pthreads overrides the functionality of the protected and private method modifiers in order to provide functionality more suited to multi-threaded objects. pthreads applies this functionality to all Threaded objects from creation.
Example #1 protected method example: protected methods can only be executed by one Thread at a time.
<?php
class ExampleThread extends Thread {
    public function run() {
        /* thread code */
        if ($this->synchronized()) {
        }
    }
    protected function exclusive() {
        /* synchronized method */
    }
}
$thread = new ExampleThread();
if ($thread->start()) {
    $thread->exclusive();
}
?>
Example #2 private method example: private methods may only be executed by the Threaded object during execution
<?php
class ExampleThread extends Thread {
    public function run() {
        /* thread code */
        if ($this->insideonly()) {
        }
    }
    private function insideonly() {
        /* private method */
    }
}
$thread = new ExampleThread();
if ($thread->start()) {
    $thread->insideonly();
}
?>