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dsa.h File Reference
#include "port/atomics.h"
#include "storage/dsm.h"
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Macros

#define SIZEOF_DSA_POINTER   8
 
#define dsa_pointer_atomic_init   pg_atomic_init_u64
 
#define dsa_pointer_atomic_read   pg_atomic_read_u64
 
#define dsa_pointer_atomic_write   pg_atomic_write_u64
 
#define dsa_pointer_atomic_fetch_add   pg_atomic_fetch_add_u64
 
#define dsa_pointer_atomic_compare_exchange   pg_atomic_compare_exchange_u64
 
#define DSA_POINTER_FORMAT   "%016" INT64_MODIFIER "x"
 
#define DSA_ALLOC_HUGE   0x01 /* allow huge allocation (> 1 GB) */
 
#define DSA_ALLOC_NO_OOM   0x02 /* no failure if out-of-memory */
 
#define DSA_ALLOC_ZERO   0x04 /* zero allocated memory */
 
#define InvalidDsaPointer   ((dsa_pointer) 0)
 
#define DsaPointerIsValid(x)   ((x) != InvalidDsaPointer)
 
#define dsa_allocate(area, size)    dsa_allocate_extended(area, size, 0)
 
#define dsa_allocate0(area, size)    dsa_allocate_extended(area, size, DSA_ALLOC_ZERO)
 

Typedefs

typedef struct dsa_area dsa_area
 
typedef uint64 dsa_pointer
 
typedef pg_atomic_uint64 dsa_pointer_atomic
 
typedef dsm_handle dsa_handle
 

Functions

dsa_areadsa_create (int tranche_id)
 
dsa_areadsa_create_in_place (void *place, size_t size, int tranche_id, dsm_segment *segment)
 
dsa_areadsa_attach (dsa_handle handle)
 
dsa_areadsa_attach_in_place (void *place, dsm_segment *segment)
 
void dsa_release_in_place (void *place)
 
void dsa_on_dsm_detach_release_in_place (dsm_segment *, Datum)
 
void dsa_on_shmem_exit_release_in_place (int, Datum)
 
void dsa_pin_mapping (dsa_area *area)
 
void dsa_detach (dsa_area *area)
 
void dsa_pin (dsa_area *area)
 
void dsa_unpin (dsa_area *area)
 
void dsa_set_size_limit (dsa_area *area, size_t limit)
 
size_t dsa_minimum_size (void)
 
dsa_handle dsa_get_handle (dsa_area *area)
 
dsa_pointer dsa_allocate_extended (dsa_area *area, size_t size, int flags)
 
void dsa_free (dsa_area *area, dsa_pointer dp)
 
void * dsa_get_address (dsa_area *area, dsa_pointer dp)
 
void dsa_trim (dsa_area *area)
 
void dsa_dump (dsa_area *area)
 

Macro Definition Documentation

◆ DSA_ALLOC_HUGE

#define DSA_ALLOC_HUGE   0x01 /* allow huge allocation (> 1 GB) */

Definition at line 73 of file dsa.h.

◆ DSA_ALLOC_NO_OOM

#define DSA_ALLOC_NO_OOM   0x02 /* no failure if out-of-memory */

Definition at line 74 of file dsa.h.

◆ DSA_ALLOC_ZERO

#define DSA_ALLOC_ZERO   0x04 /* zero allocated memory */

Definition at line 75 of file dsa.h.

◆ dsa_allocate

#define dsa_allocate (   area,
  size 
)     dsa_allocate_extended(area, size, 0)

Definition at line 84 of file dsa.h.

◆ dsa_allocate0

#define dsa_allocate0 (   area,
  size 
)     dsa_allocate_extended(area, size, DSA_ALLOC_ZERO)

Definition at line 88 of file dsa.h.

◆ dsa_pointer_atomic_compare_exchange

#define dsa_pointer_atomic_compare_exchange   pg_atomic_compare_exchange_u64

Definition at line 68 of file dsa.h.

◆ dsa_pointer_atomic_fetch_add

#define dsa_pointer_atomic_fetch_add   pg_atomic_fetch_add_u64

Definition at line 67 of file dsa.h.

◆ dsa_pointer_atomic_init

#define dsa_pointer_atomic_init   pg_atomic_init_u64

Definition at line 64 of file dsa.h.

◆ dsa_pointer_atomic_read

#define dsa_pointer_atomic_read   pg_atomic_read_u64

Definition at line 65 of file dsa.h.

◆ dsa_pointer_atomic_write

#define dsa_pointer_atomic_write   pg_atomic_write_u64

Definition at line 66 of file dsa.h.

◆ DSA_POINTER_FORMAT

#define DSA_POINTER_FORMAT   "%016" INT64_MODIFIER "x"

Definition at line 69 of file dsa.h.

◆ DsaPointerIsValid

#define DsaPointerIsValid (   x)    ((x) != InvalidDsaPointer)

Definition at line 81 of file dsa.h.

◆ InvalidDsaPointer

#define InvalidDsaPointer   ((dsa_pointer) 0)

Definition at line 78 of file dsa.h.

◆ SIZEOF_DSA_POINTER

#define SIZEOF_DSA_POINTER   8

Definition at line 42 of file dsa.h.

