PHP Pthread seems to have random memory management and memory leaks

So, I have hit a dead-end here. I have tried everything I know to isolate a memory leak and from what I've gathered, it seems to be related to the use of pthread for multithreading this script.

I am in the process of writing a bot for Wikipedia, and I am nearing completion. Functionally, the program is sound, and works as expected in both multithreading and single-threading. The memory leak only occurs when multi-threading is switched on.

Both versions use exactly the same functions on the same script/file, to allow for easy/consistent debugging.

The engine that threads is below.

//Multithread engine



//This thread class allows for asyncronous function calls.  This is useful for the functions that consume time and can run in the background.

//Caution must be excercised to ensure that the functions are thread safe.

class AsyncFunctionCall extends Thread {



    protected $method;

    protected $params;

    public $result;



    public function __construct( $method, $params ) {

        $this->method = $method;

        $this->params = $params;

        $this->result = null; 

    }



    public function run() {

        if (($this->result=call_user_func_array($this->method, $this->params))) {

            return true;

        } else return false;

    }



    public static function call($method, $params){

        $thread = new AsyncFunctionCall($method, $params);

        if($thread->start()){

            return $thread;

        } else {

            echo "Unable to initiate background function $method!\n";

            return false;

        }

    }

}



// Analyze multiple pages simultaneously and edit them.

class ThreadedBot extends Collectable {



    protected $page, $pageid, $alreadyArchived, $ARCHIVE_ALIVE, $TAG_OVERRIDE, $ARCHIVE_BY_ACCESSDATE, $TOUCH_ARCHIVE, $DEAD_ONLY, $NOTIFY_ERROR_ON_TALK, $NOTIFY_ON_TALK, $TALK_MESSAGE_HEADER, $TALK_MESSAGE, $TALK_ERROR_MESSAGE_HEADER, $TALK_ERROR_MESSAGE, $DEADLINK_TAGS, $CITATION_TAGS, $IGNORE_TAGS, $ARCHIVE_TAGS, $VERIFY_DEAD, $LINK_SCAN;



    public $result;



    public function __construct($page, $pageid, $alreadyArchived, $ARCHIVE_ALIVE, $TAG_OVERRIDE, $ARCHIVE_BY_ACCESSDATE, $TOUCH_ARCHIVE, $DEAD_ONLY, $NOTIFY_ERROR_ON_TALK, $NOTIFY_ON_TALK, $TALK_MESSAGE_HEADER, $TALK_MESSAGE, $TALK_ERROR_MESSAGE_HEADER, $TALK_ERROR_MESSAGE, $DEADLINK_TAGS, $CITATION_TAGS, $IGNORE_TAGS, $ARCHIVE_TAGS, $VERIFY_DEAD, $LINK_SCAN) {

        $this->page = $page;

        $this->pageid = $pageid;

        $this->alreadyArchived = $alreadyArchived;

        $this->ARCHIVE_ALIVE = $ARCHIVE_ALIVE;

        $this->TAG_OVERRIDE = $TAG_OVERRIDE;

        $this->ARCHIVE_BY_ACCESSDATE = $ARCHIVE_BY_ACCESSDATE;

        $this->TOUCH_ARCHIVE = $TOUCH_ARCHIVE;

        $this->DEAD_ONLY = $DEAD_ONLY;

        $this->NOTIFY_ERROR_ON_TALK = $NOTIFY_ERROR_ON_TALK;

        $this->NOTIFY_ON_TALK = $NOTIFY_ON_TALK;

        $this->TALK_MESSAGE_HEADER = $TALK_MESSAGE_HEADER;

        $this->TALK_MESSAGE = $TALK_MESSAGE;

        $this->TALK_ERROR_MESSAGE_HEADER = $TALK_ERROR_MESSAGE_HEADER;

        $this->TALK_ERROR_MESSAGE = $TALK_ERROR_MESSAGE;

        $this->DEADLINK_TAGS = $DEADLINK_TAGS;

        $this->CITATION_TAGS = $CITATION_TAGS;

        $this->IGNORE_TAGS = $IGNORE_TAGS;

