(PECL libevent >= 0.0.1)
event_base_loop — Handle events
$event_base
   [, int $flags = 0
  ] )Starts event loop for the specified event base.
event_baseValid event base resource.
flags
       Optional parameter, which can take any combination of 
       EVLOOP_ONCE and EVLOOP_NONBLOCK. 
      
event_base_loop() returns 0 on success, -1 on error and 1 if no events were registered.