PostgreSQL Source Code  git master
aset.c File Reference
#include "postgres.h"
#include "utils/memdebug.h"
#include "utils/memutils.h"
Include dependency graph for aset.c:

Go to the source code of this file.

Data Structures

struct  AllocSetContext
 
struct  AllocBlockData
 
struct  AllocChunkData
 
struct  AllocSetFreeList
 

Macros

#define ALLOC_MINBITS   3 /* smallest chunk size is 8 bytes */
 
#define ALLOCSET_NUM_FREELISTS   11
 
#define ALLOC_CHUNK_LIMIT   (1 << (ALLOCSET_NUM_FREELISTS-1+ALLOC_MINBITS))
 
#define ALLOC_CHUNK_FRACTION   4
 
#define ALLOC_BLOCKHDRSZ   MAXALIGN(sizeof(AllocBlockData))
 
#define ALLOC_CHUNKHDRSZ   sizeof(struct AllocChunkData)
 
#define ALLOCCHUNK_RAWSIZE   (SIZEOF_SIZE_T + SIZEOF_VOID_P)
 
#define ALLOCCHUNK_PRIVATE_LEN   offsetof(AllocChunkData, aset)
 
#define AllocPointerIsValid(pointer)   PointerIsValid(pointer)
 
#define AllocSetIsValid(set)   PointerIsValid(set)
 
#define AllocPointerGetChunk(ptr)   ((AllocChunk)(((char *)(ptr)) - ALLOC_CHUNKHDRSZ))
 
#define AllocChunkGetPointer(chk)   ((AllocPointer)(((char *)(chk)) + ALLOC_CHUNKHDRSZ))
 
#define MAX_FREE_CONTEXTS   100 /* arbitrary limit on freelist length */
 
#define LT16(n)   n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n
 
#define AllocFreeInfo(_cxt, _chunk)
 
#define AllocAllocInfo(_cxt, _chunk)
 

Typedefs

typedef struct AllocBlockDataAllocBlock
 
typedef struct AllocChunkDataAllocChunk
 
typedef void * AllocPointer
 
typedef struct AllocSetContext AllocSetContext
 
typedef AllocSetContextAllocSet
 
typedef struct AllocBlockData AllocBlockData
 
typedef struct AllocChunkData AllocChunkData
 
typedef struct AllocSetFreeList AllocSetFreeList
 

Functions

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 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, MemoryStatsPrintFunc printfunc, void *passthru, MemoryContextCounters *totals)
 
static int AllocSetFreeIndex (Size size)
 
MemoryContext AllocSetContextCreateInternal (MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
 

Variables

static AllocSetFreeList context_freelists [2]
 
static const MemoryContextMethods AllocSetMethods
 
static const unsigned char LogTable256 [256]
 

Macro Definition Documentation

◆ ALLOC_BLOCKHDRSZ

#define ALLOC_BLOCKHDRSZ   MAXALIGN(sizeof(AllocBlockData))

◆ ALLOC_CHUNK_FRACTION

#define ALLOC_CHUNK_FRACTION   4

Definition at line 85 of file aset.c.

Referenced by AllocSetContextCreateInternal().

◆ ALLOC_CHUNK_LIMIT

#define ALLOC_CHUNK_LIMIT   (1 << (ALLOCSET_NUM_FREELISTS-1+ALLOC_MINBITS))

Definition at line 83 of file aset.c.

Referenced by AllocSetContextCreateInternal().

◆ ALLOC_CHUNKHDRSZ

#define ALLOC_CHUNKHDRSZ   sizeof(struct AllocChunkData)

◆ ALLOC_MINBITS

#define ALLOC_MINBITS   3 /* smallest chunk size is 8 bytes */

Definition at line 81 of file aset.c.

Referenced by AllocSetAlloc(), AllocSetFreeIndex(), and AllocSetStats().

◆ AllocAllocInfo

#define AllocAllocInfo (   _cxt,
  _chunk 
)

Definition at line 325 of file aset.c.

Referenced by AllocSetAlloc().

◆ ALLOCCHUNK_PRIVATE_LEN

#define ALLOCCHUNK_PRIVATE_LEN   offsetof(AllocChunkData, aset)

◆ ALLOCCHUNK_RAWSIZE

#define ALLOCCHUNK_RAWSIZE   (SIZEOF_SIZE_T + SIZEOF_VOID_P)

Definition at line 185 of file aset.c.

◆ AllocChunkGetPointer

#define AllocChunkGetPointer (   chk)    ((AllocPointer)(((char *)(chk)) + ALLOC_CHUNKHDRSZ))

Definition at line 220 of file aset.c.

Referenced by AllocSetAlloc(), and AllocSetRealloc().

◆ AllocFreeInfo

#define AllocFreeInfo (   _cxt,
  _chunk 
)

Definition at line 324 of file aset.c.

Referenced by AllocSetFree().

◆ AllocPointerGetChunk

#define AllocPointerGetChunk (   ptr)    ((AllocChunk)(((char *)(ptr)) - ALLOC_CHUNKHDRSZ))

Definition at line 218 of file aset.c.

Referenced by AllocSetFree(), AllocSetGetChunkSpace(), and AllocSetRealloc().

◆ AllocPointerIsValid

#define AllocPointerIsValid (   pointer)    PointerIsValid(pointer)

Definition at line 210 of file aset.c.

◆ ALLOCSET_NUM_FREELISTS

#define ALLOCSET_NUM_FREELISTS   11

Definition at line 82 of file aset.c.

Referenced by AllocSetFreeIndex(), and AllocSetStats().

◆ AllocSetIsValid

#define AllocSetIsValid (   set)    PointerIsValid(set)

Definition at line 216 of file aset.c.

Referenced by AllocSetAlloc(), AllocSetDelete(), and AllocSetReset().

◆ LT16

#define LT16 (   n)    n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n

Definition at line 303 of file aset.c.

◆ MAX_FREE_CONTEXTS

#define MAX_FREE_CONTEXTS   100 /* arbitrary limit on freelist length */

Definition at line 246 of file aset.c.

Referenced by AllocSetDelete().

Typedef Documentation

◆ AllocBlock

typedef struct AllocBlockData* AllocBlock

Definition at line 105 of file aset.c.

◆ AllocBlockData

◆ AllocChunk

typedef struct AllocChunkData* AllocChunk

Definition at line 106 of file aset.c.

◆ AllocChunkData

◆ AllocPointer

typedef void* AllocPointer

Definition at line 112 of file aset.c.

◆ AllocSet

Definition at line 139 of file aset.c.

◆ AllocSetContext

◆ AllocSetFreeList

Function Documentation

◆ AllocSetAlloc()

static void * AllocSetAlloc ( MemoryContext  context,
Size  size 
)
static

Definition at line 714 of file aset.c.