        $this->ARCHIVE_TAGS = $ARCHIVE_TAGS;

        $this->VERIFY_DEAD = $VERIFY_DEAD;

        $this->LINK_SCAN = $LINK_SCAN;    

    }



    public function run() {

        ini_set( 'memory_limit', '1G' );

        echo ini_get( 'memory_limit' )."; ".(memory_get_usage( true )/1024/1024)." MB\n";

        $this->result = analyzePage( $this->page, $this->pageid, $this->alreadyArchived, $this->ARCHIVE_ALIVE, $this->TAG_OVERRIDE, $this->ARCHIVE_BY_ACCESSDATE, $this->TOUCH_ARCHIVE, $this->DEAD_ONLY, $this->NOTIFY_ERROR_ON_TALK, $this->NOTIFY_ON_TALK, $this->TALK_MESSAGE_HEADER, $this->TALK_MESSAGE, $this->TALK_ERROR_MESSAGE_HEADER, $this->TALK_ERROR_MESSAGE, $this->DEADLINK_TAGS, $this->CITATION_TAGS, $this->IGNORE_TAGS, $this->ARCHIVE_TAGS, $this->VERIFY_DEAD, $this->LINK_SCAN);

        $this->setGarbage();

        $this->page = null;

        $this->pageid = null;

        $this->alreadyArchived = null;

        $this->ARCHIVE_ALIVE = null;

        $this->TAG_OVERRIDE = null;

        $this->ARCHIVE_BY_ACCESSDATE = null;

        $this->TOUCH_ARCHIVE = null;

        $this->DEAD_ONLY = null;

        $this->NOTIFY_ERROR_ON_TALK = null;

        $this->NOTIFY_ON_TALK = null;

        $this->TALK_MESSAGE_HEADER = null;

        $this->TALK_MESSAGE = null;

        $this->TALK_ERROR_MESSAGE_HEADER = null;

        $this->TALK_ERROR_MESSAGE = null;

        $this->DEADLINK_TAGS = null;

        $this->CITATION_TAGS = null;

        $this->IGNORE_TAGS = null;

        $this->ARCHIVE_TAGS = null;

        $this->VERIFY_DEAD = null;

        $this->LINK_SCAN = null;

        unset( $this->page, $this->pageid, $this->alreadyArchived, $this->ARCHIVE_ALIVE, $this->TAG_OVERRIDE, $this->ARCHIVE_BY_ACCESSDATE, $this->TOUCH_ARCHIVE, $this->DEAD_ONLY, $this->NOTIFY_ERROR_ON_TALK, $this->NOTIFY_ON_TALK, $this->TALK_MESSAGE_HEADER, $this->TALK_MESSAGE, $this->TALK_ERROR_MESSAGE_HEADER, $this->TALK_ERROR_MESSAGE, $this->DEADLINK_TAGS, $this->CITATION_TAGS, $this->IGNORE_TAGS, $this->ARCHIVE_TAGS, $this->VERIFY_DEAD, $this->LINK_SCAN );

    }

}

if( WORKERS === false ) {

    foreach( $pages as $tid => $tpage ) {

        $pagesAnalyzed++;

        $stats = analyzePage( $tpage['title'], $tpage['pageid'], $alreadyArchived, $ARCHIVE_ALIVE, $TAG_OVERRIDE, $ARCHIVE_BY_ACCESSDATE, $TOUCH_ARCHIVE, $DEAD_ONLY, $NOTIFY_ERROR_ON_TALK, $NOTIFY_ON_TALK, $TALK_MESSAGE_HEADER, $TALK_MESSAGE, $TALK_ERROR_MESSAGE_HEADER, $TALK_ERROR_MESSAGE, $DEADLINK_TAGS, $CITATION_TAGS, $IGNORE_TAGS, $ARCHIVE_TAGS, $VERIFY_DEAD, $LINK_SCAN );

        if( $stats['pagemodified'] === true ) $pagesModified++;

        $linksAnalyzed += $stats['linksanalyzed'];

        $linksArchived += $stats['linksarchived'];

