WaitFreeComparable.java

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package sh.isaac.model;

/**
 *
 * {@code WaitFreeComparable} objects can compare the write sequence of the
 * original {@code byte[]} data from which they where deserialized, with
 * the current write sequence in a map of objects.
 * This ability to compare original
 * write sequence with current write sequence, enables compare and swap
 * updates to maps so that they may be updated using wait-free algorithms
 * (an algorithm where there is guaranteed per-thread progress). Wait-freedom is
 * the strongest non-blocking guarantee of progress).
 *
 * Also see http://minborgsjavapot.blogspot.com/2014/12/java-8-byo-super-efficient-maps.html
 * for discussion of using maps with known keyspace such as we do here...
 * @author kec
 */
public interface WaitFreeComparable {
   /**
    * Gets the write sequence.
    *
    * @return the write sequence from which this object was created.
    */
   int getWriteSequence();

   //~--- set methods ---------------------------------------------------------

   /**
    * Sets the write sequence.
    *
    * @param sequence the write sequence for which this object is to be written.
    */
   void setWriteSequence(int sequence);
}