From IO::Select man page

           use IO::Select;
           use IO::Socket;

# step 1 
           $lsn = new IO::Socket::INET(Listen => 1, LocalPort => 8080)
+; 
# do the step1 or three socket servers, of-course port has to be diffe
+rent.

           $sel = new IO::Select( $lsn ); 
# instead of passing only one socket server handle, pass all three han
+dles.

           while(@ready = $sel->can_read) {
               foreach $fh (@ready) {
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# in this place, you check 'ready file handle' with three server handles(probably with grep). if they are equal then accept the connection, otherwise process the request from the client. Simple!

                   if($fh == $lsn) { 
                       # Create a new socket
                       $new = $lsn->accept;
                       $sel->add($new);
                   }
                   else {
                       # Process socket

                       # Maybe we have finished with the socket
                       $sel->remove($fh);
                       $fh->close;
                   }
               }
           }
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Poll can be used for this purpose also, but poll is a bit generic, it can do this as well other operations also, but select is only meant for doing this readiness check on the file handles, so simply make use of that.