Delay a PHP process until previous process has been completed

Delay a PHP process until previous process has been completed

I am new to PHP so please forgive me if I have silly mistakes or my
explanation isn't clear...
I am making a local site that controls a few files and folders. The
interface uses Codemines Jquiry Form Wizard which sends the input values
to my process.php file which runs through a series of 'if' statements
based on the input values selected.
I have got my form sending the input values correctly using
$_SESSION['siteurl'] = $_POST['siteurl']; and the first process works fine
which is copying the entire contents of a folder from one destination to
another (23mb of content)... The next process is supposed to copy another
folder into the folder copied in the last step but this doesn't seem to
happen because the previous copy process is still underway due to the
amount of files being copied.
So my question is, how can I create a pause in between the first copy
process and the second (the second copy process only available once the
first is completed)?
I have tried using sleep(4000); and usleep(4000); with no luck but I
simply put that code in between the two process (not sure if that is
correct).
Here is the PHP code that I am using as part of my process.php file:
if($_SESSION['cmsbranding'] == 'withbranding'){
mkdir("/user/foldername/foldername/$_SESSION[foldername]/", 0700);
function recurse_copy($src,$dst) {
$dir = opendir($src);
@mkdir($dst);
while(false !== ( $file = readdir($dir)) ) {
if (( $file != '.' ) && ( $file != '..' )) {
if ( is_dir($src . '/' . $file) ) {
recurse_copy($src . '/' . $file,$dst . '/' . $file);
}
else {
copy($src . '/' . $file,$dst . '/' . $file);
}
}
}
closedir($dir);
}
// Source directory (can be an FTP address)
$src = "/copythisfolder/";
// Full path to the destination directory
$dst = "/user/foldername/foldername/$_SESSION[foldername]/";
set_time_limit(0);
recurse_copy($src,$dst);
mkdir("/user/foldername/foldername/$_SESSION[foldername]/placesecondfolderinhere/",
0700);
function recurse_copy($src,$dst) {
$dir = opendir($src);
@mkdir($dst);
while(false !== ( $file = readdir($dir)) ) {
if (( $file != '.' ) && ( $file != '..' )) {
if ( is_dir($src . '/' . $file) ) {
recurse_copy($src . '/' . $file,$dst . '/' . $file);
}
else {
copy($src . '/' . $file,$dst . '/' . $file);
}
}
}
closedir($dir);
}
sleep(4000);
// Source directory (can be an FTP address)
$src = "/copythisfolder-forsecondprocess/";
// Full path to the destination directory
$dst =
"/user/foldername/foldername/$_SESSION[foldername]/placesecondfolderinhere/";
set_time_limit(0);
recurse_copy($src,$dst);
}
I hope this makes sense, please don't hesitate to ask if it doesn't.
PLEASE NOTE: This is page for managing some basic folder tasks for me
alone on a local MAMP server, I understand that copying folders and such
is not a good idea for most public web applications. This is simply a
management tool for me to run personally.
PS: The if() statements all work fine, i have only pasted in a segment of
the code but the issue is definately to do with how the copying of the
first folder takes to process.
Thank you very much to anyone who takes the time to look at this for me.