References ALLOC_BLOCKHDRSZ, ALLOC_CHUNKHDRSZ, ALLOC_MINBITS, AllocAllocInfo, ALLOCCHUNK_PRIVATE_LEN, AllocChunkGetPointer, AllocSetFreeIndex(), AllocSetIsValid, AllocBlockData::aset, AllocChunkData::aset, Assert, AssertArg, AllocBlockData::endptr, AllocBlockData::freeptr, malloc, MAXALIGN, AllocBlockData::next, AllocBlockData::prev, AllocChunkData::size, VALGRIND_MAKE_MEM_NOACCESS, and VALGRIND_MAKE_MEM_UNDEFINED.

Referenced by AllocSetRealloc().

715 {
716  AllocSet set = (AllocSet) context;
717  AllocBlock block;
718  AllocChunk chunk;
719  int fidx;
720  Size chunk_size;
721  Size blksize;
722 
724 
725  /*
726  * If requested size exceeds maximum for chunks, allocate an entire block
727  * for this request.
728  */
729  if (size > set->allocChunkLimit)
730  {
731  chunk_size = MAXALIGN(size);
732  blksize = chunk_size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
733  block = (AllocBlock) malloc(blksize);
734  if (block == NULL)
735  return NULL;
736  block->aset = set;
737  block->freeptr = block->endptr = ((char *) block) + blksize;
738 
739  chunk = (AllocChunk) (((char *) block) + ALLOC_BLOCKHDRSZ);
740  chunk->aset = set;
741  chunk->size = chunk_size;
742 #ifdef MEMORY_CONTEXT_CHECKING
743  chunk->requested_size = size;
744  /* set mark to catch clobber of "unused" space */
745  if (size < chunk_size)
746  set_sentinel(AllocChunkGetPointer(chunk), size);
747 #endif
748 #ifdef RANDOMIZE_ALLOCATED_MEMORY
749  /* fill the allocated space with junk */
750  randomize_mem((char *) AllocChunkGetPointer(chunk), size);
751 #endif
752 
753  /*
754  * Stick the new block underneath the active allocation block, if any,
755  * so that we don't lose the use of the space remaining therein.
756  */
757  if (set->blocks != NULL)
758  {
759  block->prev = set->blocks;
760  block->next = set->blocks->next;
761  if (block->next)
762  block->next->prev = block;
763  set->blocks->next = block;
764  }
765  else
766  {
767  block->prev = NULL;
768  block->next = NULL;
769  set->blocks = block;
770  }
771 
772  AllocAllocInfo(set, chunk);
773 
774  /* Ensure any padding bytes are marked NOACCESS. */
775  VALGRIND_MAKE_MEM_NOACCESS((char *) AllocChunkGetPointer(chunk) + size,
776  chunk_size - size);
777 
778  /* Disallow external access to private part of chunk header. */
780 
781  return AllocChunkGetPointer(chunk);
782  }
783 
784  /*
785  * Request is small enough to be treated as a chunk. Look in the
786  * corresponding free list to see if there is a free chunk we could reuse.
787  * If one is found, remove it from the free list, make it again a member
788  * of the alloc set and return its data address.
789  */
790  fidx = AllocSetFreeIndex(size);
791  chunk = set->freelist[fidx];
792  if (chunk != NULL)
793  {
794  Assert(chunk->size >= size);
795 
796  set->freelist[fidx] = (AllocChunk) chunk->aset;
797 
798  chunk->aset = (void *) set;
799 
800 #ifdef MEMORY_CONTEXT_CHECKING
801  chunk->requested_size = size;
802  /* set mark to catch clobber of "unused" space */
803  if (size < chunk->size)
804  set_sentinel(AllocChunkGetPointer(chunk), size);
805 #endif
806 #ifdef RANDOMIZE_ALLOCATED_MEMORY
807  /* fill the allocated space with junk */
808  randomize_mem((char *) AllocChunkGetPointer(chunk), size);
809 #endif
810 
811  AllocAllocInfo(set, chunk);
812 
813  /* Ensure any padding bytes are marked NOACCESS. */
814  VALGRIND_MAKE_MEM_NOACCESS((char *) AllocChunkGetPointer(chunk) + size,
815  chunk->size - size);
816 
817  /* Disallow external access to private part of chunk header. */
819 
820  return AllocChunkGetPointer(chunk);
821  }
822 
823  /*
824  * Choose the actual chunk size to allocate.
825  */
826  chunk_size = (1 << ALLOC_MINBITS) << fidx;
827  Assert(chunk_size >= size);
828 
829  /*
830  * If there is enough room in the active allocation block, we will put the
831  * chunk into that block. Else must start a new one.
832  */
833  if ((block = set->blocks) != NULL)
834  {
835  Size availspace = block->endptr - block->freeptr;
836 
837  if (availspace < (chunk_size + ALLOC_CHUNKHDRSZ))
838  {
839  /*
840  * The existing active (top) block does not have enough room for
841  * the requested allocation, but it might still have a useful
842  * amount of space in it. Once we push it down in the block list,
843  * we'll never try to allocate more space from it. So, before we
844  * do that, carve up its free space into chunks that we can put on
845  * the set's freelists.
846  *
847  * Because we can only get here when there's less than
848  * ALLOC_CHUNK_LIMIT left in the block, this loop cannot iterate
849  * more than ALLOCSET_NUM_FREELISTS-1 times.
850  */
851  while (availspace >= ((1 << ALLOC_MINBITS) + ALLOC_CHUNKHDRSZ))
852  {
853  Size availchunk = availspace - ALLOC_CHUNKHDRSZ;
854  int a_fidx = AllocSetFreeIndex(availchunk);
855 
856  /*
857  * In most cases, we'll get back the index of the next larger
858  * freelist than the one we need to put this chunk on. The
859  * exception is when availchunk is exactly a power of 2.
860  */
861  if (availchunk != ((Size) 1 << (a_fidx + ALLOC_MINBITS)))
862  {
863  a_fidx--;
864  Assert(a_fidx >= 0);
865  availchunk = ((Size) 1 << (a_fidx + ALLOC_MINBITS));
866  }
867 
868  chunk = (AllocChunk) (block->freeptr);
869 
870  /* Prepare to initialize the chunk header. */
871  VALGRIND_MAKE_MEM_UNDEFINED(chunk, ALLOC_CHUNKHDRSZ);
872 
873  block->freeptr += (availchunk + ALLOC_CHUNKHDRSZ);
874  availspace -= (availchunk + ALLOC_CHUNKHDRSZ);
875 
876  chunk->size = availchunk;
877 #ifdef MEMORY_CONTEXT_CHECKING
878  chunk->requested_size = 0; /* mark it free */
879 #endif
880  chunk->aset = (void *) set->freelist[a_fidx];
881  set->freelist[a_fidx] = chunk;
882  }
883 
884  /* Mark that we need to create a new block */
885  block = NULL;
886  }
887  }
888 
889  /*
890  * Time to create a new regular (multi-chunk) block?
891  */
892  if (block == NULL)
893  {
894  Size required_size;
895 
896  /*
897  * The first such block has size initBlockSize, and we double the
898  * space in each succeeding block, but not more than maxBlockSize.
899  */
900  blksize = set->nextBlockSize;
901  set->nextBlockSize <<= 1;
902  if (set->nextBlockSize > set->maxBlockSize)
903  set->nextBlockSize = set->maxBlockSize;
904 
905  /*
906  * If initBlockSize is less than ALLOC_CHUNK_LIMIT, we could need more
907  * space... but try to keep it a power of 2.
908  */
909  required_size = chunk_size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
910  while (blksize < required_size)
911  blksize <<= 1;
912 
913  /* Try to allocate it */
914  block = (AllocBlock) malloc(blksize);
915 
916  /*
917  * We could be asking for pretty big blocks here, so cope if malloc
918  * fails. But give up if there's less than 1 MB or so available...
919  */
920  while (block == NULL && blksize > 1024 * 1024)
921  {
922  blksize >>= 1;
923  if (blksize < required_size)
924  break;
925  block = (AllocBlock) malloc(blksize);
926  }
927 
928  if (block == NULL)
929  return NULL;
930 
931  block->aset = set;
932  block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
933  block->endptr = ((char *) block) + blksize;
934 
935  /* Mark unallocated space NOACCESS. */
937  blksize - ALLOC_BLOCKHDRSZ);
938 
939  block->prev = NULL;
940  block->next = set->blocks;
941  if (block->next)
942  block->next->prev = block;
943  set->blocks = block;
944  }
945 
946  /*
947  * OK, do the allocation
948  */
949  chunk = (AllocChunk) (block->freeptr);
950 
951  /* Prepare to initialize the chunk header. */
952  VALGRIND_MAKE_MEM_UNDEFINED(chunk, ALLOC_CHUNKHDRSZ);
953 
954  block->freeptr += (chunk_size + ALLOC_CHUNKHDRSZ);
955  Assert(block->freeptr <= block->endptr);
956 
957  chunk->aset = (void *) set;
958  chunk->size = chunk_size;
959 #ifdef MEMORY_CONTEXT_CHECKING
960  chunk->requested_size = size;
961  /* set mark to catch clobber of "unused" space */
962  if (size < chunk->size)
963  set_sentinel(AllocChunkGetPointer(chunk), size);
964 #endif
965 #ifdef RANDOMIZE_ALLOCATED_MEMORY
966  /* fill the allocated space with junk */
967  randomize_mem((char *) AllocChunkGetPointer(chunk), size);
968 #endif
969 
970  AllocAllocInfo(set, chunk);
971 
972  /* Ensure any padding bytes are marked NOACCESS. */
973  VALGRIND_MAKE_MEM_NOACCESS((char *) AllocChunkGetPointer(chunk) + size,
974  chunk_size - size);
975 
976  /* Disallow external access to private part of chunk header. */
978 
979  return AllocChunkGetPointer(chunk);
980 }
#define AllocSetIsValid(set)
Definition: aset.c:216
#define VALGRIND_MAKE_MEM_UNDEFINED(addr, size)
Definition: memdebug.h:28
#define VALGRIND_MAKE_MEM_NOACCESS(addr, size)
Definition: memdebug.h:27
static int AllocSetFreeIndex(Size size)
Definition: aset.c:337
#define AllocChunkGetPointer(chk)
Definition: aset.c:220
#define ALLOCCHUNK_PRIVATE_LEN
Definition: aset.c:204
#define ALLOC_BLOCKHDRSZ
Definition: aset.c:102
AllocSet aset
Definition: aset.c:155
char * freeptr
Definition: aset.c:158
#define malloc(a)
Definition: header.h:50
char * endptr
Definition: aset.c:159
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
AllocBlock next
Definition: aset.c:157
#define AssertArg(condition)
Definition: c.h:734
struct AllocBlockData * AllocBlock
Definition: aset.c:105
AllocBlock prev
Definition: aset.c:156
struct AllocChunkData * AllocChunk
Definition: aset.c:106
#define Assert(condition)
Definition: c.h:732
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:685
void * aset
Definition: aset.c:194
AllocSetContext * AllocSet
Definition: aset.c:139
#define ALLOC_MINBITS
Definition: aset.c:81
#define AllocAllocInfo(_cxt, _chunk)
Definition: aset.c:325
Size size
Definition: aset.c:177

