func (r *room) delPeer(uid proto.UID) int {
	r.Lock()
	defer r.Unlock()
	delete(r.peers, uid)
	return len(r.peers)
}
// delPeer delete a peer in the room
delPeer delete a peer in the room
// delPeer delete a peer in the room
func (r *room) delPeer(uid proto.UID) int {
	r.Lock()
	defer r.Unlock()
	delete(r.peers, uid)
	return len(r.peers)
}
func ( r * room ) delPeer ( uid proto . UID ) int { r . Lock ( ) defer r . Unlock ( ) delete ( r . peers , uid ) return len ( r . peers ) }
delPeer delete a peer in the room
delPeer delete a peer in the room