title: non-fair ReentrantReadWriteLock write and read lock priorities
body: <p>If I understand correct if I use <code>fair mode</code></p>
  
  <p>read and write locks doesn't have priorities and all locks will be acquired on order of the requesting by other threads. After write request receiving - if </p>
  
  <p>But I am not sure about <strong>non-fair</strong> mode. As written in concurrency in practice it is some sort of random.</p>
  
  <p>But I am not fully inderstand this.</p>
  
  <p>If I understand correct most profit of usage RWL that readers can read in parallel.</p>
  
  <p>But Lets imagine that we have a lot of read operations. Lets say several threads constantly hold read lock(single read is not long but two neighbours read always overlaps). And sometimes write operation occures.</p>
  
  <p>Does write operations will be executed eventually?</p>