PHP socket_select() always detects socket as available to read from - php

Question

I've been searching back and forth looking for a solution to this problem I'm having. It appears that socket_select() will always find accepted sockets (resources returned by socket_accept()) as available to read from, even though there are no packets waiting. I'm sure there's a little something I forgot to do, but I can't figure out what that is.
Here's the relevant code:
while(TRUE){
$read_sockets=$this->client_sockets;
$write_sockets=NULL;
$except=NULL;
if(socket_select($read_sockets, $write_sockets, $except, NULL)<1) continue;
foreach($read_sockets as $pending_socket){
echo "Read request received...".PHP_EOL;
if($this->socket==$pending_socket){
$new_client_socket=socket_accept($this->socket);
socket_write($new_client_socket,$this->read_data($new_client_socket),2048);
$this->client_sockets[]=$new_client_socket;
echo "New client...".PHP_EOL;
} else {
$pending_socket_data=$this->read_data($pending_socket);
if($pending_socket_data===false){
unset($this->client_sockets[array_search($pending_socket,$this->client_sockets)]);
continue;
}
socket_write($pending_socket,$pending_socket_data,2048);
echo "Old client...".PHP_EOL;
}
}
}
private function read_data(&$socket){
echo 'Reading data...'.PHP_EOL;
$client_data='';$tmp='';
while(socket_recv($socket,$tmp,$this->max_length,0) > 0){
$client_data .= $tmp;
}
return $client_data;
}
I know I'm not catching some exceptions, as socket_recv === FALSE, but this code is just a proof of concept, that I had to get down to while debugging the main code.
$this->socket is the server socket, and is non-blocking.
Thank's in advance!

Answer 1

private function read_data(&$socket){
echo 'Reading data...'.PHP_EOL;
$client_data='';$tmp='';
while(socket_recv($socket,$tmp,$this->max_length,0) > 0){
$client_data .= $tmp;
}
return $client_data;
}
Method read_data never return false, so the codes below will never run.
if($pending_socket_data===false){
unset($this->client_sockets[array_search($pending_socket,$this->client_sockets)]);
continue;
}
When socket_recv return false ,you should check socket_last_error() and decide if to socket_close($pending_socket) and unset($this->client_sockets[..]).
When socket_recv return 0, may be socket closed and you should call unset($this->client_sockets[..]).