 classes.  The <code>compareAndSet</code> method is not a general
 replacement for locking.  It applies only when critical updates for an
 object are confined to a <em>single</em> variable.

 <p>Atomic classes are not general purpose replacements for
 <code>java.lang.Integer</code> and related classes.  They do <em>not</em>
 define methods such as <code>equals</code>, <code>hashCode</code> and
 <code>compareTo</code>.  (Because atomic variables are expected to be
 mutated, they are poor choices for hash tab