Typedef Documentation

◆ dsa_area

typedef struct dsa_area dsa_area

Definition at line 1 of file dsa.h.

◆ dsa_handle

Definition at line 100 of file dsa.h.

◆ dsa_pointer

typedef uint64 dsa_pointer

Definition at line 62 of file dsa.h.

◆ dsa_pointer_atomic

Definition at line 63 of file dsa.h.

Function Documentation

◆ dsa_allocate_extended()

dsa_pointer dsa_allocate_extended ( dsa_area area,
size_t  size,
int  flags 
)

Definition at line 677 of file dsa.c.

678 {
679  uint16 size_class;
680  dsa_pointer start_pointer;
681  dsa_segment_map *segment_map;
682  dsa_pointer result;
683 
684  Assert(size > 0);
685 
686  /* Sanity check on huge individual allocation size. */
687  if (((flags & DSA_ALLOC_HUGE) != 0 && !AllocHugeSizeIsValid(size)) ||
688  ((flags & DSA_ALLOC_HUGE) == 0 && !AllocSizeIsValid(size)))
689  elog(ERROR, "invalid DSA memory alloc request size %zu", size);
690 
691  /*
692  * If bigger than the largest size class, just grab a run of pages from
693  * the free page manager, instead of allocating an object from a pool.
694  * There will still be a span, but it's a special class of span that
695  * manages this whole allocation and simply gives all pages back to the
696  * free page manager when dsa_free is called.
697  */
698  if (size > dsa_size_classes[lengthof(dsa_size_classes) - 1])
699  {
700  size_t npages = fpm_size_to_pages(size);
701  size_t first_page;
702  dsa_pointer span_pointer;
704 
705  /* Obtain a span object. */
706  span_pointer = alloc_object(area, DSA_SCLASS_BLOCK_OF_SPANS);
707  if (!DsaPointerIsValid(span_pointer))
708  {
709  /* Raise error unless asked not to. */
710  if ((flags & DSA_ALLOC_NO_OOM) == 0)
711  ereport(ERROR,
712  (errcode(ERRCODE_OUT_OF_MEMORY),
713  errmsg("out of memory"),
714  errdetail("Failed on DSA request of size %zu.",
715  size)));
716  return InvalidDsaPointer;
717  }
718 
720 
721  /* Find a segment from which to allocate. */
722  segment_map = get_best_segment(area, npages);
723  if (segment_map == NULL)
724  segment_map = make_new_segment(area, npages);
725  if (segment_map == NULL)
726  {
727  /* Can't make any more segments: game over. */
729  dsa_free(area, span_pointer);
730 
731  /* Raise error unless asked not to. */
732  if ((flags & DSA_ALLOC_NO_OOM) == 0)
733  ereport(ERROR,
734  (errcode(ERRCODE_OUT_OF_MEMORY),
735  errmsg("out of memory"),
736  errdetail("Failed on DSA request of size %zu.",
737  size)));
738  return InvalidDsaPointer;
739  }
740 
741  /*
742  * Ask the free page manager for a run of pages. This should always
743  * succeed, since both get_best_segment and make_new_segment should
744  * only return a non-NULL pointer if it actually contains enough
745  * contiguous freespace. If it does fail, something in our backend
746  * private state is out of whack, so use FATAL to kill the process.
747  */
748  if (!FreePageManagerGet(segment_map->fpm, npages, &first_page))
749  elog(FATAL,
750  "dsa_allocate could not find %zu free pages", npages);
752 
753  start_pointer = DSA_MAKE_POINTER(get_segment_index(area, segment_map),
754  first_page * FPM_PAGE_SIZE);
755 
756  /* Initialize span and pagemap. */
758  LW_EXCLUSIVE);
759  init_span(area, span_pointer, pool, start_pointer, npages,
761  segment_map->pagemap[first_page] = span_pointer;
763 
764  /* Zero-initialize the memory if requested. */
765  if ((flags & DSA_ALLOC_ZERO) != 0)
766  memset(dsa_get_address(area, start_pointer), 0, size);
767 
768  return start_pointer;
769  }
770 
771  /* Map allocation to a size class. */
773  {
774  int mapidx;
775 
776  /* For smaller sizes we have a lookup table... */
777  mapidx = ((size + DSA_SIZE_CLASS_MAP_QUANTUM - 1) /
779  size_class = dsa_size_class_map[mapidx];
780  }
781  else
782  {
783  uint16 min;
784  uint16 max;
785 
786  /* ... and for the rest we search by binary chop. */
788  max = lengthof(dsa_size_classes) - 1;
789 
790  while (min < max)
791  {
792  uint16 mid = (min + max) / 2;
793  uint16 class_size = dsa_size_classes[mid];
794 
795  if (class_size < size)
796  min = mid + 1;
797  else
798  max = mid;
799  }
800 
801  size_class = min;
802  }
803  Assert(size <= dsa_size_classes[size_class]);
804  Assert(size_class == 0 || size > dsa_size_classes[size_class - 1]);
805 
806  /* Attempt to allocate an object from the appropriate pool. */
807  result = alloc_object(area, size_class);
808 
809  /* Check for failure to allocate. */
810  if (!DsaPointerIsValid(result))
811  {
812  /* Raise error unless asked not to. */
813  if ((flags & DSA_ALLOC_NO_OOM) == 0)
814  ereport(ERROR,
815  (errcode(ERRCODE_OUT_OF_MEMORY),
816  errmsg("out of memory"),
817  errdetail("Failed on DSA request of size %zu.", size)));
818  return InvalidDsaPointer;
819  }
820 
821  /* Zero-initialize the memory if requested. */
822  if ((flags & DSA_ALLOC_ZERO) != 0)
823  memset(dsa_get_address(area, result), 0, size);
824 
825  return result;
826 }
unsigned short uint16
Definition: c.h:441
#define lengthof(array)
Definition: c.h:724
static const uint16 dsa_size_classes[]
Definition: dsa.c:248
#define DSA_AREA_LOCK(area)
Definition: dsa.c:155
#define DSA_MAKE_POINTER(segment_number, offset)
Definition: dsa.c:115
#define get_segment_index(area, segment_map_ptr)
Definition: dsa.c:393
static dsa_pointer alloc_object(dsa_area *area, int size_class)
Definition: dsa.c:1449
#define DSA_SIZE_CLASS_MAP_QUANTUM
Definition: dsa.c:281
static const uint8 dsa_size_class_map[]
Definition: dsa.c:271
static dsa_segment_map * make_new_segment(dsa_area *area, size_t requested_pages)
Definition: dsa.c:2072
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:944
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:156
#define DSA_SCLASS_BLOCK_OF_SPANS
Definition: dsa.c:262
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:263
static void init_span(dsa_area *area, dsa_pointer span_pointer, dsa_area_pool *pool, dsa_pointer start, size_t npages, uint16 size_class)
Definition: dsa.c:1354
static dsa_segment_map * get_best_segment(dsa_area *area, size_t npages)
Definition: dsa.c:1980
void dsa_free(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:832
uint64 dsa_pointer
Definition: dsa.h:62
#define InvalidDsaPointer
Definition: dsa.h:78
#define DSA_ALLOC_NO_OOM
Definition: dsa.h:74
#define DsaPointerIsValid(x)
Definition: dsa.h:81
#define DSA_ALLOC_HUGE
Definition: dsa.h:73
#define DSA_ALLOC_ZERO
Definition: dsa.h:75
int errdetail(const char *fmt,...)
Definition: elog.c:1039
int errcode(int sqlerrcode)
Definition: elog.c:695
int errmsg(const char *fmt,...)
Definition: elog.c:906
#define FATAL
Definition: elog.h:37
#define ERROR
Definition: elog.h:35
#define ereport(elevel,...)
Definition: elog.h:145
bool FreePageManagerGet(FreePageManager *fpm, Size npages, Size *first_page)
Definition: freepage.c:210
#define fpm_size_to_pages(sz)
Definition: freepage.h:74
#define FPM_PAGE_SIZE
Definition: freepage.h:30
Assert(fmt[strlen(fmt) - 1] !='\n')
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1194
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1802
@ LW_EXCLUSIVE
Definition: lwlock.h:112
#define AllocHugeSizeIsValid(size)
Definition: memutils.h:49
#define AllocSizeIsValid(size)
Definition: memutils.h:42
dsa_area_pool pools[DSA_NUM_SIZE_CLASSES]
Definition: dsa.c:321
dsa_area_control * control
Definition: dsa.c:369
FreePageManager * fpm
Definition: dsa.c:356
dsa_pointer * pagemap
Definition: dsa.c:357

