Ajax request are not async

Question

I have an ajax problem:

foreach(ids as id){
  $.ajax({
    url:'script.php',
    data:'id='+id,
    cache:false,
  });
}

If I loop 6 times (in my foreach loop) I should have 6 asynchronous requests being made to the server. But the ajax calls in this case are called synchronously, and not asynchronously. Any one have any idea why this happens?

Answer 1

Ok thanks. After some hours of analysing and reflecting I realized why this script goes syncronsly: I open the script.php file and I notice this and the beginig of the file:

<?php
session_start();
$var1=$_SESSION['SOMEVAR'];
.......
//do php script.....

.......
?>

So I have parallel ajax calls to a php script that uses session, but sessions in this case locks the calls to be executed syncrosnly cause of the session vars request, so the solution of this problem is:

<?php
session_start();
$var1=$_SESSION['SOMEVAR'];
//get all session var
......
session_write_close();//then close it
.......
//do php script.....

.......
?>

With session_write_close i have my script to make the ajax calls in async way. a good explain here http://konrness.com/php5/how-to-prevent-blocking-php-requests/