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Modify hash_search() API to prevent future occurrences of the error
spotted by Qingqing Zhou. The HASH_ENTER action now automatically fails with elog(ERROR) on out-of-memory --- which incidentally lets us eliminate duplicate error checks in quite a bunch of places. If you really need the old return-NULL-on-out-of-memory behavior, you can ask for HASH_ENTER_NULL. But there is now an Assert in that path checking that you aren't hoping to get that behavior in a palloc-based hash table. Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions, which were not being used anywhere anymore, and were surely too ugly and unsafe to want to see revived again.
1 parent ecd70d7 commit e92a882

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23 files changed

+90
-213
lines changed

23 files changed

+90
-213
lines changed

‎contrib/dblink/dblink.c

Lines changed: 0 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -2061,11 +2061,6 @@ createNewConnection(const char *name, remoteConn * con)
20612061
hentry = (remoteConnHashEnt *) hash_search(remoteConnHash, key,
20622062
HASH_ENTER, &found);
20632063

2064-
if (!hentry)
2065-
ereport(ERROR,
2066-
(errcode(ERRCODE_OUT_OF_MEMORY),
2067-
errmsg("out of memory")));
2068-
20692064
if (found)
20702065
ereport(ERROR,
20712066
(errcode(ERRCODE_DUPLICATE_OBJECT),

‎contrib/tablefunc/tablefunc.c

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -144,10 +144,6 @@ do { \
144144
snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATDESC->catname); \
145145
hentry = (crosstab_HashEnt*) hash_search(crosstab_HashTable, \
146146
key, HASH_ENTER, &found); \
147-
if (hentry == NULL) \
148-
ereport(ERROR, \
149-
(errcode(ERRCODE_OUT_OF_MEMORY), \
150-
errmsg("out of memory"))); \
151147
if (found) \
152148
ereport(ERROR, \
153149
(errcode(ERRCODE_DUPLICATE_OBJECT), \

‎src/backend/access/transam/xlogutils.c

Lines changed: 1 addition & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@
1111
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
1212
* Portions Copyright (c) 1994, Regents of the University of California
1313
*
14-
* $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.36 2005/01/10 20:02:19 tgl Exp $
14+
* $PostgreSQL: pgsql/src/backend/access/transam/xlogutils.c,v 1.37 2005/05/29 04:23:03 tgl Exp $
1515
*
1616
*-------------------------------------------------------------------------
1717
*/
@@ -223,9 +223,6 @@ XLogOpenRelation(bool redo, RmgrId rmid, RelFileNode rnode)
223223
hentry = (XLogRelCacheEntry *)
224224
hash_search(_xlrelcache, (void *) &rnode, HASH_ENTER, &found);
225225

226-
if (hentry == NULL)
227-
elog(PANIC, "XLogOpenRelation: out of memory for cache");
228-
229226
if (found)
230227
elog(PANIC, "XLogOpenRelation: file found on insert into cache");
231228

‎src/backend/commands/prepare.c

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -10,7 +10,7 @@
1010
* Copyright (c) 2002-2005, PostgreSQL Global Development Group
1111
*
1212
* IDENTIFICATION
13-
* $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.37 2005/05/24 04:18:04 momjian Exp $
13+
* $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.38 2005/05/29 04:23:03 tgl Exp $
1414
*
1515
*-------------------------------------------------------------------------
1616
*/
@@ -346,9 +346,9 @@ StorePreparedStatement(const char *stmt_name,
346346
HASH_ENTER,
347347
&found);
348348

349-
/* Shouldn't get a failure, nor a duplicate entry */
350-
if (!entry || found)
351-
elog(ERROR, "could not store prepared statement \"%s\"",
349+
/* Shouldn't get a duplicate entry */
350+
if (found)
351+
elog(ERROR, "duplicate prepared statement \"%s\"",
352352
stmt_name);
353353

354354
/* Fill in the hash table entry with copied data */

‎src/backend/executor/execGrouping.c

Lines changed: 3 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/executor/execGrouping.c,v 1.14 2005/03/16 21:38:06 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/executor/execGrouping.c,v 1.15 2005/05/29 04:23:03 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -379,13 +379,9 @@ LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
379379
}
380380
else
381381
{
382-
/* created new entry ... we hope */
383-
if (entry == NULL)
384-
ereport(ERROR,
385-
(errcode(ERRCODE_OUT_OF_MEMORY),
386-
errmsg("out of memory")));
387-
388382
/*
383+
* created new entry
384+
*
389385
* Zero any caller-requested space in the entry. (This zaps
390386
* the "key data" dynahash.c copied into the new entry, but we
391387
* don't care since we're about to overwrite it anyway.)

