I wrote:
> I've not done any benchmarking on this yet, just confirmed that it
> compiles and passes check-world.
So once I'd done some benchmarking, I was a bit disappointed: I could
not measure any difference anymore in "pgbench -S", and poking into
other scenarios found cases that were actually slower, like
do $$
begin
for i in 1..10000000 loop
declare x int;
begin
x := 42;
exception when others then null;
end;
end loop;
end$$;
which went from about 12.4 seconds in HEAD to about 13.6 with my
v2 patch. When I looked into the reason, I found that my earlier
blithe pronouncement that "optimizing for the unused-context case
seems like the wrong thing" was too simple. In this example we
create and delete two memory contexts per loop (a subtransaction
context and an ExprContext) and neither of them receives any
palloc requests. Some of the contexts created in a "pgbench -S"
scenario are the same way. So in these examples, we were on the
losing side of the replace-a-palloc-with-a-malloc trade.
However, if we can predict which contexts are more likely not to
receive traffic, we can fix this by doing things the old way for
those contexts. I instrumented AllocSetDelete to log whether
the target context had received any requests in its lifespan,
and aggregated the reports over a run of the core regression tests.
I found these cases where there were significantly more reports
of "context was never used" than "context was used":
379 CurTransactionContext was never used
24 CurTransactionContext was used
66978 ExprContext was never used
17364 ExprContext was used
993 HashTableContext was never used
25 HashTableContext was used
88 Logical Replication Launcher sublist was never used
2 Logical Replication Launcher sublist was used
11139 SPI Exec was never used
2421 SPI Exec was used
36 SetOp was never used
2 SetOp was used
185 Statistics snapshot was never used
104 Subplan HashTable Context was never used
44 Subplan HashTable Context was used
148 Subplan HashTable Temp Context was never used
1481 Table function arguments was never used
45 Table function arguments was used
22 TableFunc per value context was never used
52 Unique was never used
4 Unique was used
137 WindowAgg Aggregates was never used
2 WindowAgg Aggregates was used
127 WindowAgg Partition was never used
12 WindowAgg Partition was used
288 _bt_pagedel was never used
14 _bt_pagedel was used
35 event trigger context was never used
3 event trigger context was used
38386 ginPlaceToPage temporary context was never used
3348 ginPlaceToPage temporary context was used
454 ident parser context was never used
229 tSRF function arguments was never used
46 tSRF function arguments was used
A lot of these probably aren't bothering with optimizing because they just
don't occur often enough to move the needle. (And in workloads where that
wasn't true, maybe the usage statistics would be different anyway.) But
it looked to me like CurTransactionContext, ExprContext, HashTableContext,
SPI Exec, and ginPlaceToPage temporary context would be worth doing it
the old way for.
Accordingly, attached is a v3 patch that adds another flag to
AllocSetContextCreateExtended telling it to do things the old way
with the context header in TopMemoryContext. (We can still optimize
context name copying as before.) This fixes the subtransaction case
I showed above, bringing it to 10.7 sec which is noticeably better
than HEAD. I now see maybe a 1 or 2 percent improvement in "pgbench -S",
which isn't much, but it turns out that that test case only involves
half a dozen context creations/deletions per transaction. So probably
we aren't going to get any noticeable movement on that benchmark, and
it'd be brighter to look for test cases where more contexts are involved.
regards, tom lane
diff --git a/contrib/amcheck/verify_nbtree.c b/contrib/amcheck/verify_nbtree.c
index 868c14e..adbbc44 100644
*** a/contrib/amcheck/verify_nbtree.c
--- b/contrib/amcheck/verify_nbtree.c
*************** bt_check_every_level(Relation rel, bool
*** 295,303 ****
/* Create context for page */
state->targetcontext = AllocSetContextCreate(CurrentMemoryContext,
"amcheck context",
! ALLOCSET_DEFAULT_MINSIZE,
! ALLOCSET_DEFAULT_INITSIZE,
! ALLOCSET_DEFAULT_MAXSIZE);
state->checkstrategy = GetAccessStrategy(BAS_BULKREAD);
/* Get true root block from meta-page */
--- 295,301 ----
/* Create context for page */
state->targetcontext = AllocSetContextCreate(CurrentMemoryContext,
"amcheck context",
! ALLOCSET_DEFAULT_SIZES);
state->checkstrategy = GetAccessStrategy(BAS_BULKREAD);
/* Get true root block from meta-page */
diff --git a/src/backend/access/gin/ginbtree.c b/src/backend/access/gin/ginbtree.c
index 1b920fa..ce7856e 100644
*** a/src/backend/access/gin/ginbtree.c
--- b/src/backend/access/gin/ginbtree.c
*************** ginPlaceToPage(GinBtree btree, GinBtreeS
*** 345,355 ****
* We do all the work of this function and its subfunctions in a temporary
* memory context. This avoids leakages and simplifies APIs, since some
* subfunctions allocate storage that has to survive until we've finished
! * the WAL insertion.
*/
! tmpCxt = AllocSetContextCreate(CurrentMemoryContext,
! "ginPlaceToPage temporary context",
! ALLOCSET_DEFAULT_SIZES);
oldCxt = MemoryContextSwitchTo(tmpCxt);
if (GinPageIsData(page))
--- 345,357 ----
* We do all the work of this function and its subfunctions in a temporary
* memory context. This avoids leakages and simplifies APIs, since some
* subfunctions allocate storage that has to survive until we've finished
! * the WAL insertion. However, it's not unusual for the context to go
! * unused, so tell aset.c to optimize for that case.
*/
! tmpCxt = AllocSetContextCreateExtended(CurrentMemoryContext,
! "ginPlaceToPage temporary context",
! MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
oldCxt = MemoryContextSwitchTo(tmpCxt);
if (GinPageIsData(page))
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 046898c..d864be9 100644
*** a/src/backend/access/transam/xact.c
--- b/src/backend/access/transam/xact.c
*************** AtStart_Memory(void)
*** 997,1007 ****
*/
if (TransactionAbortContext == NULL)
TransactionAbortContext =
! AllocSetContextCreate(TopMemoryContext,
! "TransactionAbortContext",
! 32 * 1024,
! 32 * 1024,
! 32 * 1024);
/*
* We shouldn't have a transaction context already.
--- 997,1008 ----
*/
if (TransactionAbortContext == NULL)
TransactionAbortContext =
! AllocSetContextCreateExtended(TopMemoryContext,
! "TransactionAbortContext",
! 0,
! 32 * 1024,
! 32 * 1024,
! 32 * 1024);
/*
* We shouldn't have a transaction context already.
*************** AtSubStart_Memory(void)
*** 1069,1078 ****
* Create a CurTransactionContext, which will be used to hold data that
* survives subtransaction commit but disappears on subtransaction abort.
* We make it a child of the immediate parent's CurTransactionContext.
*/
! CurTransactionContext = AllocSetContextCreate(CurTransactionContext,
! "CurTransactionContext",
! ALLOCSET_DEFAULT_SIZES);
s->curTransactionContext = CurTransactionContext;
/* Make the CurTransactionContext active. */
--- 1070,1083 ----
* Create a CurTransactionContext, which will be used to hold data that
* survives subtransaction commit but disappears on subtransaction abort.
* We make it a child of the immediate parent's CurTransactionContext.
+ * Often, nothing ever gets put in a subtransaction's context, so tell
+ * aset.c to optimize for that case.
*/
! CurTransactionContext =
! AllocSetContextCreateExtended(CurTransactionContext,
! "CurTransactionContext",
! MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
s->curTransactionContext = CurTransactionContext;
/* Make the CurTransactionContext active. */
diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
index ef156e4..5c4018e 100644
*** a/src/backend/catalog/partition.c
--- b/src/backend/catalog/partition.c
*************** RelationBuildPartitionDesc(Relation rel)
*** 520,528 ****
}
/* Now build the actual relcache partition descriptor */
! rel->rd_pdcxt = AllocSetContextCreate(CacheMemoryContext,
! RelationGetRelationName(rel),
! ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(rel->rd_pdcxt);
result = (PartitionDescData *) palloc0(sizeof(PartitionDescData));
--- 520,529 ----
}
/* Now build the actual relcache partition descriptor */
! rel->rd_pdcxt = AllocSetContextCreateExtended(CacheMemoryContext,
! RelationGetRelationName(rel),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(rel->rd_pdcxt);
result = (PartitionDescData *) palloc0(sizeof(PartitionDescData));
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 086a6ef..a7f426d 100644
*** a/src/backend/commands/subscriptioncmds.c
--- b/src/backend/commands/subscriptioncmds.c
*************** publicationListToArray(List *publist)
*** 259,267 ****
/* Create memory context for temporary allocations. */
memcxt = AllocSetContextCreate(CurrentMemoryContext,
"publicationListToArray to array",
! ALLOCSET_DEFAULT_MINSIZE,
! ALLOCSET_DEFAULT_INITSIZE,
! ALLOCSET_DEFAULT_MAXSIZE);
oldcxt = MemoryContextSwitchTo(memcxt);
datums = (Datum *) palloc(sizeof(Datum) * list_length(publist));
--- 259,265 ----
/* Create memory context for temporary allocations. */
memcxt = AllocSetContextCreate(CurrentMemoryContext,
"publicationListToArray to array",
! ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(memcxt);
datums = (Datum *) palloc(sizeof(Datum) * list_length(publist));
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index 8764398..cc7b81a 100644
*** a/src/backend/executor/execUtils.c
--- b/src/backend/executor/execUtils.c
*************** CreateExprContext(EState *estate)
*** 241,252 ****
econtext->ecxt_per_query_memory = estate->es_query_cxt;
/*
! * Create working memory for expression evaluation in this context.
