Consider 3 PHP files that are called asynchronously via XMLHttpRequest:

// s1.php
session_start();
sleep(1);

// s2.php
session_start();
sleep(2);

// s3.php
session_start();
sleep(3);

Which of the following statements is true? (Choose two.)

Question

Consider 3 PHP files that are called asynchronously via XMLHttpRequest:

// s1.php
session_start();
sleep(1);

// s2.php
session_start();
sleep(2);

// s3.php
session_start();
sleep(3);

Which of the following statements is true? (Choose two.)

Accepted Answer

A. The total execution time for all 3 requests will be the maximum of the longest sleep() call

Answer

B. The requests may be processed out of order

Answer

C. The requests are guaranteed to be executed in order

Answer

D. Concurrent requests will be blocked until the session lock is released

200-710 Question #4: Real Exam Question with Answer & Explanation