Use this function to check current status of a connection:
<?php
$c=stream_socket_server("tcp://127.0.0.1:1100");
while(1){
if(is_resource($a=stream_socket_accept($c))){
# do something time-consuming
if(stream_socket_get_name($a,true)!==false){
fwrite($a,"Regards form Berlin");
}
}
} ?>
stream_socket_enable_crypto