Allow memory contexts to have both fixed and variable ident strings.

Originally, we treated memory context names as potentially variable in
all cases, and therefore always copied them into the context header.
Commit 9fa6f00b1 rethought this a little bit and invented a distinction
between fixed and variable names, skipping the copy step for the former.
But we can make things both simpler and more useful by instead allowing
there to be two parts to a context's identification, a fixed "name" and
an optional, variable "ident".  The name supplied in the context create
call is now required to be a compile-time-constant string in all cases,
as it is never copied but just pointed to.  The "ident" string, if
wanted, is supplied later.  This is needed because typically we want
the ident to be stored inside the context so that it's cleaned up
automatically on context deletion; that means it has to be copied into
the context before we can set the pointer.

The cost of this approach is basically just an additional pointer field
in struct MemoryContextData, which isn't much overhead, and is bought
back entirely in the AllocSet case by not needing a headerSize field
anymore, since we no longer have to cope with variable header length.
In addition, we can simplify the internal interfaces for memory context
creation still further, saving a few cycles there.  And it's no longer
true that a custom identifier disqualifies a context from participating
in aset.c's freelist scheme, so possibly there's some win on that end.

All the places that were using non-compile-time-constant context names
are adjusted to put the variable info into the "ident" instead.  This
allows more effective identification of those contexts in many cases;
for example, subsidary contexts of relcache entries are now identified
by both type (e.g. "index info") and relname, where before you got only
one or the other.  Contexts associated with PL function cache entries
are now identified more fully and uniformly, too.

I also arranged for plancache contexts to use the query source string
as their identifier.  This is basically free for CachedPlanSources, as
they contained a copy of that string already.  We pay an extra pstrdup
to do it for CachedPlans.  That could perhaps be avoided, but it would
make things more fragile (since the CachedPlanSource is sometimes
destroyed first).  I suspect future improvements in error reporting will
require CachedPlans to have a copy of that string anyway, so it's not
clear that it's worth moving mountains to avoid it now.

This also changes the APIs for context statistics routines so that the
context-specific routines no longer assume that output goes straight
to stderr, nor do they know all details of the output format.  This
is useful immediately to reduce code duplication, and it also allows
for external code to do something with stats output that's different
from printing to stderr.

The reason for pushing this now rather than waiting for v12 is that
it rethinks some of the API changes made by commit 9fa6f00b1.  Seems
better for extension authors to endure just one round of API changes
not two.

Discussion: https://postgr.es/m/CAB=Je-FdtmFZ9y9REHD7VsSrnCkiBhsA4mdsLKSPauwXtQBeNA@mail.gmail.com
This commit is contained in:
Tom Lane 2018-03-27 16:46:47 -04:00
parent c203d6cf81
commit 442accc3fe
20 changed files with 261 additions and 208 deletions

View File

@ -999,7 +999,6 @@ AtStart_Memory(void)
TransactionAbortContext =
AllocSetContextCreateExtended(TopMemoryContext,
"TransactionAbortContext",
0,
32 * 1024,
32 * 1024,
32 * 1024);

View File

@ -525,10 +525,11 @@ RelationBuildPartitionDesc(Relation rel)
}
/* Now build the actual relcache partition descriptor */
rel->rd_pdcxt = AllocSetContextCreateExtended(CacheMemoryContext,
RelationGetRelationName(rel),
MEMCONTEXT_COPY_NAME,
ALLOCSET_DEFAULT_SIZES);
rel->rd_pdcxt = AllocSetContextCreate(CacheMemoryContext,
"partition descriptor",
ALLOCSET_DEFAULT_SIZES);
MemoryContextCopySetIdentifier(rel->rd_pdcxt, RelationGetRelationName(rel));
oldcxt = MemoryContextSwitchTo(rel->rd_pdcxt);
result = (PartitionDescData *) palloc0(sizeof(PartitionDescData));

View File

@ -214,6 +214,9 @@ RelationBuildRowSecurity(Relation relation)
SysScanDesc sscan;
HeapTuple tuple;
MemoryContextCopySetIdentifier(rscxt,
RelationGetRelationName(relation));
rsdesc = MemoryContextAllocZero(rscxt, sizeof(RowSecurityDesc));
rsdesc->rscxt = rscxt;

