Some problems using Connection handling functions

ftrudeau

Greetings all. Im somewhat confused regarding the use of connection handling features of PHP.

Im building a chat application, the output frame is basically a script that runs forever. The point is that i need to know if the user disconnected / reloaded / pressed the stop button of his browser / closed his browser, in order to clean the DB.

Here is some bits and pieces of code :

<?
set_time_limit(0);

// ignore_user_abort(true);

require_once 'lib/Log.php';

$mask = Log::UPTO(PEAR_LOG_DEBUG);
$cnf = array('mode' => 0600, 'timeFormat' => '%x %X');
$logger = &Log::singleton('file', 'logs/system.log', 'agora', $cnf);
$logger->setMask($mask);

$logger->log("[output.php] Connection established for " . $_GET['cu'], PEAR_LOG_DEBUG);
$logger->flush();

while(!connection_aborted())
{
   // chat code here
}

register_shutdown_function('close');

function close()
{
   global $logger;

   if(connection_aborted())
   {
      $logger->log("[output.php] Connection closed for " . $_GET['cu'], PEAR_LOG_INFO);
   }
}

?>

Weird fact #1 : The log entry "Connection established" is only shown in the logs after i do an explicit reload of the frame, if i press the stop button of my browser, or if i close the browser.

Weird fact #2 : If uncomment the ignore_user_abort(true) function, then my script runs forever and ever, and is soon taking all the CPU ressources on the machine.

Im running PHP's CGI btw, dont know if this is relevant or not.

Any pointers appreciated 🙂
Thanks in advance.

Sgarissta

As for question #1
Near as I can tell this is because of how PHP outputs data to the browser. It has a tendency during long loops to "buffer" (for lack of a better word) data that should have already been displayed, until the loop completes.

That doesn't mean you aren't connected, it just means PHP hasn't decided its time to write data to the screen yet.

As far as #2 goes, i think that's the expected result. You're telling PHP to ignore the user quitting, and continue running the script regardless.

ftrudeau

Humm that does not make any sense, since im using pear Log package to log the messages. afaik, this should not be buffered, since it is not sent to the browser at all.

regarding question #2, yes, that is what i wanted. that is why also i registered the shutdown function 'close' in my script. regardless of whre i put it, i get nothing in the logs, and teh script keeps running forever (of course, i should habe put an exit call un the close function, which was not in my first post, sorry)

register_shutdown_function('close'); 

function close() 
{ 
   global $logger; 

   if(connection_aborted()) 
   { 
      $logger->log("[output.php] Connection closed for " . $_GET['cu'], PEAR_LOG_INFO);
      // do some session and DB cleaning
      exit;
   } 
}