diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/nodes/list.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c index 6bf13ae0d4a..5109ac9cde9 100644 --- a/src/backend/nodes/list.c +++ b/src/backend/nodes/list.c @@ -18,6 +18,7 @@ #include "postgres.h" #include "nodes/pg_list.h" +#include "utils/memdebug.h" #include "utils/memutils.h" @@ -172,8 +173,6 @@ enlarge_list(List *list, int min_size) if (list->elements == list->initial_elements) { - List *newlist PG_USED_FOR_ASSERTS_ONLY; - /* * Replace original in-line allocation with a separate palloc block. * Ensure it is in the same memory context as the List header. (The @@ -188,16 +187,18 @@ enlarge_list(List *list, int min_size) list->length * sizeof(ListCell)); /* - * Currently, asking aset.c to reduce the allocated size of the List - * header is pointless in terms of reclaiming space, unless the list - * is very long. However, it seems worth doing anyway to cause the - * no-longer-needed initial_elements[] space to be cleared in - * debugging builds. + * We must not move the list header, so it's unsafe to try to reclaim + * the initial_elements[] space via repalloc. In debugging builds, + * however, we can clear that space and/or mark it inaccessible. + * (wipe_mem includes VALGRIND_MAKE_MEM_NOACCESS.) */ - newlist = (List *) repalloc(list, offsetof(List, initial_elements)); - - /* That better not have failed, nor moved the list header */ - Assert(newlist == list); +#ifdef CLOBBER_FREED_MEMORY + wipe_mem(list->initial_elements, + list->max_length * sizeof(ListCell)); +#else + VALGRIND_MAKE_MEM_NOACCESS(list->initial_elements, + list->max_length * sizeof(ListCell)); +#endif } else { @@ -736,13 +737,16 @@ list_delete_nth_cell(List *list, int n) else { /* - * As in enlarge_list(), tell palloc code we're not using the - * initial_elements space anymore. + * As in enlarge_list(), clear the initial_elements[] space and/or + * mark it inaccessible. */ - List *newlist PG_USED_FOR_ASSERTS_ONLY; - - newlist = (List *) repalloc(list, offsetof(List, initial_elements)); - Assert(newlist == list); +#ifdef CLOBBER_FREED_MEMORY + wipe_mem(list->initial_elements, + list->max_length * sizeof(ListCell)); +#else + VALGRIND_MAKE_MEM_NOACCESS(list->initial_elements, + list->max_length * sizeof(ListCell)); +#endif } list->elements = newelems; list->max_length = newmaxlen; |