View File

@ -612,7 +612,7 @@ init_sql_fcache(FmgrInfo *finfo, Oid collation, bool lazyEvalOK)
* must be a child of whatever context holds the FmgrInfo.
*/
fcontext = AllocSetContextCreate(finfo->fn_mcxt,
"SQL function data",
"SQL function",
ALLOCSET_DEFAULT_SIZES);
oldcontext = MemoryContextSwitchTo(fcontext);
@ -635,9 +635,11 @@ init_sql_fcache(FmgrInfo *finfo, Oid collation, bool lazyEvalOK)
procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
/*
* copy function name immediately for use by error reporting callback
* copy function name immediately for use by error reporting callback, and
* for use as memory context identifier
*/
fcache->fname = pstrdup(NameStr(procedureStruct->proname));
MemoryContextSetIdentifier(fcontext, fcache->fname);
/*
* get the result type from the procedure tuple, and check for polymorphic

View File

@ -243,19 +243,16 @@ ReorderBufferAllocate(void)
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);

View File

@ -74,7 +74,8 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
MemoryContext cxt;
MemoryContext oldcxt;
cxt = AllocSetContextCreate(CurrentMemoryContext, "stats ext",
cxt = AllocSetContextCreate(CurrentMemoryContext,
"BuildRelationExtStatistics",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);

View File

@ -180,6 +180,7 @@ CreateCachedPlan(RawStmt *raw_parse_tree,
plansource->magic = CACHEDPLANSOURCE_MAGIC;
plansource->raw_parse_tree = copyObject(raw_parse_tree);
plansource->query_string = pstrdup(query_string);
MemoryContextSetIdentifier(source_context, plansource->query_string);
plansource->commandTag = commandTag;
plansource->param_types = NULL;
plansource->num_params = 0;
@ -951,6 +952,7 @@ BuildCachedPlan(CachedPlanSource *plansource, List *qlist,
plan_context = AllocSetContextCreate(CurrentMemoryContext,
"CachedPlan",
ALLOCSET_START_SMALL_SIZES);
MemoryContextCopySetIdentifier(plan_context, plansource->query_string);
/*
* Copy plan into the new context.
@ -1346,6 +1348,7 @@ CopyCachedPlan(CachedPlanSource *plansource)
newsource->magic = CACHEDPLANSOURCE_MAGIC;
newsource->raw_parse_tree = copyObject(plansource->raw_parse_tree);
newsource->query_string = pstrdup(plansource->query_string);
MemoryContextSetIdentifier(source_context, newsource->query_string);
newsource->commandTag = plansource->commandTag;
if (plansource->num_params > 0)
{

View File

@ -675,11 +675,12 @@ RelationBuildRuleLock(Relation relation)
/*
* Make the private context. Assume it'll not contain much data.
*/
rulescxt = AllocSetContextCreateExtended(CacheMemoryContext,
RelationGetRelationName(relation),
MEMCONTEXT_COPY_NAME,
ALLOCSET_SMALL_SIZES);
rulescxt = AllocSetContextCreate(CacheMemoryContext,
"relation rules",
ALLOCSET_SMALL_SIZES);
relation->rd_rulescxt = rulescxt;
MemoryContextCopySetIdentifier(rulescxt,
RelationGetRelationName(relation));
/*
* allocate an array to hold the rewrite rules (the array is extended if
@ -852,10 +853,11 @@ RelationBuildPartitionKey(Relation relation)
if (!HeapTupleIsValid(tuple))
return;
partkeycxt = AllocSetContextCreateExtended(CurTransactionContext,
RelationGetRelationName(relation),
MEMCONTEXT_COPY_NAME,
ALLOCSET_SMALL_SIZES);
partkeycxt = AllocSetContextCreate(CurTransactionContext,
"partition key",
ALLOCSET_SMALL_SIZES);
MemoryContextCopySetIdentifier(partkeycxt,
RelationGetRelationName(relation));
key = (PartitionKey) MemoryContextAllocZero(partkeycxt,
sizeof(PartitionKeyData));
@ -1533,11 +1535,12 @@ RelationInitIndexAccessInfo(Relation relation)
* 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);
indexcxt = AllocSetContextCreate(CacheMemoryContext,
"index info",
ALLOCSET_SMALL_SIZES);
relation->rd_indexcxt = indexcxt;
MemoryContextCopySetIdentifier(indexcxt,
RelationGetRelationName(relation));
/*
* Now we can fetch the index AM's API struct
@ -5603,12 +5606,12 @@ load_relcache_init_file(bool shared)
* prepare index info context --- parameters should match
* RelationInitIndexAccessInfo
*/
indexcxt =
AllocSetContextCreateExtended(CacheMemoryContext,
RelationGetRelationName(rel),
MEMCONTEXT_COPY_NAME,
ALLOCSET_SMALL_SIZES);
indexcxt = AllocSetContextCreate(CacheMemoryContext,
"index info",
ALLOCSET_SMALL_SIZES);
rel->rd_indexcxt = indexcxt;
MemoryContextCopySetIdentifier(indexcxt,
RelationGetRelationName(rel));
/*
* Now we can fetch the index AM's API struct. (We can't store