‎src/backend/nodes/tidbitmap.c

Lines changed: 1 addition & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,7 @@
2323
* Copyright (c) 2003-2005, PostgreSQL Global Development Group
2424
*
2525
* IDENTIFICATION
26-
* $PostgreSQL: pgsql/src/backend/nodes/tidbitmap.c,v 1.3 2005/05/17 00:43:47 tgl Exp $
26+
* $PostgreSQL: pgsql/src/backend/nodes/tidbitmap.c,v 1.4 2005/05/29 04:23:03 tgl Exp $
2727
*
2828
*-------------------------------------------------------------------------
2929
*/
@@ -220,10 +220,6 @@ tbm_create_pagetable(TIDBitmap *tbm)
220220
page = (PagetableEntry *) hash_search(tbm->pagetable,
221221
(void *) &tbm->entry1.blockno,
222222
HASH_ENTER, &found);
223-
if (page == NULL)
224-
ereport(ERROR,
225-
(errcode(ERRCODE_OUT_OF_MEMORY),
226-
errmsg("out of memory")));
227223
Assert(!found);
228224
memcpy(page, &tbm->entry1, sizeof(PagetableEntry));
229225
}
@@ -726,10 +722,6 @@ tbm_get_pageentry(TIDBitmap *tbm, BlockNumber pageno)
726722
page = (PagetableEntry *) hash_search(tbm->pagetable,
727723
(void *) &pageno,
728724
HASH_ENTER, &found);
729-
if (page == NULL)
730-
ereport(ERROR,
731-
(errcode(ERRCODE_OUT_OF_MEMORY),
732-
errmsg("out of memory")));
733725
}
734726

735727
/* Initialize it if not present before */
@@ -820,10 +812,6 @@ tbm_mark_page_lossy(TIDBitmap *tbm, BlockNumber pageno)
820812
page = (PagetableEntry *) hash_search(tbm->pagetable,
821813
(void *) &chunk_pageno,
822814
HASH_ENTER, &found);
823-
if (page == NULL)
824-
ereport(ERROR,
825-
(errcode(ERRCODE_OUT_OF_MEMORY),
826-
errmsg("out of memory")));
827815

828816
/* Initialize it if not present before */
829817
if (!found)

‎src/backend/postmaster/pgstat.c

Lines changed: 1 addition & 23 deletions
Original file line numberDiff line numberDiff line change
@@ -13,7 +13,7 @@
1313
*
1414
* Copyright (c) 2001-2005, PostgreSQL Global Development Group
1515
*
16-
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.94 2005/05/11 01:41:40 neilc Exp $
16+
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.95 2005/05/29 04:23:03 tgl Exp $
1717
* ----------
1818
*/
1919
#include "postgres.h"
@@ -2061,10 +2061,6 @@ pgstat_get_db_entry(int databaseid)
20612061
result = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
20622062
&databaseid,
20632063
HASH_ENTER, &found);
2064-
if (result == NULL)
2065-
ereport(ERROR,
2066-
(errcode(ERRCODE_OUT_OF_MEMORY),
2067-
errmsg("out of memory in statistics collector --- abort")));
20682064

20692065
/* If not found, initialize the new one. */
20702066
if (!found)
@@ -2126,10 +2122,6 @@ pgstat_sub_backend(int procpid)
21262122
(void *) &procpid,
21272123
HASH_ENTER,
21282124
&found);
2129-
if (deadbe == NULL)
2130-
ereport(ERROR,
2131-
(errcode(ERRCODE_OUT_OF_MEMORY),
2132-
errmsg("out of memory in statistics collector --- abort")));
21332125

21342126
if (!found)
21352127
{
@@ -2435,12 +2427,6 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
24352427
(void *) &dbbuf.databaseid,
24362428
HASH_ENTER,
24372429
&found);
2438-
if (dbentry == NULL)
2439-
{
2440-
ereport(ERROR,
2441-
(errcode(ERRCODE_OUT_OF_MEMORY),
2442-
errmsg("out of memory")));
2443-
}
24442430
if (found)
24452431
{
24462432
ereport(pgStatRunningInCollector ? LOG : WARNING,
@@ -2503,10 +2489,6 @@ pgstat_read_statsfile(HTAB **dbhash, Oid onlydb,
25032489
tabentry = (PgStat_StatTabEntry *) hash_search(tabhash,
25042490
(void *) &tabbuf.tableid,
25052491
HASH_ENTER, &found);
2506-
if (tabentry == NULL)
2507-
ereport(ERROR,
2508-
(errcode(ERRCODE_OUT_OF_MEMORY),
2509-
errmsg("out of memory")));
25102492

