diff -Nru a/include/asterisk/linkedlists.h b/include/asterisk/linkedlists.h
--- a/include/asterisk/linkedlists.h	2005-01-01 09:26:16 -07:00
+++ b/include/asterisk/linkedlists.h	2005-01-01 09:26:16 -07:00
@@ -148,6 +148,51 @@
 	for((var) = (head)->first; (var); (var) = (var)->field.next)
 
 /*!
+  \brief Loops safely over (traverses) the entries in a list.
+  \param head This is a pointer to the list head structure
+  \param var This is the name of the variable that will hold a pointer to the
+  current list entry on each iteration. It must be declared before calling
+  this macro.
+  \param type This is the type of each list entry.
+  \param field This is the name of the field (declared using AST_LIST_ENTRY())
+  used to link entries of this list together.
+
+  This macro is used to safely loop over (traverse) the entries in a list. It
+  uses a \a for loop, and supplies the enclosed code with a pointer to each list
+  entry as it loops. It is typically used as follows:
+  \code
+  static AST_LIST_HEAD(entry_list, list_entry) entries;
+  ...
+  struct list_entry {
+  	...
+  	AST_LIST_ENTRY(list_entry) list;
+  }
+  ...
+  struct list_entry *current;
+  ...
+  AST_LIST_TRAVERSE_SAFE_BEGIN(&entries, current, list_entry, list) {
+     (do something with current here)
+  }
+  AST_LIST_TRAVERSE_SAFE_END
+  \endcode
+
+  It differs from AST_LIST_TRAVERSE in that the code inside the loop can modify
+  (or even free) the entry pointed to by the \a current pointer without affecting
+  the loop traversal.
+*/
+#define AST_LIST_TRAVERSE_SAFE_BEGIN(head,var,type,field) {				\
+	struct type *__list_next;							\
+	for ((var) = (head)->first,  __list_next = (var) ? (var)->field.next : NULL;	\
+	     (var);									\
+	     (var) = __list_next,  __list_next = (var) ? (var)->field.next : NULL	\
+	    )
+
+/*!
+  \brief Closes a safe loop traversal block.
+ */
+#define AST_LIST_TRAVERSE_SAFE_END  }
+
+/*!
   \brief Initializes a list head structure.
   \param head This is a pointer to the list head structure