does connection->processUntil is a blocking call?

[GoogleCodeExporter]

Hi,

I have used the following php code in order to achieve XMPP communication, 

$conn = new XMPPHP_XMPP("SERVER_NAME", 5222, 'username', 'password', 'xmpphp', 
'example.com', $printlog=false, $loglevel=XMPPHP_Log::LEVEL_INFO);

try {
     $conn->connect();
     $conn->processUntil('session_start');
       .
       .
       .
So here my question is does this processUntill is a blocking call,Since it 
almost takes 100% of my CPU.

Any help will be highly appreciated.

Best Regards,
~Anup Rojekar

Original issue reported on code.google.com by nproje...@gmail.com on 16 Aug 2012 at 9:55