References alloc_object(), AllocHugeSizeIsValid, AllocSizeIsValid, Assert(), dsa_area::control, DSA_ALLOC_HUGE, DSA_ALLOC_NO_OOM, DSA_ALLOC_ZERO, DSA_AREA_LOCK, dsa_free(), dsa_get_address(), DSA_MAKE_POINTER, DSA_SCLASS_BLOCK_OF_SPANS, DSA_SCLASS_LOCK, DSA_SCLASS_SPAN_LARGE, dsa_size_class_map, DSA_SIZE_CLASS_MAP_QUANTUM, dsa_size_classes, DsaPointerIsValid, elog(), ereport, errcode(), errdetail(), errmsg(), ERROR, FATAL, dsa_segment_map::fpm, FPM_PAGE_SIZE, fpm_size_to_pages, FreePageManagerGet(), get_best_segment(), get_segment_index, init_span(), InvalidDsaPointer, lengthof, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), make_new_segment(), dsa_segment_map::pagemap, and dsa_area_control::pools.

Referenced by dshash_create(), and pagetable_allocate().

◆ dsa_attach()

dsa_area* dsa_attach ( dsa_handle  handle)

Definition at line 518 of file dsa.c.

519 {
520  dsm_segment *segment;
521  dsa_area *area;
522 
523  /*
524  * An area handle is really a DSM segment handle for the first segment, so
525  * we go ahead and attach to that.
526  */
527  segment = dsm_attach(handle);
528  if (segment == NULL)
529  ereport(ERROR,
530  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
531  errmsg("could not attach to dynamic shared area")));
532 
533  area = attach_internal(dsm_segment_address(segment), segment, handle);
534 
535  /* Clean up when the control segment detaches. */
538 
539  return area;
540 }
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:584
static dsa_area * attach_internal(void *place, dsm_segment *segment, dsa_handle handle)
Definition: dsa.c:1303
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1067
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1104
dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:639
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:670
Definition: dsa.c:367

References attach_internal(), dsa_on_dsm_detach_release_in_place(), dsm_attach(), dsm_segment_address(), ereport, errcode(), errmsg(), ERROR, on_dsm_detach(), and PointerGetDatum().

