title: Filter algorithm for mutual exclusion: Weak fairness
body: <p>I was referring to this filter algorithm notes:
  <a href="http://cs.nyu.edu/wies/teaching/ppc-14/material/lecture02.pdf" rel="nofollow">http://cs.nyu.edu/wies/teaching/ppc-14/material/lecture02.pdf</a></p>
  
  <p>It says, It provides weak fairness and some thread can be taken overtaken arbitary number of times. (slide 98)</p>
  
  <p>I am not able to understand this part, as last one to write the victim value has to wait and already waiting thread moves to next level, so how can one thread be overtaken here?.</p>