// initialize basic variables for further work
$maxexecutiontime = (int)ini_get('max_execution_time');
$estimatecycletime = 0;
$starttime = microtime(true);

// for demonstration purposes, we use an "infinite" loop with a simulated task lasting 10 seconds
while (true) {
   sleep(10);

   // calculate the current runtime
   $currentruntime = microtime(true) - $starttime;

   // termination can be done either with a fixed constant
   // or by measuring the time of one pass and trying to use
   // the longest possible segment of the runtime
   // limit (has its problem).
   if ($estimatecycletime === 0) {
       $estimatecycletime = $currentruntime;
   }

   // check if the iteration stop time is approaching.
   // subtract the time of one pass, which likely won't fit
   // within the window. 
   if (($maxexecutiontime - $estimatecycletime) 



<p>基于一轮计算的提前终止适用于需要在尽可能少的新执行中处理大量轮次的情况，并且一轮中的每个操作同样耗时。如果各个通行证的时间要求不同，则必须在通行证时间上添加一个系数。另一种选择是使用预定义的时间：<br></p>

<pre class="brush:php;toolbar:false">$beforeEndTime = 1;

if (($maxExecutionTime - $beforeEndTime) 



<p>如果脚本在迭代后继续，例如关闭与 api 端点的连接、关闭文件或执行其他操作，则必须记住添加此时间。</p>