◆ dsa_attach_in_place()

dsa_area* dsa_attach_in_place ( void *  place,
dsm_segment segment 
)

Definition at line 553 of file dsa.c.

554 {
555  dsa_area *area;
556 
557  area = attach_internal(place, NULL, DSM_HANDLE_INVALID);
558 
559  /*
560  * Clean up when the control segment detaches, if a containing DSM segment
561  * was provided.
562  */
563  if (segment != NULL)
565  PointerGetDatum(place));
566 
567  return area;
568 }
#define DSM_HANDLE_INVALID
Definition: dsm.h:23

References attach_internal(), dsa_on_dsm_detach_release_in_place(), DSM_HANDLE_INVALID, on_dsm_detach(), and PointerGetDatum().

Referenced by AttachSession(), ParallelQueryMain(), and pgstat_attach_shmem().

◆ dsa_create()

dsa_area* dsa_create ( int  tranche_id)

Definition at line 432 of file dsa.c.

433 {
434  dsm_segment *segment;
435  dsa_area *area;
436 
437  /*
438  * Create the DSM segment that will hold the shared control object and the
439  * first segment of usable space.
440  */
441  segment = dsm_create(DSA_INITIAL_SEGMENT_SIZE, 0);
442 
443  /*
444  * All segments backing this area are pinned, so that DSA can explicitly
445  * control their lifetime (otherwise a newly created segment belonging to
446  * this area might be freed when the only backend that happens to have it
447  * mapped in ends, corrupting the area).
448  */
449  dsm_pin_segment(segment);
450 
451  /* Create a new DSA area with the control object in this segment. */
452  area = create_internal(dsm_segment_address(segment),
454  tranche_id,
455  dsm_segment_handle(segment), segment);
456 
457  /* Clean up when the control segment detaches. */
460 
461  return area;
462 }
#define DSA_INITIAL_SEGMENT_SIZE
Definition: dsa.c:69
static dsa_area * create_internal(void *place, size_t size, int tranche_id, dsm_handle control_handle, dsm_segment *control_segment)
Definition: dsa.c:1203
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1095
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:490
void dsm_pin_segment(dsm_segment *seg)
Definition: dsm.c:929

References create_internal(), DSA_INITIAL_SEGMENT_SIZE, dsa_on_dsm_detach_release_in_place(), dsm_create(), dsm_pin_segment(), dsm_segment_address(), dsm_segment_handle(), on_dsm_detach(), and PointerGetDatum().

◆ dsa_create_in_place()

dsa_area* dsa_create_in_place ( void *  place,
size_t  size,
int  tranche_id,
dsm_segment segment 
)

Definition at line 481 of file dsa.c.

483 {
484  dsa_area *area;
485 
486  area = create_internal(place, size, tranche_id,
487  DSM_HANDLE_INVALID, NULL);
488 
489  /*
490  * Clean up when the control segment detaches, if a containing DSM segment
491  * was provided.
492  */
493  if (segment != NULL)
495  PointerGetDatum(place));
496 
497  return area;
498 }

References create_internal(), dsa_on_dsm_detach_release_in_place(), DSM_HANDLE_INVALID, on_dsm_detach(), and PointerGetDatum().

Referenced by ExecInitParallelPlan(), GetSessionDsmHandle(), and StatsShmemInit().

◆ dsa_detach()

void dsa_detach ( dsa_area area)

Definition at line 1922 of file dsa.c.

1923 {
1924  int i;
1925 
1926  /* Detach from all segments. */
1927  for (i = 0; i <= area->high_segment_index; ++i)
1928  if (area->segment_maps[i].segment != NULL)
1929  dsm_detach(area->segment_maps[i].segment);
1930 
1931  /*
1932  * Note that 'detaching' (= detaching from DSM segments) doesn't include
1933  * 'releasing' (= adjusting the reference count). It would be nice to
1934  * combine these operations, but client code might never get around to
1935  * calling dsa_detach because of an error path, and a detach hook on any
1936  * particular segment is too late to detach other segments in the area
1937  * without risking a 'leak' warning in the non-error path.
1938  */
1939 
1940  /* Free the backend-local area object. */
1941  pfree(area);
1942 }
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:777
int i
Definition: isn.c:73
void pfree(void *pointer)
Definition: mcxt.c:1306
dsa_segment_map segment_maps[DSA_MAX_SEGMENTS]
Definition: dsa.c:380
dsa_segment_index high_segment_index
Definition: dsa.c:383
dsm_segment * segment
Definition: dsa.c:353

References dsm_detach(), dsa_area::high_segment_index, i, pfree(), dsa_segment_map::segment, and dsa_area::segment_maps.

Referenced by DetachSession(), ExecParallelCleanup(), ParallelQueryMain(), pgstat_detach_shmem(), and StatsShmemInit().

