cURL: PHP并发处理方式

function classic_curl($urls, $delay) {
    $queue = curl_multi_init();
    $map = array(); 

    foreach ($urls as $url) {
        // create cURL resources
        $ch = curl_init(); 

        // set URL and other appropriate options
        curl_setopt($ch, CURLOPT_URL, $url); 

        curl_setopt($ch, CURLOPT_TIMEOUT, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_NOSIGNAL, true); 

        // add handle
        curl_multi_add_handle($queue, $ch);
        $map[$url] = $ch;
    } 

    $active = null; 

    // execute the handles
    do {
        $mrc = curl_multi_exec($queue, $active);
    } while ($mrc == CURLM_CALL_MULTI_PERFORM); 

    while ($active > 0 && $mrc == CURLM_OK) {
        if (curl_multi_select($queue, 0.5) != -1) {
            do {
                $mrc = curl_multi_exec($queue, $active);
            } while ($mrc == CURLM_CALL_MULTI_PERFORM);
        }
    } 

    $responses = array();
    foreach ($map as $url=>$ch) {
        $responses[$url] = callback(curl_multi_getcontent($ch), $delay);
        curl_multi_remove_handle($queue, $ch);
        curl_close($ch);
    } 

    curl_multi_close($queue);
    return $responses;
}

二

function rolling_curl($urls, $delay) {
    $queue = curl_multi_init();
    $map = array(); 

    foreach ($urls as $url) {
        $ch = curl_init(); 

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_TIMEOUT, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_NOSIGNAL, true); 

        curl_multi_add_handle($queue, $ch);
        $map[(string) $ch] = $url;
    } 

    $responses = array();
    do {
        while (($code = curl_multi_exec($queue, $active)) == CURLM_CALL_MULTI_PERFORM) ; 

        if ($code != CURLM_OK) { break; } 

        // a request was just completed -- find out which one
        while ($done = curl_multi_info_read($queue)) { 

            // get the info and content returned on the request
            $info = curl_getinfo($done['handle']);
            $error = curl_error($done['handle']);
            $results = callback(curl_multi_getcontent($done['handle']), $delay);
            $responses[$map[(string) $done['handle']]] = compact('info', 'error', 'results'); 

            // remove the curl handle that just completed
            curl_multi_remove_handle($queue, $done['handle']);
            curl_close($done['handle']);
        } 

        // Block for data in / output; error handling is done by curl_multi_exec
        if ($active > 0) {
            curl_multi_select($queue, 0.5);
        } 

    } while ($active); 

    curl_multi_close($queue);
    return $responses;
}