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                 if (!isFull()) {
  34                         nbObj++;
  35                         tampon[prem] = obj;
  36                         prem = (prem + 1) % taille;
  37                         System.out.println(Thread.currentThread().getName() + " a depose " + (Integer)obj);
  38                 } else {
  39                         System.out.println("Buffer plein pour " + Thread.currentThread().getName());
  40                 }
  41         }
  42
  43
  44         public synchronized Object preleve() {
  45                 Object outObj = null;
  46                 if (isEmpty()) {
  47                         nbObj--;
  48                         outObj = tampon[der];
  49                         der = (der + 1) % taille;
  50                         System.out.println(Thread.currentThread().getName() + " a preleve " + (Integer)outObj);
  51                 } else {
  52                         System.out.println("Buffer vide pour " + Thread.currentThread().getName());
  53                 }
  54                 return outObj;
  55         }
  56
  57 } // fin class BufferCirc