25112493
if (found)
25122494
{
@@ -2730,10 +2712,6 @@ pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len)
27302712
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
27312713
(void *) &(tabmsg[i].t_id),
27322714
HASH_ENTER, &found);
2733-
if (tabentry == NULL)
2734-
ereport(ERROR,
2735-
(errcode(ERRCODE_OUT_OF_MEMORY),
2736-
errmsg("out of memory in statistics collector --- abort")));
27372715

27382716
if (!found)
27392717
{

‎src/backend/storage/buffer/buf_table.c

Lines changed: 1 addition & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -13,7 +13,7 @@
1313
*
1414
*
1515
* IDENTIFICATION
16-
* $PostgreSQL: pgsql/src/backend/storage/buffer/buf_table.c,v 1.40 2005/03/04 20:21:06 tgl Exp $
16+
* $PostgreSQL: pgsql/src/backend/storage/buffer/buf_table.c,v 1.41 2005/05/29 04:23:04 tgl Exp $
1717
*
1818
*-------------------------------------------------------------------------
1919
*/
@@ -110,11 +110,6 @@ BufTableInsert(BufferTag *tagPtr, int buf_id)
110110
result = (BufferLookupEnt *)
111111
hash_search(SharedBufHash, (void *) tagPtr, HASH_ENTER, &found);
112112

113-
if (!result)
114-
ereport(ERROR,
115-
(errcode(ERRCODE_OUT_OF_MEMORY),
116-
errmsg("out of shared memory")));
117-
118113
if (found) /* found something already in the table */
119114
return result->id;
120115

‎src/backend/storage/buffer/localbuf.c

Lines changed: 1 addition & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@
99
*
1010
*
1111
* IDENTIFICATION
12-
* $PostgreSQL: pgsql/src/backend/storage/buffer/localbuf.c,v 1.66 2005/03/19 23:27:05 tgl Exp $
12+
* $PostgreSQL: pgsql/src/backend/storage/buffer/localbuf.c,v 1.67 2005/05/29 04:23:04 tgl Exp $
1313
*
1414
*-------------------------------------------------------------------------
1515
*/
@@ -192,10 +192,6 @@ LocalBufferAlloc(Relation reln, BlockNumber blockNum, bool *foundPtr)
192192

193193
hresult = (LocalBufferLookupEnt *)
194194
hash_search(LocalBufHash, (void *) &newTag, HASH_ENTER, &found);
195-
if (!hresult)
196-
ereport(ERROR,
197-
(errcode(ERRCODE_OUT_OF_MEMORY),
198-
errmsg("out of memory")));
199195
if (found) /* shouldn't happen */
200196
elog(ERROR, "local buffer hash table corrupted");
201197
hresult->id = b;

‎src/backend/storage/freespace/freespace.c

Lines changed: 1 addition & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.44 2005/04/24 03:51:49 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/storage/freespace/freespace.c,v 1.45 2005/05/29 04:23:04 tgl Exp $
1212
*
1313
*
1414
* NOTES:
@@ -1036,10 +1036,6 @@ create_fsm_rel(RelFileNode *rel)
10361036
(void *) rel,
10371037
HASH_ENTER,
10381038
&found);
1039-
if (!fsmrel)
1040-
ereport(ERROR,
1041-
(errcode(ERRCODE_OUT_OF_MEMORY),
1042-
errmsg("out of shared memory")));
10431039

10441040
if (!found)
10451041
{

‎src/backend/storage/ipc/shmem.c

Lines changed: 2 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.83 2005/04/04 04:34:41 neilc Exp $
11+
* $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.84 2005/05/29 04:23:04 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -235,10 +235,6 @@ InitShmemIndex(void)
235235

236236
result = (ShmemIndexEnt *)
237237
hash_search(ShmemIndex, (void *) &item, HASH_ENTER, &found);
238-
if (!result)
239-
ereport(FATAL,
240-
(errcode(ERRCODE_OUT_OF_MEMORY),
241-
errmsg("out of shared memory")));
242238

