Testing various curl functions for async

curl_test.php

function make_request($url, $waitResult=true){
    $cmi = curl_multi_init();

    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

    curl_multi_add_handle($cmi, $curl);

    $running = null;
    do {
        curl_multi_exec($cmi, $running);
        sleep(.1);
        if(!$waitResult)
        break;
    } while ($running > 0);
    curl_multi_remove_handle($cmi, $curl);
    if($waitResult){
        $curlInfos = curl_getinfo($curl);
        if((int) $curlInfos['http_code'] == 200){
            curl_multi_close($cmi);
            return curl_multi_getcontent($curl);
        }
    }
    curl_multi_close($cmi);
}

// http://php.net/manual/en/function.curl-multi-init.php
// Build the multi-curl handle, adding both $ch
$mh = curl_multi_init();

// Build the individual requests, but do not execute them
$chs = [];
$chs['ID0001'] = curl_init('http://webservice.example.com/?method=say&word=Hello');
$chs['ID0002'] = curl_init('http://webservice.example.com/?method=say&word=World');
// $chs[] = ...
foreach ($chs as $ch) {
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,  // Return requested content as string
        CURLOPT_HEADER => false,         // Don't save returned headers to result
        CURLOPT_CONNECTTIMEOUT => 10,    // Max seconds wait for connect
        CURLOPT_TIMEOUT => 20,           // Max seconds on all of request
        CURLOPT_USERAGENT => 'Robot YetAnotherRobo 1.0',
    ]);

    // Well, with a little more of code you can use POST queries too
    // Also, useful options above can be  CURLOPT_SSL_VERIFYHOST => 0  
    // and  CURLOPT_SSL_VERIFYPEER => false ...

    // Add every $ch to the multi-curl handle
    curl_multi_add_handle($mh, $ch);
}

// Execute all of queries simultaneously, and continue when ALL OF THEM are complete
$running = null;
do {
    curl_multi_exec($mh, $running);
} while ($running);

// Close the handles
foreach ($chs as $ch) {
    curl_multi_remove_handle($mh, $ch);
}
curl_multi_close($mh);

// All of our requests are done, we can now access the results
// With a help of ids we can understand what response was given
// on every concrete our request
$responses = [];
foreach ($chs as $id => $ch) {
    $responses[$id] = curl_multi_getcontent($ch);
    curl_close($ch);
}
unset($chs); // Finita, no more need any curls :-)

print_r($responses); // output results