First phase of memory management rewrite (see backend/utils/mmgr/README

for details).  It doesn't really do that much yet, since there are no
short-term memory contexts in the executor, but the infrastructure is
in place and long-term contexts are handled reasonably.  A few long-
standing bugs have been fixed, such as 'VACUUM; anything' in a single
query string crashing.  Also, out-of-memory is now considered a
recoverable ERROR, not FATAL.
Eliminate a large amount of crufty, now-dead code in and around
memory management.
Fix problem with holding off SIGTRAP, SIGSEGV, etc in postmaster and
backend startup.

3 files changed, 8 insertions, 156 deletions

diff --git a/src/backend/lib/Makefile b/src/backend/lib/Makefile
index 6b8a9d72022..428935f255a 100644
--- a/src/backend/lib/Makefile
+++ b/src/backend/lib/Makefile
@@ -4,14 +4,14 @@
 #    Makefile for lib (miscellaneous stuff)
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/lib/Makefile,v 1.13 2000/05/29 05:44:45 tgl Exp $
+#    $Header: /cvsroot/pgsql/src/backend/lib/Makefile,v 1.14 2000/06/28 03:31:34 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
 SRCDIR = ../..
 include ../../Makefile.global
 
-OBJS = bit.o fstack.o hasht.o lispsort.o stringinfo.o dllist.o
+OBJS = bit.o hasht.o lispsort.o stringinfo.o dllist.o
 
 all: SUBSYS.o
 
diff --git a/src/backend/lib/fstack.c b/src/backend/lib/fstack.c
deleted file mode 100644
index 9552909bc01..00000000000
--- a/src/backend/lib/fstack.c
+++ /dev/null
@@ -1,145 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * fstack.c
- *	  Fixed format stack definitions.
- *
- * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/lib/Attic/fstack.c,v 1.14 2000/01/26 05:56:26 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-#include "lib/fstack.h"
-
-/*
- * Internal function definitions
- */
-
-/*
- * FixedItemIsValid
- *		True iff item is valid.
- */
-#define FixedItemIsValid(item)	PointerIsValid(item)
-
-/*
- * FixedStackGetItemBase
- *		Returns base of enclosing structure.
- */
-#define FixedStackGetItemBase(stack, item) \
-		((Pointer)((char *)(item) - (stack)->offset))
-
-/*
- * FixedStackGetItem
- *		Returns item of given pointer to enclosing structure.
- */
-#define FixedStackGetItem(stack, pointer) \
-		((FixedItem)((char *)(pointer) + (stack)->offset))
-
-#define FixedStackIsValid(stack) ((bool)PointerIsValid(stack))
-
-/*
- * External functions
- */
-
-void
-FixedStackInit(FixedStack stack, Offset offset)
-{
-	AssertArg(PointerIsValid(stack));
-
-	stack->top = NULL;
-	stack->offset = offset;
-}
-
-Pointer
-FixedStackPop(FixedStack stack)
-{
-	Pointer		pointer;
-
-	AssertArg(FixedStackIsValid(stack));
-
-	if (!PointerIsValid(stack->top))
-		return NULL;
-
-	pointer = FixedStackGetItemBase(stack, stack->top);
-	stack->top = stack->top->next;
-
-	return pointer;
-}
-
-void
-FixedStackPush(FixedStack stack, Pointer pointer)
-{
-	FixedItem	item = FixedStackGetItem(stack, pointer);
-
-	AssertArg(FixedStackIsValid(stack));
-	AssertArg(PointerIsValid(pointer));
-
-	item->next = stack->top;
-	stack->top = item;
-}
-
-#ifdef USE_ASSERT_CHECKING
-/*
- * FixedStackContains
- *		True iff ordered stack contains given element.
- *
- * Note:
- *		This is inefficient.  It is intended for debugging use only.
- *
- * Exceptions:
- *		BadArg if stack is invalid.
- *		BadArg if pointer is invalid.
- */
-static bool
-FixedStackContains(FixedStack stack, Pointer pointer)
-{
-	FixedItem	next;
-	FixedItem	item;
-
-	AssertArg(FixedStackIsValid(stack));
-	AssertArg(PointerIsValid(pointer));
-
-	item = FixedStackGetItem(stack, pointer);
-
-	for (next = stack->top; FixedItemIsValid(next); next = next->next)
-	{
-		if (next == item)
-			return true;
-	}
-	return false;
-}
-
-#endif
-
-Pointer
-FixedStackGetTop(FixedStack stack)
-{
-	AssertArg(FixedStackIsValid(stack));
-
-	if (!PointerIsValid(stack->top))
-		return NULL;
-
-	return FixedStackGetItemBase(stack, stack->top);
-}
-
-Pointer
-FixedStackGetNext(FixedStack stack, Pointer pointer)
-{
-	FixedItem	item;
-
-	/* AssertArg(FixedStackIsValid(stack)); */
-	/* AssertArg(PointerIsValid(pointer)); */
-	AssertArg(FixedStackContains(stack, pointer));
-
-	item = FixedStackGetItem(stack, pointer)->next;
-
-	if (!PointerIsValid(item))
-		return NULL;
-
-	return FixedStackGetItemBase(stack, item);
-}
diff --git a/src/backend/lib/stringinfo.c b/src/backend/lib/stringinfo.c
index 4f2df746843..379cd795029 100644
--- a/src/backend/lib/stringinfo.c
+++ b/src/backend/lib/stringinfo.c
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	  $Id: stringinfo.c,v 1.25 2000/04/12 17:15:11 momjian Exp $
+ *	  $Id: stringinfo.c,v 1.26 2000/06/28 03:31:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,8 +29,6 @@ makeStringInfo(void)
 	StringInfo	res;
 
 	res = (StringInfo) palloc(sizeof(StringInfoData));
-	if (res == NULL)
-		elog(ERROR, "makeStringInfo: Out of memory");
 
 	initStringInfo(res);
 
@@ -49,9 +47,6 @@ initStringInfo(StringInfo str)
 	int			size = 256;		/* initial default buffer size */
 
 	str->data = (char *) palloc(size);
-	if (str->data == NULL)
-		elog(ERROR,
-			 "initStringInfo: Out of memory (%d bytes requested)", size);
 	str->maxlen = size;
 	str->len = 0;
 	str->data[0] = '\0';
@@ -62,6 +57,11 @@ initStringInfo(StringInfo str)
  *
  * Internal routine: make sure there is enough space for 'needed' more bytes
  * ('needed' does not include the terminating null).
+ *
+ * NB: because we use repalloc() to enlarge the buffer, the string buffer
+ * will remain allocated in the same memory context that was current when
+ * initStringInfo was called, even if another context is now current.
+ * This is the desired and indeed critical behavior!
  */
 static void
 enlargeStringInfo(StringInfo str, int needed)
@@ -83,9 +83,6 @@ enlargeStringInfo(StringInfo str, int needed)
 		newlen = 2 * newlen;
 
 	str->data = (char *) repalloc(str->data, newlen);
-	if (str->data == NULL)
-		elog(ERROR,
-		"enlargeStringInfo: Out of memory (%d bytes requested)", newlen);
 
 	str->maxlen = newlen;
 }