[root@74-82-173-217 ~]# cat runtime.php
<?php
class runtime
{
  var $StartTime = 0;
  var $StopTime = 0;
  
  function get_microtime()
  {
    list($usec, $sec) = explode(' ', microtime());
    return ((float)$usec + (float)$sec);
  }

  function start()
  {
    $this->StartTime = $this->get_microtime();
  }

  function stop()
  {
    $this->StopTime = $this->get_microtime();
  }

  function spent()
  {
    return round(($this->StopTime - $this->StartTime) * 1000, 1);
  }
}
?>

include ("runtime.php");
$runtime= new runtime;
$runtime->start();

$runtime->stop();
echo "页面执行时间: ".$runtime->spent()." 毫秒";