243239
Assert(!found);
244240

@@ -367,15 +363,14 @@ ShmemInitStruct(const char *name, Size size, bool *foundPtr)
367363

368364
/* look it up in the shmem index */
369365
result = (ShmemIndexEnt *)
370-
hash_search(ShmemIndex, (void *) &item, HASH_ENTER, foundPtr);
366+
hash_search(ShmemIndex, (void *) &item, HASH_ENTER_NULL, foundPtr);
371367

372368
if (!result)
373369
{
374370
SpinLockRelease(ShmemIndexLock);
375371
ereport(ERROR,
376372
(errcode(ERRCODE_OUT_OF_MEMORY),
377373
errmsg("out of shared memory")));
378-
return NULL;
379374
}
380375

381376
if (*foundPtr)

‎src/backend/storage/lmgr/lock.c

Lines changed: 3 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.152 2005/05/19 23:30:18 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.153 2005/05/29 04:23:04 tgl Exp $
1212
*
1313
* NOTES
1414
* Outside modules can create a lock table and acquire/release
@@ -470,10 +470,6 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag,
470470
locallock = (LOCALLOCK *) hash_search(LockMethodLocalHash[lockmethodid],
471471
(void *) &localtag,
472472
HASH_ENTER, &found);
473-
if (!locallock)
474-
ereport(ERROR,
475-
(errcode(ERRCODE_OUT_OF_MEMORY),
476-
errmsg("out of memory")));
477473

478474
/*
479475
* if it's a new locallock object, initialize it
@@ -531,7 +527,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag,
531527
*/
532528
lock = (LOCK *) hash_search(LockMethodLockHash[lockmethodid],
533529
(void *) locktag,
534-
HASH_ENTER, &found);
530+
HASH_ENTER_NULL, &found);
535531
if (!lock)
536532
{
537533
LWLockRelease(masterLock);
@@ -578,7 +574,7 @@ LockAcquire(LOCKMETHODID lockmethodid, LOCKTAG *locktag,
578574
*/
579575
proclock = (PROCLOCK *) hash_search(LockMethodProcLockHash[lockmethodid],
580576
(void *) &proclocktag,
581-
HASH_ENTER, &found);
577+
HASH_ENTER_NULL, &found);
582578
if (!proclock)
583579
{
584580
/* Ooops, not enough shmem for the proclock */

‎src/backend/storage/smgr/md.c

Lines changed: 4 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.114 2004/12/31 22:01:13 pgsql Exp $
11+
* $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.115 2005/05/29 04:23:05 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -805,9 +805,8 @@ register_dirty_segment(SMgrRelation reln, MdfdVec *seg)
805805
entry.rnode = reln->smgr_rnode;
806806
entry.segno = seg->mdfd_segno;
807807

808-
if (hash_search(pendingOpsTable, &entry, HASH_ENTER, NULL) != NULL)
809-
return true;
810-
/* out of memory: fall through to do it locally */
808+
(void) hash_search(pendingOpsTable, &entry, HASH_ENTER, NULL);
809+
return true;
811810
}
812811
else
813812
{
@@ -838,10 +837,7 @@ RememberFsyncRequest(RelFileNode rnode, BlockNumber segno)
838837
entry.rnode = rnode;
839838
entry.segno = segno;
840839

841-
if (hash_search(pendingOpsTable, &entry, HASH_ENTER, NULL) == NULL)
842-
ereport(FATAL,
843-
(errcode(ERRCODE_OUT_OF_MEMORY),
844-
errmsg("out of memory")));
840+
(void) hash_search(pendingOpsTable, &entry, HASH_ENTER, NULL);
845841
}
846842

847843
/*

‎src/backend/storage/smgr/smgr.c

Lines changed: 1 addition & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@
1111
*
1212
*
1313
* IDENTIFICATION
14-
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.86 2005/03/20 22:00:53 tgl Exp $
14+
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.87 2005/05/29 04:23:05 tgl Exp $
1515
*
1616
*-------------------------------------------------------------------------
1717
*/
@@ -207,10 +207,6 @@ smgropen(RelFileNode rnode)
207207
reln = (SMgrRelation) hash_search(SMgrRelationHash,
208208
(void *) &rnode,
209209
HASH_ENTER, &found);
210-
if (reln == NULL)
211-
ereport(ERROR,
212-
(errcode(ERRCODE_OUT_OF_MEMORY),
213-
errmsg("out of memory")));
214210

215211
/* Initialize it if not present before */
216212
if (!found)

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