rather than returning NULL for some-but-not-all failures as they used to.
Remove now-redundant tests for NULL from call sites.
We had to do something about this because many call sites were failing to
check for NULL; and changing it like this seems a lot more useful and
mistake-proof than adding checks to the call sites without them.
* Copyright (c) 2008-2010, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/contrib/pg_stat_statements/pg_stat_statements.c,v 1.13 2010/02/26 02:00:32 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/pg_stat_statements/pg_stat_statements.c,v 1.14 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
pgss = ShmemInitStruct("pg_stat_statements",
sizeof(pgssSharedState),
&found);
- if (!pgss)
- elog(ERROR, "out of shared memory");
if (!found)
{
pgss_max, pgss_max,
&info,
HASH_ELEM | HASH_FUNCTION | HASH_COMPARE);
- if (!pgss_hash)
- elog(ERROR, "out of shared memory");
LWLockRelease(AddinShmemInitLock);
-<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.145 2010/04/03 07:22:56 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/xfunc.sgml,v 1.146 2010/04/28 16:54:15 tgl Exp $ -->
<sect1 id="xfunc">
<title>User-Defined Functions</title>
LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
ptr = ShmemInitStruct("my struct name", size, &found);
- if (!ptr)
- elog(ERROR, "out of shared memory");
if (!found)
{
initialize contents of shmem area;
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/access/transam/slru.c,v 1.49 2010/02/16 22:34:43 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/slru.c,v 1.50 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
shared = (SlruShared) ShmemInitStruct(name,
SimpleLruShmemSize(nslots, nlsns),
&found);
- if (!shared)
- elog(ERROR, "out of shared memory");
if (!IsUnderPostmaster)
{
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.156 2010/04/05 00:42:24 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/async.c,v 1.157 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
asyncQueueControl = (AsyncQueueControl *)
ShmemInitStruct("Async Queue Control", size, &found);
- if (!asyncQueueControl)
- elog(ERROR, "out of shared memory");
-
if (!found)
{
/* First time through, so initialize it */
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.109 2010/02/26 02:00:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.110 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
ShmemInitStruct("AutoVacuum Data",
AutoVacuumShmemSize(),
&found);
- if (AutoVacuumShmem == NULL)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("not enough shared memory for autovacuum")));
if (!IsUnderPostmaster)
{
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.67 2010/02/05 23:37:43 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.68 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
ShmemInitStruct("Background Writer Data",
BgWriterShmemSize(),
&found);
- if (BgWriterShmem == NULL)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("not enough shared memory for background writer")));
- if (found)
- return; /* already initialized */
-
- MemSet(BgWriterShmem, 0, sizeof(BgWriterShmemStruct));
- SpinLockInit(&BgWriterShmem->ckpt_lck);
- BgWriterShmem->max_requests = NBuffers;
+
+ if (!found)
+ {
+ /* First time through, so initialize */
+ MemSet(BgWriterShmem, 0, sizeof(BgWriterShmemStruct));
+ SpinLockInit(&BgWriterShmem->ckpt_lck);
+ BgWriterShmem->max_requests = NBuffers;
+ }
}
/*
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/replication/walreceiverfuncs.c,v 1.4 2010/02/26 02:00:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/replication/walreceiverfuncs.c,v 1.5 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
WalRcv = (WalRcvData *)
ShmemInitStruct("Wal Receiver Ctl", WalRcvShmemSize(), &found);
- if (WalRcv == NULL)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("not enough shared memory for walreceiver")));
- if (found)
- return; /* already initialized */
-
- /* Initialize the data structures */
- MemSet(WalRcv, 0, WalRcvShmemSize());
- WalRcv->walRcvState = WALRCV_STOPPED;
- SpinLockInit(&WalRcv->mutex);
+ if (!found)
+ {
+ /* First time through, so initialize */
+ MemSet(WalRcv, 0, WalRcvShmemSize());
+ WalRcv->walRcvState = WALRCV_STOPPED;
+ SpinLockInit(&WalRcv->mutex);
+ }
}
/* Is walreceiver in progress (or starting up)? */
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/replication/walsender.c,v 1.18 2010/04/28 16:10:42 heikki Exp $
