Now I use two clients to connect to the server, assuming that create the conn for 5 and 6 respectively, so this time I'm conn is 6 input data on the client, the server did not take 5 in the collection after the select set to 0, so after always get stuck in the 5 readline, normally in the collection will only have 6, the other will be set to 0, but I this 5 also exist, is this why?????



While (1) {
Rset=allset;

Printf (" wait... \n");

Nready=select (maxfd + 1, & amp; Rset, NULL, NULL, NULL);//nready is received several concern

If (nready==1) {
If (errno==EINTR)
continue;
ERR_EXIT (" select ");
}
If (nready==0)
continue;

If (FD_ISSET (listenfd, & amp; Rset)) {
Peerlen=sizeof (peeraddr);

Conn=accept (listenfd, (struct sockaddr *) & amp; Peeraddr, & amp; Peerlen);
Printf (" conn==% d \ n ", conn);

If (conn==1)
ERR_EXIT (" accept ");

for (i=0; I & lt; FD_SETSIZE; I++) {//to find an empty position to prevent the conn
If (client [I]==1) {
The client [I]=conn.
If (I & gt; Maxi)
Maxi=I;

break;
}
}
If (I==FD_SETSIZE) {//can't find the empty position to prevent the conn
Fprintf (stderr, "many clients");
The exit (EXIT_FAILURE);
}



Printf (" IP port=% d=% s \ n ", inet_ntoa (peeraddr. Sin_addr), ntohs (peeraddr. Sin_port));


FD_SET (conn, & amp; Allset);

If (conn & gt; Maxfd)
Maxfd=conn.

If (- nready & lt;=0)//if the event number==0, then returned directly
Printf (" duqujieshu \ n ");
continue;

}

for (i=0; I & lt;=maxi; I++) {
Conn=client [I];
If (conn==1)
continue;
If (FD_ISSET (conn, & amp; Rset));//in the collection, it must produce the data
{
Printf (" conn=% d \ n ", conn);
Char recvbuf [1024]={0};
Memset (recvbuf, 0, sizeof (recvbuf));
Int ret=readline (conn, recvbuf, 1024);//now, the question is, if I opened the two clients, such as their conn is 5 and 6, so if I when the client sends data 6, because of the order, will first enter the 5, then stuck in the input buffer read 5
If (ret==1)

ERR_EXIT (" readline ");
If (ret==0)
{
Printf (" the client close \ n ");
The client [I]=1;
FD_CLR (conn, & amp; Allset);
}

The fputs (recvbuf, stdout);

Writen (conn, recvbuf, strlen (recvbuf));

If (- nready & lt;=0)
break;


}
}





}

CodePudding user response:

This is what network programming, 5 connection didn't release?

CodePudding user response:

Is the select function

Nready=select (maxfd + 1, & amp; Rset, NULL, NULL, NULL);

Nready to return to my attention by the number of file descriptors

First of all, is now two client connection -- -- -- -- -- 5 and 6

If I were in the client 6 write data

So should be accepted by the select through a interface to

At this point the select end block

Nready return 1

But at this point I shouldn't the rset of only 6
?
But when the conn=5
FD_ISSET (conn, & amp; Rset) can also be successful

But normally not should fail

Only FD_ISSET (6, & amp; Rset) to succeed?