View File

@ -294,16 +294,19 @@ lookup_ts_dictionary_cache(Oid dictId)
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);
saveCtx = AllocSetContextCreate(CacheMemoryContext,
"TS dictionary",
ALLOCSET_SMALL_SIZES);
MemoryContextCopySetIdentifier(saveCtx, NameStr(dict->dictname));
}
else
{
/* Clear the existing entry's private context */
saveCtx = entry->dictCtx;
MemoryContextResetAndDeleteChildren(saveCtx);
/* Don't let context's ident pointer dangle while we reset it */
MemoryContextSetIdentifier(saveCtx, NULL);
MemoryContextReset(saveCtx);
MemoryContextCopySetIdentifier(saveCtx, NameStr(dict->dictname));
}
MemSet(entry, 0, sizeof(TSDictionaryCacheEntry));

View File

@ -340,11 +340,9 @@ hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
CurrentDynaHashCxt = info->hcxt;
else
CurrentDynaHashCxt = TopMemoryContext;
CurrentDynaHashCxt =
AllocSetContextCreateExtended(CurrentDynaHashCxt,
tabname,
MEMCONTEXT_COPY_NAME,
ALLOCSET_DEFAULT_SIZES);
CurrentDynaHashCxt = AllocSetContextCreate(CurrentDynaHashCxt,
"dynahash",
ALLOCSET_DEFAULT_SIZES);
}
/* Initialize the hash header, plus a copy of the table name */
@ -354,6 +352,10 @@ hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
hashp->tabname = (char *) (hashp + 1);
strcpy(hashp->tabname, tabname);
/* If we have a private context, label it with hashtable's name */
if (!(flags & HASH_SHARED_MEM))
MemoryContextSetIdentifier(CurrentDynaHashCxt, hashp->tabname);
/*
* Select the appropriate hash function (see comments at head of file).
*/

