Throttle cURL using usleep()

I'm using a web service to send 100's of http posts. How开发者_开发百科ever, the service only allows 5 per second. I'm wondering if the usleep command is the best way to do this. For example:

foreach($JSONarray['DATABASE'] as $E) 
{
    $aws = curl_init();
    //curl stuff
    curl_exec($aws);
    curl_close($aws);
    usleep(200000);
}

Now this is untested, but it should provide you with the idea of what I would do(and perhaps this snippet just work as it is - who knows...) :

// presets
$thissecond = time();
$cnt = 0;

foreach($JSONarray['DATABASE'] as $E) 
{
  while ($thissecond == time() && $cnt > 4) { // go into "waiting" when we going to fast
    usleep(100000); // wait .1 second and ask again
  }

  if ($thissecond != time()) { // remember to reset this second and the cnt
    $thissecond = time();
    $cnt = 0;
  }

  // off with the payload
  $aws = curl_init();
  //curl stuf
  curl_exec($aws);
  curl_close($aws);

  // remember to count it all
  $cnt++;
}