Aerys\Websocket\Rfc6455Endpoint::update PHP Method

    public function update(Server $server) : Promise
    {
        switch ($this->state = $server->state()) {
            case Server::STARTING:
                $result = $this->application->onStart($this->proxy);
                if ($result instanceof \Generator) {
                    return resolve($result);
                }
                break;
            case Server::STARTED:
                $f = (new \ReflectionClass($this))->getMethod("timeout")->getClosure($this);
                $this->timeoutWatcher = \Amp\repeat($f, 1000);
                break;
            case Server::STOPPING:
                $result = $this->application->onStop();
                if ($result instanceof \Generator) {
                    $promise = resolve($result);
                } elseif ($result instanceof Promise) {
                    $promise = $result;
                } else {
                    $promise = new Success();
                }
                $promise->when(function () {
                    $code = Code::GOING_AWAY;
                    $reason = "Server shutting down!";
                    foreach ($this->clients as $client) {
                        $this->close($client->id, $code, $reason);
                    }
                });
                \Amp\cancel($this->timeoutWatcher);
                $this->timeoutWatcher = null;
                return $promise;
            case Server::STOPPED:
                $promises = [];
                // we are not going to wait for a proper self::OP_CLOSE answer (because else we'd need to timeout for 3 seconds, not worth it), but we will ensure to at least *have written* it
                foreach ($this->clients as $client) {
                    // only if we couldn't successfully send it in STOPPING
                    $code = Code::GOING_AWAY;
                    $reason = "Server shutting down!";
                    $result = $this->doClose($client, $code, $reason);
                    if ($result instanceof \Generator) {
                        $promise[] = resolve($result);
                    }
                    if (!empty($client->writeDeferredControlQueue)) {
                        $promise = end($client->writeDeferredControlQueue)->promise();
                        if ($promise) {
                            $promises[] = $promise;
                        }
                    }
                }
                $promise = any($promises);
                $promise->when(function () {
                    foreach ($this->clients as $client) {
                        $this->unloadClient($client);
                    }
                });
                return $promise;
        }
        return new Success();
    }