*/
econtext->ecxt_per_tuple_memory =
! AllocSetContextCreate(estate->es_query_cxt,
! "ExprContext",
! ALLOCSET_DEFAULT_SIZES);
econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
econtext->ecxt_param_list_info = estate->es_param_list_info;
--- 241,255 ----
econtext->ecxt_per_query_memory = estate->es_query_cxt;
/*
! * Create working memory for expression evaluation in this context. If
! * the expression uses only pass-by-value data types, the context may well
! * go unused, so tell aset.c to optimize for that case.
*/
econtext->ecxt_per_tuple_memory =
! AllocSetContextCreateExtended(estate->es_query_cxt,
! "ExprContext",
! MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
econtext->ecxt_param_list_info = estate->es_param_list_info;
*************** CreateStandaloneExprContext(void)
*** 313,321 ****
* Create working memory for expression evaluation in this context.
*/
econtext->ecxt_per_tuple_memory =
! AllocSetContextCreate(CurrentMemoryContext,
! "ExprContext",
! ALLOCSET_DEFAULT_SIZES);
econtext->ecxt_param_exec_vals = NULL;
econtext->ecxt_param_list_info = NULL;
--- 316,325 ----
* Create working memory for expression evaluation in this context.
*/
econtext->ecxt_per_tuple_memory =
! AllocSetContextCreateExtended(CurrentMemoryContext,
! "Standalone ExprContext",
! MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
econtext->ecxt_param_exec_vals = NULL;
econtext->ecxt_param_list_info = NULL;
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index 6fe5d69..8c30f8c 100644
*** a/src/backend/executor/nodeHash.c
--- b/src/backend/executor/nodeHash.c
*************** ExecHashTableCreate(Hash *node, List *ha
*** 337,347 ****
/*
* Create temporary memory contexts in which to keep the hashtable working
! * storage. See notes in executor/hashjoin.h.
*/
! hashtable->hashCxt = AllocSetContextCreate(CurrentMemoryContext,
! "HashTableContext",
! ALLOCSET_DEFAULT_SIZES);
hashtable->batchCxt = AllocSetContextCreate(hashtable->hashCxt,
"HashBatchContext",
--- 337,351 ----
/*
* Create temporary memory contexts in which to keep the hashtable working
! * storage. See notes in executor/hashjoin.h. If we are only expecting
! * one batch, it's likely that hashCxt will never receive any allocations,
! * so tell aset.c to optimize for that case.
*/
! hashtable->hashCxt =
! AllocSetContextCreateExtended(CurrentMemoryContext,
! "HashTableContext",
! (nbatch > 1) ? 0 : MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
hashtable->batchCxt = AllocSetContextCreate(hashtable->hashCxt,
"HashBatchContext",
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index f3da2dd..dd461cd 100644
*** a/src/backend/executor/spi.c
--- b/src/backend/executor/spi.c
*************** SPI_connect(void)
*** 130,144 ****
*
* XXX it would be better to use PortalContext as the parent context, but
* we may not be inside a portal (consider deferred-trigger execution).
! * Perhaps CurTransactionContext would do? For now it doesn't matter
! * because we clean up explicitly in AtEOSubXact_SPI().
*/
_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
"SPI Proc",
ALLOCSET_DEFAULT_SIZES);
! _SPI_current->execCxt = AllocSetContextCreate(TopTransactionContext,
! "SPI Exec",
! ALLOCSET_DEFAULT_SIZES);
/* ... and switch to procedure's context */
_SPI_current->savedcxt = MemoryContextSwitchTo(_SPI_current->procCxt);
--- 130,147 ----
*
* XXX it would be better to use PortalContext as the parent context, but
* we may not be inside a portal (consider deferred-trigger execution).
! * Perhaps CurTransactionContext would do? For now it doesn't matter
! * because we clean up explicitly in AtEOSubXact_SPI(). In practice, it
! * seems that execCxt often goes unused, so optimize for that.
*/
_SPI_current->procCxt = AllocSetContextCreate(TopTransactionContext,
"SPI Proc",
ALLOCSET_DEFAULT_SIZES);
! _SPI_current->execCxt =
! AllocSetContextCreateExtended(TopTransactionContext,
! "SPI Exec",
! MEMCONTEXT_OPTIMIZE_EMPTY,
! ALLOCSET_DEFAULT_SIZES);
/* ... and switch to procedure's context */
_SPI_current->savedcxt = MemoryContextSwitchTo(_SPI_current->procCxt);
diff --git a/src/backend/lib/knapsack.c b/src/backend/lib/knapsack.c
index ddf2b9a..490c0cc 100644
*** a/src/backend/lib/knapsack.c
--- b/src/backend/lib/knapsack.c
*************** DiscreteKnapsack(int max_weight, int num
*** 57,65 ****
{
MemoryContext local_ctx = AllocSetContextCreate(CurrentMemoryContext,
"Knapsack",
! ALLOCSET_SMALL_MINSIZE,
! ALLOCSET_SMALL_INITSIZE,
! ALLOCSET_SMALL_MAXSIZE);
MemoryContext oldctx = MemoryContextSwitchTo(local_ctx);
double *values;
Bitmapset **sets;
--- 57,63 ----
{
MemoryContext local_ctx = AllocSetContextCreate(CurrentMemoryContext,
"Knapsack",
! ALLOCSET_SMALL_SIZES);
MemoryContext oldctx = MemoryContextSwitchTo(local_ctx);
double *values;
Bitmapset **sets;
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index a613ef4..24be3ce 100644
*** a/src/backend/replication/logical/launcher.c
--- b/src/backend/replication/logical/launcher.c
*************** ApplyLauncherMain(Datum main_arg)
*** 925,933 ****
/* Use temporary context for the database list and worker info. */
subctx = AllocSetContextCreate(TopMemoryContext,
"Logical Replication Launcher sublist",
! ALLOCSET_DEFAULT_MINSIZE,
! ALLOCSET_DEFAULT_INITSIZE,
! ALLOCSET_DEFAULT_MAXSIZE);
oldctx = MemoryContextSwitchTo(subctx);
/* search for subscriptions to start or stop. */
--- 925,931 ----
/* Use temporary context for the database list and worker info. */
subctx = AllocSetContextCreate(TopMemoryContext,
"Logical Replication Launcher sublist",
! ALLOCSET_DEFAULT_SIZES);
oldctx = MemoryContextSwitchTo(subctx);
/* search for subscriptions to start or stop. */
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index fa95bab..5ac391d 100644
*** a/src/backend/replication/logical/reorderbuffer.c
--- b/src/backend/replication/logical/reorderbuffer.c
*************** ReorderBufferAllocate(void)
*** 237,252 ****
--- 237,255 ----
buffer->change_context = SlabContextCreate(new_ctx,
"Change",
+ 0,
SLAB_DEFAULT_BLOCK_SIZE,
sizeof(ReorderBufferChange));
buffer->txn_context = SlabContextCreate(new_ctx,
"TXN",
+ 0,
SLAB_DEFAULT_BLOCK_SIZE,
sizeof(ReorderBufferTXN));
buffer->tup_context = GenerationContextCreate(new_ctx,
"Tuples",
+ 0,
SLAB_LARGE_BLOCK_SIZE);
hash_ctl.keysize = sizeof(TransactionId);
diff --git a/src/backend/replication/pgoutput/pgoutput.c b/src/backend/replication/pgoutput/pgoutput.c
index c312654..550b156 100644
*** a/src/backend/replication/pgoutput/pgoutput.c
--- b/src/backend/replication/pgoutput/pgoutput.c
*************** pgoutput_startup(LogicalDecodingContext
*** 152,160 ****
/* Create our memory context for private allocations. */
data->context = AllocSetContextCreate(ctx->context,
"logical replication output context",
! ALLOCSET_DEFAULT_MINSIZE,
! ALLOCSET_DEFAULT_INITSIZE,
! ALLOCSET_DEFAULT_MAXSIZE);
ctx->output_plugin_private = data;
--- 152,158 ----
/* Create our memory context for private allocations. */
data->context = AllocSetContextCreate(ctx->context,
"logical replication output context",
! ALLOCSET_DEFAULT_SIZES);
ctx->output_plugin_private = data;
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 12a5f15..3a9233e 100644
*** a/src/backend/utils/cache/relcache.c
--- b/src/backend/utils/cache/relcache.c
*************** RelationBuildRuleLock(Relation relation)
*** 669,677 ****
/*
* Make the private context. Assume it'll not contain much data.
