Clean up possible memory leakage in nodeSubplan

This commit is contained in:
Tom Lane 1999-11-15 03:28:07 +00:00
parent f68e11f373
commit c8c3e07e58
5 changed files with 50 additions and 17 deletions

View File

@ -6,7 +6,7 @@
* Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.16 1999/11/15 02:00:01 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.17 1999/11/15 03:28:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -107,9 +107,18 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
if (found)
elog(ERROR, "ExecSubPlan: more than one tuple returned by expression subselect");
found = true;
/* XXX need to copy tuple in case pass by ref */
/* XXX need to ref-count the tuple to avoid mem leak! */
/*
* We need to copy the subplan's tuple in case the result is of
* pass-by-ref type --- our return value will point into this
* copied tuple! Can't use the subplan's instance of the tuple
* since it won't still be valid after next ExecProcNode() call.
* node->curTuple keeps track of the copied tuple for eventual
* freeing.
*/
tup = heap_copytuple(tup);
if (node->curTuple)
pfree(node->curTuple);
node->curTuple = tup;
result = heap_getattr(tup, col, tdesc, isNull);
/* keep scanning subplan to make sure there's only one tuple */
continue;
@ -253,10 +262,13 @@ ExecInitSubPlan(SubPlan *node, EState *estate, Plan *parent)
ExecCreateTupleTable(ExecCountSlotsNode(node->plan) + 10);
sp_estate->es_snapshot = estate->es_snapshot;
node->shutdown = false;
node->curTuple = NULL;
if (!ExecInitNode(node->plan, sp_estate, NULL))
return false;
node->shutdown = true;
node->shutdown = true; /* now we need to shutdown the subplan */
/*
* If this plan is un-correlated or undirect correlated one and want
@ -332,13 +344,15 @@ ExecSetParamPlan(SubPlan *node)
found = true;
/*
* If this is uncorrelated subquery then its plan will be closed
* (see below) and this tuple will be free-ed - bad for not byval
* types... But is free-ing possible in the next ExecProcNode in
* this loop ? Who knows... Someday we'll keep track of saved
* tuples...
* We need to copy the subplan's tuple in case any of the params
* are pass-by-ref type --- the pointers stored in the param structs
* will point at this copied tuple! node->curTuple keeps track
* of the copied tuple for eventual freeing.
*/
tup = heap_copytuple(tup);
if (node->curTuple)
pfree(node->curTuple);
node->curTuple = tup;
foreach(lst, node->setParam)
{
@ -387,13 +401,16 @@ ExecSetParamPlan(SubPlan *node)
void
ExecEndSubPlan(SubPlan *node)
{
if (node->shutdown)
{
ExecEndNode(node->plan, node->plan);
node->shutdown = false;
}
if (node->curTuple)
{
pfree(node->curTuple);
node->curTuple = NULL;
}
}
void

View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.95 1999/11/15 02:00:01 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.96 1999/11/15 03:28:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -551,6 +551,10 @@ _copySubPlan(SubPlan *from)
newnode->parParam = listCopy(from->parParam);
Node_Copy(from, newnode, sublink);
/* do not copy execution state */
newnode->shutdown = false;
newnode->curTuple = NULL;
return newnode;
}

View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.50 1999/10/07 04:23:04 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.51 1999/11/15 03:28:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -406,9 +406,13 @@ _equalIndexScan(IndexScan *a, IndexScan *b)
static bool
_equalSubPlan(SubPlan *a, SubPlan *b)
{
/* should compare plans, but have to settle for comparing plan IDs */
if (a->plan_id != b->plan_id)
return false;
if (!equal(a->rtable, b->rtable))
return false;
if (!equal(a->sublink, b->sublink))
return false;

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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/Attic/freefuncs.c,v 1.26 1999/08/21 03:48:57 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/Attic/freefuncs.c,v 1.27 1999/11/15 03:28:07 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -441,6 +441,9 @@ _freeSubPlan(SubPlan *node)
freeList(node->parParam);
freeObject(node->sublink);
if (node->curTuple)
pfree(node->curTuple);
pfree(node);
}

View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: plannodes.h,v 1.32 1999/11/15 02:00:13 tgl Exp $
* $Id: plannodes.h,v 1.33 1999/11/15 03:28:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -352,13 +352,18 @@ typedef struct SubPlan
* funcs for plan nodes... actually, we
* could put *plan itself somewhere else
* (TopPlan node ?)... */
List *rtable; /* range table */
List *rtable; /* range table for subselect */
/* setParam and parParam are lists of integers (param IDs) */
List *setParam; /* non-correlated EXPR & EXISTS subqueries
* have to set some Params for paren Plan */
List *parParam; /* indices of corr. Vars from parent plan */
SubLink *sublink; /* SubLink node from parser; holds info about
* what to do with subselect's results */
bool shutdown; /* shutdown plan if TRUE */
/*
* Remaining fields are working state for executor; not used in planning
*/
bool shutdown; /* TRUE = need to shutdown plan */
HeapTuple curTuple; /* copy of most recent tuple from subplan */
} SubPlan;
#endif /* PLANNODES_H */