+ * $PostgreSQL: pgsql/src/backend/replication/walsender.c,v 1.19 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
if (wal_level == WAL_LEVEL_MINIMAL)
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
- errmsg("standby connections not allowed because wal_level='minimal'")));
-
+ errmsg("standby connections not allowed because wal_level=\"minimal\"")));
/* Send a CopyOutResponse message, and start streaming */
pq_beginmessage(&buf, 'H');
WalSndCtl = (WalSndCtlData *)
ShmemInitStruct("Wal Sender Ctl", WalSndShmemSize(), &found);
- if (WalSndCtl == NULL)
- ereport(FATAL,
- (errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("not enough shared memory for walsender")));
- if (found)
- return; /* already initialized */
-
- /* Initialize the data structures */
- MemSet(WalSndCtl, 0, WalSndShmemSize());
-
- for (i = 0; i < max_wal_senders; i++)
+ if (!found)
{
- WalSnd *walsnd = &WalSndCtl->walsnds[i];
+ /* First time through, so initialize */
+ MemSet(WalSndCtl, 0, WalSndShmemSize());
+
+ for (i = 0; i < max_wal_senders; i++)
+ {
+ WalSnd *walsnd = &WalSndCtl->walsnds[i];
- SpinLockInit(&walsnd->mutex);
+ SpinLockInit(&walsnd->mutex);
+ }
}
}
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/storage/buffer/buf_table.c,v 1.51 2010/01/02 16:57:51 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/buffer/buf_table.c,v 1.52 2010/04/28 16:54:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
size, size,
&info,
HASH_ELEM | HASH_FUNCTION | HASH_PARTITION);
-
- if (!SharedBufHash)
- elog(FATAL, "could not initialize shared buffer hash table");
}
/*
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.103 2010/01/02 16:57:51 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.104 2010/04/28 16:54:16 tgl Exp $
*
*-------------------------------------------------------------------------
*/
int hash_flags;
/*
+ * Create the shared memory shmem index.
+ *
* Since ShmemInitHash calls ShmemInitStruct, which expects the ShmemIndex
* hashtable to exist already, we have a bit of a circularity problem in
* initializing the ShmemIndex itself. The special "ShmemIndex" hash
* table name will tell ShmemInitStruct to fake it.
*/
-
- /* create the shared memory shmem index */
info.keysize = SHMEM_INDEX_KEYSIZE;
info.entrysize = sizeof(ShmemIndexEnt);
hash_flags = HASH_ELEM;
ShmemIndex = ShmemInitHash("ShmemIndex",
SHMEM_INDEX_SIZE, SHMEM_INDEX_SIZE,
&info, hash_flags);
- if (!ShmemIndex)
- elog(FATAL, "could not initialize Shmem Index");
}
/*
* shared memory hash table.
*
* We assume caller is doing some kind of synchronization
- * so that two people don't try to create/initialize the
- * table at once.
+ * so that two processes don't try to create/initialize the same
+ * table at once. (In practice, all creations are done in the postmaster
+ * process; child processes should always be attaching to existing tables.)
*
* max_size is the estimated maximum number of hashtable entries. This is
* not a hard limit, but the access efficiency will degrade if it is
* init_size is the number of hashtable entries to preallocate. For a table
* whose maximum size is certain, this should be equal to max_size; that
* ensures that no run-time out-of-shared-memory failures can occur.
+ *
+ * Note: before Postgres 9.0, this function returned NULL for some failure
+ * cases. Now, it always throws error instead, so callers need not check
+ * for NULL.
*/
HTAB *
ShmemInitHash(const char *name, /* table string name for shmem index */
&found);
/*
- * If fail, shmem index is corrupted. Let caller give the error message
- * since it has more information
- */
- if (location == NULL)
- return NULL;
-
- /*
* if it already exists, attach to it rather than allocate and initialize
* new space
*/
}
/*
- * ShmemInitStruct -- Create/attach to a structure in shared
- * memory.
+ * ShmemInitStruct -- Create/attach to a structure in shared memory.
*
- * This is called during initialization to find or allocate
+ * This is called during initialization to find or allocate
* a data structure in shared memory. If no other process
* has created the structure, this routine allocates space
* for it. If it exists already, a pointer to the existing
- * table is returned.
+ * structure is returned.
+ *
+ * Returns: pointer to the object. *foundPtr is set TRUE if the object was
+ * already in the shmem index (hence, already initialized).
*
- * Returns: real pointer to the object. FoundPtr is TRUE if
- * the object is already in the shmem index (hence, already
- * initialized).