View File

@ -130,7 +130,6 @@ typedef struct AllocSetContext
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; /* keep this block over resets */
/* freelist this context could be put in, or -1 if not a candidate: */
@ -228,10 +227,7 @@ typedef struct AllocChunkData
* only its initial malloc chunk and no others. To be a candidate for a
* freelist, a context must have the same minContextSize/initBlockSize as
* other contexts in the list; but its maxBlockSize is irrelevant since that
* doesn't affect the size of the initial chunk. Also, candidate contexts
* *must not* use MEMCONTEXT_COPY_NAME since that would make their header size
* variable. (We currently insist that all flags be zero, since other flags
* would likely make the contexts less interchangeable, too.)
* doesn't affect the size of the initial chunk.
*
* We currently provide one freelist for ALLOCSET_DEFAULT_SIZES contexts
* and one for ALLOCSET_SMALL_SIZES contexts; the latter works for
@ -276,7 +272,8 @@ static void AllocSetReset(MemoryContext context);
static void AllocSetDelete(MemoryContext context);
static Size AllocSetGetChunkSpace(MemoryContext context, void *pointer);
static bool AllocSetIsEmpty(MemoryContext context);
static void AllocSetStats(MemoryContext context, int level, bool print,
static void AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals);
#ifdef MEMORY_CONTEXT_CHECKING
@ -378,14 +375,11 @@ AllocSetFreeIndex(Size size)
* 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
* name: name of context (must be statically allocated)
* minContextSize: minimum context size
* 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.)
@ -393,13 +387,11 @@ AllocSetFreeIndex(Size size)
MemoryContext
AllocSetContextCreateExtended(MemoryContext parent,
const char *name,
int flags,
Size minContextSize,
Size initBlockSize,
Size maxBlockSize)
{
int freeListIndex;
Size headerSize;
Size firstBlockSize;
AllocSet set;
AllocBlock block;
@ -431,12 +423,10 @@ AllocSetContextCreateExtended(MemoryContext parent,
* Check whether the parameters match either available freelist. We do
* not need to demand a match of maxBlockSize.
*/
if (flags == 0 &&
minContextSize == ALLOCSET_DEFAULT_MINSIZE &&
if (minContextSize == ALLOCSET_DEFAULT_MINSIZE &&
initBlockSize == ALLOCSET_DEFAULT_INITSIZE)
freeListIndex = 0;
else if (flags == 0 &&
minContextSize == ALLOCSET_SMALL_MINSIZE &&
else if (minContextSize == ALLOCSET_SMALL_MINSIZE &&
initBlockSize == ALLOCSET_SMALL_INITSIZE)
freeListIndex = 1;
else
@ -462,25 +452,17 @@ AllocSetContextCreateExtended(MemoryContext parent,
/* Reinitialize its header, installing correct name and parent */
MemoryContextCreate((MemoryContext) set,
T_AllocSetContext,
set->headerSize,
sizeof(AllocSetContext),
&AllocSetMethods,
parent,
name,
flags);
name);
return (MemoryContext) set;
}
}
/* 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));
/* Determine size of initial block */
firstBlockSize = headerSize + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
firstBlockSize = MAXALIGN(sizeof(AllocSetContext)) +
ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
if (minContextSize != 0)
firstBlockSize = Max(firstBlockSize, minContextSize);
else
@ -508,7 +490,7 @@ AllocSetContextCreateExtended(MemoryContext parent,
*/
/* Fill in the initial block's block header */
block = (AllocBlock) (((char *) set) + headerSize);
block = (AllocBlock) (((char *) set) + MAXALIGN(sizeof(AllocSetContext)));
block->aset = set;
block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
block->endptr = ((char *) set) + firstBlockSize;
@ -529,7 +511,6 @@ AllocSetContextCreateExtended(MemoryContext parent,
set->initBlockSize = initBlockSize;
set->maxBlockSize = maxBlockSize;
set->nextBlockSize = initBlockSize;
set->headerSize = headerSize;
set->freeListIndex = freeListIndex;
/*
@ -559,12 +540,9 @@ AllocSetContextCreateExtended(MemoryContext parent,
/* Finally, do the type-independent part of context creation */
MemoryContextCreate((MemoryContext) set,
T_AllocSetContext,
headerSize,
sizeof(AllocSetContext),
&AllocSetMethods,
parent,
name,
flags);
name);
return (MemoryContext) set;
}
@ -1327,12 +1305,13 @@ AllocSetIsEmpty(MemoryContext context)
* AllocSetStats
* Compute stats about memory consumption of an allocset.
*
* level: recursion level (0 at top level); used for print indentation.
* print: true to print stats to stderr.
* totals: if not NULL, add stats about this allocset into *totals.
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
*/
static void
AllocSetStats(MemoryContext context, int level, bool print,
AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals)
{
AllocSet set = (AllocSet) context;
@ -1344,7 +1323,7 @@ AllocSetStats(MemoryContext context, int level, bool print,
int fidx;
/* Include context header in totalspace */
totalspace = set->headerSize;
totalspace = MAXALIGN(sizeof(AllocSetContext));
for (block = set->blocks; block != NULL; block = block->next)
{
@ -1364,16 +1343,15 @@ AllocSetStats(MemoryContext context, int level, bool print,
}
}
if (print)
if (printfunc)
{
int i;
char stats_string[200];
for (i = 0; i < level; i++)
fprintf(stderr, " ");
fprintf(stderr,
"%s: %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
set->header.name, totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
snprintf(stats_string, sizeof(stats_string),
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
printfunc(context, passthru, stats_string);
}
if (totals)