*/
! rulescxt = AllocSetContextCreate(CacheMemoryContext,
! RelationGetRelationName(relation),
! ALLOCSET_SMALL_SIZES);
relation->rd_rulescxt = rulescxt;
/*
--- 669,678 ----
/*
* Make the private context. Assume it'll not contain much data.
*/
! rulescxt = AllocSetContextCreateExtended(CacheMemoryContext,
! RelationGetRelationName(relation),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
relation->rd_rulescxt = rulescxt;
/*
*************** RelationBuildPartitionKey(Relation relat
*** 984,992 ****
ReleaseSysCache(tuple);
/* Success --- now copy to the cache memory */
! partkeycxt = AllocSetContextCreate(CacheMemoryContext,
! RelationGetRelationName(relation),
! ALLOCSET_SMALL_SIZES);
relation->rd_partkeycxt = partkeycxt;
oldcxt = MemoryContextSwitchTo(relation->rd_partkeycxt);
relation->rd_partkey = copy_partition_key(key);
--- 985,994 ----
ReleaseSysCache(tuple);
/* Success --- now copy to the cache memory */
! partkeycxt = AllocSetContextCreateExtended(CacheMemoryContext,
! RelationGetRelationName(relation),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
relation->rd_partkeycxt = partkeycxt;
oldcxt = MemoryContextSwitchTo(relation->rd_partkeycxt);
relation->rd_partkey = copy_partition_key(key);
*************** RelationInitIndexAccessInfo(Relation rel
*** 1566,1574 ****
* a context, and not just a couple of pallocs, is so that we won't leak
* any subsidiary info attached to fmgr lookup records.
*/
! indexcxt = AllocSetContextCreate(CacheMemoryContext,
! RelationGetRelationName(relation),
! ALLOCSET_SMALL_SIZES);
relation->rd_indexcxt = indexcxt;
/*
--- 1568,1577 ----
* a context, and not just a couple of pallocs, is so that we won't leak
* any subsidiary info attached to fmgr lookup records.
*/
! indexcxt = AllocSetContextCreateExtended(CacheMemoryContext,
! RelationGetRelationName(relation),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
relation->rd_indexcxt = indexcxt;
/*
*************** load_relcache_init_file(bool shared)
*** 5537,5545 ****
* prepare index info context --- parameters should match
* RelationInitIndexAccessInfo
*/
! indexcxt = AllocSetContextCreate(CacheMemoryContext,
! RelationGetRelationName(rel),
! ALLOCSET_SMALL_SIZES);
rel->rd_indexcxt = indexcxt;
/*
--- 5540,5550 ----
* prepare index info context --- parameters should match
* RelationInitIndexAccessInfo
*/
! indexcxt =
! AllocSetContextCreateExtended(CacheMemoryContext,
! RelationGetRelationName(rel),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
rel->rd_indexcxt = indexcxt;
/*
diff --git a/src/backend/utils/cache/ts_cache.c b/src/backend/utils/cache/ts_cache.c
index da5c8ea..29cf93a 100644
*** a/src/backend/utils/cache/ts_cache.c
--- b/src/backend/utils/cache/ts_cache.c
*************** lookup_ts_dictionary_cache(Oid dictId)
*** 294,302 ****
Assert(!found); /* it wasn't there a moment ago */
/* Create private memory context the first time through */
! saveCtx = AllocSetContextCreate(CacheMemoryContext,
! NameStr(dict->dictname),
! ALLOCSET_SMALL_SIZES);
}
else
{
--- 294,303 ----
Assert(!found); /* it wasn't there a moment ago */
/* Create private memory context the first time through */
! saveCtx = AllocSetContextCreateExtended(CacheMemoryContext,
! NameStr(dict->dictname),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
}
else
{
diff --git a/src/backend/utils/hash/dynahash.c b/src/backend/utils/hash/dynahash.c
index 71f5f06..c88efc3 100644
*** a/src/backend/utils/hash/dynahash.c
--- b/src/backend/utils/hash/dynahash.c
*************** hash_create(const char *tabname, long ne
*** 340,348 ****
CurrentDynaHashCxt = info->hcxt;
else
CurrentDynaHashCxt = TopMemoryContext;
! CurrentDynaHashCxt = AllocSetContextCreate(CurrentDynaHashCxt,
! tabname,
! ALLOCSET_DEFAULT_SIZES);
}
/* Initialize the hash header, plus a copy of the table name */
--- 340,350 ----
CurrentDynaHashCxt = info->hcxt;
else
CurrentDynaHashCxt = TopMemoryContext;
! CurrentDynaHashCxt =
! AllocSetContextCreateExtended(CurrentDynaHashCxt,
! tabname,
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_DEFAULT_SIZES);
}
/* Initialize the hash header, plus a copy of the table name */
diff --git a/src/backend/utils/mmgr/README b/src/backend/utils/mmgr/README
index 296fa19..f0db836 100644
*** a/src/backend/utils/mmgr/README
--- b/src/backend/utils/mmgr/README
*************** every other context is a direct or indir
*** 177,184 ****
here is essentially the same as "malloc", because this context will never
be reset or deleted. This is for stuff that should live forever, or for
stuff that the controlling module will take care of deleting at the
! appropriate time. An example is fd.c's tables of open files, as well as
! the context management nodes for memory contexts themselves. Avoid
allocating stuff here unless really necessary, and especially avoid
running with CurrentMemoryContext pointing here.
--- 177,183 ----
here is essentially the same as "malloc", because this context will never
be reset or deleted. This is for stuff that should live forever, or for
stuff that the controlling module will take care of deleting at the
! appropriate time. An example is fd.c's tables of open files. Avoid
allocating stuff here unless really necessary, and especially avoid
running with CurrentMemoryContext pointing here.
diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index 1bd1c34..acc15f9 100644
*** a/src/backend/utils/mmgr/aset.c
--- b/src/backend/utils/mmgr/aset.c
***************
*** 93,98 ****
--- 93,101 ----
*
* Blocks allocated to hold oversize chunks do not follow this rule, however;
* they are just however big they need to be to hold that single chunk.
+ *
+ * Also, if a minContextSize is specified, the first block has that size,
+ * and then initBlockSize is used for the next one.
*--------------------
*/
*************** typedef struct AllocSetContext
*** 127,134 ****
--- 130,139 ----
Size initBlockSize; /* initial block size */
Size maxBlockSize; /* maximum block size */
Size nextBlockSize; /* next block size to allocate */
+ Size headerSize; /* allocated size of context header */
Size allocChunkLimit; /* effective chunk size limit */
AllocBlock keeper; /* if not NULL, keep this block over resets */
+ bool separateHeader; /* if F, header + keeper block are 1 malloc */
} AllocSetContext;
typedef AllocSetContext *AllocSet;
*************** typedef struct AllocChunkData
*** 221,227 ****
static void *AllocSetAlloc(MemoryContext context, Size size);
static void AllocSetFree(MemoryContext context, void *pointer);
static void *AllocSetRealloc(MemoryContext context, void *pointer, Size size);
- static void AllocSetInit(MemoryContext context);
static void AllocSetReset(MemoryContext context);
static void AllocSetDelete(MemoryContext context);
static Size AllocSetGetChunkSpace(MemoryContext context, void *pointer);
--- 226,231 ----
*************** static void AllocSetCheck(MemoryContext
*** 236,246 ****
/*
* This is the virtual function table for AllocSet contexts.
*/
! static MemoryContextMethods AllocSetMethods = {
AllocSetAlloc,
AllocSetFree,
AllocSetRealloc,
- AllocSetInit,
AllocSetReset,
AllocSetDelete,
AllocSetGetChunkSpace,
--- 240,249 ----
/*
* This is the virtual function table for AllocSet contexts.
*/
! static const MemoryContextMethods AllocSetMethods = {
AllocSetAlloc,
AllocSetFree,
AllocSetRealloc,
AllocSetReset,
AllocSetDelete,
AllocSetGetChunkSpace,
*************** AllocSetFreeIndex(Size size)
*** 325,350 ****
/*
! * AllocSetContextCreate
* Create a new AllocSet context.
*
* parent: parent context, or NULL if top-level context
* name: name of context (for debugging only, need not be unique)
! * minContextSize: minimum context size
* initBlockSize: initial allocation block size
* maxBlockSize: maximum allocation block size
*
! * Notes: the name string will be copied into context-lifespan storage.
* Most callers should abstract the context size parameters using a macro
! * such as ALLOCSET_DEFAULT_SIZES.
*/
MemoryContext
! AllocSetContextCreate(MemoryContext parent,
! const char *name,
! Size minContextSize,
! Size initBlockSize,
! Size maxBlockSize)
{
AllocSet set;
/* Assert we padded AllocChunkData properly */
--- 328,358 ----
/*
! * AllocSetContextCreateExtended
* Create a new AllocSet context.