◆ AllocSetContextCreateInternal()

MemoryContext AllocSetContextCreateInternal ( MemoryContext  parent,
const char *  name,
Size  minContextSize,
Size  initBlockSize,
Size  maxBlockSize 
)

Definition at line 390 of file aset.c.

References ALLOC_BLOCKHDRSZ, ALLOC_CHUNK_FRACTION, ALLOC_CHUNK_LIMIT, ALLOC_CHUNKHDRSZ, AllocHugeSizeIsValid, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MINSIZE, ALLOCSET_SEPARATE_THRESHOLD, ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MINSIZE, AllocSetMethods, AllocBlockData::aset, Assert, AllocBlockData::endptr, ereport, errcode(), errdetail(), errmsg(), ERROR, AllocSetFreeList::first_free, AllocSetContext::freelist, AllocSetContext::freeListIndex, AllocBlockData::freeptr, AllocSetContext::header, AllocSetContext::initBlockSize, malloc, Max, MAXALIGN, AllocSetContext::maxBlockSize, MemoryContextCreate(), MemoryContextStats(), MemSetAligned, name, AllocBlockData::next, MemoryContextData::nextchild, AllocSetFreeList::num_free, offsetof, AllocBlockData::prev, StaticAssertStmt, T_AllocSetContext, TopMemoryContext, and VALGRIND_MAKE_MEM_NOACCESS.

Referenced by GetMemoryChunkContext().

