Change SearchSysCache coding conventions so that a reference count is

maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.

9 files changed, 90 insertions, 47 deletions

diff --git a/src/include/executor/hashjoin.h b/src/include/executor/hashjoin.h
index 25a8174f294..28581ad425a 100644
--- a/src/include/executor/hashjoin.h
+++ b/src/include/executor/hashjoin.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: hashjoin.h,v 1.19 2000/08/22 04:06:21 tgl Exp $
+ * $Id: hashjoin.h,v 1.20 2000/11/16 22:30:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -73,8 +73,8 @@ typedef struct HashTableData
 	 * and outer sides of the hash are the same type, or at least
 	 * binary-compatible types.
 	 */
+	int16		typLen;
 	bool		typByVal;
-	int			typLen;
 
 	/*
 	 * During 1st scan of inner relation, we get tuples from executor. If
diff --git a/src/include/lib/dllist.h b/src/include/lib/dllist.h
index 9e357a7fd76..9306d4e6b67 100644
--- a/src/include/lib/dllist.h
+++ b/src/include/lib/dllist.h
@@ -2,12 +2,11 @@
  *
  * dllist.h
  *		simple doubly linked list primitives
- *		the elements of the list are void* so the lists can contain
- *		anything
+ *		the elements of the list are void* so the lists can contain anything
  *		Dlelem can only be in one list at a time
  *
  *
- *	 Here's a small example of how to use Dllist's :
+ *	 Here's a small example of how to use Dllists:
  *
  *	 Dllist *lst;
  *	 Dlelem *elt;
@@ -24,10 +23,18 @@
  *	 DLFreeElem(elt);				   -- free the element since we don't
  *										  use it anymore
  *
+ *
+ * It is also possible to use Dllist objects that are embedded in larger
+ * structures instead of being separately malloc'd.  To do this, use
+ * DLInitElem() to initialize a Dllist field within a larger object.
+ * Don't forget to DLRemove() each field from its list (if any) before
+ * freeing the larger object!
+ *
+ *
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: dllist.h,v 1.13 2000/06/08 22:37:46 momjian Exp $
+ * $Id: dllist.h,v 1.14 2000/11/16 22:30:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -35,7 +42,6 @@
 #ifndef DLLIST_H
 #define DLLIST_H
 
-
 struct Dllist;
 struct Dlelem;
 
@@ -53,21 +59,27 @@ typedef struct Dllist
 	Dlelem	   *dll_tail;
 } Dllist;
 
-extern Dllist *DLNewList(void); /* initialize a new list */
-extern void DLFreeList(Dllist *);		/* free up a list and all the
+extern Dllist *DLNewList(void); /* allocate and initialize a list header */
+extern void DLInitList(Dllist *list);	/* init a header alloced by caller */
+extern void DLFreeList(Dllist *list);	/* free up a list and all the
 										 * nodes in it */
 extern Dlelem *DLNewElem(void *val);
-extern void DLFreeElem(Dlelem *);
-extern Dlelem *DLGetHead(Dllist *);
-extern Dlelem *DLGetTail(Dllist *);
-extern Dlelem *DLRemTail(Dllist *l);
-extern Dlelem *DLGetSucc(Dlelem *);		/* get successor */
-extern void DLRemove(Dlelem *); /* removes node from list */
+extern void DLInitElem(Dlelem *e, void *val);
+extern void DLFreeElem(Dlelem *e);
+extern void DLRemove(Dlelem *e);		/* removes node from list */
 extern void DLAddHead(Dllist *list, Dlelem *node);
 extern void DLAddTail(Dllist *list, Dlelem *node);
 extern Dlelem *DLRemHead(Dllist *list); /* remove and return the head */
-extern void DLMoveToFront(Dlelem *);	/* move node to front of its list */
+extern Dlelem *DLRemTail(Dllist *list);
+extern void DLMoveToFront(Dlelem *e);	/* move node to front of its list */
+
+/* These are macros for speed */
+#define DLGetHead(list)  ((list)->dll_head)
+#define DLGetTail(list)  ((list)->dll_tail)
+#define DLGetSucc(elem)  ((elem)->dle_next)
+#define DLGetPred(elem)  ((elem)->dle_prev)
+#define DLGetListHdr(elem)  ((elem)->dle_list)
 
-#define DLE_VAL(x)	(x->dle_val)
+#define DLE_VAL(elem)	((elem)->dle_val)
 
 #endif	 /* DLLIST_H */
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 1ec37fc7b6f..08b0007fcaf 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: makefuncs.h,v 1.25 2000/08/08 15:42:59 tgl Exp $
+ * $Id: makefuncs.h,v 1.26 2000/11/16 22:30:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,7 +42,8 @@ extern Const *makeConst(Oid consttype,
 		  bool constisset,
 		  bool constiscast);
 
