curl multi curl_errno always returning 0 instead of 6

curl multi curl_errno always returning 0 instead of 6

I'm using the following code.
For some reason curl always returning 0 instead of 6 or other error codes.
Can someone tell me what's wrong with my code?
Here is my code
<?php
protected function curl($url)
{
$mh = curl_multi_init();
$handles = array();
foreach ($url as $link)
{
$handles[$link] = curl_init($link);
curl_setopt($handles[$link], CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($handles[$link], CURLOPT_HEADER, true);
curl_setopt($handles[$link], CURLOPT_RETURNTRANSFER, true);
curl_setopt($handles[$link],CURLOPT_FAILONERROR,true);
curl_setopt($handles[$link], CURLOPT_FOLLOWLOCATION,
$this->curlFollowLocation);
curl_setopt($handles[$link], CURLOPT_MAXREDIRS,
$this->curlMaxRedirects);
curl_setopt($handles[$link], CURLOPT_TIMEOUT,
$this->curlTimeout);
curl_setopt($handles[$link], CURLOPT_USERAGENT,
$this->curlUserAgent);
curl_setopt($handles[$link], CURLOPT_AUTOREFERER, true);
curl_multi_add_handle($mh, $handles[$link]);
}
$running = null;
do {
curl_multi_exec($mh, $running);
usleep(200000);
} while ($running > 0);
foreach ($handles as $key => $value)
{
$handles[$key] = false;
$handles[$key]['error_code'] = false;
if (curl_errno($value))
{
$handles[$key]['error_code'] = curl_errno($value);
} else {
$response = curl_multi_getcontent($value);
$httpCode = curl_getinfo($value, CURLINFO_HTTP_CODE);
if ( $httpCode != 200 ) {
$handles[$key]['error_code'] = $httpCode;
} else {
$handles[$key]['html'] = $response;
}
}
curl_multi_remove_handle($mh, $value);
curl_close($value);
}
curl_multi_close($mh);
return $handles;
}