added xchange atomic

LRU.c

@@ -5,9 +5,11 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h> 
+#include <stdatomic.h>
 #define MAX_SIZE 10
-#define ALLOTMEMORY (KV *)malloc(sizeof(KV)*MAX_SIZE)
 
+#define ALLOTMEMORY (KV *)malloc(sizeof(KV)*MAX_SIZE)
+// static unsigned _Atomic active[10];
 typedef enum{
     FALSE,TRUE
 }bool;
@@ -18,7 +20,10 @@ struct KV{
     bool valid;
     bool modified;
     int lock;
+    // unsigned _Atomic lock;
 };
+
+int lockers[10];
 typedef struct KV KV;
 
 struct queue{
@@ -104,10 +109,10 @@ void delet(char *key)
     {
         if(array[i]->key == key)
         {
-            while(cas(&(array[i]->lock),0,1) == FALSE) ;
+            while(atomic_exchange_explicit(&(array[i]->lock),1,0) == 1);
             remove_element_from_deque(key);
             array[i]->valid = FALSE;
-            cas(&(array[i]->lock),1,0);
+            atomic_exchange_explicit(&(array[i]->lock),0,1);
             break;
         }
     }
@@ -134,13 +139,13 @@ void put(char *key, char *value)
         // replacment from cache
     }
 
-    while(cas(&(array[indx]->lock),0,1) == FALSE) ;
+    while(atomic_exchange_explicit(&(array[indx]->lock),1,0) == 1);
     array[indx]->key = key;
     array[indx]->value = value;
     array[indx]->valid = TRUE;
     array[indx]->modified = TRUE;
     insert_into_queue(key);
-    cas(&(array[indx]->lock),1,0);
+    atomic_exchange_explicit(&(array[indx]->lock),0,1);
 }
 
 char* get(char *key)
@@ -149,10 +154,10 @@ char* get(char *key)
     {
         if(array[i]->key == key)
         {
-            while(cas(&(array[i]->lock),0,1) == FALSE);
+            while(atomic_exchange_explicit(&(array[i]->lock),1,0) == 1);
             remove_element_from_deque(key);
             insert_into_queue(key);
-            cas(&(array[i]->lock),1,0);
+            atomic_exchange_explicit(&(array[i]->lock),0,1);
             return array[i]->value;
         }
     }
@@ -166,6 +171,7 @@ int main()
     {
         array[j] = (KV *)malloc(sizeof(KV));
         array[j]->valid = FALSE;
+        array[j]->lock = 0;
     }
     char key1[250]="Hello world1";
     char value1[256] = "THIS IS  Vlaue1";