View File

@ -61,7 +61,6 @@ typedef struct GenerationContext
/* 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 */
@ -154,7 +153,8 @@ static void GenerationReset(MemoryContext context);
static void GenerationDelete(MemoryContext context);
static Size GenerationGetChunkSpace(MemoryContext context, void *pointer);
static bool GenerationIsEmpty(MemoryContext context);
static void GenerationStats(MemoryContext context, int level, bool print,
static void GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals);
#ifdef MEMORY_CONTEXT_CHECKING
@ -203,14 +203,16 @@ static const MemoryContextMethods GenerationMethods = {
/*
* GenerationContextCreate
* Create a new Generation context.
*
* parent: parent context, or NULL if top-level context
* name: name of context (must be statically allocated)
* blockSize: generation block size
*/
MemoryContext
GenerationContextCreate(MemoryContext parent,
const char *name,
int flags,
Size blockSize)
{
Size headerSize;
GenerationContext *set;
/* Assert we padded GenerationChunk properly */
@ -238,13 +240,7 @@ GenerationContextCreate(MemoryContext parent,
* 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);
set = (GenerationContext *) malloc(MAXALIGN(sizeof(GenerationContext)));
if (set == NULL)
{
MemoryContextStats(TopMemoryContext);
@ -262,19 +258,15 @@ GenerationContextCreate(MemoryContext parent,
/* 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);
name);
return (MemoryContext) set;
}
@ -683,15 +675,16 @@ GenerationIsEmpty(MemoryContext context)
* 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.
* totals: if not NULL, add stats about this Generation into *totals.
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
*
* XXX freespace only accounts for empty space at the end of the block, not
* space of freed chunks (which is unknown).
*/
static void
GenerationStats(MemoryContext context, int level, bool print,
GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals)
{
GenerationContext *set = (GenerationContext *) context;
@ -703,7 +696,7 @@ GenerationStats(MemoryContext context, int level, bool print,
dlist_iter iter;
/* Include context header in totalspace */
totalspace = set->headerSize;
totalspace = MAXALIGN(sizeof(GenerationContext));
dlist_foreach(iter, &set->blocks)
{
@ -716,16 +709,15 @@ GenerationStats(MemoryContext context, int level, bool print,
freespace += (block->endptr - block->freeptr);
}
if (print)
if (printfunc)
{
int i;
char stats_string[200];
for (i = 0; i < level; i++)
fprintf(stderr, " ");
fprintf(stderr,
"Generation: %s: %zu total in %zd blocks (%zd chunks); %zu free (%zd chunks); %zu used\n",
((MemoryContext) set)->name, totalspace, nblocks, nchunks, freespace,
nfreechunks, totalspace - freespace);
snprintf(stats_string, sizeof(stats_string),
"%zu total in %zd blocks (%zd chunks); %zu free (%zd chunks); %zu used",
totalspace, nblocks, nchunks, freespace,
nfreechunks, totalspace - freespace);
printfunc(context, passthru, stats_string);
}
if (totals)

