(PECL ev >= 0.2.0)
EvLoop::run — Begin checking for events and calling callbacks for the loop
   Begin checking for events and calling callbacks for the current event loop.
   Returns when a callback calls
   Ev::stop()
   method, or the flags are nonzero(in which case the return value is true) or
   when there are no active watchers which reference the loop(
   EvWatcher::keepalive()
   is true), in which case the return value will be false. The return
   value can generally be interpreted as
   if true, there is more work left
  to do.
  
flags
    
      Optional parameter
      flags
      can be one of the following:
      
| flags | Description | 
|---|---|
| 0 | The default behavior described above | 
| Ev::RUN_ONCE | Block at most one(wait, but don't loop) | 
| Ev::RUN_NOWAIT | Don't block at all(fetch/handle events, but don't wait) | 
Не повертає значень.