395 {
396  int freeListIndex;
397  Size firstBlockSize;
398  AllocSet set;
399  AllocBlock block;
400 
401  /* Assert we padded AllocChunkData properly */
403  "sizeof(AllocChunkData) is not maxaligned");
406  "padding calculation in AllocChunkData is wrong");
407 
408  /*
409  * First, validate allocation parameters. Once these were regular runtime
410  * test and elog's, but in practice Asserts seem sufficient because nobody
411  * varies their parameters at runtime. We somewhat arbitrarily enforce a
412  * minimum 1K block size.
413  */
414  Assert(initBlockSize == MAXALIGN(initBlockSize) &&
415  initBlockSize >= 1024);
416  Assert(maxBlockSize == MAXALIGN(maxBlockSize) &&
417  maxBlockSize >= initBlockSize &&
418  AllocHugeSizeIsValid(maxBlockSize)); /* must be safe to double */
419  Assert(minContextSize == 0 ||
420  (minContextSize == MAXALIGN(minContextSize) &&
421  minContextSize >= 1024 &&
422  minContextSize <= maxBlockSize));
423 
424  /*
425  * Check whether the parameters match either available freelist. We do
426  * not need to demand a match of maxBlockSize.
427  */
428  if (minContextSize == ALLOCSET_DEFAULT_MINSIZE &&
429  initBlockSize == ALLOCSET_DEFAULT_INITSIZE)
430  freeListIndex = 0;
431  else if (minContextSize == ALLOCSET_SMALL_MINSIZE &&
432  initBlockSize == ALLOCSET_SMALL_INITSIZE)
433  freeListIndex = 1;
434  else
435  freeListIndex = -1;
436 
437  /*
438  * If a suitable freelist entry exists, just recycle that context.
439  */
440  if (freeListIndex >= 0)
441  {
442  AllocSetFreeList *freelist = &context_freelists[freeListIndex];
443 
444  if (freelist->first_free != NULL)
445  {
446  /* Remove entry from freelist */
447  set = freelist->first_free;
448  freelist->first_free = (AllocSet) set->header.nextchild;
449  freelist->num_free--;
450 
451  /* Update its maxBlockSize; everything else should be OK */
452  set->maxBlockSize = maxBlockSize;
453 
454  /* Reinitialize its header, installing correct name and parent */
458  parent,
459  name);
460 
461  return (MemoryContext) set;
462  }
463  }
464 
465  /* Determine size of initial block */
466  firstBlockSize = MAXALIGN(sizeof(AllocSetContext)) +
468  if (minContextSize != 0)
469  firstBlockSize = Max(firstBlockSize, minContextSize);
470  else
471  firstBlockSize = Max(firstBlockSize, initBlockSize);
472 
473  /*
474  * Allocate the initial block. Unlike other aset.c blocks, it starts with
475  * the context header and its block header follows that.
476  */
477  set = (AllocSet) malloc(firstBlockSize);
478  if (set == NULL)
479  {
480  if (TopMemoryContext)
482  ereport(ERROR,
483  (errcode(ERRCODE_OUT_OF_MEMORY),
484  errmsg("out of memory"),
485  errdetail("Failed while creating memory context \"%s\".",
486  name)));
487  }
488 
489  /*
490  * Avoid writing code that can fail between here and MemoryContextCreate;
491  * we'd leak the header/initial block if we ereport in this stretch.
492  */
493 
494  /* Fill in the initial block's block header */
495  block = (AllocBlock) (((char *) set) + MAXALIGN(sizeof(AllocSetContext)));
496  block->aset = set;
497  block->freeptr = ((char *) block) + ALLOC_BLOCKHDRSZ;
498  block->endptr = ((char *) set) + firstBlockSize;
499  block->prev = NULL;
500  block->next = NULL;
501 
502  /* Mark unallocated space NOACCESS; leave the block header alone. */
503  VALGRIND_MAKE_MEM_NOACCESS(block->freeptr, block->endptr - block->freeptr);
504 
505  /* Remember block as part of block list */
506  set->blocks = block;
507  /* Mark block as not to be released at reset time */
508  set->keeper = block;
509 
510  /* Finish filling in aset-specific parts of the context header */
511  MemSetAligned(set->freelist, 0, sizeof(set->freelist));
512 
513  set->initBlockSize = initBlockSize;
514  set->maxBlockSize = maxBlockSize;
515  set->nextBlockSize = initBlockSize;
516  set->freeListIndex = freeListIndex;
517 
518  /*
519  * Compute the allocation chunk size limit for this context. It can't be
520  * more than ALLOC_CHUNK_LIMIT because of the fixed number of freelists.
521  * If maxBlockSize is small then requests exceeding the maxBlockSize, or
522  * even a significant fraction of it, should be treated as large chunks
523  * too. For the typical case of maxBlockSize a power of 2, the chunk size
524  * limit will be at most 1/8th maxBlockSize, so that given a stream of
525  * requests that are all the maximum chunk size we will waste at most
526  * 1/8th of the allocated space.
527  *
528  * We have to have allocChunkLimit a power of two, because the requested
529  * and actually-allocated sizes of any chunk must be on the same side of
530  * the limit, else we get confused about whether the chunk is "big".
531  *
532  * Also, allocChunkLimit must not exceed ALLOCSET_SEPARATE_THRESHOLD.
533  */
535  "ALLOC_CHUNK_LIMIT != ALLOCSET_SEPARATE_THRESHOLD");
536 
537  set->allocChunkLimit = ALLOC_CHUNK_LIMIT;
538  while ((Size) (set->allocChunkLimit + ALLOC_CHUNKHDRSZ) >
539  (Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
540  set->allocChunkLimit >>= 1;
541 
542  /* Finally, do the type-independent part of context creation */
546  parent,
547  name);
548 
549  return (MemoryContext) set;
550 }
#define MemSetAligned(start, val, len)
Definition: c.h:988
MemoryContextData header
Definition: aset.c:125
#define VALGRIND_MAKE_MEM_NOACCESS(addr, size)
Definition: memdebug.h:27
int num_free
Definition: aset.c:250
int errcode(int sqlerrcode)
Definition: elog.c:570
#define ALLOC_BLOCKHDRSZ
Definition: aset.c:102
AllocSet aset
Definition: aset.c:155
char * freeptr
Definition: aset.c:158
#define ALLOCSET_DEFAULT_MINSIZE
Definition: memutils.h:188
#define ALLOCSET_SMALL_MINSIZE
Definition: memutils.h:198
AllocSetContext * first_free
Definition: aset.c:251
#define malloc(a)
Definition: header.h:50
#define StaticAssertStmt(condition, errmessage)
Definition: c.h:842
static AllocSetFreeList context_freelists[2]
Definition: aset.c:255
#define ERROR
Definition: elog.h:43
#define ALLOC_CHUNK_LIMIT
Definition: aset.c:83
void MemoryContextStats(MemoryContext context)
Definition: mcxt.c:474
char * endptr
Definition: aset.c:159
#define ALLOCSET_SEPARATE_THRESHOLD
Definition: memutils.h:218
int errdetail(const char *fmt,...)
Definition: elog.c:860
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
AllocBlock next
Definition: aset.c:157
void MemoryContextCreate(MemoryContext node, NodeTag tag, const MemoryContextMethods *methods, MemoryContext parent, const char *name)
Definition: mcxt.c:724
#define ereport(elevel, rest)
Definition: elog.h:141
MemoryContext TopMemoryContext
Definition: mcxt.c:44
#define ALLOCSET_SMALL_INITSIZE
Definition: memutils.h:199
#define ALLOC_CHUNK_FRACTION
Definition: aset.c:85
struct AllocBlockData * AllocBlock
Definition: aset.c:105
AllocBlock prev
Definition: aset.c:156
#define Max(x, y)
Definition: c.h:898
#define Assert(condition)
Definition: c.h:732
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:685
const char * name
Definition: encode.c:521
#define AllocHugeSizeIsValid(size)
Definition: memutils.h:46
int errmsg(const char *fmt,...)
Definition: elog.c:784
#define ALLOCSET_DEFAULT_INITSIZE
Definition: memutils.h:189
static const MemoryContextMethods AllocSetMethods
Definition: aset.c:286
AllocSetContext * AllocSet
Definition: aset.c:139
#define offsetof(type, field)
Definition: c.h:655
MemoryContext nextchild
Definition: memnodes.h:86

◆ AllocSetDelete()

static void AllocSetDelete ( MemoryContext  context)
static

Definition at line 627 of file aset.c.