*
* parent: parent context, or NULL if top-level context
* name: name of context (for debugging only, need not be unique)
! * flags: bitmask of MEMCONTEXT_XXX option flags
! * minContextSize: minimum context size (ignored if MEMCONTEXT_OPTIMIZE_EMPTY)
* initBlockSize: initial allocation block size
* maxBlockSize: maximum allocation block size
*
! * Notes: if flags & MEMCONTEXT_COPY_NAME, the name string will be copied into
! * context-lifespan storage; otherwise, it had better be statically allocated.
* Most callers should abstract the context size parameters using a macro
! * such as ALLOCSET_DEFAULT_SIZES. (This is now *required* when going
! * through the AllocSetContextCreate macro.)
*/
MemoryContext
! AllocSetContextCreateExtended(MemoryContext parent,
! const char *name,
! int flags,
! Size minContextSize,
! Size initBlockSize,
! Size maxBlockSize)
{
+ Size headerSize;
AllocSet set;
/* Assert we padded AllocChunkData properly */
*************** AllocSetContextCreate(MemoryContext pare
*** 370,390 ****
maxBlockSize);
if (minContextSize != 0 &&
(minContextSize != MAXALIGN(minContextSize) ||
! minContextSize <= ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ))
elog(ERROR, "invalid minContextSize for memory context: %zu",
minContextSize);
! /* Do the type-independent part of context creation */
! set = (AllocSet) MemoryContextCreate(T_AllocSetContext,
! sizeof(AllocSetContext),
! &AllocSetMethods,
! parent,
! name);
- /* Save allocation parameters */
set->initBlockSize = initBlockSize;
set->maxBlockSize = maxBlockSize;
set->nextBlockSize = initBlockSize;
/*
* Compute the allocation chunk size limit for this context. It can't be
--- 378,467 ----
maxBlockSize);
if (minContextSize != 0 &&
(minContextSize != MAXALIGN(minContextSize) ||
! minContextSize < 1024 ||
! minContextSize > maxBlockSize))
elog(ERROR, "invalid minContextSize for memory context: %zu",
minContextSize);
! /* Size of the memory context header, including name storage if needed */
! if (flags & MEMCONTEXT_COPY_NAME)
! headerSize = MAXALIGN(sizeof(AllocSetContext) + strlen(name) + 1);
! else
! headerSize = MAXALIGN(sizeof(AllocSetContext));
!
! /*
! * If we are optimizing for the possibility that the context is never
! * used, we allocate the context header in TopMemoryContext (which had
! * better already exist). Otherwise, create a keeper block immediately
! * and make the context header part of that same malloc request, so as to
! * save a palloc/pfree cycle.
! *
! * Avoid writing code that can fail between here and MemoryContextCreate;
! * we'd leak the header/initial block if we ereport in this stretch.
! */
! if (flags & MEMCONTEXT_OPTIMIZE_EMPTY)
! {
! set = (AllocSet) MemoryContextAlloc(TopMemoryContext, headerSize);
!
! /* Flag header as separate, and show that there's no initial block */
! set->separateHeader = true;
! set->blocks = NULL;
! set->keeper = NULL;
! }
! else
! {
! Size firstBlockSize;
! AllocBlock block;
!
! /* Determine size of initial block */
! firstBlockSize = headerSize + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
! if (minContextSize != 0)
! firstBlockSize = Max(firstBlockSize, minContextSize);
! else
! firstBlockSize = Max(firstBlockSize, initBlockSize);
!
! /*
! * Allocate the initial block. Unlike other aset.c blocks, it starts
! * with the context header and its block header follows that.
! */
! set = (AllocSet) malloc(firstBlockSize);
! if (set == NULL)
! {
! if (TopMemoryContext)
! MemoryContextStats(TopMemoryContext);
! ereport(ERROR,
! (errcode(ERRCODE_OUT_OF_MEMORY),
! errmsg("out of memory"),
! errdetail("Failed while creating memory context \"%s\".",
! name)));
! }
!
! /* Fill in the initial block's block header */
! block = (AllocBlock) (((char *) set) + headerSize);
! block->aset = set;
! block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
! block->endptr = ((char *) set) + firstBlockSize;
! block->prev = NULL;
! block->next = NULL;
!
! /* Mark unallocated space NOACCESS; leave the block header alone. */
! VALGRIND_MAKE_MEM_NOACCESS(block->freeptr, block->endptr - block->freeptr);
!
! /* Mark header as part of initial block */
! set->separateHeader = false;
! /* Remember block as part of block list */
! set->blocks = block;
! /* Mark block as not to be released at reset time */
! set->keeper = block;
! }
!
! /* Finish filling in aset-specific parts of the context header */
! MemSetAligned(set->freelist, 0, sizeof(set->freelist));
set->initBlockSize = initBlockSize;
set->maxBlockSize = maxBlockSize;
set->nextBlockSize = initBlockSize;
+ set->headerSize = headerSize;
/*
* Compute the allocation chunk size limit for this context. It can't be
*************** AllocSetContextCreate(MemoryContext pare
*** 410,474 ****
(Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
set->allocChunkLimit >>= 1;
! /*
! * Grab always-allocated space, if requested
! */
! if (minContextSize > 0)
! {
! Size blksize = minContextSize;
! AllocBlock block;
!
! block = (AllocBlock) malloc(blksize);
! if (block == NULL)
! {
! MemoryContextStats(TopMemoryContext);
! ereport(ERROR,
! (errcode(ERRCODE_OUT_OF_MEMORY),
! errmsg("out of memory"),
! errdetail("Failed while creating memory context \"%s\".",
! name)));
! }
! block->aset = set;
! block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
! block->endptr = ((char *) block) + blksize;
! block->prev = NULL;
! block->next = set->blocks;
! if (block->next)
! block->next->prev = block;
! set->blocks = block;
! /* Mark block as not to be released at reset time */
! set->keeper = block;
!
! /* Mark unallocated space NOACCESS; leave the block header alone. */
! VALGRIND_MAKE_MEM_NOACCESS(block->freeptr,
! blksize - ALLOC_BLOCKHDRSZ);
! }
return (MemoryContext) set;
}
/*
- * AllocSetInit
- * Context-type-specific initialization routine.
- *
- * This is called by MemoryContextCreate() after setting up the
- * generic MemoryContext fields and before linking the new context
- * into the context tree. We must do whatever is needed to make the
- * new context minimally valid for deletion. We must *not* risk
- * failure --- thus, for example, allocating more memory is not cool.
- * (AllocSetContextCreate can allocate memory when it gets control
- * back, however.)
- */
- static void
- AllocSetInit(MemoryContext context)
- {
- /*
- * Since MemoryContextCreate already zeroed the context node, we don't
- * have to do anything here: it's already OK.
- */
- }
-
- /*
* AllocSetReset
* Frees all memory which is allocated in the given set.
*
--- 487,506 ----
(Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
set->allocChunkLimit >>= 1;
! /* Finally, do the type-independent part of context creation */
! MemoryContextCreate((MemoryContext) set,
! T_AllocSetContext,
! headerSize,
! sizeof(AllocSetContext),
! &AllocSetMethods,
! parent,
! name,
! flags);
return (MemoryContext) set;
}
/*
* AllocSetReset
* Frees all memory which is allocated in the given set.
*
*************** AllocSetInit(MemoryContext context)
*** 477,483 ****
* give back all the resources the set owns. Our actual implementation is
* that we hang onto any "keeper" block specified for the set. In this way,
* we don't thrash malloc() when a context is repeatedly reset after small
! * allocations, which is typical behavior for per-tuple contexts.
*/
static void
AllocSetReset(MemoryContext context)
--- 509,517 ----
* give back all the resources the set owns. Our actual implementation is
* that we hang onto any "keeper" block specified for the set. In this way,
* we don't thrash malloc() when a context is repeatedly reset after small
! * allocations, which is typical behavior for per-tuple contexts. In the
! * !separateHeader case, we'd have to keep the keeper block anyway, since
! * that malloc chunk also holds the context header.
*/
static void
AllocSetReset(MemoryContext context)
*************** AllocSetReset(MemoryContext context)
*** 540,546 ****
* in preparation for deletion of the set.
*
* Unlike AllocSetReset, this *must* free all resources of the set.
- * But note we are not responsible for deleting the context node itself.
*/
static void
AllocSetDelete(MemoryContext context)
--- 574,579 ----
*************** AllocSetDelete(MemoryContext context)
*** 555,565 ****
AllocSetCheck(context);
#endif
! /* Make it look empty, just in case... */
! MemSetAligned(set->freelist, 0, sizeof(set->freelist));
! set->blocks = NULL;
! set->keeper = NULL;
!
while (block != NULL)
{
AllocBlock next = block->next;
--- 588,594 ----
AllocSetCheck(context);
#endif
! /* Free all blocks, except the keeper if it is part of context header */
while (block != NULL)
{
AllocBlock next = block->next;
*************** AllocSetDelete(MemoryContext context)
*** 567,575 ****
#ifdef CLOBBER_FREED_MEMORY
wipe_mem(block, block->freeptr - ((char *) block));
#endif
! free(block);
block = next;
}
}
/*
--- 596,613 ----
#ifdef CLOBBER_FREED_MEMORY
wipe_mem(block, block->freeptr - ((char *) block));
#endif
!
