title: mmap system call usage
body: <p>I heard about using a mmap system call for merging two blocks of memory into one continuous with MAP_ANONYMOUS flag, but I can't find any simple example how to use this trick.</p>
  
  <p>The example on the Wikipedia which implements an optimized circular buffer, is too complicated for me (<a href="http://en.wikipedia.org/wiki/Circular_buffer" rel="nofollow">Circular Buffer article</a>).</p>
  
  <p>Can you give me any usage example for MAP_ANONYMOUS flag?</p>