References AllocSetIsValid, Assert, AssertArg, AllocSetFreeList::first_free, free, AllocSetContext::freelist, AllocBlockData::freeptr, AllocSetContext::header, MemoryContextData::isReset, MAX_FREE_CONTEXTS, MemoryContextResetOnly(), AllocBlockData::next, next, MemoryContextData::nextchild, and AllocSetFreeList::num_free.

628 {
629  AllocSet set = (AllocSet) context;
630  AllocBlock block = set->blocks;
631 
633 
634 #ifdef MEMORY_CONTEXT_CHECKING
635  /* Check for corruption and leaks before freeing */
636  AllocSetCheck(context);
637 #endif
638 
639  /*
640  * If the context is a candidate for a freelist, put it into that freelist
641  * instead of destroying it.
642  */
643  if (set->freeListIndex >= 0)
644  {
645  AllocSetFreeList *freelist = &context_freelists[set->freeListIndex];
646 
647  /*
648  * Reset the context, if it needs it, so that we aren't hanging on to
649  * more than the initial malloc chunk.
650  */
651  if (!context->isReset)
652  MemoryContextResetOnly(context);
653 
654  /*
655  * If the freelist is full, just discard what's already in it. See
656  * comments with context_freelists[].
657  */
658  if (freelist->num_free >= MAX_FREE_CONTEXTS)
659  {
660  while (freelist->first_free != NULL)
661  {
662  AllocSetContext *oldset = freelist->first_free;
663 
664  freelist->first_free = (AllocSetContext *) oldset->header.nextchild;
665  freelist->num_free--;
666 
667  /* All that remains is to free the header/initial block */
668  free(oldset);
669  }
670  Assert(freelist->num_free == 0);
671  }
672 
673  /* Now add the just-deleted context to the freelist. */
674  set->header.nextchild = (MemoryContext) freelist->first_free;
675  freelist->first_free = set;
676  freelist->num_free++;
677 
678  return;
679  }
680 
681  /* Free all blocks, except the keeper which is part of context header */
682  while (block != NULL)
683  {
684  AllocBlock next = block->next;
685 
686 #ifdef CLOBBER_FREED_MEMORY
687  wipe_mem(block, block->freeptr - ((char *) block));
688 #endif
689 
690  if (block != set->keeper)
691  free(block);
692 
693  block = next;
694  }
695 
696  /* Finally, free the context header, including the keeper block */
697  free(set);
698 }
static int32 next
Definition: blutils.c:213
MemoryContextData header
Definition: aset.c:125
#define AllocSetIsValid(set)
Definition: aset.c:216
int num_free
Definition: aset.c:250
char * freeptr
Definition: aset.c:158
void MemoryContextResetOnly(MemoryContext context)
Definition: mcxt.c:155
AllocSetContext * first_free
Definition: aset.c:251
static AllocSetFreeList context_freelists[2]
Definition: aset.c:255
AllocBlock next
Definition: aset.c:157
#define AssertArg(condition)
Definition: c.h:734
struct MemoryContextData * MemoryContext
Definition: palloc.h:36
#define MAX_FREE_CONTEXTS
Definition: aset.c:246
#define free(a)
Definition: header.h:65
#define Assert(condition)
Definition: c.h:732
AllocSetContext * AllocSet
Definition: aset.c:139
MemoryContext nextchild
Definition: memnodes.h:86

◆ AllocSetFree()

static void AllocSetFree ( MemoryContext  context,
void *  pointer 
)
static

Definition at line 987 of file aset.c.

References ALLOC_BLOCKHDRSZ, ALLOC_CHUNKHDRSZ, ALLOCCHUNK_PRIVATE_LEN, AllocFreeInfo, AllocPointerGetChunk, AllocSetFreeIndex(), AllocBlockData::aset, AllocChunkData::aset, elog, AllocBlockData::endptr, ERROR, free, AllocBlockData::freeptr, AllocChunkData::size, VALGRIND_MAKE_MEM_DEFINED, and WARNING.

Referenced by AllocSetRealloc().

988 {
989  AllocSet set = (AllocSet) context;
990  AllocChunk chunk = AllocPointerGetChunk(pointer);
991 
992  /* Allow access to private part of chunk header. */
994 
995  AllocFreeInfo(set, chunk);
996 
997 #ifdef MEMORY_CONTEXT_CHECKING
998  /* Test for someone scribbling on unused space in chunk */
999  if (chunk->requested_size < chunk->size)
1000  if (!sentinel_ok(pointer, chunk->requested_size))
1001  elog(WARNING, "detected write past chunk end in %s %p",
1002  set->header.name, chunk);
1003 #endif
1004 
1005  if (chunk->size > set->allocChunkLimit)
1006  {
1007  /*
1008  * Big chunks are certain to have been allocated as single-chunk
1009  * blocks. Just unlink that block and return it to malloc().
1010  */
1011  AllocBlock block = (AllocBlock) (((char *) chunk) - ALLOC_BLOCKHDRSZ);
1012 
1013  /*
1014  * Try to verify that we have a sane block pointer: it should
1015  * reference the correct aset, and freeptr and endptr should point
1016  * just past the chunk.
1017  */
1018  if (block->aset != set ||
1019  block->freeptr != block->endptr ||
1020  block->freeptr != ((char *) block) +
1021  (chunk->size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ))
1022  elog(ERROR, "could not find block containing chunk %p", chunk);
1023 
1024  /* OK, remove block from aset's list and free it */
1025  if (block->prev)
1026  block->prev->next = block->next;
1027  else
1028  set->blocks = block->next;
1029  if (block->next)
1030  block->next->prev = block->prev;
1031 #ifdef CLOBBER_FREED_MEMORY
1032  wipe_mem(block, block->freeptr - ((char *) block));
1033 #endif
1034  free(block);
1035  }
1036  else
1037  {
1038  /* Normal case, put the chunk into appropriate freelist */
1039  int fidx = AllocSetFreeIndex(chunk->size);
1040 
1041  chunk->aset = (void *) set->freelist[fidx];
1042 
1043 #ifdef CLOBBER_FREED_MEMORY
1044  wipe_mem(pointer, chunk->size);
1045 #endif
1046 
1047 #ifdef MEMORY_CONTEXT_CHECKING
1048  /* Reset requested_size to 0 in chunks that are on freelist */
1049  chunk->requested_size = 0;
1050 #endif
1051  set->freelist[fidx] = chunk;
1052  }
1053 }
#define AllocFreeInfo(_cxt, _chunk)
Definition: aset.c:324
#define VALGRIND_MAKE_MEM_DEFINED(addr, size)
Definition: memdebug.h:26
static int AllocSetFreeIndex(Size size)
Definition: aset.c:337
#define ALLOCCHUNK_PRIVATE_LEN
Definition: aset.c:204
#define ALLOC_BLOCKHDRSZ
Definition: aset.c:102
AllocSet aset
Definition: aset.c:155
char * freeptr
Definition: aset.c:158
#define ERROR
Definition: elog.h:43
char * endptr
Definition: aset.c:159
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
#define WARNING
Definition: elog.h:40
struct AllocBlockData * AllocBlock
Definition: aset.c:105
#define free(a)
Definition: header.h:65
#define elog(elevel,...)
Definition: elog.h:226
AllocSetContext * AllocSet
Definition: aset.c:139
Size size
Definition: aset.c:177
#define AllocPointerGetChunk(ptr)
Definition: aset.c:218

◆ AllocSetFreeIndex()

static int AllocSetFreeIndex ( Size  size)
inlinestatic

Definition at line 337 of file aset.c.