View File

@ -21,6 +21,7 @@
#include "postgres.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "utils/memdebug.h"
#include "utils/memutils.h"
@ -55,6 +56,8 @@ static void MemoryContextCallResetCallbacks(MemoryContext context);
static void MemoryContextStatsInternal(MemoryContext context, int level,
bool print, int max_children,
MemoryContextCounters *totals);
static void MemoryContextStatsPrint(MemoryContext context, void *passthru,
const char *stats_string);
/*
* You should not do memory allocations within a critical section, because
@ -118,7 +121,6 @@ MemoryContextInit(void)
*/
ErrorContext = AllocSetContextCreateExtended(TopMemoryContext,
"ErrorContext",
0,
8 * 1024,
8 * 1024,
8 * 1024);
@ -158,6 +160,17 @@ MemoryContextResetOnly(MemoryContext context)
if (!context->isReset)
{
MemoryContextCallResetCallbacks(context);
/*
* If context->ident points into the context's memory, it will become
* a dangling pointer. We could prevent that by setting it to NULL
* here, but that would break valid coding patterns that keep the
* ident elsewhere, e.g. in a parent context. Another idea is to use
* MemoryContextContains(), but we don't require ident strings to be
* in separately-palloc'd chunks, so that risks false positives. So
* for now we assume the programmer got it right.
*/
context->methods->reset(context);
context->isReset = true;
VALGRIND_DESTROY_MEMPOOL(context);
@ -222,6 +235,13 @@ MemoryContextDelete(MemoryContext context)
*/
MemoryContextSetParent(context, NULL);
/*
* Also reset the context's ident pointer, in case it points into the
* context. This would only matter if someone tries to get stats on the
* (already unlinked) context, which is unlikely, but let's be safe.
*/
context->ident = NULL;
context->methods->delete_context(context);
VALGRIND_DESTROY_MEMPOOL(context);
@ -295,6 +315,23 @@ MemoryContextCallResetCallbacks(MemoryContext context)
}
}
/*
* MemoryContextSetIdentifier
* Set the identifier string for a memory context.
*
* An identifier can be provided to help distinguish among different contexts
* of the same kind in memory context stats dumps. The identifier string
* must live at least as long as the context it is for; typically it is
* allocated inside that context, so that it automatically goes away on
* context deletion. Pass id = NULL to forget any old identifier.
*/
void
MemoryContextSetIdentifier(MemoryContext context, const char *id)
{
AssertArg(MemoryContextIsValid(context));
context->ident = id;
}
/*
* MemoryContextSetParent
* Change a context to belong to a new parent (or no parent).
@ -480,7 +517,10 @@ MemoryContextStatsInternal(MemoryContext context, int level,
AssertArg(MemoryContextIsValid(context));
/* Examine the context itself */
context->methods->stats(context, level, print, totals);
context->methods->stats(context,
print ? MemoryContextStatsPrint : NULL,
(void *) &level,
totals);
/*
* Examine children. If there are more than max_children of them, we do
@ -531,6 +571,67 @@ MemoryContextStatsInternal(MemoryContext context, int level,
}
}
/*
* MemoryContextStatsPrint
* Print callback used by MemoryContextStatsInternal
*
* For now, the passthru pointer just points to "int level"; later we might
* make that more complicated.
*/
static void
MemoryContextStatsPrint(MemoryContext context, void *passthru,
const char *stats_string)
{
int level = *(int *) passthru;
const char *name = context->name;
const char *ident = context->ident;
int i;
/*
* It seems preferable to label dynahash contexts with just the hash table
* name. Those are already unique enough, so the "dynahash" part isn't
* very helpful, and this way is more consistent with pre-v11 practice.
*/
if (ident && strcmp(name, "dynahash") == 0)
{
name = ident;
ident = NULL;
}
for (i = 0; i < level; i++)
fprintf(stderr, " ");
fprintf(stderr, "%s: %s", name, stats_string);
if (ident)
{
/*
* Some contexts may have very long identifiers (e.g., SQL queries).
* Arbitrarily truncate at 100 bytes, but be careful not to break
* multibyte characters. Also, replace ASCII control characters, such
* as newlines, with spaces.
*/
int idlen = strlen(ident);
bool truncated = false;
if (idlen > 100)
{
idlen = pg_mbcliplen(ident, idlen, 100);
truncated = true;
}
fprintf(stderr, ": ");
while (idlen-- > 0)
{
unsigned char c = *ident++;
if (c < ' ')
c = ' ';
fputc(c, stderr);
}
if (truncated)
fprintf(stderr, "...");
}
fputc('\n', stderr);
}
/*
* MemoryContextCheck
* Check all chunks in the named context.
@ -612,34 +713,23 @@ MemoryContextContains(MemoryContext context, void *pointer)
*
* 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.
* name: name of context (must be statically allocated).
*
* 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,
NodeTag tag,
const MemoryContextMethods *methods,
MemoryContext parent,
const char *name,
int flags)
const char *name)
{
/* 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;
@ -647,22 +737,10 @@ MemoryContextCreate(MemoryContext node,
node->parent = parent;
node->firstchild = NULL;
node->prevchild = NULL;
node->name = name;
node->ident = 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)
{

View File

@ -131,7 +131,8 @@ static void SlabReset(MemoryContext context);
static void SlabDelete(MemoryContext context);
static Size SlabGetChunkSpace(MemoryContext context, void *pointer);
static bool SlabIsEmpty(MemoryContext context);
static void SlabStats(MemoryContext context, int level, bool print,
static void SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals);
#ifdef MEMORY_CONTEXT_CHECKING
static void SlabCheck(MemoryContext context);
@ -176,27 +177,22 @@ static const MemoryContextMethods SlabMethods = {
* 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
* name: name of context (must be statically allocated)
* 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;
@ -231,12 +227,8 @@ SlabContextCreate(MemoryContext parent,
* 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;
/* Size of the memory context header */
headerSize = offsetof(SlabContext, freelist) + freelistSize;
slab = (SlabContext *) malloc(headerSize);
if (slab == NULL)
@ -270,12 +262,9 @@ SlabContextCreate(MemoryContext parent,
/* Finally, do the type-independent part of context creation */
MemoryContextCreate((MemoryContext) slab,
T_SlabContext,
headerSize,
nameOffset,
&SlabMethods,
parent,
name,
flags);
name);
return (MemoryContext) slab;
}
@ -634,12 +623,13 @@ SlabIsEmpty(MemoryContext context)
* 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.
* totals: if not NULL, add stats about this Slab into *totals.
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
*/
static void
SlabStats(MemoryContext context, int level, bool print,
SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals)
{
SlabContext *slab = castNode(SlabContext, context);
@ -667,14 +657,15 @@ SlabStats(MemoryContext context, int level, bool print,
}
}
if (print)
if (printfunc)
{
for (i = 0; i < level; i++)
fprintf(stderr, " ");
fprintf(stderr,
"Slab: %s: %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
slab->header.name, totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
char stats_string[200];
snprintf(stats_string, sizeof(stats_string),
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
printfunc(context, passthru, stats_string);
}
if (totals)

