From 8f3915908e39ece6572198decb16d91a76de6947 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sun, 11 May 2025 13:09:53 -0400 Subject: [PATCH v1 04/11] Silence complaints about leaked catcache entries. Put the dlist_node fields of catctup and catclist structs first. This ensures that the dlist pointers point to the starts of these palloc blocks, and thus that Valgrind won't consider them "possibly lost". This is a hack, since it implies a similar requirement for every other struct that we chain into slists or dlists (unless there are other pointers to them, as there are for the CatCache structs). But there is no other obvious alternative. Fixing these two places seems to be enough to silence all such Valgrind complaints in simple test cases. Author: Tom Lane Discussion: https://postgr.es/m/285483.1746756246@sss.pgh.pa.us --- src/include/utils/catcache.h | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h index 277ec33c00b..00808e23f49 100644 --- a/src/include/utils/catcache.h +++ b/src/include/utils/catcache.h @@ -87,6 +87,14 @@ typedef struct catcache typedef struct catctup { + /* + * Each tuple in a cache is a member of a dlist that stores the elements + * of its hash bucket. We keep each dlist in LRU order to speed repeated + * lookups. Keep the dlist_node field first so that Valgrind understands + * the struct is reachable. + */ + dlist_node cache_elem; /* list member of per-bucket list */ + int ct_magic; /* for identifying CatCTup entries */ #define CT_MAGIC 0x57261502 @@ -98,13 +106,6 @@ typedef struct catctup */ Datum keys[CATCACHE_MAXKEYS]; - /* - * Each tuple in a cache is a member of a dlist that stores the elements - * of its hash bucket. We keep each dlist in LRU order to speed repeated - * lookups. - */ - dlist_node cache_elem; /* list member of per-bucket list */ - /* * A tuple marked "dead" must not be returned by subsequent searches. * However, it won't be physically deleted from the cache until its @@ -158,13 +159,17 @@ typedef struct catctup */ typedef struct catclist { + /* + * Keep the dlist_node field first so that Valgrind understands the struct + * is reachable. + */ + dlist_node cache_elem; /* list member of per-catcache list */ + int cl_magic; /* for identifying CatCList entries */ #define CL_MAGIC 0x52765103 uint32 hash_value; /* hash value for lookup keys */ - dlist_node cache_elem; /* list member of per-catcache list */ - /* * Lookup keys for the entry, with the first nkeys elements being valid. * All by-reference are separately allocated. -- 2.43.5