BSD Sockety a funkce select()

[Ladislav Vaiz]

Zdravim,
neanalyzoval jsem to do detailu, tak se treba mylim:
1) FD_ZERO je na miste
2) FD_SET(sock /* =server.sock */ ) take
Select() vam sock_set cely predela podle toho, jake udalosti nastaly. 
Musite ho vytvorit znovu nebo si ho pamatovat.
Kdyby vam to neslo ani tak, poslete vystup strace.

Lada

Antonín Kolísek napsal(a):
> Dobry den,
>  
>  cely den se marne snazim rozbehnout jeden program, aby pracoval jako 
> klient/server
> (lokalni socket). Program obslouzi jen prvniho klienta a druhy se k nemu 
> vubec nepripoji.
>
> Nerad bych se priklanel k reseni pomoci podprocesu (fork(),...) a vlakna 
> nepripadaji vubec v uvahu.
> Vim ze to musi jit nejak pomoci fce select(),ale proste se mi to nedari. 
> Pripadne mi to jako bych
> pri spojeni (accept()) zapomel nebo si prepsal puvodni socket vytvoreny 
> serverem...
>
> Pokud by nekdo vedel kde delam chybu velmi by mi to pomohlo. Uvadim zde 
> kratky priklad
> na kterem sve kroky testuji.
>
> *********** server.c *************
> #include <stdio.h>
> #include <stdlib.h>
> #include <errno.h>
> #include <string.h>
> #include <fcntl.h>
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <sys/un.h>
>
>
> #define SOCK_PATH "socket"
>
> struct server_sock {
>     int sock; /*socket serveru*/
>     int sock_c[256]; /*klientske sockety*/
>     int len; /*velikost vyhrazene pameti*/
>     int t;
>     int n; /*pocet klientskych socketu*/
>     struct sockaddr_un local, remote;
> };
>
> struct server_sock create_sock(void);
>
> struct server_sock create_sock(void)
> {
> struct server_sock server;
> char str[100];
>
>     if ((server.sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
>     {
>         fprintf(stdout, "socket : %s\n",strerror(errno));
>         exit(1);
>     }
>
>     server.local.sun_family = PF_UNIX;
>
>     strcpy(server.local.sun_path, SOCK_PATH);
>     unlink(server.local.sun_path);
>
>     server.len = strlen(server.local.sun_path) + 
> sizeof(server.local.sun_family);
>
>     if (bind(server.sock, (struct sockaddr *)&server.local, server.len) 
> == -1)
>     {
>         fprintf(stdout, "bind : %s\n",strerror(errno));
>         exit(1);
>     }
>
>     if (listen(server.sock, 10) == -1)
>     {
>         fprintf(stdout, "listen on server socket : %s\n",strerror(errno));
>         exit(1);
>     }
>
>     return(server);
> }
>
> int main(void)
> {
> struct server_sock server;
> char str[100];
> int i = 0, n;
> int sockn = 0;
> int len;
> int sock;
> fd_set sock_set;
>
>     /*vytvoreni socketu*/
>     server = create_sock();
>
>     sock = server.sock;
>
>     //tv.tv_sec = 3;
>     //tv.tv_usec = 0;
>
>     printf("Cekam na spojeni...\n");
>
>     len = sizeof(server.remote);
>
>     FD_ZERO(&sock_set);
>     FD_SET(sock, &sock_set);
>
>     while (1)
>     {
>         //FD_ZERO(&sock_set);
>         //FD_SET(sock, &sock_set);
>
>         for (i = 0; i < sockn; i++)
>             FD_SET(server.sock_c[i], &sock_set);
>        
>         if (select(sock + 1, &sock_set, NULL, NULL, NULL) < 0)
>         {
>             fprintf(stdout, "select : %s\n",strerror(errno));
>             close(server.sock);
>             unlink(SOCK_PATH);
>             exit(1);
>         }
>
>          if (FD_ISSET(server.sock, &sock_set))
>         {
>             len = sizeof(server.remote);
>
>             if ((server.sock_c[sockn] = accept(server.sock, (struct 
> sockaddr *)&server.remote, &len)) == -1)
>             {
>                 fprintf(stdout, "accept : %s\n",strerror(errno));
>                 close(server.sock);
>                 unlink(SOCK_PATH);
>                 exit(1);
>             }
>
>             FD_SET(server.sock_c[sockn], &sock_set);
>             server.n = sockn++;
>
>             fprintf(stdout, "Connected.\n");
>         }
>
>         for (i = 0; i < sockn; i++)
>         {
>             if (FD_ISSET(server.sock_c[i], &sock_set))
>             {
>                 n = recv(server.sock_c[i], str, 100, 0);
>                 if (n <= 0)
>                 {
>                     fprintf(stdout, "recv : %s\n",strerror(errno));
>                     FD_CLR(server.sock_c[i], &sock_set);
>                     close(server.sock_c[i]);
>                     exit (1);
>                 }
>
>                 printf("DDD: send\n");
>                 if (send(server.sock_c[i], str, n, 0) <= 0)
>                 {
>                     fprintf(stdout, "send : %s\n",strerror(errno));
>                     close(server.sock_c[i]);
>                     exit (1);
>                 }
>             }
>         }
>         printf("go to back  - select\n");
>     }
>
>     close(server.sock);
>     unlink(SOCK_PATH);
>
>     return (0);
> }
>
> *************konec****************
>
> Omlouvam se za delku prikladu, ale pro nazornost jej posilam cely.
> Dekuji za kazdou radu.
>
> A.K.
>
> _______________________________________________
> Linux mailing list
> Linux na linux.cz
> http://www.linux.cz/mailman/listinfo/linux
>