cc: extend queue module

- add function to reinit tailq which supports pointer arithmetics
twitter · Jun 14, 2019 · 328ca05 · 328ca05
1 parent 6c98c8e
commit 328ca05
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/deps/ccommon/include/cc_queue.h b/deps/ccommon/include/cc_queue.h
@@ -127,6 +127,7 @@ extern "C" {
  * _INSERT_TAIL         -       -       +       +       +
  * _REMOVE_HEAD         +       -       +       -       -
  * _REMOVE              +       +       +       +       +
+ * _REINIT              -       -       -       +       -
  *
  */
 
@@ -691,6 +692,23 @@ struct {                                                                \
         (head2)->tqh_last = &(head2)->tqh_first;                        \
 } while (0)
 
+#define TAILQ_REINIT(head, var, field, offset) do {                     \
+    TAILQ_FIRST((head)) = var;                                          \
+    *(head)->tqh_last = NULL;                                           \
+    TAILQ_FOREACH(var, head, s_tqe) {                                   \
+        if ((TAILQ_NEXT((var), field)) != NULL) {                       \
+            TAILQ_NEXT((var), field) =                                  \
+                (void *)((char *)(TAILQ_NEXT((var), field)) + (offset));\
+        }                                                               \
+        if ((var) == TAILQ_FIRST(head)) {                               \
+            (var)->field.tqe_prev = &TAILQ_FIRST(head);                 \
+        } else {                                                        \
+            (var)->field.tqe_prev =                                     \
+                (void *)((char *)((var)->field.tqe_prev) + (offset));   \
+        }                                                               \
+    }                                                                   \
+} while (0)
+
 /*
  * Circular queue declarations.
  */