View File

@ -39,18 +39,21 @@ typedef struct MemoryContextCounters
* A logical context in which memory allocations occur.
*
* MemoryContext itself is an abstract type that can have multiple
* implementations, though for now we have only AllocSetContext.
* implementations.
* The function pointers in MemoryContextMethods define one specific
* implementation of MemoryContext --- they are a virtual function table
* in C++ terms.
*
* Node types that are actual implementations of memory contexts must
* begin with the same fields as MemoryContext.
* begin with the same fields as MemoryContextData.
*
* Note: for largely historical reasons, typedef MemoryContext is a pointer
* to the context struct rather than the struct type itself.
*/
typedef void (*MemoryStatsPrintFunc) (MemoryContext context, void *passthru,
const char *stats_string);
typedef struct MemoryContextMethods
{
void *(*alloc) (MemoryContext context, Size size);
@ -61,7 +64,8 @@ typedef struct MemoryContextMethods
void (*delete_context) (MemoryContext context);
Size (*get_chunk_space) (MemoryContext context, void *pointer);
bool (*is_empty) (MemoryContext context);
void (*stats) (MemoryContext context, int level, bool print,
void (*stats) (MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals);
#ifdef MEMORY_CONTEXT_CHECKING
void (*check) (MemoryContext context);
@ -81,6 +85,7 @@ typedef struct MemoryContextData
MemoryContext prevchild; /* previous child of same parent */
MemoryContext nextchild; /* next child of same parent */
const char *name; /* context name (just for debugging) */
const char *ident; /* context ID if any (just for debugging) */
MemoryContextCallback *reset_cbs; /* list of reset/delete callbacks */
} MemoryContextData;

View File

@ -76,6 +76,7 @@ extern void MemoryContextDelete(MemoryContext context);
extern void MemoryContextResetOnly(MemoryContext context);
extern void MemoryContextResetChildren(MemoryContext context);
extern void MemoryContextDeleteChildren(MemoryContext context);
extern void MemoryContextSetIdentifier(MemoryContext context, const char *id);
extern void MemoryContextSetParent(MemoryContext context,
MemoryContext new_parent);
extern Size GetMemoryChunkSpace(void *pointer);
@ -91,6 +92,10 @@ extern void MemoryContextCheck(MemoryContext context);
#endif
extern bool MemoryContextContains(MemoryContext context, void *pointer);
/* Handy macro for copying and assigning context ID ... but note double eval */
#define MemoryContextCopySetIdentifier(cxt, id) \
MemoryContextSetIdentifier(cxt, MemoryContextStrdup(cxt, id))
/*
* GetMemoryChunkContext
* Given a currently-allocated chunk, determine the context
@ -133,11 +138,10 @@ GetMemoryChunkContext(void *pointer)
* specific creation routines, and noplace else.
*/
extern void MemoryContextCreate(MemoryContext node,
NodeTag tag, Size size, Size nameoffset,
NodeTag tag,
const MemoryContextMethods *methods,
MemoryContext parent,
const char *name,
int flags);
const char *name);
/*
@ -147,46 +151,37 @@ extern void MemoryContextCreate(MemoryContext node,
/* 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.
* This wrapper macro exists to check for non-constant strings used as context
* names; that's no longer supported. (Use MemoryContextSetIdentifier if you
* want to provide a variable identifier.) Note 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))
"memory context names must be constant strings"), \
AllocSetContextCreateExtended(parent, name, allocparams))
#else
#define AllocSetContextCreate(parent, name, allocparams) \
AllocSetContextCreateExtended(parent, name, 0, allocparams)
AllocSetContextCreateExtended(parent, name, 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
*/
#define MEMCONTEXT_COPY_NAME 0x0001 /* is passed name transient? */
/*
* Recommended default alloc parameters, suitable for "ordinary" contexts
* that might hold quite a lot of data.