        $linksFixed += $stats['linksrescued'];

        $linksTagged += $stats['linkstagged'];

        $alreadyArchived = array_merge( $stats['newlyArchived'], $alreadyArchived );

        $failedToArchive = array_merge( $failedToArchive, $stats['archiveProblems'] );

        $allerrors = array_merge( $allerrors, $stats['errors'] );

        file_put_contents( $dlaaLocation, serialize( $alreadyArchived ) );

    }

} else {

    //for( $i = 0; $i < count( $pages ); $i += $workerLimit ) {

        $workerQueue = new Pool( $workerLimit );

        //$tpages = array_slice( $pages, $i, $workerLimit );

        foreach( $pages as $tid => $tpage ) {

            $pagesAnalyzed++;

            echo "Submitted {$tpage['title']}, job ".($tid+1)." for analyzing...\n";

            $workerQueue->submit( new ThreadedBot( $tpage['title'], $tpage['pageid'], $alreadyArchived, $ARCHIVE_ALIVE, $TAG_OVERRIDE, $ARCHIVE_BY_ACCESSDATE, $TOUCH_ARCHIVE, $DEAD_ONLY, $NOTIFY_ERROR_ON_TALK, $NOTIFY_ON_TALK, $TALK_MESSAGE_HEADER, $TALK_MESSAGE, $TALK_ERROR_MESSAGE_HEADER, $TALK_ERROR_MESSAGE, $DEADLINK_TAGS, $CITATION_TAGS, $IGNORE_TAGS, $ARCHIVE_TAGS, $VERIFY_DEAD, $LINK_SCAN ) );



        }

        $workerQueue->shutdown();

        $workerQueue->collect(

        function( $thread ) {

            global $pagesModified, $linksAnalyzed, $linksArchived, $linksFixed, $linksTagged, $alreadyArchived, $failedToArchive, $allerrors;

            $stats = $thread->result;

            if( $stats['pagemodified'] === true ) $pagesModified++;

            $linksAnalyzed += $stats['linksanalyzed'];

            $linksArchived += $stats['linksarchived'];

            $linksFixed += $stats['linksrescued'];

            $linksTagged += $stats['linkstagged'];

            $alreadyArchived = array_merge( $stats['newlyArchived'], $alreadyArchived );

            $failedToArchive = array_merge( $failedToArchive, $stats['archiveProblems'] );

            $allerrors = array_merge( $allerrors, $stats['errors'] );

            return $thread->isGarbage();

        });

        echo "!!!!!!!!!!!!!!Links analyzed so far: $linksAnalyzed\n\n";

        file_put_contents( $dlaaLocation, serialize( $alreadyArchived ) );

        //$workerQueue = null;

        //unset( $workerQueue );

    //}

}

Analyzed Stanley Hartt (8742961)

Rescued: 0; Tagged dead: 0; Archived: 0; Max System Memory Used: 1.25 MB



PHP Fatal error:  Out of memory (allocated 46661632) (tried to allocate 6557907 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259



Fatal error: Out of memory (allocated 46661632) (tried to allocate 6557907 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259

Analyzed High-explosive anti-tank warhead (255968)

Rescued: 0; Tagged dead: 0; Archived: 5; Max System Memory Used: 22.75 MB



PHP Fatal error:  Out of memory (allocated 14680064) (tried to allocate 6341940 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1261



Fatal error: Out of memory (allocated 14680064) (tried to allocate 6341940 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1261

PHP Fatal error:  Out of memory (allocated 6291456) (tried to allocate 5243257 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259



Fatal error: Out of memory (allocated 6291456) (tried to allocate 5243257 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259

PHP Fatal error:  Out of memory (allocated 7864320) (tried to allocate 5245685 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259



Fatal error: Out of memory (allocated 7864320) (tried to allocate 5245685 bytes) in C:\Users\Maximilian Doerr\Documents\GitHub\Cyberbot_II\deadlink.php on line 1259

Analyzed Nadezhda Tylik (2896780)

Rescued: 0; Tagged dead: 0; Archived: 5; Max System Memory Used: 2.75 MB