References ALLOC_MINBITS, ALLOCSET_NUM_FREELISTS, Assert, idx(), and LogTable256.

Referenced by AllocSetAlloc(), and AllocSetFree().

338 {
339  int idx;
340  unsigned int t,
341  tsize;
342 
343  if (size > (1 << ALLOC_MINBITS))
344  {
345  tsize = (size - 1) >> ALLOC_MINBITS;
346 
347  /*
348  * At this point we need to obtain log2(tsize)+1, ie, the number of
349  * not-all-zero bits at the right. We used to do this with a
350  * shift-and-count loop, but this function is enough of a hotspot to
351  * justify micro-optimization effort. The best approach seems to be
352  * to use a lookup table. Note that this code assumes that
353  * ALLOCSET_NUM_FREELISTS <= 17, since we only cope with two bytes of
354  * the tsize value.
355  */
356  t = tsize >> 8;
357  idx = t ? LogTable256[t] + 8 : LogTable256[tsize];
358 
360  }
361  else
362  idx = 0;
363 
364  return idx;
365 }
Datum idx(PG_FUNCTION_ARGS)
Definition: _int_op.c:264
#define ALLOCSET_NUM_FREELISTS
Definition: aset.c:82
static const unsigned char LogTable256[256]
Definition: aset.c:305
#define Assert(condition)
Definition: c.h:732
#define ALLOC_MINBITS
Definition: aset.c:81

◆ AllocSetGetChunkSpace()

static Size AllocSetGetChunkSpace ( MemoryContext  context,
void *  pointer 
)
static

Definition at line 1277 of file aset.c.

References ALLOC_CHUNKHDRSZ, ALLOCCHUNK_PRIVATE_LEN, AllocPointerGetChunk, AllocChunkData::size, VALGRIND_MAKE_MEM_DEFINED, and VALGRIND_MAKE_MEM_NOACCESS.

1278 {
1279  AllocChunk chunk = AllocPointerGetChunk(pointer);
1280  Size result;
1281 
1283  result = chunk->size + ALLOC_CHUNKHDRSZ;
1285  return result;
1286 }
#define VALGRIND_MAKE_MEM_DEFINED(addr, size)
Definition: memdebug.h:26
#define VALGRIND_MAKE_MEM_NOACCESS(addr, size)
Definition: memdebug.h:27
#define ALLOCCHUNK_PRIVATE_LEN
Definition: aset.c:204
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
size_t Size
Definition: c.h:466
Size size
Definition: aset.c:177
#define AllocPointerGetChunk(ptr)
Definition: aset.c:218

◆ AllocSetIsEmpty()

static bool AllocSetIsEmpty ( MemoryContext  context)
static

Definition at line 1293 of file aset.c.

References MemoryContextData::isReset.

1294 {
1295  /*
1296  * For now, we say "empty" only if the context is new or just reset. We
1297  * could examine the freelists to determine if all space has been freed,
1298  * but it's not really worth the trouble for present uses of this
1299  * functionality.
1300  */
1301  if (context->isReset)
1302  return true;
1303  return false;
1304 }

◆ AllocSetRealloc()

static void * AllocSetRealloc ( MemoryContext  context,
void *  pointer,
Size  size 
)
static

Definition at line 1068 of file aset.c.

References ALLOC_BLOCKHDRSZ, ALLOC_CHUNKHDRSZ, ALLOCCHUNK_PRIVATE_LEN, AllocChunkGetPointer, AllocPointerGetChunk, AllocSetAlloc(), AllocSetFree(), AllocBlockData::aset, elog, AllocBlockData::endptr, ERROR, AllocBlockData::freeptr, MAXALIGN, realloc, AllocChunkData::size, VALGRIND_MAKE_MEM_DEFINED, VALGRIND_MAKE_MEM_NOACCESS, VALGRIND_MAKE_MEM_UNDEFINED, and WARNING.

