Feat: kernel thread done

kernel/lib/queue.c

@@ -6,9 +6,11 @@
 queue_t *make_queue()
 {
   queue_t *ret = kmalloc(sizeof(queue_t));
-  ret->size = 0;
-  ret->begin = kmalloc(sizeof(queue_node_t));
-  ret->end = kmalloc(sizeof(queue_node_t));
+  *ret = (queue_t){
+    .size  = 0,
+    .begin = kmalloc(sizeof(queue_node_t)),
+    .end   = kmalloc(sizeof(queue_node_t)),
+  };
   *ret->begin = *ret->end = (queue_node_t){
     .prev = (queue_node_t *)ret->begin,
     .next = (queue_node_t *)ret->end,
@@ -42,6 +44,7 @@ void queue_push_back(queue_t *queue, uint64_t val)
     .value = 0,
   };
   queue->end = queue->end->next;
+  ++queue->size;
 }
 
 void queue_push_front(queue_t *queue, uint64_t val)
@@ -54,4 +57,31 @@ void queue_push_front(queue_t *queue, uint64_t val)
     .value = 0,
   };
   queue->begin = queue->begin->prev;
+  ++queue->size;
+}
+
+uint64_t queue_pop_back(queue_t *queue)
+{
+  if (!queue->size)
+    exit(ERR_OUT_OF_BOUND);
+
+  uint64_t ret = queue->end->prev->value;
+  queue->end->prev = queue->end->prev->prev;
+  queue->end->prev->next = queue->end;
+
+  --queue->size;
+  return ret;
+}
+
+uint64_t queue_pop_front(queue_t *queue)
+{
+  if (!queue->size)
+    exit(ERR_OUT_OF_BOUND);
+
+  uint64_t ret = queue->begin->next->value;
+  queue->begin->next = queue->begin->next->next;
+  queue->begin->next->prev = queue->begin;
+
+  --queue->size;
+  return ret;
 }