◆ dsa_dump()

void dsa_dump ( dsa_area area)

Definition at line 1077 of file dsa.c.

1078 {
1079  size_t i,
1080  j;
1081 
1082  /*
1083  * Note: This gives an inconsistent snapshot as it acquires and releases
1084  * individual locks as it goes...
1085  */
1086 
1089  fprintf(stderr, "dsa_area handle %x:\n", area->control->handle);
1090  fprintf(stderr, " max_total_segment_size: %zu\n",
1092  fprintf(stderr, " total_segment_size: %zu\n",
1093  area->control->total_segment_size);
1094  fprintf(stderr, " refcnt: %d\n", area->control->refcnt);
1095  fprintf(stderr, " pinned: %c\n", area->control->pinned ? 't' : 'f');
1096  fprintf(stderr, " segment bins:\n");
1097  for (i = 0; i < DSA_NUM_SEGMENT_BINS; ++i)
1098  {
1100  {
1101  dsa_segment_index segment_index;
1102 
1103  fprintf(stderr,
1104  " segment bin %zu (at least %d contiguous pages free):\n",
1105  i, 1 << (i - 1));
1106  segment_index = area->control->segment_bins[i];
1107  while (segment_index != DSA_SEGMENT_INDEX_NONE)
1108  {
1109  dsa_segment_map *segment_map;
1110 
1111  segment_map =
1112  get_segment_by_index(area, segment_index);
1113 
1114  fprintf(stderr,
1115  " segment index %zu, usable_pages = %zu, "
1116  "contiguous_pages = %zu, mapped at %p\n",
1117  segment_index,
1118  segment_map->header->usable_pages,
1119  fpm_largest(segment_map->fpm),
1120  segment_map->mapped_address);
1121  segment_index = segment_map->header->next;
1122  }
1123  }
1124  }
1126 
1127  fprintf(stderr, " pools:\n");
1128  for (i = 0; i < DSA_NUM_SIZE_CLASSES; ++i)
1129  {
1130  bool found = false;
1131 
1133  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1134  if (DsaPointerIsValid(area->control->pools[i].spans[j]))
1135  found = true;
1136  if (found)
1137  {
1139  fprintf(stderr, " pool for blocks of span objects:\n");
1140  else if (i == DSA_SCLASS_SPAN_LARGE)
1141  fprintf(stderr, " pool for large object spans:\n");
1142  else
1143  fprintf(stderr,
1144  " pool for size class %zu (object size %hu bytes):\n",
1145  i, dsa_size_classes[i]);
1146  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1147  {
1148  if (!DsaPointerIsValid(area->control->pools[i].spans[j]))
1149  fprintf(stderr, " fullness class %zu is empty\n", j);
1150  else
1151  {
1152  dsa_pointer span_pointer = area->control->pools[i].spans[j];
1153 
1154  fprintf(stderr, " fullness class %zu:\n", j);
1155  while (DsaPointerIsValid(span_pointer))
1156  {
1157  dsa_area_span *span;
1158 
1159  span = dsa_get_address(area, span_pointer);
1160  fprintf(stderr,
1161  " span descriptor at "
1162  DSA_POINTER_FORMAT ", superblock at "
1164  ", pages = %zu, objects free = %hu/%hu\n",
1165  span_pointer, span->start, span->npages,
1166  span->nallocatable, span->nmax);
1167  span_pointer = span->nextspan;
1168  }
1169  }
1170  }
1171  }
1173  }
1174 }
#define DSA_SEGMENT_INDEX_NONE
Definition: dsa.c:128
static void check_for_freed_segments_locked(dsa_area *area)
Definition: dsa.c:2277
size_t dsa_segment_index
Definition: dsa.c:125
static dsa_segment_map * get_segment_by_index(dsa_area *area, dsa_segment_index index)
Definition: dsa.c:1734
#define DSA_NUM_SIZE_CLASSES
Definition: dsa.c:259
#define DSA_FULLNESS_CLASSES
Definition: dsa.c:289
#define DSA_NUM_SEGMENT_BINS
Definition: dsa.c:134
#define DSA_POINTER_FORMAT
Definition: dsa.h:69
#define fpm_largest(fpm)
Definition: freepage.h:88
int j
Definition: isn.c:74
#define fprintf
Definition: port.h:242
size_t total_segment_size
Definition: dsa.c:323
bool pinned
Definition: dsa.c:331
size_t max_total_segment_size
Definition: dsa.c:325
dsa_segment_index segment_bins[DSA_NUM_SEGMENT_BINS]
Definition: dsa.c:319
int refcnt
Definition: dsa.c:329
dsa_handle handle
Definition: dsa.c:315
dsa_pointer spans[DSA_FULLNESS_CLASSES]
Definition: dsa.c:302
dsa_pointer nextspan
Definition: dsa.c:210
dsa_pointer start
Definition: dsa.c:211
uint16 nallocatable
Definition: dsa.c:215
uint16 nmax
Definition: dsa.c:217
size_t npages
Definition: dsa.c:212
dsa_segment_index next
Definition: dsa.c:182
size_t usable_pages
Definition: dsa.c:168
dsa_segment_header * header
Definition: dsa.c:355
char * mapped_address
Definition: dsa.c:354