-extern Attr *
-			makeAttr(char *relname, char *attname);
+extern Const *makeNullConst(Oid consttype);
+
+extern Attr *makeAttr(char *relname, char *attname);
 
 #endif	 /* MAKEFUNC_H */
diff --git a/src/include/parser/parse_oper.h b/src/include/parser/parse_oper.h
index 4162cd6d234..4e3c784c0dc 100644
--- a/src/include/parser/parse_oper.h
+++ b/src/include/parser/parse_oper.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parse_oper.h,v 1.11 2000/01/26 05:58:27 momjian Exp $
+ * $Id: parse_oper.h,v 1.12 2000/11/16 22:30:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,10 +18,13 @@
 
 typedef HeapTuple Operator;
 
-extern Oid	any_ordering_op(Oid restype);
-extern Oid	oprid(Operator op);
-extern Operator oper(char *op, Oid arg1, Oid arg2, bool noWarnings);
+extern Operator oper(char *op, Oid arg1, Oid arg2, bool noError);
 extern Operator right_oper(char *op, Oid arg);
 extern Operator left_oper(char *op, Oid arg);
 
+extern Oid	oper_oid(char *op, Oid arg1, Oid arg2, bool noError);
+extern Oid	oprid(Operator op);
+
+extern Oid	any_ordering_op(Oid restype);
+
 #endif	 /* PARSE_OPER_H */
diff --git a/src/include/parser/parse_type.h b/src/include/parser/parse_type.h
index e2cfd7f4a2d..0d8ba2f1bce 100644
--- a/src/include/parser/parse_type.h
+++ b/src/include/parser/parse_type.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parse_type.h,v 1.14 2000/06/08 22:37:53 momjian Exp $
+ * $Id: parse_type.h,v 1.15 2000/11/16 22:30:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,15 +21,18 @@ typedef HeapTuple Type;
 extern bool typeidIsValid(Oid id);
 extern Type typeidType(Oid id);
 extern Type typenameType(char *s);
-extern char *typeidTypeName(Oid id);
+
 extern Oid	typeTypeId(Type tp);
 extern int16 typeLen(Type t);
 extern bool typeByVal(Type t);
 extern char *typeTypeName(Type t);
 extern char typeTypeFlag(Type t);
+extern Oid	typeTypeRelid(Type typ);
 extern Datum stringTypeDatum(Type tp, char *string, int32 atttypmod);
+
+extern char *typeidTypeName(Oid id);
 extern Oid	typeidTypeRelid(Oid type_id);
-extern Oid	typeTypeRelid(Type typ);
+extern Oid	typenameTypeId(char *s);
 
 #define ISCOMPLEX(typeid) (typeidTypeRelid(typeid) != InvalidOid)
 
diff --git a/src/include/rewrite/rewriteSupport.h b/src/include/rewrite/rewriteSupport.h
index 39605df47ad..20cf82cbd91 100644
--- a/src/include/rewrite/rewriteSupport.h
+++ b/src/include/rewrite/rewriteSupport.h
@@ -7,14 +7,14 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rewriteSupport.h,v 1.13 2000/09/29 18:21:24 tgl Exp $
+ * $Id: rewriteSupport.h,v 1.14 2000/11/16 22:30:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef REWRITESUPPORT_H
 #define REWRITESUPPORT_H
 
-extern int	IsDefinedRewriteRule(char *ruleName);
+extern bool IsDefinedRewriteRule(char *ruleName);
 
 extern void SetRelationRuleStatus(Oid relationId, bool relHasRules,
 								  bool relIsBecomingView);
diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h
index e55b6492d8c..ed78284a478 100644
--- a/src/include/utils/catcache.h
+++ b/src/include/utils/catcache.h
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catcache.h,v 1.27 2000/11/10 00:33:12 tgl Exp $
+ * $Id: catcache.h,v 1.28 2000/11/16 22:30:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,18 +32,29 @@
 
 typedef struct catctup
 {
-	HeapTuple	ct_tup;			/* A pointer to a tuple */
+	int			ct_magic;		/* for Assert checks */
+#define CT_MAGIC   0x57261502
+
 	/*
-	 * Each tuple in the cache has two catctup items, one in the LRU list
-	 * and one in the hashbucket list for its hash value.  ct_node in each
-	 * one points to the other one.
+	 * Each tuple in a cache is a member of two lists: one lists all the
+	 * elements in that cache in LRU order, and the other lists just the
+	 * elements in one hashbucket, also in LRU order.
+	 *
+	 * A tuple marked "dead" must not be returned by subsequent searches.
+	 * However, it won't be physically deleted from the cache until its
+	 * refcount goes to zero.
 	 */
-	Dlelem	   *ct_node;		/* the other catctup for this tuple */
+	Dlelem		lrulist_elem;	/* list member of global LRU list */
+	Dlelem		cache_elem;		/* list member of per-bucket list */
+	int			refcount;		/* number of active references */
+	bool		dead;			/* dead but not yet removed? */
+	HeapTupleData tuple;		/* tuple management header */
 } CatCTup;
 
