Date: Sat, 15 Sep 2001 17:53:44 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: Stephen Montgomery-Smith <stephen@math.missouri.edu> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Could not bind Message-ID: <Pine.BSF.4.21.0109151753130.11145-100000@beppo> In-Reply-To: <3BA3F70D.27C2136@math.missouri.edu>
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You should always use perror or strerror if a system call fails so you know
*why* it fails. Then you can cross-references with the man(2) and man(3) pages
to figure out what's up.
On Sat, 15 Sep 2001, Stephen Montgomery-Smith wrote:
> I have written a server program that listens on port 3000. The program
> works very well except for one feature. I am asking if that is normal,
> or whether I forgot something.
>
> If I run the program it does fine. If I then kill the program (after it
> has accepted connections), and then run the program again, the bind
> function fails to work, and I get a message like "Could not bind" (see
> program below). If I wait a while, like a minute or two, then the
> program will work again. Is this normal behavior, or did I miss
> something?
>
> I got the programming style from Richard Steven's book on network
> programming. The structure of the program is something like this:
>
>
> typedef struct {
> int connfd;
> struct in_addr addr;
> u_short port;
> }
> arg_pass_type;
>
> void *process_client(void *arg) {
> int connfd = ((arg_pass_type*)arg)->connfd;
> struct in_addr addr = ((arg_pass_type*)arg)->addr;
> u_short port = ((arg_pass_type*)arg)->port;
>
> free(arg);
> pthread_detach(pthread_self());
> do_lots_of_stuff();
>
> }
>
> int main () {
> int listenfd;
> struct sockaddr_in servaddr;
> socklen_t slen;
> pthread_t tid;
> arg_pass_type *arg;
>
> listenfd=socket(AF_INET,SOCK_STREAM,0);
> bzero(&servaddr,sizeof(servaddr));
> servaddr.sin_family=AF_INET;
> servaddr.sin_addr.s_addr=htonl(INADDR_ANY);
> servaddr.sin_port=htons(3000);
> if (bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr)) < 0)
> {
> fprintf(stderr,"Could not bind\n");
> exit(1);
> }
> listen(listenfd,6);
>
> while (1)
> {
> slen=sizeof(servaddr);
> arg = malloc(sizeof(arg_pass_type));
> arg->connfd = accept(listenfd,(struct sockaddr*)&servaddr,&slen);
> arg->addr = servaddr.sin_addr;
> arg->port = servaddr.sin_port;
> pthread_create(&tid,NULL,process_client,(void*) arg);
> }
> exit(0);
> }
>
> --
> Stephen Montgomery-Smith
> stephen@math.missouri.edu
> http://www.math.missouri.edu/~stephen
>
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