
FD_SET(hListenSocketfd, &fdset_readfd);
FD_SET(hListenSocketfd, &fdset_writefd);
FD_SET(hListenSocketfd, &fdset_errorfd)
nmaxfds = hListenSocketfd;

while(true)
{
int nselectresult;

        for(int ncount = 0; ncount < NUM_SOCKFD; ncount++)
  {
   if(arraysockfd[ncount] != 0)
   {
    FD_SET(arraysockfd[ncount], &fdset_readfd );
   }

  }
  timeval.tv_sec = 30;
  timeval.tv_usec =0;

  nselectresult = select(nmaxfds + 1, &fdset_readfd, &fdset_writefd, &fdset_errorfd, &timeval );
  if(nselectresult == -1 && fdset_errorfd == EINTR)
   continue;
  if(nselectresult < 0)
  {
   perror("select(nmaxfds + 1, &fdset_readfd, &fdset_writefd, &fdset_errorfd, NULL )");
   exit(1);

  }
  if(FD_ISSET(hListenSocketfd, &fdset_readfd))
  {
   struct sockaddr_in client_address;
    memset (&client_address, 0,  sizeof (client_address));
    int clienaddrlength = sizeof(client_address);
    newclientsocketfd = accept (hListenSocketfd, (struct sockaddr *)&client_address, &clienaddrlength);

    for(int i = 0 ; i < NUM_SOCKFD; i++)
    {
      if(arraysockfd[i] == 0)
     {
                      arraysockfd[i]  = newclientsocketfd;
       break;

     }

    }
    if(newclientsocketfd > nmaxfds)
     nmaxfds = newclientsocketfd;

         // if(read(client_fd,buf,MAXDATASIZE)<0){
    read(newclientsocketfd, strdatabuffer1, MAX_DATABUFFER_SIZE, 0);
    printf("receive a connection: %s\n",  strdatabuffer1);
    close(newclientsocketfd);
  }

  for(int i = 0 ; i < NUM_SOCKFD; i++)
  {
   if(FD_ISSET(arraysockfd[i] , &fdset_readfd))
   {
    int nrecvCnt = read(newclientsocketfd, strdatabuffer1, MAX_DATABUFFER_SIZE, 0);
    if(nrecvCnt <= 0)
    {
     printf("client[%d] close\n",i);
     close(arraysockfd[i]);
     FD_CLR(arraysockfd[i], &fdset_readfd);

arraysockfd[i] = 0;

    }
    else
    {
     memset(&strdatabuffer1[nrecvCnt], '/0', 1);
     printf("client[%d] send:%s\n", i, strdatabuffer1);

    }
   }
  }
}
}

static unsigned long init_socket_listen(const int listen_port, int listensocket)
{
int listensocketfd;
struct sockaddr_in serversockaddr;
listensocketfd = socket(AF_INET, SOCK_STREAM, 0);
if(listensocketfd < 0)
{
  perror("socket(AF_INET, SOCK_STREAM, 0)");
  return -1;
}
int optIndexVal = 1;
setsockopt(listensocketfd, SOL_SOCKET,  SO_REUSEADDR, (char*)&optIndexVal, sizeof(optIndexVal));
memset(&serversockaddr, 0, sizeof(serversockaddr));
serversockaddr.sin_family = AF_INET;
    serversockaddr.sin_port = htons(listen_port);
serversockaddr.sin_addr.s_addr=INADDR_ANY;
bzero(&(serversockaddr.sin_zero), 8);
if(bind(listensocketfd, (struct sockaddr *)&serversockaddr, sizeof(serversockaddr)) < 0)
{
  perror("bind(listensocketfd, (struct sockaddr *)&serversockaddr, sizeof(serversockaddr))");
  close(listensocketfd);
  exit(1);
}
printf("listen socket bind to the server port sucess!");