References check_for_freed_segments_locked(), dsa_area::control, DSA_AREA_LOCK, DSA_FULLNESS_CLASSES, dsa_get_address(), DSA_NUM_SEGMENT_BINS, DSA_NUM_SIZE_CLASSES, DSA_POINTER_FORMAT, DSA_SCLASS_BLOCK_OF_SPANS, DSA_SCLASS_LOCK, DSA_SCLASS_SPAN_LARGE, DSA_SEGMENT_INDEX_NONE, dsa_size_classes, DsaPointerIsValid, dsa_segment_map::fpm, fpm_largest, fprintf, get_segment_by_index(), dsa_area_control::handle, dsa_segment_map::header, i, j, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_segment_map::mapped_address, dsa_area_control::max_total_segment_size, dsa_area_span::nallocatable, dsa_segment_header::next, dsa_area_span::nextspan, dsa_area_span::nmax, dsa_area_span::npages, dsa_area_control::pinned, dsa_area_control::pools, dsa_area_control::refcnt, dsa_area_control::segment_bins, dsa_area_pool::spans, dsa_area_span::start, dsa_area_control::total_segment_size, and dsa_segment_header::usable_pages.

◆ dsa_free()

void dsa_free ( dsa_area area,
dsa_pointer  dp 
)

Definition at line 832 of file dsa.c.

833 {
834  dsa_segment_map *segment_map;
835  int pageno;
836  dsa_pointer span_pointer;
837  dsa_area_span *span;
838  char *superblock;
839  char *object;
840  size_t size;
841  int size_class;
842 
843  /* Make sure we don't have a stale segment in the slot 'dp' refers to. */
845 
846  /* Locate the object, span and pool. */
847  segment_map = get_segment_by_index(area, DSA_EXTRACT_SEGMENT_NUMBER(dp));
848  pageno = DSA_EXTRACT_OFFSET(dp) / FPM_PAGE_SIZE;
849  span_pointer = segment_map->pagemap[pageno];
850  span = dsa_get_address(area, span_pointer);
851  superblock = dsa_get_address(area, span->start);
852  object = dsa_get_address(area, dp);
853  size_class = span->size_class;
854  size = dsa_size_classes[size_class];
855 
856  /*
857  * Special case for large objects that live in a special span: we return
858  * those pages directly to the free page manager and free the span.
859  */
860  if (span->size_class == DSA_SCLASS_SPAN_LARGE)
861  {
862 
863 #ifdef CLOBBER_FREED_MEMORY
864  memset(object, 0x7f, span->npages * FPM_PAGE_SIZE);
865 #endif
866 
867  /* Give pages back to free page manager. */
869  FreePageManagerPut(segment_map->fpm,
871  span->npages);
873  /* Unlink span. */
875  LW_EXCLUSIVE);
876  unlink_span(area, span);
878  /* Free the span object so it can be reused. */
879  dsa_free(area, span_pointer);
880  return;
881  }
882 
883 #ifdef CLOBBER_FREED_MEMORY
884  memset(object, 0x7f, size);
885 #endif
886 
887  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
888 
889  /* Put the object on the span's freelist. */
890  Assert(object >= superblock);
891  Assert(object < superblock + DSA_SUPERBLOCK_SIZE);
892  Assert((object - superblock) % size == 0);
893  NextFreeObjectIndex(object) = span->firstfree;
894  span->firstfree = (object - superblock) / size;
895  ++span->nallocatable;
896 
897  /*
898  * See if the span needs to moved to a different fullness class, or be
899  * freed so its pages can be given back to the segment.
900  */
901  if (span->nallocatable == 1 && span->fclass == DSA_FULLNESS_CLASSES - 1)
902  {
903  /*
904  * The block was completely full and is located in the
905  * highest-numbered fullness class, which is never scanned for free
906  * chunks. We must move it to the next-lower fullness class.
907  */
908  unlink_span(area, span);
909  add_span_to_fullness_class(area, span, span_pointer,
911 
912  /*
913  * If this is the only span, and there is no active span, then we
914  * should probably move this span to fullness class 1. (Otherwise if
915  * you allocate exactly all the objects in the only span, it moves to
916  * class 3, then you free them all, it moves to 2, and then is given
917  * back, leaving no active span).
918  */
919  }
920  else if (span->nallocatable == span->nmax &&
921  (span->fclass != 1 || span->prevspan != InvalidDsaPointer))
922  {
923  /*
924  * This entire block is free, and it's not the active block for this
925  * size class. Return the memory to the free page manager. We don't
926  * do this for the active block to prevent hysteresis: if we
927  * repeatedly allocate and free the only chunk in the active block, it
928  * will be very inefficient if we deallocate and reallocate the block
929  * every time.
930  */
931  destroy_superblock(area, span_pointer);
932  }
933 
934  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
935 }
static void check_for_freed_segments(dsa_area *area)
Definition: dsa.c:2241
#define DSA_EXTRACT_SEGMENT_NUMBER(dp)
Definition: dsa.c:119
static void add_span_to_fullness_class(dsa_area *area, dsa_area_span *span, dsa_pointer span_pointer, int fclass)
Definition: dsa.c:1899
#define DSA_SUPERBLOCK_SIZE
Definition: dsa.c:390
#define DSA_EXTRACT_OFFSET(dp)
Definition: dsa.c:122
static void destroy_superblock(dsa_area *area, dsa_pointer span_pointer)
Definition: dsa.c:1812
static void unlink_span(dsa_area *area, dsa_area_span *span)
Definition: dsa.c:1876
#define NextFreeObjectIndex(object)
Definition: dsa.c:225
void FreePageManagerPut(FreePageManager *fpm, Size first_page, Size npages)
Definition: freepage.c:379
uint16 fclass
Definition: dsa.c:218
dsa_pointer prevspan
Definition: dsa.c:209
uint16 size_class
Definition: dsa.c:213
uint16 firstfree
Definition: dsa.c:216

