/* 
 * ReaderWriterRSem.java (Implements Readers/Writers Reader.)
 *
 * Written by : Nitin  Motgi (nmotgi@cs.ucf.edu)
 *
 * This file implements Reader problem.
 * 
 * Portions copyright(c) 2000 to School of Electrical Engineering and 
 * Computer Science, UCF, Orlando.                   
 *
 * Use and distribution of this source code are strictly governed by 
 * terms and conditions set by the authors.
 * 
 * $Id : ReaderWriterRSem.java, v1.0.0 02/12/2001. $
 *
 * Revision History Revisited:
*/

/* Start of ReaderWriterRSem.*/
public class ReaderWriterRSem extends Thread{

  /* Each consumer is given an ID so that the higher level
     routine can interact with a specific Reader.*/
     int nID;

  /* This is up level pointer points to the parent class
     which provides mechanism for synchronization.*/
     ReaderWriterSem RWSem;

  /* End condition indicator set to push the Producer from
     endlessly producing an item and put in the queue.*/
     boolean bEndCondition;

     public int nToken;


     /* 
      * This function is constructor for this class.
      */
     public ReaderWriterRSem(int nID,ReaderWriterSem RWSem){
       this.nID   = nID;                  /* Store ID.*/
       this.RWSem = RWSem;                /* Pointer to Higher class.*/
       bEndCondition = true;              /* Produce one item and put in
                                             shared data structure.*/
       nToken = -1;
     }/* End of ReaderWriterRSem.*/

     /*
      * This program is heart of this thread.
      */
     public void run(){
         int nPrevToken=-1;

         /* Till the indicator turns false.*/
         while(bEndCondition){

          RWSem.ReadDatabase(nToken,this);
          if(nPrevToken != nToken){
            nPrevToken = nToken;
          }

         }/* End of while.*/
      }/* End of run.*/

      /*
       * Sets the end codition to true or false.
       */
      public void SetEndCondition(boolean bState){
        bEndCondition = bState;
      }/* End of SetEndCondition.*/

}/* End of ReaderWriterRSem*/