+ * Note: before Postgres 9.0, this function returned NULL for some failure
+ * cases. Now, it always throws error instead, so callers need not check
+ * for NULL.
*/
void *
ShmemInitStruct(const char *name, Size size, bool *foundPtr)
{
PGShmemHeader *shmemseghdr = ShmemSegHdr;
+ /* Must be trying to create/attach to ShmemIndex itself */
Assert(strcmp(name, "ShmemIndex") == 0);
+
if (IsUnderPostmaster)
{
/* Must be initializing a (non-standalone) backend */
*/
Assert(shmemseghdr->index == NULL);
structPtr = ShmemAlloc(size);
+ if (structPtr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("not enough shared memory for data structure"
+ " \"%s\" (%lu bytes requested)",
+ name, (unsigned long) size)));
shmemseghdr->index = structPtr;
*foundPtr = FALSE;
}
LWLockRelease(ShmemIndexLock);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("out of shared memory")));
+ errmsg("could not create ShmemIndex entry for data structure \"%s\"",
+ name)));
}
if (*foundPtr)
/*
* Structure is in the shmem index so someone else has allocated it
* already. The size better be the same as the size we are trying to
- * initialize to or there is a name conflict (or worse).
+ * initialize to, or there is a name conflict (or worse).
*/
if (result->size != size)
{
LWLockRelease(ShmemIndexLock);
-
- elog(WARNING, "ShmemIndex entry size is wrong");
- /* let caller print its message too */
- return NULL;
+ ereport(ERROR,
+ (errmsg("ShmemIndex entry size is wrong for data structure"
+ " \"%s\": expected %lu, actual %lu",
+ name,
+ (unsigned long) size,
+ (unsigned long) result->size)));
}
structPtr = result->location;
}
{
/* It isn't in the table yet. allocate and initialize it */
structPtr = ShmemAlloc(size);
- if (!structPtr)
+ if (structPtr == NULL)
{
- /* out of memory */
- Assert(ShmemIndex);
+ /* out of memory; remove the failed ShmemIndex entry */
hash_search(ShmemIndex, name, HASH_REMOVE, NULL);
LWLockRelease(ShmemIndexLock);
-
- ereport(WARNING,
+ ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
- errmsg("could not allocate shared memory segment \"%s\"",
- name)));
- *foundPtr = FALSE;
- return NULL;
+ errmsg("not enough shared memory for data structure"
+ " \"%s\" (%lu bytes requested)",
+ name, (unsigned long) size)));
}
result->size = size;
result->location = structPtr;
}
- Assert(ShmemAddrIsValid(structPtr));
LWLockRelease(ShmemIndexLock);
+
+ Assert(ShmemAddrIsValid(structPtr));
return structPtr;
}
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.196 2010/03/21 00:17:58 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.197 2010/04/28 16:54:16 tgl Exp $
*
* NOTES
* A lock table is a shared memory hash table. When
max_table_size,
&info,
hash_flags);
- if (!LockMethodLockHash)
- elog(FATAL, "could not initialize lock hash table");
/* Assume an average of 2 holders per lock */
max_table_size *= 2;
max_table_size,
&info,
hash_flags);
- if (!LockMethodProcLockHash)
- elog(FATAL, "could not initialize proclock hash table");
/*
* Allocate non-shared hash table for LOCALLOCK structs. This stores lock
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.217 2010/02/26 02:01:01 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/lmgr/proc.c,v 1.218 2010/04/28 16:54:16 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*
* ProcQueueAlloc -- alloc/attach to a shared memory process queue
*
- * Returns: a pointer to the queue or NULL
- * Side Effects: Initializes the queue if we allocated one
+ * Returns: a pointer to the queue
+ * Side Effects: Initializes the queue if it wasn't there before
*/
#ifdef NOT_USED
PROC_QUEUE *
-ProcQueueAlloc(char *name)
+ProcQueueAlloc(const char *name)
{
+ PROC_QUEUE *queue;
bool found;
- PROC_QUEUE *queue = (PROC_QUEUE *)
- ShmemInitStruct(name, sizeof(PROC_QUEUE), &found);
- if (!queue)
- return NULL;
+ queue = (PROC_QUEUE *)
+ ShmemInitStruct(name, sizeof(PROC_QUEUE), &found);
+
if (!found)
ProcQueueInit(queue);
+
return queue;
}
#endif
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