如何用curl_multi_init将单线程CURL请求改写成多线程版本以提升效率？

for ($i=0; $i < 100; $i++) {     $res[$key] = post($url, 'key='.$i); }

$newData = array_chunk($data, 10, true); foreach ($newData as $k => $tmp) {     $mh = curl_multi_init();     $chs = [];     foreach ($tmp as $key => $url) {         $ch = curl_init();         $chs[$key] = $ch;         curl_setopt($ch, CURLOPT_URL, $url);         curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-type:application/x-www-form-urlencoded;charset=utf-8;'));         curl_setopt($ch, CURLOPT_TIMEOUT, 30);         curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);         curl_setopt($ch, CURLOPT_HEADER, 0);         curl_setopt($ch, CURLOPT_POST, 1);         curl_setopt($ch, CURLOPT_POSTFIELDS, $tmp);         curl_multi_add_handle($mh, $ch);     }     $active = null;     do {         $mrc = curl_multi_exec($mh, $active);     } while ($mrc == CURLM_CALL_MULTI_PERFORM);     while ($active && $mrc == CURLM_OK) {         if (curl_multi_select($mh) != -1) {             do {                 $mrc = curl_multi_exec($mh, $active);             } while ($mrc == CURLM_CALL_MULTI_PERFORM);         }     }     foreach ($chs as $key => $ch) {         $res[$k][$key] = curl_multi_getcontent($ch);         curl_multi_remove_handle($mh, $ch);     }      curl_multi_close($mh); }