add queue_free and return a copy of the data to the user

lab01/zad1/include/queue.h

@@ -8,6 +8,8 @@ typedef struct Queue Queue;
 
 Queue *queue_new(size_t size, size_t element_size);
 
+void queue_free(Queue *queue);
+
 void *queue_read(Queue *queue);
 
 bool queue_write(Queue *queue, void *value);

lab01/zad1/src/main.c

@@ -28,7 +28,10 @@ int main(void) {
 
         long val = *(long*)val_ptr;
         printf("%zu: read %ld from fifo\n", i, val);
+        free(val_ptr);
     }
+
+    queue_free(q);
     
     return 0;
 }

lab01/zad1/src/queue.c

@@ -22,12 +22,20 @@ Queue *queue_new(size_t size, size_t element_size) {
     return ret;
 }
 
+void queue_free(Queue *q) {
+    for (size_t i = q->front; i < q->back; ++i) {
+        free(q->data[i]);
+    }
+    free(q->data);
+    free(q);
+}
+
 void *queue_read(Queue *q) {
     if (q->front == q->back) {
         return NULL;
     }
 
-    void* ret = q->data[q->front];
+    void* ret = memcpy(malloc(q->element_size), q->data[q->front], q->element_size);
     q->data[q->front] = NULL;
 
     q->front = (q->front + 1) % q->size;