code: protected function alloc() {
          if (null !== $this->memcached) {
              return;
          }
          $this->memcached = new \Memcache('fork_pool');
          $connexion = @$this->memcached->connect($this->config['host'], $this->config['port']);
          if (!$connexion) {
              throw new RuntimeException('Connexion to memcache refused.');
          }
      }
docs: Memory alloc