1069 {
1070  AllocSet set = (AllocSet) context;
1071  AllocChunk chunk = AllocPointerGetChunk(pointer);
1072  Size oldsize;
1073 
1074  /* Allow access to private part of chunk header. */
1076 
1077  oldsize = chunk->size;
1078 
1079 #ifdef MEMORY_CONTEXT_CHECKING
1080  /* Test for someone scribbling on unused space in chunk */
1081  if (chunk->requested_size < oldsize)
1082  if (!sentinel_ok(pointer, chunk->requested_size))
1083  elog(WARNING, "detected write past chunk end in %s %p",
1084  set->header.name, chunk);
1085 #endif
1086 
1087  /*
1088  * Chunk sizes are aligned to power of 2 in AllocSetAlloc(). Maybe the
1089  * allocated area already is >= the new size. (In particular, we always
1090  * fall out here if the requested size is a decrease.)
1091  */
1092  if (oldsize >= size)
1093  {
1094 #ifdef MEMORY_CONTEXT_CHECKING
1095  Size oldrequest = chunk->requested_size;
1096 
1097 #ifdef RANDOMIZE_ALLOCATED_MEMORY
1098  /* We can only fill the extra space if we know the prior request */
1099  if (size > oldrequest)
1100  randomize_mem((char *) pointer + oldrequest,
1101  size - oldrequest);
1102 #endif
1103 
1104  chunk->requested_size = size;
1105 
1106  /*
1107  * If this is an increase, mark any newly-available part UNDEFINED.
1108  * Otherwise, mark the obsolete part NOACCESS.
1109  */
1110  if (size > oldrequest)
1111  VALGRIND_MAKE_MEM_UNDEFINED((char *) pointer + oldrequest,
1112  size - oldrequest);
1113  else
1114  VALGRIND_MAKE_MEM_NOACCESS((char *) pointer + size,
1115  oldsize - size);
1116 
1117  /* set mark to catch clobber of "unused" space */
1118  if (size < oldsize)
1119  set_sentinel(pointer, size);
1120 #else /* !MEMORY_CONTEXT_CHECKING */
1121 
1122  /*
1123  * We don't have the information to determine whether we're growing
1124  * the old request or shrinking it, so we conservatively mark the
1125  * entire new allocation DEFINED.
1126  */
1127  VALGRIND_MAKE_MEM_NOACCESS(pointer, oldsize);
1128  VALGRIND_MAKE_MEM_DEFINED(pointer, size);
1129 #endif
1130 
1131  /* Disallow external access to private part of chunk header. */
1133 
1134  return pointer;
1135  }
1136 
1137  if (oldsize > set->allocChunkLimit)
1138  {
1139  /*
1140  * The chunk must have been allocated as a single-chunk block. Use
1141  * realloc() to make the containing block bigger with minimum space
1142  * wastage.
1143  */
1144  AllocBlock block = (AllocBlock) (((char *) chunk) - ALLOC_BLOCKHDRSZ);
1145  Size chksize;
1146  Size blksize;
1147 
1148  /*
1149  * Try to verify that we have a sane block pointer: it should
1150  * reference the correct aset, and freeptr and endptr should point
1151  * just past the chunk.
1152  */
1153  if (block->aset != set ||
1154  block->freeptr != block->endptr ||
1155  block->freeptr != ((char *) block) +
1156  (chunk->size + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ))
1157  elog(ERROR, "could not find block containing chunk %p", chunk);
1158 
1159  /* Do the realloc */
1160  chksize = MAXALIGN(size);
1161  blksize = chksize + ALLOC_BLOCKHDRSZ + ALLOC_CHUNKHDRSZ;
1162  block = (AllocBlock) realloc(block, blksize);
1163  if (block == NULL)
1164  {
1165  /* Disallow external access to private part of chunk header. */
1167  return NULL;
1168  }
1169  block->freeptr = block->endptr = ((char *) block) + blksize;
1170 
1171  /* Update pointers since block has likely been moved */
1172  chunk = (AllocChunk) (((char *) block) + ALLOC_BLOCKHDRSZ);
1173  pointer = AllocChunkGetPointer(chunk);
1174  if (block->prev)
1175  block->prev->next = block;
1176  else
1177  set->blocks = block;
1178  if (block->next)
1179  block->next->prev = block;
1180  chunk->size = chksize;
1181 
1182 #ifdef MEMORY_CONTEXT_CHECKING
1183 #ifdef RANDOMIZE_ALLOCATED_MEMORY
1184  /* We can only fill the extra space if we know the prior request */
1185  randomize_mem((char *) pointer + chunk->requested_size,
1186  size - chunk->requested_size);
1187 #endif
1188 
1189  /*
1190  * realloc() (or randomize_mem()) will have left the newly-allocated
1191  * part UNDEFINED, but we may need to adjust trailing bytes from the
1192  * old allocation.
1193  */
1194  VALGRIND_MAKE_MEM_UNDEFINED((char *) pointer + chunk->requested_size,
1195  oldsize - chunk->requested_size);
1196 
1197  chunk->requested_size = size;
1198 
1199  /* set mark to catch clobber of "unused" space */
1200  if (size < chunk->size)
1201  set_sentinel(pointer, size);
1202 #else /* !MEMORY_CONTEXT_CHECKING */
1203 
1204  /*
1205  * We don't know how much of the old chunk size was the actual
1206  * allocation; it could have been as small as one byte. We have to be
1207  * conservative and just mark the entire old portion DEFINED.
1208  */
1209  VALGRIND_MAKE_MEM_DEFINED(pointer, oldsize);
1210 #endif
1211 
1212  /* Ensure any padding bytes are marked NOACCESS. */
1213  VALGRIND_MAKE_MEM_NOACCESS((char *) pointer + size, chksize - size);
1214 
1215  /* Disallow external access to private part of chunk header. */
1217 
1218  return pointer;
1219  }
1220  else
1221  {
1222  /*
1223  * Small-chunk case. We just do this by brute force, ie, allocate a
1224  * new chunk and copy the data. Since we know the existing data isn't
1225  * huge, this won't involve any great memcpy expense, so it's not
1226  * worth being smarter. (At one time we tried to avoid memcpy when it
1227  * was possible to enlarge the chunk in-place, but that turns out to
1228  * misbehave unpleasantly for repeated cycles of
1229  * palloc/repalloc/pfree: the eventually freed chunks go into the
1230  * wrong freelist for the next initial palloc request, and so we leak
1231  * memory indefinitely. See pgsql-hackers archives for 2007-08-11.)
1232  */
1233  AllocPointer newPointer;
1234 
1235  /* allocate new chunk */
1236  newPointer = AllocSetAlloc((MemoryContext) set, size);
1237 
1238  /* leave immediately if request was not completed */
1239  if (newPointer == NULL)
1240  {
1241  /* Disallow external access to private part of chunk header. */
1243  return NULL;
1244  }
1245 
1246  /*
1247  * AllocSetAlloc() may have returned a region that is still NOACCESS.
1248  * Change it to UNDEFINED for the moment; memcpy() will then transfer
1249  * definedness from the old allocation to the new. If we know the old
1250  * allocation, copy just that much. Otherwise, make the entire old
1251  * chunk defined to avoid errors as we copy the currently-NOACCESS
1252  * trailing bytes.
1253  */
1254  VALGRIND_MAKE_MEM_UNDEFINED(newPointer, size);
1255 #ifdef MEMORY_CONTEXT_CHECKING
1256  oldsize = chunk->requested_size;
1257 #else
1258  VALGRIND_MAKE_MEM_DEFINED(pointer, oldsize);
1259 #endif
1260 
1261  /* transfer existing data (certain to fit) */
1262  memcpy(newPointer, pointer, oldsize);
1263 
1264  /* free old chunk */
1265  AllocSetFree((MemoryContext) set, pointer);
1266 
1267  return newPointer;
1268  }
1269 }
#define VALGRIND_MAKE_MEM_DEFINED(addr, size)
Definition: memdebug.h:26
void * AllocPointer
Definition: aset.c:112
#define VALGRIND_MAKE_MEM_UNDEFINED(addr, size)
Definition: memdebug.h:28
#define VALGRIND_MAKE_MEM_NOACCESS(addr, size)
Definition: memdebug.h:27
#define AllocChunkGetPointer(chk)
Definition: aset.c:220
#define ALLOCCHUNK_PRIVATE_LEN
Definition: aset.c:204
#define ALLOC_BLOCKHDRSZ
Definition: aset.c:102
AllocSet aset
Definition: aset.c:155
char * freeptr
Definition: aset.c:158
#define ERROR
Definition: elog.h:43
char * endptr
Definition: aset.c:159
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
#define WARNING
Definition: elog.h:40
struct AllocBlockData * AllocBlock
Definition: aset.c:105
struct AllocChunkData * AllocChunk
Definition: aset.c:106
static void AllocSetFree(MemoryContext context, void *pointer)
Definition: aset.c:987
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:685
#define realloc(a, b)
Definition: header.h:60
#define elog(elevel,...)
Definition: elog.h:226
static void * AllocSetAlloc(MemoryContext context, Size size)
Definition: aset.c:714
AllocSetContext * AllocSet
Definition: aset.c:139
Size size
Definition: aset.c:177
#define AllocPointerGetChunk(ptr)
Definition: aset.c:218

◆ AllocSetReset()

static void AllocSetReset ( MemoryContext  context)
static

Definition at line 565 of file aset.c.

References ALLOC_BLOCKHDRSZ, AllocSetIsValid, AssertArg, free, AllocBlockData::freeptr, MemSetAligned, AllocBlockData::next, next, AllocBlockData::prev, and VALGRIND_MAKE_MEM_NOACCESS.