! if (block != set->keeper || set->separateHeader)
! free(block);
!
block = next;
}
+
+ /* Finally, free the context header, which may include the keeper block */
+ if (set->separateHeader)
+ pfree(set);
+ else
+ free(set);
}
/*
*************** AllocSetAlloc(MemoryContext context, Siz
*** 811,820 ****
* If this is the first block of the set, make it the "keeper" block.
* Formerly, a keeper block could only be created during context
* creation, but allowing it to happen here lets us have fast reset
! * cycling even for contexts created with minContextSize = 0; that way
! * we don't have to force space to be allocated in contexts that might
! * never need any space. Don't mark an oversize block as a keeper,
! * however.
*/
if (set->keeper == NULL && blksize == set->initBlockSize)
set->keeper = block;
--- 849,858 ----
* If this is the first block of the set, make it the "keeper" block.
* Formerly, a keeper block could only be created during context
* creation, but allowing it to happen here lets us have fast reset
! * cycling even for contexts created with MEMCONTEXT_OPTIMIZE_EMPTY;
! * that way we don't have to force space to be allocated in contexts
! * that might never need any space. Don't mark an oversize block as a
! * keeper, however.
*/
if (set->keeper == NULL && blksize == set->initBlockSize)
set->keeper = block;
*************** AllocSetStats(MemoryContext context, int
*** 1210,1215 ****
--- 1248,1260 ----
AllocBlock block;
int fidx;
+ /*
+ * Include context header in totalspace, unless it's separately allocated,
+ * in which case it'll have been counted in TopMemoryContext.
+ */
+ if (!set->separateHeader)
+ totalspace += set->headerSize;
+
for (block = set->blocks; block != NULL; block = block->next)
{
nblocks++;
*************** static void
*** 1264,1270 ****
AllocSetCheck(MemoryContext context)
{
AllocSet set = (AllocSet) context;
! char *name = set->header.name;
AllocBlock prevblock;
AllocBlock block;
--- 1309,1315 ----
AllocSetCheck(MemoryContext context)
{
AllocSet set = (AllocSet) context;
! const char *name = set->header.name;
AllocBlock prevblock;
AllocBlock block;
diff --git a/src/backend/utils/mmgr/generation.c b/src/backend/utils/mmgr/generation.c
index 19390fa..10d0fc1 100644
*** a/src/backend/utils/mmgr/generation.c
--- b/src/backend/utils/mmgr/generation.c
*************** typedef struct GenerationContext
*** 61,66 ****
--- 61,67 ----
/* Generational context parameters */
Size blockSize; /* standard block size */
+ Size headerSize; /* allocated size of context header */
GenerationBlock *block; /* current (most recently allocated) block */
dlist_head blocks; /* list of blocks */
*************** struct GenerationChunk
*** 149,155 ****
static void *GenerationAlloc(MemoryContext context, Size size);
static void GenerationFree(MemoryContext context, void *pointer);
static void *GenerationRealloc(MemoryContext context, void *pointer, Size size);
- static void GenerationInit(MemoryContext context);
static void GenerationReset(MemoryContext context);
static void GenerationDelete(MemoryContext context);
static Size GenerationGetChunkSpace(MemoryContext context, void *pointer);
--- 150,155 ----
*************** static void GenerationCheck(MemoryContex
*** 164,174 ****
/*
* This is the virtual function table for Generation contexts.
*/
! static MemoryContextMethods GenerationMethods = {
GenerationAlloc,
GenerationFree,
GenerationRealloc,
- GenerationInit,
GenerationReset,
GenerationDelete,
GenerationGetChunkSpace,
--- 164,173 ----
/*
* This is the virtual function table for Generation contexts.
*/
! static const MemoryContextMethods GenerationMethods = {
GenerationAlloc,
GenerationFree,
GenerationRealloc,
GenerationReset,
GenerationDelete,
GenerationGetChunkSpace,
*************** static MemoryContextMethods GenerationMe
*** 208,215 ****
--- 207,216 ----
MemoryContext
GenerationContextCreate(MemoryContext parent,
const char *name,
+ int flags,
Size blockSize)
{
+ Size headerSize;
GenerationContext *set;
/* Assert we padded GenerationChunk properly */
*************** GenerationContextCreate(MemoryContext pa
*** 231,259 ****
elog(ERROR, "invalid blockSize for memory context: %zu",
blockSize);
! /* Do the type-independent part of context creation */
! set = (GenerationContext *) MemoryContextCreate(T_GenerationContext,
! sizeof(GenerationContext),
! &GenerationMethods,
! parent,
! name);
! set->blockSize = blockSize;
! return (MemoryContext) set;
! }
! /*
! * GenerationInit
! * Context-type-specific initialization routine.
! */
! static void
! GenerationInit(MemoryContext context)
! {
! GenerationContext *set = (GenerationContext *) context;
set->block = NULL;
dlist_init(&set->blocks);
}
/*
--- 232,282 ----
elog(ERROR, "invalid blockSize for memory context: %zu",
blockSize);
! /*
! * Allocate the context header. Unlike aset.c, we never try to combine
! * this with the first regular block, since that would prevent us from
! * freeing the first generation of allocations.
! */
! /* Size of the memory context header, including name storage if needed */
! if (flags & MEMCONTEXT_COPY_NAME)
! headerSize = MAXALIGN(sizeof(GenerationContext) + strlen(name) + 1);
! else
! headerSize = MAXALIGN(sizeof(GenerationContext));
! set = (GenerationContext *) malloc(headerSize);
! if (set == NULL)
! {
! MemoryContextStats(TopMemoryContext);
! ereport(ERROR,
! (errcode(ERRCODE_OUT_OF_MEMORY),
! errmsg("out of memory"),
! errdetail("Failed while creating memory context \"%s\".",
! name)));
! }
! /*
! * Avoid writing code that can fail between here and MemoryContextCreate;
! * we'd leak the header if we ereport in this stretch.
! */
+ /* Fill in GenerationContext-specific header fields */
+ set->blockSize = blockSize;
+ set->headerSize = headerSize;
set->block = NULL;
dlist_init(&set->blocks);
+
+ /* Finally, do the type-independent part of context creation */
+ MemoryContextCreate((MemoryContext) set,
+ T_GenerationContext,
+ headerSize,
+ sizeof(GenerationContext),
+ &GenerationMethods,
+ parent,
+ name,
+ flags);
+
+ return (MemoryContext) set;
}
/*
*************** GenerationReset(MemoryContext context)
*** 296,311 ****
/*
* GenerationDelete
! * Frees all memory which is allocated in the given set, in preparation
! * for deletion of the set. We simply call GenerationReset() which does
! * all the dirty work.
*/
static void
GenerationDelete(MemoryContext context)
{
! /* just reset to release all the GenerationBlocks */
GenerationReset(context);
! /* we are not responsible for deleting the context node itself */
}
/*
--- 319,333 ----
/*
* GenerationDelete
! * Free all memory which is allocated in the given context.
*/
static void
GenerationDelete(MemoryContext context)
{
! /* Reset to release all the GenerationBlocks */
GenerationReset(context);
! /* And free the context header */
! free(context);
}
/*
*************** GenerationIsEmpty(MemoryContext context)
*** 659,665 ****
/*
* GenerationStats
! * Compute stats about memory consumption of an Generation.
*
* level: recursion level (0 at top level); used for print indentation.
* print: true to print stats to stderr.
--- 681,687 ----
/*
* GenerationStats
! * Compute stats about memory consumption of a Generation context.
*
* level: recursion level (0 at top level); used for print indentation.
* print: true to print stats to stderr.
*************** GenerationStats(MemoryContext context, i
*** 676,685 ****
Size nblocks = 0;
Size nchunks = 0;
Size nfreechunks = 0;
! Size totalspace = 0;
Size freespace = 0;
dlist_iter iter;
dlist_foreach(iter, &set->blocks)
{
GenerationBlock *block = dlist_container(GenerationBlock, node, iter.cur);
--- 698,710 ----
Size nblocks = 0;
Size nchunks = 0;
Size nfreechunks = 0;
! Size totalspace;
Size freespace = 0;
dlist_iter iter;
+ /* Include context header in totalspace */
+ totalspace = set->headerSize;
+
dlist_foreach(iter, &set->blocks)
{
GenerationBlock *block = dlist_container(GenerationBlock, node, iter.cur);
*************** static void
*** 727,733 ****
GenerationCheck(MemoryContext context)
{
GenerationContext *gen = (GenerationContext *) context;
! char *name = context->name;
dlist_iter iter;
/* walk all blocks in this context */
--- 752,758 ----
GenerationCheck(MemoryContext context)
{
GenerationContext *gen = (GenerationContext *) context;
! const char *name = context->name;
dlist_iter iter;
/* walk all blocks in this context */
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index c5c311f..97382a6 100644
*** a/src/backend/utils/mmgr/mcxt.c
--- b/src/backend/utils/mmgr/mcxt.c
*************** MemoryContextInit(void)
*** 91,99 ****
AssertState(TopMemoryContext == NULL);
/*
! * First, initialize TopMemoryContext, which will hold the MemoryContext
! * nodes for all other contexts. (There is special-case code in
! * MemoryContextCreate() to handle this call.)
