<?php
class server {
    public $ch;
    public $ip;
    public $port;
    public $enabled;
    public $prev;

    function check() {
        $socket = @fsockopen($this->ip, $this->port, $errno, $errstr, 0.1);
        $running;

        if ($socket) {
            $running = true;
            fclose($socket);
        } else
            $running = false;

        if ($running && !$this->prev) {
            $this->enabled = date('Y-m-d H:i:s');
            $this->prev = 1;
            return true;
        }

        if (!$running && $this->prev) {
            $this->enabled = NULL;
            $this->prev = 0;
            return true;
        }

        return false;
    }
}

$host = "localhost";
$user = "root";
$password = "root";
$dbName = "metin";
$dsn = 'mysql:host='.$host.';dbname='.$dbName;
$options = array(
            PDO::ATTR_PERSISTENT => true,
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
        );

$db = new PDO($dsn, $user, $password, $options);

$stmt = $db->prepare("SELECT * FROM czech");
$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_CLASS, "server");

$changed = array();

foreach ($result as $server) {
    if ($server->check())
        $changed[] = $server;
}

if (!empty($changed)) {
    $enabled;
    $prev;
    $ch;

    try {
        $db->beginTransaction();

        $stmt = $db->prepare("UPDATE czech SET enabled=:enabled, prev=:prev WHERE ch=:ch");
        $stmt->bindParam(':enabled', $enabled);
        $stmt->bindParam(':prev', $prev);
        $stmt->bindParam(':ch', $ch, PDO::PARAM_INT);

        foreach ($changed as $server) {
            $enabled = $server->enabled;
            $ch = $server->ch;
            $prev = $server->prev;
            $stmt->execute();
        }

        $db->commit();
    } catch (PDOException $ex) {
        echo $ex->getMessage();
        $db->rollBack();
    }
}