php使用curl_init()和curl_multi_init()多线程的速度比较详解

<?php
$mtime = explode(" ", microtime());
$mtime = $mtime[1].($mtime[0] * 1000);
$mtime2 = explode(".", $mtime);
$mtime = $mtime2[0];
echo $mtime;
echo "<br>";
for($i=1; $i<=5; $i++){
$szUrl = 'http://www.webkaka.com/';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $szUrl);
curl_setopt($curl, CURLOPT_HEADER, 0);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_ENCODING, '');
$data=curl_exec($curl);
echo $data;
echo "<br>";
$mtime_ = explode(" ", microtime());
$mtime_ = $mtime_[1].($mtime_[0] * 1000);
$mtime2_ = explode(".", $mtime_);
$mtime_ = $mtime2_[0];
echo $mtime_;
echo "<br>";
echo $mtime_ - $mtime;
}
?>

<?php
echo date("Y-m-d H:m:s",time());
echo " ";
echo floor(microtime()*1000);
echo "<br>";
$mtime = explode(" ", microtime());
$mtime = $mtime[1].($mtime[0] * 1000);
$mtime2 = explode(".", $mtime);
$mtime = $mtime2[0];
echo $mtime;
echo "<br>";
$urls = array(
'http://www.webkaka.com',
'http://www.webkaka.com',
'http://www.webkaka.com',
'http://www.webkaka.com',
'http://www.webkaka.com');
print_r(async_get_url($urls)); // [0] => example1, [1] => example2
echo "<br>";
echo date("Y-m-d H:m:s",time());
echo " ";
echo floor(microtime()*1000);
echo "<br>";
$mtime_ = explode(" ", microtime());
$mtime_ = $mtime_[1].($mtime_[0] * 1000);
$mtime2_ = explode(".", $mtime_);
$mtime_ = $mtime2_[0];
echo $mtime_;
echo "<br>";
echo $mtime_ - $mtime;
function async_get_url($url_array, $wait_usec = 0)
{
  if (!is_array($url_array))
    return false;
  $wait_usec = intval($wait_usec);
  $data  = array();
  $handle = array();
  $running = 0;
  $mh = curl_multi_init(); // multi curl handler
  $i = 0;
  foreach($url_array as $url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // return don't print
    curl_setopt($ch, CURLOPT_TIMEOUT, 30);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)');
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); // 302 redirect
    curl_setopt($ch, CURLOPT_MAXREDIRS, 7);
    curl_multi_add_handle($mh, $ch); // 把 curl resource 放进 multi curl handler 里
    $handle[$i++] = $ch;
  }
  /* 执行 */
  do {
    curl_multi_exec($mh, $running);
    if ($wait_usec > 0) /* 每个 connect 要间隔多久 */
      usleep($wait_usec); // 250000 = 0.25 sec
  } while ($running > 0);
  /* 读取资料 */
  foreach($handle as $i => $ch) {
    $content = curl_multi_getcontent($ch);
    $data[$i] = (curl_errno($ch) == 0) ? $content : false;
  }
  /* 移除 handle*/
  foreach($handle as $ch) {
    curl_multi_remove_handle($mh, $ch);
  }
  curl_multi_close($mh);
  return $data;
}
?>