TD1/exo3/BufferCirc.java

   1
   2
   3 /**
   4  * implementation du producteur consommateur avec un buffer circulaire
   5  */
   6 public class BufferCirc {
   7
   8         private Object[] tampon;
   9         private int taille;
  10         private int prem, der, nbObj;
  11
  12
  13         public BufferCirc (int t) {
  14                 taille = t;
  15                 tampon = new Object[taille];
  16                 prem = 0;
  17                 der = 0;
  18                 nbObj = 0;
  19         }
  20
  21
  22         public boolean isEmpty() {
  23                 return nbObj == 0;
  24         }
  25
  26
  27         public boolean isFull() {
  28                 return nbObj == taille;
  29         }
  30
  31
  32         public synchronized void depose(Object obj) {
  33                 while(isFull()) {
  34                         try {
  35                                 wait();
  36                         }
  37                         catch (InterruptedException e) {}
  38                 }
  39                 nbObj++;
  40                 tampon[prem] = obj;
  41                 prem = (prem + 1) % taille;
  42                 notify();
  43                 System.out.println(Thread.currentThread().getName() + " a depose " + (Integer)obj);
  44         }
  45
  46
  47         public synchronized Object preleve() {
  48                 while(isEmpty()) {
  49                         try {
  50                                 wait();
  51                         }
  52                         catch (InterruptedException e) {}
  53                 }
  54                 Object outObj = null;
  55                 nbObj--;
  56                 outObj = tampon[der];
  57                 der = (der + 1) % taille;
  58                 notify();
  59                 System.out.println(Thread.currentThread().getName() + " a preleve " + (Integer)outObj);
  60                 return outObj;
  61         }
  62
  63 } // fin class BufferCirc