*/
TopMemoryContext = AllocSetContextCreate((MemoryContext) NULL,
"TopMemoryContext",
--- 91,97 ----
AssertState(TopMemoryContext == NULL);
/*
! * First, initialize TopMemoryContext, which is the parent of all others.
*/
TopMemoryContext = AllocSetContextCreate((MemoryContext) NULL,
"TopMemoryContext",
*************** MemoryContextInit(void)
*** 118,128 ****
* This should be the last step in this function, as elog.c assumes memory
* management works once ErrorContext is non-null.
*/
! ErrorContext = AllocSetContextCreate(TopMemoryContext,
! "ErrorContext",
! 8 * 1024,
! 8 * 1024,
! 8 * 1024);
MemoryContextAllowInCriticalSection(ErrorContext, true);
}
--- 116,127 ----
* This should be the last step in this function, as elog.c assumes memory
* management works once ErrorContext is non-null.
*/
! ErrorContext = AllocSetContextCreateExtended(TopMemoryContext,
! "ErrorContext",
! 0,
! 8 * 1024,
! 8 * 1024,
! 8 * 1024);
MemoryContextAllowInCriticalSection(ErrorContext, true);
}
*************** MemoryContextResetChildren(MemoryContext
*** 191,200 ****
* Delete a context and its descendants, and release all space
* allocated therein.
*
! * The type-specific delete routine removes all subsidiary storage
! * for the context, but we have to delete the context node itself,
! * as well as recurse to get the children. We must also delink the
! * node from its parent, if it has one.
*/
void
MemoryContextDelete(MemoryContext context)
--- 190,198 ----
* Delete a context and its descendants, and release all space
* allocated therein.
*
! * The type-specific delete routine removes all storage for the context,
! * but we have to recurse to handle the children.
! * We must also delink the context from its parent, if it has one.
*/
void
MemoryContextDelete(MemoryContext context)
*************** MemoryContextDelete(MemoryContext contex
*** 205,211 ****
/* And not CurrentMemoryContext, either */
Assert(context != CurrentMemoryContext);
! MemoryContextDeleteChildren(context);
/*
* It's not entirely clear whether 'tis better to do this before or after
--- 203,211 ----
/* And not CurrentMemoryContext, either */
Assert(context != CurrentMemoryContext);
! /* save a function call in common case where there are no children */
! if (context->firstchild != NULL)
! MemoryContextDeleteChildren(context);
/*
* It's not entirely clear whether 'tis better to do this before or after
*************** MemoryContextDelete(MemoryContext contex
*** 223,230 ****
MemoryContextSetParent(context, NULL);
context->methods->delete_context(context);
VALGRIND_DESTROY_MEMPOOL(context);
- pfree(context);
}
/*
--- 223,230 ----
MemoryContextSetParent(context, NULL);
context->methods->delete_context(context);
+
VALGRIND_DESTROY_MEMPOOL(context);
}
/*
*************** MemoryContextContains(MemoryContext cont
*** 587,686 ****
return ptr_context == context;
}
! /*--------------------
* MemoryContextCreate
* Context-type-independent part of context creation.
*
* This is only intended to be called by context-type-specific
* context creation routines, not by the unwashed masses.
*
! * The context creation procedure is a little bit tricky because
! * we want to be sure that we don't leave the context tree invalid
! * in case of failure (such as insufficient memory to allocate the
! * context node itself). The procedure goes like this:
! * 1. Context-type-specific routine first calls MemoryContextCreate(),
! * passing the appropriate tag/size/methods values (the methods
! * pointer will ordinarily point to statically allocated data).
! * The parent and name parameters usually come from the caller.
! * 2. MemoryContextCreate() attempts to allocate the context node,
! * plus space for the name. If this fails we can ereport() with no
! * damage done.
! * 3. We fill in all of the type-independent MemoryContext fields.
! * 4. We call the type-specific init routine (using the methods pointer).
! * The init routine is required to make the node minimally valid
! * with zero chance of failure --- it can't allocate more memory,
! * for example.
! * 5. Now we have a minimally valid node that can behave correctly
! * when told to reset or delete itself. We link the node to its
! * parent (if any), making the node part of the context tree.
! * 6. We return to the context-type-specific routine, which finishes
* up type-specific initialization. This routine can now do things
* that might fail (like allocate more memory), so long as it's
* sure the node is left in a state that delete will handle.
*
! * This protocol doesn't prevent us from leaking memory if step 6 fails
! * during creation of a top-level context, since there's no parent link
! * in that case. However, if you run out of memory while you're building
! * a top-level context, you might as well go home anyway...
! *
! * Normally, the context node and the name are allocated from
! * TopMemoryContext (NOT from the parent context, since the node must
! * survive resets of its parent context!). However, this routine is itself
! * used to create TopMemoryContext! If we see that TopMemoryContext is NULL,
! * we assume we are creating TopMemoryContext and use malloc() to allocate
! * the node.
*
! * Note that the name field of a MemoryContext does not point to
! * separately-allocated storage, so it should not be freed at context
! * deletion.
! *--------------------
*/
! MemoryContext
! MemoryContextCreate(NodeTag tag, Size size,
! MemoryContextMethods *methods,
MemoryContext parent,
! const char *name)
{
! MemoryContext node;
! Size needed = size + strlen(name) + 1;
!
! /* creating new memory contexts is not allowed in a critical section */
Assert(CritSectionCount == 0);
! /* Get space for node and name */
! if (TopMemoryContext != NULL)
! {
! /* Normal case: allocate the node in TopMemoryContext */
! node = (MemoryContext) MemoryContextAlloc(TopMemoryContext,
! needed);
! }
! else
! {
! /* Special case for startup: use good ol' malloc */
! node = (MemoryContext) malloc(needed);
! Assert(node != NULL);
! }
! /* Initialize the node as best we can */
! MemSet(node, 0, size);
node->type = tag;
node->methods = methods;
! node->parent = NULL; /* for the moment */
node->firstchild = NULL;
node->prevchild = NULL;
! node->nextchild = NULL;
! node->isReset = true;
! node->name = ((char *) node) + size;
! strcpy(node->name, name);
! /* Type-specific routine finishes any other essential initialization */
! node->methods->init(node);
! /* OK to link node to parent (if any) */
! /* Could use MemoryContextSetParent here, but doesn't seem worthwhile */
if (parent)
{
- node->parent = parent;
node->nextchild = parent->firstchild;
if (parent->firstchild != NULL)
parent->firstchild->prevchild = node;
--- 587,671 ----
return ptr_context == context;
}
! /*
* MemoryContextCreate
* Context-type-independent part of context creation.
*
* This is only intended to be called by context-type-specific
* context creation routines, not by the unwashed masses.
*
! * The memory context creation procedure goes like this:
! * 1. Context-type-specific routine makes some initial space allocation,
! * including enough space for the context header. If it fails,
! * it can ereport() with no damage done.
! * 2. Context-type-specific routine sets up all type-specific fields of
! * the header (those beyond MemoryContextData proper), as well as any
! * other management fields it needs to have a fully valid context.
! * Usually, failure in this step is impossible, but if it's possible
! * the initial space allocation should be freed before ereport'ing.
! * 3. Context-type-specific routine calls MemoryContextCreate() to fill in
! * the generic header fields and link the context into the context tree.
! * 4. We return to the context-type-specific routine, which finishes
* up type-specific initialization. This routine can now do things
* that might fail (like allocate more memory), so long as it's
* sure the node is left in a state that delete will handle.
*
! * node: the as-yet-uninitialized common part of the context header node.
! * tag: NodeTag code identifying the memory context type.
! * size: total size of context header including context-type-specific fields,
! * as well as space for the context name if MEMCONTEXT_COPY_NAME is set.
! * nameoffset: where within the "size" space to insert the context name.
! * methods: context-type-specific methods (usually statically allocated).
! * parent: parent context, or NULL if this will be a top-level context.
! * name: name of context (for debugging only, need not be unique).
! * flags: bitmask of MEMCONTEXT_XXX option flags.
*
! * Context routines generally assume that MemoryContextCreate can't fail,
! * so this can contain Assert but not elog/ereport.
*/
! void
! MemoryContextCreate(MemoryContext node,
! NodeTag tag, Size size, Size nameoffset,
! const MemoryContextMethods *methods,
MemoryContext parent,
! const char *name,
! int flags)
{
! /* Creating new memory contexts is not allowed in a critical section */
Assert(CritSectionCount == 0);
! /* Check size is sane */
! Assert(nameoffset >= sizeof(MemoryContextData));
! Assert((flags & MEMCONTEXT_COPY_NAME) ?
