lib/Loop/Driver.php
public function run()
    {
        $this->running = true;

        try {
            while ($this->running) {
                if ($this->isEmpty()) {
                    return;
                }
                $this->tick();
            }
        } finally {
            $this->stop();
        }
    }
public function run()
    {
        $this->running = true;

        try {
            while ($this->running) {
                if ($this->isEmpty()) {
                    return;
                }
                $this->tick();
            }
        } finally {
            $this->stop();
        }
    }
public function run ( ) { $ this -> running = true ; try { while ( $ this -> running ) { if ( $ this -> isEmpty ( ) ) { return ; } $ this -> tick ( ) ; } } finally { $ this -> stop ( ) ; } }
Run the event loop.

One iteration of the loop is called one "tick". A tick covers the following steps:

1. Activate watchers created / enabled in the last tick / before `run()`.
2. Execute all enabled defer watchers.
3. Execute all due timer, pending signal and actionable stream callbacks, each only once per tick.

The loop MUST continue to run until it is either stopped explicitly, no referenced watchers exist anymore, or an
exception is thrown that cannot be handled. Exceptions that cannot be handled are exceptions thrown from an
error handler or exceptions that would be passed to an error handler but none exists to handle them.

@return void
Run the event loop .