References add_span_to_fullness_class(), Assert(), check_for_freed_segments(), destroy_superblock(), DSA_AREA_LOCK, DSA_EXTRACT_OFFSET, DSA_EXTRACT_SEGMENT_NUMBER, DSA_FULLNESS_CLASSES, dsa_get_address(), DSA_SCLASS_LOCK, DSA_SCLASS_SPAN_LARGE, dsa_size_classes, DSA_SUPERBLOCK_SIZE, dsa_area_span::fclass, dsa_area_span::firstfree, dsa_segment_map::fpm, FPM_PAGE_SIZE, FreePageManagerPut(), get_segment_by_index(), InvalidDsaPointer, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_area_span::nallocatable, NextFreeObjectIndex, dsa_area_span::nmax, dsa_area_span::npages, dsa_segment_map::pagemap, dsa_area_span::prevspan, dsa_area_span::size_class, dsa_area_span::start, and unlink_span().

Referenced by delete_item_from_bucket(), delete_key_from_bucket(), destroy_superblock(), dsa_allocate_extended(), dshash_create(), dshash_destroy(), ExecHashTableDetach(), ExecHashTableDetachBatch(), ExecParallelCleanup(), ExecParallelHashIncreaseNumBatches(), ExecParallelHashIncreaseNumBuckets(), ExecParallelHashRepartitionFirst(), ExecParallelReinitialize(), find_or_make_matching_shared_tupledesc(), pagetable_free(), pgstat_free_entry(), resize(), and tbm_free_shared_area().

◆ dsa_get_address()

void* dsa_get_address ( dsa_area area,
dsa_pointer  dp 
)

Definition at line 944 of file dsa.c.

945 {
947  size_t offset;
948 
949  /* Convert InvalidDsaPointer to NULL. */
950  if (!DsaPointerIsValid(dp))
951  return NULL;
952 
953  /* Process any requests to detach from freed segments. */
955 
956  /* Break the dsa_pointer into its components. */
958  offset = DSA_EXTRACT_OFFSET(dp);
960 
961  /* Check if we need to cause this segment to be mapped in. */
962  if (unlikely(area->segment_maps[index].mapped_address == NULL))
963  {
964  /* Call for effect (we don't need the result). */
966  }
967 
968  return area->segment_maps[index].mapped_address + offset;
969 }
#define unlikely(x)
Definition: c.h:295
#define DSA_MAX_SEGMENTS
Definition: dsa.c:95
Definition: type.h:95

References Assert(), check_for_freed_segments(), DSA_EXTRACT_OFFSET, DSA_EXTRACT_SEGMENT_NUMBER, DSA_MAX_SEGMENTS, DsaPointerIsValid, get_segment_by_index(), dsa_segment_map::mapped_address, dsa_area::segment_maps, and unlikely.

Referenced by add_span_to_fullness_class(), alloc_object(), delete_item_from_bucket(), delete_key_from_bucket(), destroy_superblock(), dsa_allocate_extended(), dsa_dump(), dsa_free(), dsa_trim(), dshash_attach(), dshash_create(), dshash_destroy(), dshash_dump(), dshash_seq_next(), ensure_active_superblock(), ensure_valid_bucket_pointers(), ExecHashTableDetachBatch(), ExecParallelHashEnsureBatchAccessors(), ExecParallelHashFirstTuple(), ExecParallelHashIncreaseNumBatches(), ExecParallelHashIncreaseNumBuckets(), ExecParallelHashJoinSetUpBatches(), ExecParallelHashNextTuple(), ExecParallelHashPopChunkQueue(), ExecParallelHashRepartitionRest(), ExecParallelHashTableAlloc(), ExecParallelHashTableSetCurrentBatch(), ExecParallelHashTupleAlloc(), find_in_bucket(), find_or_make_matching_shared_tupledesc(), init_span(), insert_into_bucket(), insert_item_into_bucket(), lookup_rowtype_tupdesc_internal(), pagetable_allocate(), ParallelQueryMain(), pgstat_build_snapshot(), pgstat_get_entry_ref(), pgstat_init_entry(), pgstat_reinit_entry(), pgstat_reset_matching_entries(), pgstat_write_statsfile(), resize(), SerializeParamExecParams(), share_tupledesc(), shared_record_table_compare(), shared_record_table_hash(), tbm_attach_shared_iterate(), tbm_free_shared_area(), tbm_prepare_shared_iterate(), transfer_first_span(), and unlink_span().

