sub exclusive_lockfile {

# check to see if we got an exclusive lock on the file
# and if not, sleep 1 second and try again until we have
# tried for a total of 20 seconds. If we could not get
# an exclusive lock within 20 seconds, let's exit with an
# error message.

my ($file_handle) = @_;
$lock_file = "$file_handle.lock";
$sleep_count = 0;
$request = "$as{'request'}";

if (-M "$require_path/$file_handle/$lock_file" > .001) {
unlink("$require_path/$file_handle/$lock_file");
rmdir("$require_path/$file_handle");
&log_flock($file_handle, "Forced Unlock Performed", $request);
}

# perform a check for a lock that may have gotten left behind
# because an error occurred previously.

while ($sleep_count < 20) {

if (!-e "$require_path/$file_handle") {
mkdir("$require_path/$file_handle", 0777);
chmod(0777, "$require_path/$file_handle");
open(LOCK_FILE, ">$require_path/$file_handle/$lock_file");
flock(LOCK_FILE, 2) if ($flock == 1);
last;
} else {
$sleep_count++;

if ($sleep_count > 19) {
&log_flock($file_handle, "Standard Timeout", $request);
&error_cannot_lock;
}
sleep(1);
next;
}
} # end of while

} # end of sub