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--- boundedbuffer [2007/09/24 17:16] – jyang
+++ boundedbuffer [2007/09/25 05:20] (current) – nshafiei
@@ Line 1: / Line 1: @@
 How do you implement a bounded FIFO buffer in C-Linda?
 Assume the buffer contains integers (to make life a little
-easier).  There are a number of producers and a number of
+ easier).  There are a number of producers and a number of
 consumer.  Assume that the functions consume and produce
 have already been defined.  Now consider the functions consumer
 and producer.
-<code c>
+ <code c>
 void consumer()
 {
@@ Line 216: / Line 216: @@
   int i,j, data;
   in("head",?i);
+  rd("tail",?j);
+  #wait when the buffer is empty
+  while (i==j) rd("tail",?j);
   in("buffer",i,?data);
   i=(i+1)%BUFFERSIZE;
@@ Line 221: / Line 224: @@
   return data;
 }
 void put(int data)
 {
@@ Line 227: / Line 230: @@
   in("tail",?j);
   rd("head",?i);
-  #loop when the buffer is full
+  #wait when the buffer is full
   while ( j-i==BUFFERSIZE-1 || i-j==1 ) rd("head",?i);
   j=(j+1)%BUFFERSIZE;
@@ Line 233: / Line 236: @@
   out("tail",j);
 }
+</code>
+Another Version
+<code c>
+#define SIZE 100
+Void Initialize()
+{
+ out("head", 0);
+ out("tail", 0);
+}
+int get()
+{
+  int head, tail, data;
+  in("head",?head);
+  rd("tail",?tail);
+  while(tail == head) rd("tail",?tail);
+  in("data",?data, head);
+  out("head",(head+1)%SIZE);
+  return data;
+}
+void put(int data)
+{
+  int head,tail;
+  in("tail",?tail);
+  rd("head",?head);
+  while( head == (tail+1)%SIZE ) rd("head",?head);
+  out("data",data, tail);
+  out("tail",(tail+1)%SIZE);
+}
+</code>
+<code c>
+// i1 and i2 are initialized to 0
+void put(int data)
+{
+      int i1, i2;
+      read("consumer", ?i2);
+      in("producer",?i1);
+      if(i1==size)i1=0;
+      while(i1+1==i2 || (i1+1==size && i2==0))
+         read("consumer",?i2);
+      out("data", data, i1);
+      out("producer", i1+1);
+}
+int get()
+{
+      int i2, data;
+      in("consumer",?i2);
+      if(i2==size)i2=0;
+      in("data",?data,i2);
+      out("consumer", i2+1);
+      return data;
+}
 </code>