Select模式和超时

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 1      fd_set rset;
 2         FD_ZERO(&rset);
 3 
 4         int nready;
 5         int maxfd;
 6         int fd_stdin = fileno(stdin);
 7         if(fd_stdin > sock)
 8         {
 9                 maxfd = fd_stdin;
10         }
11         else
12         {
13                 maxfd = sock;
14         }
15 
16         char sendbuf[1024] = { 0 };
17         char recvbuf[1024] = { 0 };
18         while(1)
19         {
20                 FD_SET(fd_stdin,&rset);
21                 FD_SET(sock,&rset);
22                 nready = select(maxfd+1,&rset,NULL,NULL,NULL);
23                 if(nready == -1)
24                         ERR_EXIT("select");
25                 if(nready == 0)
26                         continue;
27 
28                 if(FD_ISSET(sock,&rset))
29                 {
30 
31                         int ret = readline(sock,recvbuf,sizeof(sendbuf));
32                         if(ret == -1)
33                                 ERR_EXIT("readn");
34                         else if(ret ==  0)
35                         {
36                                 printf("server close");
37                                 break;
38                         }
39 
40                         fputs(recvbuf,stdout);
41                         memset(sendbuf,0, sizeof(sendbuf));
42                         memset(recvbuf,0, sizeof(recvbuf));
43                 }
44 
45                 if(FD_ISSET(fd_stdin,&rset))
46                 {
47                         if(fgets(sendbuf,sizeof(sendbuf),stdin) == NULL)
48                                 break;
49                         writen(sock,sendbuf,strlen(sendbuf));
50                 }
51         }
52         close(sock);

View Code

• void FD_CLR(int fd,fd_set *set);
• int FD_ISSET(int fd,fd_set *set);
• void FD_SET(int fd,fd_set *set);
• void FD_ZERO(fd_set *set);
• select的超时
  • 　　
    

      1 //读超时
      2 int read_timeout(int fd,unsigned int wait_seconds)
      3 {
      4     int ret = 0;
      5     if(wait_seconds > 0)
      6     {
      7         fd_set read_fdset;
      8         struct timeval timeout;
      9         
     10         FD_ZERO(&read_fdset);
     11         FD_SET(fd,&read_fdset);
     12         
     13         timeout.tv_sec = wait_seconds;
     14         timeout.tv_usec = 0;
     15         do
     16         {
     17             ret = select(fd+1,&read_fdset,NULL,NULL,&timeout);
     18         }while(ret < 0 && errno == EINTR)
     19 
     20         if(ret == 0)
     21         {
     22             ret = -1;
     23             errno = ETIMEDOUT;
     24         }
     25         else if(ret == 1)
     26             ret = 0;
     27     }
     28     return ret;
     29 }
     30 
     31 
     32 //接收超时
     33 int accept_timeout(int fd,struct sockaddr_in *addr,unsigned int wait_seconds)
     34 {
     35     int ret;
     36     socklen_t addrlen = sizeof(struct sockaddr_in);
     37     
     38     if(wait_seconds > 0)
     39     {
     40         fd_set accept_fdset;
     41         struct timeval timeout;
     42         FD_ZERO(&accept_fdset);
     43         FD_SET(fd,&accept_fdset);
     44         timeout.tv_sec = wait_seconds;
     45         timeout.tv_usec = 0;
     46         do
     47         {
     48             ret = select(fd+1,&accept_fdset,NULL,NULL,&timeout);
     49         }while(ret < 0 && errno == EINTR)
     50         
     51         if(ret == -1)
     52             return -1;
     53         else if(ret == 0)
     54         {
     55             errno = ETIMEDOUT;
     56             return -1;
     57         }
     58     }
     59     if(addr != NULL)
     60         ret = accept(fd,(struct sockaddr*)addr,&addrlen);
     61     else
     62         ret = accept(fd,NULL,NULL);
     63     if(ret == -1)
     64         ERR_EXIT("accept");
     65     return ret;
     66 }
     67 
     68 void activate_nonblock(int fd)
     69 {
     70     int ret;
     71     int flags = fcntl(fd,F_GETFL);
     72     if(flags == -1)
     73         ERR_EXIT("fcntl");
     74     flags |= O_NONBLOCK;
     75     ret = fcntl(fd,F_SETFL,flags);
     76     if(ret == -1)
     77         ERR_EXIT("fcntl");
     78 }
     79 
     80 void deactivate_nonblock(int fd)
     81 {
     82     int ret;
     83     int flags = fcntl(fd,F_GETFL);
     84     if(flags == -1)
     85         ERR_EXIT("fcntl");
     86     flags &~ O_NONBLOCK;
     87     ret = fcntl(fd,F_SETFL,flags);
     88     if(ret == -1)
     89         ERR_EXIT("fcntl");
     90 }
     91 
     92 //连接超时
     93 int connect_timeout(int fd,struct sockaddr_in *addr, unsigned int wait_seconds)
     94 {
     95     int ret;
     96     socklen_t addrlen = sizeof(struct sockaddr_in);
     97 
     98     if(wait_seconds > 0)
     99         activat_nonblock(fd);
    100     
    101     ret = connect(fd,(struct sockaddr*)addr,addrlen);
    102     if(ret < 0 && errno == EINPROGRESS)
    103     {
    104         fd_set connect_fdset;
    105         struct timeval timeout;
    106         FD_ZERO(&connect_fdset);
    107         FD_SET(fd,&connect_fdset);
    108         timeout.tv_sec = wait_seconds;
    109         timeout.tv_usec = 0;
    110         do
    111         {
    112             ret = select(fd+1,NULL,&connect_fdset,NULL,&timeout);
    113         }while(ret < 0 && errno == EINTR)
    114         if(ret == 0)
    115         {
    116             ret = -1;
    117             errno = ETIMEDOUT;
    118         }
    119         else if(ret < 0)
    120             return -1;
    121         else if(ret == 1)
    122         {
    123             int err;
    124             socklen_t socklen = sizeof(err);
    125             int sockoptret = getsockopt(fd,SOL_SOCKET,SO_ERROR,&err,&socklen);
    126             if(sockoptret == -1)
    127             {
    128                 return -1;
    129             }
    130             if(err == 0)
    131                 ret = 0;
    132             else
    133             {
    134                 errno = err;
    135                 ret = -1;
    136             }
    137         }
    138     }
    139 
    140     if(wait_seconds > 0)
    141     {
    142         deactivate_nonblock(fd);
    143     }
    144     return ret;
    145 }

    View Code

     

Select模式和超时

标签：pen   signed   splay   col   bsp   recv   cond   技术   gre   

原文地址：https://www.cnblogs.com/zhaohu/p/8972315.html