View File

@ -2782,10 +2782,9 @@ compile_plperl_function(Oid fn_oid, bool is_trigger, bool is_event_trigger)
/************************************************************
* 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);
proc_cxt = AllocSetContextCreate(TopMemoryContext,
"PL/Perl function",
ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
@ -2794,6 +2793,7 @@ compile_plperl_function(Oid fn_oid, bool is_trigger, bool is_event_trigger)
oldcontext = MemoryContextSwitchTo(proc_cxt);
prodesc = (plperl_proc_desc *) palloc0(sizeof(plperl_proc_desc));
prodesc->proname = pstrdup(NameStr(procStruct->proname));
MemoryContextSetIdentifier(proc_cxt, prodesc->proname);
prodesc->fn_cxt = proc_cxt;
prodesc->fn_refcount = 0;
prodesc->fn_xmin = HeapTupleHeaderGetRawXmin(procTup->t_data);

View File

@ -342,11 +342,12 @@ do_compile(FunctionCallInfo fcinfo,
* per-function memory context, so it can be reclaimed easily.
*/
func_cxt = AllocSetContextCreate(TopMemoryContext,
"PL/pgSQL function context",
"PL/pgSQL function",
ALLOCSET_DEFAULT_SIZES);
plpgsql_compile_tmp_cxt = MemoryContextSwitchTo(func_cxt);
function->fn_signature = format_procedure(fcinfo->flinfo->fn_oid);
MemoryContextSetIdentifier(func_cxt, function->fn_signature);
function->fn_oid = fcinfo->flinfo->fn_oid;
function->fn_xmin = HeapTupleHeaderGetRawXmin(procTup->t_data);
function->fn_tid = procTup->t_self;
@ -2453,7 +2454,7 @@ plpgsql_HashTableInit(void)
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(PLpgSQL_func_hashkey);
ctl.entrysize = sizeof(plpgsql_HashEnt);
plpgsql_HashTable = hash_create("PLpgSQL function cache",
plpgsql_HashTable = hash_create("PLpgSQL function hash",
FUNCS_PER_USER,
&ctl,
HASH_ELEM | HASH_BLOBS);

View File

@ -164,10 +164,9 @@ PLy_procedure_create(HeapTuple procTup, Oid fn_oid, bool is_trigger)
}
/* Create long-lived context that all procedure info will live in */
cxt = AllocSetContextCreateExtended(TopMemoryContext,
procName,
MEMCONTEXT_COPY_NAME,
ALLOCSET_DEFAULT_SIZES);
cxt = AllocSetContextCreate(TopMemoryContext,
"PL/Python function",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
@ -183,6 +182,7 @@ PLy_procedure_create(HeapTuple procTup, Oid fn_oid, bool is_trigger)
int i;
proc->proname = pstrdup(NameStr(procStruct->proname));
MemoryContextSetIdentifier(cxt, proc->proname);
proc->pyname = pstrdup(procName);
proc->fn_xmin = HeapTupleHeaderGetRawXmin(procTup->t_data);
proc->fn_tid = procTup->t_self;

View File

@ -1479,12 +1479,10 @@ compile_pltcl_function(Oid fn_oid, Oid tgreloid,
/************************************************************
* 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);
proc_cxt = AllocSetContextCreate(TopMemoryContext,
"PL/Tcl function",
ALLOCSET_SMALL_SIZES);
/************************************************************
* Allocate and fill a new procedure description block.
@ -1493,6 +1491,7 @@ compile_pltcl_function(Oid fn_oid, Oid tgreloid,
oldcontext = MemoryContextSwitchTo(proc_cxt);
prodesc = (pltcl_proc_desc *) palloc0(sizeof(pltcl_proc_desc));
prodesc->user_proname = pstrdup(NameStr(procStruct->proname));
MemoryContextSetIdentifier(proc_cxt, prodesc->user_proname);
prodesc->internal_proname = pstrdup(internal_proname);
prodesc->fn_cxt = proc_cxt;
prodesc->fn_refcount = 0;