(PECL event >= 1.2.6-beta)
EventBufferEvent::setWatermark — Adjusts read and/or write watermarks
$events
   
   , 
    int
     $lowmark
   
   , 
    int
     $highmark
   
   )Adjusts the read watermarks, the write watermarks , or both, of a single buffer event.
A buffer event watermark is an edge, a value specifying number of bytes to be read or written before callback is invoked. By default every read/write event triggers a callback invokation. See » Fast portable non-blocking network programming with Libevent: Callbacks and watermarks
events
    
      Bitmask of
      Event::READ
      ,
      Event::WRITE
      , or both.
     
lowmark
    Minimum watermark value.
highmark
    
      Maximum watermark value.
      0
      means "unlimited".
     
No value is returned.