566 {
567  AllocSet set = (AllocSet) context;
568  AllocBlock block;
569 
571 
572 #ifdef MEMORY_CONTEXT_CHECKING
573  /* Check for corruption and leaks before freeing */
574  AllocSetCheck(context);
575 #endif
576 
577  /* Clear chunk freelists */
578  MemSetAligned(set->freelist, 0, sizeof(set->freelist));
579 
580  block = set->blocks;
581 
582  /* New blocks list will be just the keeper block */
583  set->blocks = set->keeper;
584 
585  while (block != NULL)
586  {
587  AllocBlock next = block->next;
588 
589  if (block == set->keeper)
590  {
591  /* Reset the block, but don't return it to malloc */
592  char *datastart = ((char *) block) + ALLOC_BLOCKHDRSZ;
593 
594 #ifdef CLOBBER_FREED_MEMORY
595  wipe_mem(datastart, block->freeptr - datastart);
596 #else
597  /* wipe_mem() would have done this */
598  VALGRIND_MAKE_MEM_NOACCESS(datastart, block->freeptr - datastart);
599 #endif
600  block->freeptr = datastart;
601  block->prev = NULL;
602  block->next = NULL;
603  }
604  else
605  {
606  /* Normal case, release the block */
607 #ifdef CLOBBER_FREED_MEMORY
608  wipe_mem(block, block->freeptr - ((char *) block));
609 #endif
610  free(block);
611  }
612  block = next;
613  }
614 
615  /* Reset block size allocation sequence, too */
616  set->nextBlockSize = set->initBlockSize;
617 }
#define MemSetAligned(start, val, len)
Definition: c.h:988
static int32 next
Definition: blutils.c:213
#define AllocSetIsValid(set)
Definition: aset.c:216
#define VALGRIND_MAKE_MEM_NOACCESS(addr, size)
Definition: memdebug.h:27
#define ALLOC_BLOCKHDRSZ
Definition: aset.c:102
char * freeptr
Definition: aset.c:158
AllocBlock next
Definition: aset.c:157
#define AssertArg(condition)
Definition: c.h:734
AllocBlock prev
Definition: aset.c:156
#define free(a)
Definition: header.h:65
AllocSetContext * AllocSet
Definition: aset.c:139

◆ AllocSetStats()

static void AllocSetStats ( MemoryContext  context,
MemoryStatsPrintFunc  printfunc,
void *  passthru,
MemoryContextCounters totals 
)
static

Definition at line 1315 of file aset.c.

References ALLOC_BLOCKHDRSZ, ALLOC_CHUNKHDRSZ, ALLOC_MINBITS, ALLOCCHUNK_PRIVATE_LEN, ALLOCSET_NUM_FREELISTS, AllocBlockData::aset, AllocChunkData::aset, elog, AllocBlockData::endptr, MemoryContextCounters::freechunks, AllocBlockData::freeptr, MemoryContextCounters::freespace, MAXALIGN, name, MemoryContextCounters::nblocks, AllocBlockData::next, AllocBlockData::prev, AllocChunkData::size, snprintf, MemoryContextCounters::totalspace, VALGRIND_MAKE_MEM_DEFINED, VALGRIND_MAKE_MEM_NOACCESS, and WARNING.

1318 {
1319  AllocSet set = (AllocSet) context;
1320  Size nblocks = 0;
1321  Size freechunks = 0;
1322  Size totalspace;
1323  Size freespace = 0;
1324  AllocBlock block;
1325  int fidx;
1326 
1327  /* Include context header in totalspace */
1328  totalspace = MAXALIGN(sizeof(AllocSetContext));
1329 
1330  for (block = set->blocks; block != NULL; block = block->next)
1331  {
1332  nblocks++;
1333  totalspace += block->endptr - ((char *) block);
1334  freespace += block->endptr - block->freeptr;
1335  }
1336  for (fidx = 0; fidx < ALLOCSET_NUM_FREELISTS; fidx++)
1337  {
1338  AllocChunk chunk;
1339 
1340  for (chunk = set->freelist[fidx]; chunk != NULL;
1341  chunk = (AllocChunk) chunk->aset)
1342  {
1343  freechunks++;
1344  freespace += chunk->size + ALLOC_CHUNKHDRSZ;
1345  }
1346  }
1347 
1348  if (printfunc)
1349  {
1350  char stats_string[200];
1351 
1352  snprintf(stats_string, sizeof(stats_string),
1353  "%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
1354  totalspace, nblocks, freespace, freechunks,
1355  totalspace - freespace);
1356  printfunc(context, passthru, stats_string);
1357  }
1358 
1359  if (totals)
1360  {
1361  totals->nblocks += nblocks;
1362  totals->freechunks += freechunks;
1363  totals->totalspace += totalspace;
1364  totals->freespace += freespace;
1365  }
1366 }
char * freeptr
Definition: aset.c:158
char * endptr
Definition: aset.c:159
#define ALLOCSET_NUM_FREELISTS
Definition: aset.c:82
#define ALLOC_CHUNKHDRSZ
Definition: aset.c:103
AllocBlock next
Definition: aset.c:157
size_t Size
Definition: c.h:466
#define MAXALIGN(LEN)
Definition: c.h:685
void * aset
Definition: aset.c:194
AllocSetContext * AllocSet
Definition: aset.c:139
#define snprintf
Definition: port.h:192
Size size
Definition: aset.c:177

Variable Documentation

◆ AllocSetMethods

const MemoryContextMethods AllocSetMethods
static
Initial value:
= {
}
static Size AllocSetGetChunkSpace(MemoryContext context, void *pointer)
Definition: aset.c:1277
static void AllocSetReset(MemoryContext context)
Definition: aset.c:565
static void * AllocSetRealloc(MemoryContext context, void *pointer, Size size)
Definition: aset.c:1068
static void AllocSetStats(MemoryContext context, MemoryStatsPrintFunc printfunc, void *passthru, MemoryContextCounters *totals)
Definition: aset.c:1315
static bool AllocSetIsEmpty(MemoryContext context)
Definition: aset.c:1293
static void AllocSetFree(MemoryContext context, void *pointer)
Definition: aset.c:987
static void AllocSetDelete(MemoryContext context)
Definition: aset.c:627
static void * AllocSetAlloc(MemoryContext context, Size size)
Definition: aset.c:714

Definition at line 286 of file aset.c.

Referenced by AllocSetContextCreateInternal().

◆ context_freelists

AllocSetFreeList context_freelists[2]
static
Initial value:
=
{
{
0, NULL
},
{
0, NULL
}
}

Definition at line 255 of file aset.c.

◆ LogTable256

const unsigned char LogTable256[256]
static
Initial value:
=
{
0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
LT16(5), LT16(6), LT16(6), LT16(7), LT16(7), LT16(7), LT16(7),
LT16(8), LT16(8), LT16(8), LT16(8), LT16(8), LT16(8), LT16(8), LT16(8)
}
#define LT16(n)
Definition: aset.c:303

Definition at line 305 of file aset.c.

Referenced by AllocSetFreeIndex().