+
 /* voodoo constants */
 #define NCCBUCK 500				/* CatCache buckets */
-#define MAXTUP 300				/* Maximum # of tuples stored per cache */
+#define MAXTUP 500				/* Maximum # of tuples stored per cache */
 
 
 typedef struct catcache
@@ -60,8 +71,8 @@ typedef struct catcache
 	short		cc_key[4];		/* AttrNumber of each key */
 	PGFunction	cc_hashfunc[4]; /* hash function to use for each key */
 	ScanKeyData cc_skey[4];		/* precomputed key info for indexscans */
-	Dllist	   *cc_lrulist;		/* LRU list, most recent first */
-	Dllist	   *cc_cache[NCCBUCK + 1];	/* hash buckets */
+	Dllist		cc_lrulist;		/* overall LRU list, most recent first */
+	Dllist		cc_cache[NCCBUCK]; /* hash buckets */
 } CatCache;
 
 #define InvalidCatalogCacheId	(-1)
@@ -70,12 +81,15 @@ typedef struct catcache
 extern MemoryContext CacheMemoryContext;
 
 extern void CreateCacheMemoryContext(void);
+extern void AtEOXact_CatCache(bool isCommit);
 
-extern CatCache *InitSysCache(int id, char *relname, char *indname,
+extern CatCache *InitCatCache(int id, char *relname, char *indname,
 							  int nkeys, int *key);
-extern HeapTuple SearchSysCache(CatCache *cache,
+
+extern HeapTuple SearchCatCache(CatCache *cache,
 								Datum v1, Datum v2,
 								Datum v3, Datum v4);
+extern void ReleaseCatCache(HeapTuple tuple);
 
 extern void ResetSystemCache(void);
 extern void SystemCacheRelationFlushed(Oid relId);
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 516949d1de9..f8547baa884 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lsyscache.h,v 1.26 2000/10/05 19:48:34 momjian Exp $
+ * $Id: lsyscache.h,v 1.27 2000/11/16 22:30:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,7 +29,6 @@ extern bool op_mergejoinable(Oid opno, Oid ltype, Oid rtype,
 				 Oid *leftOp, Oid *rightOp);
 extern Oid	op_hashjoinable(Oid opno, Oid ltype, Oid rtype);
 extern bool op_iscachable(Oid opno);
-extern HeapTuple get_operator_tuple(Oid opno);
 extern Oid	get_commutator(Oid opno);
 extern Oid	get_negator(Oid opno);
 extern RegProcedure get_oprrest(Oid opno);
@@ -39,6 +38,7 @@ extern bool func_iscachable(Oid funcid);
 extern char *get_rel_name(Oid relid);
 extern int16 get_typlen(Oid typid);
 extern bool get_typbyval(Oid typid);
+extern void get_typlenbyval(Oid typid, int16 *typlen, bool *typbyval);
 extern Datum get_typdefault(Oid typid);
 
 #endif	 /* LSYSCACHE_H */
diff --git a/src/include/utils/syscache.h b/src/include/utils/syscache.h
index 5d17e8db44c..73abd53e134 100644
--- a/src/include/utils/syscache.h
+++ b/src/include/utils/syscache.h
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: syscache.h,v 1.26 2000/06/17 04:56:29 tgl Exp $
+ * $Id: syscache.h,v 1.27 2000/11/16 22:30:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -57,12 +57,22 @@
 #define TYPENAME		26
 #define TYPEOID			27
 
-extern void zerocaches(void);
 extern void InitCatalogCache(void);
-extern HeapTuple SearchSysCacheTuple(int cacheId,
+
+extern HeapTuple SearchSysCache(int cacheId,
+					Datum key1, Datum key2, Datum key3, Datum key4);
+extern void ReleaseSysCache(HeapTuple tuple);
+
+/* convenience routines */
+extern HeapTuple SearchSysCacheCopy(int cacheId,
 					Datum key1, Datum key2, Datum key3, Datum key4);
-extern HeapTuple SearchSysCacheTupleCopy(int cacheId,
-						Datum key1, Datum key2, Datum key3, Datum key4);
+extern Oid GetSysCacheOid(int cacheId,
+					Datum key1, Datum key2, Datum key3, Datum key4);
+
+/* macro for just probing for existence of a tuple via the syscache */
+#define SearchSysCacheExists(c,k1,k2,k3,k4)  \
+	OidIsValid(GetSysCacheOid(c,k1,k2,k3,k4))
+
 extern Datum SysCacheGetAttr(int cacheId, HeapTuple tup,
 				AttrNumber attributeNumber, bool *isNull);