curl_multi_exec(): is not a valid cURL handle resource - php

Question

I need to make multiple API calls to the uClassify Sentiment classifier to get the sentiment for a number of tweets. Since I have a lot of tweets to index, simply using cURL is not enough (it takes nearly 2 minutes to fully index around 228 tweets).
Without sentiment analysis, indexing is almost instantaneous so the problem is definitely due to the high number of API calls.
I have instead considered to use the curl_multi_init. Whenever an API call is made, curl_init() is called and rather than processing the call, the handle is added to curl_multi. Once all the handles are added, I use the curl_multi_exec() function to process all the handles.
Here is a simplified version of my application to only show the sentiment part:
$mh = curl_multi_init ();
foreach ($tweets as $tweet){
getSentiment ( $tweet, $mh );
}
executeHandles($mh);
function getSentiment($tweet, $mh) {
$tweet = str_replace ( ' ', '+', $tweet );
$prefix = 'http://uclassify.com/browse/uClassify/Sentiment/ClassifyText?';
$key = 'readkey=' . CLASSIFY_KEY . '&';
$text = 'text=' . $tweet . '&';
$version = 'version=1.01';
$url = $prefix . $key . $text . $version;
// $xml = getXML($url, $mh);
addHandle ( $url, $mh );
// $xml = file_get_contents($url, false, $context); ---- TOO SLOWh
// $mood = parseSentiment($xml);
// return $mood;
}
function addHandle($url, $mh) {
$ch = curl_init ();
$timeout = 5;
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt ( $ch, CURLOPT_CONNECTTIMEOUT, $timeout );
curl_multi_add_handle ( $mh, $ch );
// $xml = curl_exec($ch);
curl_close ( $ch );
// return $xml;
}
function executeHandles($mh) {
if (! empty ( $mh )) {
$active = null;
// execute the handles
do {
$mrc = curl_multi_exec ( $mh, $active );
} while ( $mrc == CURLM_CALL_MULTI_PERFORM );
while ( $active && $mrc == CURLM_OK ) {
if (curl_multi_select ( $mh ) == - 1) {
usleep ( 100 );
}
do {
$mrc = curl_multi_exec ( $mh, $active );
} while ( $mrc == CURLM_CALL_MULTI_PERFORM );
}
}
}
This is returning
curl_multi_exec(): 12 is not a valid cURL handle resource in C:\xampp\htdocs\Twitter\twitteroauth-master\index.php on line 299
This is referring to this line of code:
$mrc = curl_multi_exec ( $mh, $active );
Now this is just my first time using cURL so I am not sure if I am missing some important detail. I cannot understand why this error is happening, I do not have any curl statements that are happening after curl_close() etc.
Any help would be greatly appreciated, thank you!

Answer 1

so if you need those handles, why did you close them?
function addHandle($url, $mh) {
$ch = curl_init ();
$timeout = 5;
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt ( $ch, CURLOPT_CONNECTTIMEOUT, $timeout );
curl_multi_add_handle ( $mh, $ch );
}