php script locked because of 'require'

Question

Hello I have code like this:

file1.php:

session_start();
$object1 = new object1($_SESSION['variable']);

switch($_GET['variableGet']){
    case 'a': $object2 = new object2(); break;
    case 'b': $object2 = new object2(); break;
}
/*
etc etc
*/

file2.php:

require_once('file1.php');
sleep(5);
$object2->doSomethingForFile2();
echo 'file2 is done!';

file3.php:

require_once('file1.php');
sleep(7);
$object2->doSomethingForFile3();
echo 'file 3 is done!';

With AJAX I am calling file2.php and file3.php.

What I want to do:

I want the file2 and file3 start at the same moment.

Problem:

file3 is waiting for file2 -> when file2 is finished (after 5 seconds), then file3 starts script and whole ajax is loading in 12 seconds (sleep(5) + sleep(7)), not in 7 seconds.

Own observations:

This problem depends on *require_once(file1.php)*, which is used in file2 and file3. If i will run code like this:

file2.php:

sleep(5);
echo 'file2 is done!';

file3.php:

sleep(7);
echo 'file 3 is done!';

Whole data loads in 7 seconds (after 5 seconds file2.php and then after 2 seconds file3.php)

Answer 1

Session data is locked to prevent concurrent writes only one script may operate on a session at any time . Therefore your second script waits for the first to finish. You should use session_write_close to close the session when you are no longer using session variables.