Aerys\Server::doStop PHP Method

    private function doStop() : \Generator
    {
        assert($this->logDebug("stopping"));
        $this->state = self::STOPPING;
        foreach ($this->acceptWatcherIds as $watcherId) {
            \Amp\cancel($watcherId);
        }
        $this->boundServers = [];
        $this->acceptWatcherIds = [];
        foreach ($this->pendingTlsStreams as list(, $socket)) {
            $this->failCryptoNegotiation($socket, key($this->clientsPerIP));
        }
        $this->stopPromisor = new Deferred();
        if (empty($this->clients)) {
            $this->stopPromisor->succeed();
        } else {
            foreach ($this->clients as $client) {
                if (empty($client->requestCycles)) {
                    $this->close($client);
                } else {
                    $client->remainingKeepAlives = PHP_INT_MIN;
                }
            }
        }
        (yield all([$this->stopPromisor->promise(), $this->notify()]));
        assert($this->logDebug("stopped"));
        $this->state = self::STOPPED;
        $this->stopPromisor = null;
        (yield $this->notify());
    }