! size >= nameoffset + strlen(name) + 1 :
! size >= nameoffset);
! /* Initialize all standard fields of memory context header */
node->type = tag;
+ node->isReset = true;
node->methods = methods;
! node->parent = parent;
node->firstchild = NULL;
node->prevchild = NULL;
! node->reset_cbs = NULL;
! if (flags & MEMCONTEXT_COPY_NAME)
! {
! /* Insert context name into space reserved for it */
! char *namecopy = ((char *) node) + nameoffset;
! node->name = namecopy;
! strcpy(namecopy, name);
! }
! else
! {
! /* Assume the passed-in name is statically allocated */
! node->name = name;
! }
!
! /* OK to link node into context tree */
if (parent)
{
node->nextchild = parent->firstchild;
if (parent->firstchild != NULL)
parent->firstchild->prevchild = node;
*************** MemoryContextCreate(NodeTag tag, Size si
*** 688,698 ****
/* inherit allowInCritSection flag from parent */
node->allowInCritSection = parent->allowInCritSection;
}
VALGRIND_CREATE_MEMPOOL(node, 0, false);
-
- /* Return to type-specific creation routine to finish up */
- return node;
}
/*
--- 673,685 ----
/* inherit allowInCritSection flag from parent */
node->allowInCritSection = parent->allowInCritSection;
}
+ else
+ {
+ node->nextchild = NULL;
+ node->allowInCritSection = false;
+ }
VALGRIND_CREATE_MEMPOOL(node, 0, false);
}
/*
diff --git a/src/backend/utils/mmgr/slab.c b/src/backend/utils/mmgr/slab.c
index ee21752..42c0882 100644
*** a/src/backend/utils/mmgr/slab.c
--- b/src/backend/utils/mmgr/slab.c
*************** typedef struct SlabContext
*** 67,72 ****
--- 67,73 ----
Size chunkSize; /* chunk size */
Size fullChunkSize; /* chunk size including header and alignment */
Size blockSize; /* block size */
+ Size headerSize; /* allocated size of context header */
int chunksPerBlock; /* number of chunks per block */
int minFreeChunks; /* min number of free chunks in any block */
int nblocks; /* number of blocks allocated */
*************** typedef struct SlabChunk
*** 126,132 ****
static void *SlabAlloc(MemoryContext context, Size size);
static void SlabFree(MemoryContext context, void *pointer);
static void *SlabRealloc(MemoryContext context, void *pointer, Size size);
- static void SlabInit(MemoryContext context);
static void SlabReset(MemoryContext context);
static void SlabDelete(MemoryContext context);
static Size SlabGetChunkSpace(MemoryContext context, void *pointer);
--- 127,132 ----
*************** static void SlabCheck(MemoryContext cont
*** 140,150 ****
/*
* This is the virtual function table for Slab contexts.
*/
! static MemoryContextMethods SlabMethods = {
SlabAlloc,
SlabFree,
SlabRealloc,
- SlabInit,
SlabReset,
SlabDelete,
SlabGetChunkSpace,
--- 140,149 ----
/*
* This is the virtual function table for Slab contexts.
*/
! static const MemoryContextMethods SlabMethods = {
SlabAlloc,
SlabFree,
SlabRealloc,
SlabReset,
SlabDelete,
SlabGetChunkSpace,
*************** static MemoryContextMethods SlabMethods
*** 177,200 ****
* Create a new Slab context.
*
* parent: parent context, or NULL if top-level context
! * name: name of context (for debugging --- string will be copied)
* blockSize: allocation block size
* chunkSize: allocation chunk size
*
* The chunkSize may not exceed:
* MAXALIGN_DOWN(SIZE_MAX) - MAXALIGN(sizeof(SlabBlock)) - SLAB_CHUNKHDRSZ
- *
*/
MemoryContext
SlabContextCreate(MemoryContext parent,
const char *name,
Size blockSize,
Size chunkSize)
{
int chunksPerBlock;
Size fullChunkSize;
Size freelistSize;
SlabContext *slab;
/* Assert we padded SlabChunk properly */
StaticAssertStmt(sizeof(SlabChunk) == MAXALIGN(sizeof(SlabChunk)),
--- 176,205 ----
* Create a new Slab context.
*
* parent: parent context, or NULL if top-level context
! * name: name of context (for debugging only, need not be unique)
! * flags: bitmask of MEMCONTEXT_XXX option flags
* blockSize: allocation block size
* chunkSize: allocation chunk size
*
+ * Notes: if flags & MEMCONTEXT_COPY_NAME, the name string will be copied into
+ * context-lifespan storage; otherwise, it had better be statically allocated.
* The chunkSize may not exceed:
* MAXALIGN_DOWN(SIZE_MAX) - MAXALIGN(sizeof(SlabBlock)) - SLAB_CHUNKHDRSZ
*/
MemoryContext
SlabContextCreate(MemoryContext parent,
const char *name,
+ int flags,
Size blockSize,
Size chunkSize)
{
int chunksPerBlock;
Size fullChunkSize;
Size freelistSize;
+ Size nameOffset;
+ Size headerSize;
SlabContext *slab;
+ int i;
/* Assert we padded SlabChunk properly */
StaticAssertStmt(sizeof(SlabChunk) == MAXALIGN(sizeof(SlabChunk)),
*************** SlabContextCreate(MemoryContext parent,
*** 227,265 ****
/* make sure the chunks actually fit on the block */
Assert((fullChunkSize * chunksPerBlock) + sizeof(SlabBlock) <= blockSize);
! /* Do the type-independent part of context creation */
! slab = (SlabContext *)
! MemoryContextCreate(T_SlabContext,
! (offsetof(SlabContext, freelist) + freelistSize),
! &SlabMethods,
! parent,
! name);
! slab->blockSize = blockSize;
slab->chunkSize = chunkSize;
slab->fullChunkSize = fullChunkSize;
slab->chunksPerBlock = chunksPerBlock;
- slab->nblocks = 0;
slab->minFreeChunks = 0;
!
! return (MemoryContext) slab;
! }
!
! /*
! * SlabInit
! * Context-type-specific initialization routine.
! */
! static void
! SlabInit(MemoryContext context)
! {
! int i;
! SlabContext *slab = castNode(SlabContext, context);
!
! Assert(slab);
/* initialize the freelist slots */
for (i = 0; i < (slab->chunksPerBlock + 1); i++)
dlist_init(&slab->freelist[i]);
}
/*
--- 232,289 ----
/* make sure the chunks actually fit on the block */
Assert((fullChunkSize * chunksPerBlock) + sizeof(SlabBlock) <= blockSize);
! /*
! * Allocate the context header. Unlike aset.c, we never try to combine
! * this with the first regular block; not worth the extra complication.
! */
! /* Size of the memory context header, including name storage if needed */
! nameOffset = offsetof(SlabContext, freelist) + freelistSize;
! if (flags & MEMCONTEXT_COPY_NAME)
! headerSize = nameOffset + strlen(name) + 1;
! else
! headerSize = nameOffset;
!
! slab = (SlabContext *) malloc(headerSize);
! if (slab == NULL)
! {
! MemoryContextStats(TopMemoryContext);
! ereport(ERROR,
! (errcode(ERRCODE_OUT_OF_MEMORY),
! errmsg("out of memory"),
! errdetail("Failed while creating memory context \"%s\".",
! name)));
! }
!
! /*
! * Avoid writing code that can fail between here and MemoryContextCreate;
! * we'd leak the header if we ereport in this stretch.
! */
!
! /* Fill in SlabContext-specific header fields */
slab->chunkSize = chunkSize;
slab->fullChunkSize = fullChunkSize;
+ slab->blockSize = blockSize;
+ slab->headerSize = headerSize;
slab->chunksPerBlock = chunksPerBlock;
slab->minFreeChunks = 0;
! slab->nblocks = 0;
/* initialize the freelist slots */
for (i = 0; i < (slab->chunksPerBlock + 1); i++)
dlist_init(&slab->freelist[i]);
+
+ /* Finally, do the type-independent part of context creation */
+ MemoryContextCreate((MemoryContext) slab,
+ T_SlabContext,
+ headerSize,
+ nameOffset,
+ &SlabMethods,
+ parent,
+ name,
+ flags);
+
+ return (MemoryContext) slab;
}
/*
*************** SlabReset(MemoryContext context)
*** 308,321 ****
/*
* SlabDelete
! * Frees all memory which is allocated in the given slab, in preparation
! * for deletion of the slab. We simply call SlabReset().
*/
static void
SlabDelete(MemoryContext context)
{
! /* just reset the context */
SlabReset(context);
}
/*
--- 332,346 ----
/*
* SlabDelete
! * Free all memory which is allocated in the given context.
