list: check against double node insertion

Tighten debug consistency checks in ADDHEAD(), ADDTAIL() and ENQUEUE()
through the macro LIST_ASSERT_NOT_CONTAINS().  Suggestions for a
better name very welcome.

This check is expensive (O(n)) and too permissive, as what we should
really check for is the node not being already part of *any* list.

This could be simplified by changing the list API to demand
pre-initialization of the node pointers to NULL.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1772 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/struct/list.h b/bertos/struct/list.h
index e0bb2338dab1d7a0d4d5beacbc7cda628afc25fc..05223caa01f70705e23435ce795c968470e98c80 100644 (file)
--- a/bertos/struct/list.h
+++ b/bertos/struct/list.h
@@ -104,7 +104,7 @@ typedef struct _PriNode
  *        ADDHEAD(&foo_list, &foo1);
  *        INSERT_BEFORE(&foo_list, &foo2);
  *        FOREACH_NODE(fp, &foo_list)
- *             fp->a = 10;
+ *            fp->a = 10;
  *    }
  *
  * \endcode
@@ -203,17 +203,29 @@ typedef struct _PriNode
                        ASSERT(n == &(l)->tail); \
                } while (0)
 
+       /// Checks that a node isn't part of a given list
+       #define LIST_ASSERT_NOT_CONTAINS(list,node) \
+               do { \
+                       Node *ln; \
+                       ASSERT_VALID_PTR(list); \
+                       ASSERT_VALID_PTR(node); \
+                       FOREACH_NODE(ln, list) \
+                               ASSERT(ln != (Node *)(node)); \
+               } while (0)
+
        #define INVALIDATE_NODE(n) ((n)->succ = (n)->pred = NULL)
 #else
        #define LIST_ASSERT_VALID(l) do {} while (0)
        #define INVALIDATE_NODE(n) do {} while (0)
 #endif
 
+/** Tell whether a list is empty. */
+#define LIST_EMPTY(l)  ( (void *)((l)->head.succ) == (void *)(&(l)->tail) )
+
 /** Add node to list head. */
 #define ADDHEAD(l,n) \
        do { \
-               ASSERT_VALID_PTR(l); \
-               ASSERT_VALID_PTR(n); \
+               LIST_ASSERT_NOT_CONTAINS((l),(n)); \
                (n)->succ = (l)->head.succ; \
                (n)->pred = (l)->head.succ->pred; \
                (n)->succ->pred = (n); \
@@ -223,8 +235,7 @@ typedef struct _PriNode
 /** Add node to list tail. */
 #define ADDTAIL(l,n) \
        do { \
-               ASSERT_VALID_PTR(l); \
-               ASSERT_VALID_PTR(n); \
+               LIST_ASSERT_NOT_CONTAINS((l),(n)); \
                (n)->succ = &(l)->tail; \
                (n)->pred = (l)->tail.pred; \
                (n)->pred->succ = (n); \
@@ -261,9 +272,6 @@ typedef struct _PriNode
                INVALIDATE_NODE(n); \
        } while (0)
 
-/** Tell whether a list is empty. */
-#define LIST_EMPTY(l)  ( (void *)((l)->head.succ) == (void *)(&(l)->tail) )
-
 /**
  * Insert a priority node in a priority queue.
  *
@@ -274,8 +282,7 @@ typedef struct _PriNode
 #define LIST_ENQUEUE(list, node) \
        do { \
                PriNode *ln; \
-               ASSERT_VALID_PTR(list); \
-               ASSERT_VALID_PTR(node); \
+               LIST_ASSERT_NOT_CONTAINS((list),(node)); \
                FOREACH_NODE(ln, (list)) \
                        if (ln->pri < (node)->pri) \
                                break; \