*/
static void
SlabDelete(MemoryContext context)
{
! /* Reset to release all the SlabBlocks */
SlabReset(context);
+ /* And free the context header */
+ free(context);
}
/*
*************** SlabIsEmpty(MemoryContext context)
*** 613,619 ****
/*
* SlabStats
! * Compute stats about memory consumption of an Slab.
*
* level: recursion level (0 at top level); used for print indentation.
* print: true to print stats to stderr.
--- 638,644 ----
/*
* SlabStats
! * Compute stats about memory consumption of a Slab context.
*
* level: recursion level (0 at top level); used for print indentation.
* print: true to print stats to stderr.
*************** SlabStats(MemoryContext context, int lev
*** 626,636 ****
SlabContext *slab = castNode(SlabContext, context);
Size nblocks = 0;
Size freechunks = 0;
! Size totalspace = 0;
Size freespace = 0;
int i;
! Assert(slab);
for (i = 0; i <= slab->chunksPerBlock; i++)
{
--- 651,662 ----
SlabContext *slab = castNode(SlabContext, context);
Size nblocks = 0;
Size freechunks = 0;
! Size totalspace;
Size freespace = 0;
int i;
! /* Include context header in totalspace */
! totalspace = slab->headerSize;
for (i = 0; i <= slab->chunksPerBlock; i++)
{
*************** SlabCheck(MemoryContext context)
*** 682,688 ****
{
int i;
SlabContext *slab = castNode(SlabContext, context);
! char *name = slab->header.name;
char *freechunks;
Assert(slab);
--- 708,714 ----
{
int i;
SlabContext *slab = castNode(SlabContext, context);
! const char *name = slab->header.name;
char *freechunks;
Assert(slab);
diff --git a/src/include/nodes/memnodes.h b/src/include/nodes/memnodes.h
index e22d9fb..c7eb1e7 100644
*** a/src/include/nodes/memnodes.h
--- b/src/include/nodes/memnodes.h
*************** typedef struct MemoryContextMethods
*** 57,63 ****
/* call this free_p in case someone #define's free() */
void (*free_p) (MemoryContext context, void *pointer);
void *(*realloc) (MemoryContext context, void *pointer, Size size);
- void (*init) (MemoryContext context);
void (*reset) (MemoryContext context);
void (*delete_context) (MemoryContext context);
Size (*get_chunk_space) (MemoryContext context, void *pointer);
--- 57,62 ----
*************** typedef struct MemoryContextData
*** 76,87 ****
/* these two fields are placed here to minimize alignment wastage: */
bool isReset; /* T = no space alloced since last reset */
bool allowInCritSection; /* allow palloc in critical section */
! MemoryContextMethods *methods; /* virtual function table */
MemoryContext parent; /* NULL if no parent (toplevel context) */
MemoryContext firstchild; /* head of linked list of children */
MemoryContext prevchild; /* previous child of same parent */
MemoryContext nextchild; /* next child of same parent */
! char *name; /* context name (just for debugging) */
MemoryContextCallback *reset_cbs; /* list of reset/delete callbacks */
} MemoryContextData;
--- 75,86 ----
/* these two fields are placed here to minimize alignment wastage: */
bool isReset; /* T = no space alloced since last reset */
bool allowInCritSection; /* allow palloc in critical section */
! const MemoryContextMethods *methods; /* virtual function table */
MemoryContext parent; /* NULL if no parent (toplevel context) */
MemoryContext firstchild; /* head of linked list of children */
MemoryContext prevchild; /* previous child of same parent */
MemoryContext nextchild; /* next child of same parent */
! const char *name; /* context name (just for debugging) */
MemoryContextCallback *reset_cbs; /* list of reset/delete callbacks */
} MemoryContextData;
diff --git a/src/include/utils/memutils.h b/src/include/utils/memutils.h
index d177b0c..0799259 100644
*** a/src/include/utils/memutils.h
--- b/src/include/utils/memutils.h
*************** GetMemoryChunkContext(void *pointer)
*** 132,141 ****
* context creation. It's intended to be called from context-type-
* specific creation routines, and noplace else.
*/
! extern MemoryContext MemoryContextCreate(NodeTag tag, Size size,
! MemoryContextMethods *methods,
MemoryContext parent,
! const char *name);
/*
--- 132,143 ----
* context creation. It's intended to be called from context-type-
* specific creation routines, and noplace else.
*/
! extern void MemoryContextCreate(MemoryContext node,
! NodeTag tag, Size size, Size nameoffset,
! const MemoryContextMethods *methods,
MemoryContext parent,
! const char *name,
! int flags);
/*
*************** extern MemoryContext MemoryContextCreate
*** 143,166 ****
*/
/* aset.c */
! extern MemoryContext AllocSetContextCreate(MemoryContext parent,
! const char *name,
! Size minContextSize,
! Size initBlockSize,
! Size maxBlockSize);
/* slab.c */
extern MemoryContext SlabContextCreate(MemoryContext parent,
const char *name,
Size blockSize,
Size chunkSize);
/* generation.c */
extern MemoryContext GenerationContextCreate(MemoryContext parent,
const char *name,
Size blockSize);
/*
* Recommended default alloc parameters, suitable for "ordinary" contexts
* that might hold quite a lot of data.
*/
--- 145,195 ----
*/
/* aset.c */
! extern MemoryContext AllocSetContextCreateExtended(MemoryContext parent,
! const char *name,
! int flags,
! Size minContextSize,
! Size initBlockSize,
! Size maxBlockSize);
!
! /*
! * This backwards compatibility macro only works for constant context names,
! * and you must specify block sizes with one of the abstraction macros below.
! */
! #ifdef HAVE__BUILTIN_CONSTANT_P
! #define AllocSetContextCreate(parent, name, allocparams) \
! (StaticAssertExpr(__builtin_constant_p(name), \
! "Use AllocSetContextCreateExtended with MEMCONTEXT_COPY_NAME for non-constant context names"), \
! AllocSetContextCreateExtended(parent, name, 0, allocparams))
! #else
! #define AllocSetContextCreate(parent, name, allocparams) \
! AllocSetContextCreateExtended(parent, name, 0, allocparams)
! #endif
/* slab.c */
extern MemoryContext SlabContextCreate(MemoryContext parent,
const char *name,
+ int flags,
Size blockSize,
Size chunkSize);
/* generation.c */
extern MemoryContext GenerationContextCreate(MemoryContext parent,
const char *name,
+ int flags,
Size blockSize);
/*
+ * Flag option bits for FooContextCreate functions.
+ * In future, some of these might be relevant to only some context types.
+ *
+ * COPY_NAME: FooContextCreate's name argument is not a constant string
+ * OPTIMIZE_EMPTY: optimize for case that nothing gets allocated in context
+ */
+ #define MEMCONTEXT_COPY_NAME 0x0001 /* is passed name transient? */
+ #define MEMCONTEXT_OPTIMIZE_EMPTY 0x0002 /* expect context goes unused? */
+
+ /*
* Recommended default alloc parameters, suitable for "ordinary" contexts
* that might hold quite a lot of data.
*/
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 9f53132..41fd0ba 100644
*** a/src/pl/plperl/plperl.c
--- b/src/pl/plperl/plperl.c
*************** compile_plperl_function(Oid fn_oid, bool
*** 2777,2785 ****
/************************************************************
* Allocate a context that will hold all PG data for the procedure.
************************************************************/
! proc_cxt = AllocSetContextCreate(TopMemoryContext,
! NameStr(procStruct->proname),
! ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
--- 2777,2786 ----
/************************************************************
* Allocate a context that will hold all PG data for the procedure.
************************************************************/
! proc_cxt = AllocSetContextCreateExtended(TopMemoryContext,
! NameStr(procStruct->proname),
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
diff --git a/src/pl/plpython/plpy_procedure.c b/src/pl/plpython/plpy_procedure.c
index b7c24e3..990a33c 100644
*** a/src/pl/plpython/plpy_procedure.c
--- b/src/pl/plpython/plpy_procedure.c
*************** PLy_procedure_create(HeapTuple procTup,
*** 166,174 ****
}
/* Create long-lived context that all procedure info will live in */
! cxt = AllocSetContextCreate(TopMemoryContext,
! procName,
! ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
--- 166,175 ----
}
/* Create long-lived context that all procedure info will live in */
! cxt = AllocSetContextCreateExtended(TopMemoryContext,
! procName,
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
index e0792d9..8069784 100644
*** a/src/pl/tcl/pltcl.c
--- b/src/pl/tcl/pltcl.c
*************** compile_pltcl_function(Oid fn_oid, Oid t
*** 1471,1479 ****
* Allocate a context that will hold all PG data for the procedure.
* We use the internal proc name as the context name.
************************************************************/
! proc_cxt = AllocSetContextCreate(TopMemoryContext,
! internal_proname,
! ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
--- 1471,1480 ----
* Allocate a context that will hold all PG data for the procedure.
* We use the internal proc name as the context name.
************************************************************/
! proc_cxt = AllocSetContextCreateExtended(TopMemoryContext,
! internal_proname,
! MEMCONTEXT_COPY_NAME,
! ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