◆ dsa_get_handle()

dsa_handle dsa_get_handle ( dsa_area area)

Definition at line 506 of file dsa.c.

507 {
509  return area->control->handle;
510 }

References Assert(), dsa_area::control, DSM_HANDLE_INVALID, and dsa_area_control::handle.

◆ dsa_minimum_size()

size_t dsa_minimum_size ( void  )

Definition at line 1181 of file dsa.c.

1182 {
1183  size_t size;
1184  int pages = 0;
1185 
1186  size = MAXALIGN(sizeof(dsa_area_control)) +
1187  MAXALIGN(sizeof(FreePageManager));
1188 
1189  /* Figure out how many pages we need, including the page map... */
1190  while (((size + FPM_PAGE_SIZE - 1) / FPM_PAGE_SIZE) > pages)
1191  {
1192  ++pages;
1193  size += sizeof(dsa_pointer);
1194  }
1195 
1196  return pages * FPM_PAGE_SIZE;
1197 }
#define MAXALIGN(LEN)
Definition: c.h:747

References FPM_PAGE_SIZE, and MAXALIGN.

Referenced by create_internal(), ExecInitParallelPlan(), and pgstat_dsa_init_size().

◆ dsa_on_dsm_detach_release_in_place()

void dsa_on_dsm_detach_release_in_place ( dsm_segment segment,
Datum  place 
)

Definition at line 584 of file dsa.c.

585 {
587 }
void dsa_release_in_place(void *place)
Definition: dsa.c:613
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:660

References DatumGetPointer(), and dsa_release_in_place().

Referenced by dsa_attach(), dsa_attach_in_place(), dsa_create(), and dsa_create_in_place().

◆ dsa_on_shmem_exit_release_in_place()

void dsa_on_shmem_exit_release_in_place ( int  code,
Datum  place 
)

Definition at line 598 of file dsa.c.

599 {
601 }

References DatumGetPointer(), and dsa_release_in_place().

◆ dsa_pin()

void dsa_pin ( dsa_area area)

Definition at line 977 of file dsa.c.

978 {
980  if (area->control->pinned)
981  {
983  elog(ERROR, "dsa_area already pinned");
984  }
985  area->control->pinned = true;
986  ++area->control->refcnt;
988 }

References dsa_area::control, DSA_AREA_LOCK, elog(), ERROR, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_area_control::pinned, and dsa_area_control::refcnt.

Referenced by StatsShmemInit().

◆ dsa_pin_mapping()

void dsa_pin_mapping ( dsa_area area)

Definition at line 643 of file dsa.c.

644 {
645  int i;
646 
647  Assert(!area->mapping_pinned);
648  area->mapping_pinned = true;
649 
650  for (i = 0; i <= area->high_segment_index; ++i)
651  if (area->segment_maps[i].segment != NULL)
653 }
void dsm_pin_mapping(dsm_segment *seg)
Definition: dsm.c:889
bool mapping_pinned
Definition: dsa.c:372

References Assert(), dsm_pin_mapping(), dsa_area::high_segment_index, i, dsa_area::mapping_pinned, dsa_segment_map::segment, and dsa_area::segment_maps.

Referenced by AttachSession(), GetSessionDsmHandle(), and pgstat_attach_shmem().

◆ dsa_release_in_place()

void dsa_release_in_place ( void *  place)

Definition at line 613 of file dsa.c.

614 {
615  dsa_area_control *control = (dsa_area_control *) place;
616  int i;
617 
618  LWLockAcquire(&control->lock, LW_EXCLUSIVE);
619  Assert(control->segment_header.magic ==
620  (DSA_SEGMENT_HEADER_MAGIC ^ control->handle ^ 0));
621  Assert(control->refcnt > 0);
622  if (--control->refcnt == 0)
623  {
624  for (i = 0; i <= control->high_segment_index; ++i)
625  {
626  dsm_handle handle;
627 
628  handle = control->segment_handles[i];
629  if (handle != DSM_HANDLE_INVALID)
630  dsm_unpin_segment(handle);
631  }
632  }
633  LWLockRelease(&control->lock);
634 }
#define DSA_SEGMENT_HEADER_MAGIC
Definition: dsa.c:112
void dsm_unpin_segment(dsm_handle handle)
Definition: dsm.c:961
uint32 dsm_handle
Definition: dsm_impl.h:55
dsa_segment_header segment_header
Definition: dsa.c:313
dsa_segment_index high_segment_index
Definition: dsa.c:327
LWLock lock
Definition: dsa.c:337
dsm_handle segment_handles[DSA_MAX_SEGMENTS]
Definition: dsa.c:317
uint32 magic
Definition: dsa.c:166

References Assert(), DSA_SEGMENT_HEADER_MAGIC, DSM_HANDLE_INVALID, dsm_unpin_segment(), dsa_area_control::handle, dsa_area_control::high_segment_index, i, dsa_area_control::lock, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_segment_header::magic, dsa_area_control::refcnt, dsa_area_control::segment_handles, and dsa_area_control::segment_header.

Referenced by dsa_on_dsm_detach_release_in_place(), and dsa_on_shmem_exit_release_in_place().

◆ dsa_set_size_limit()

void dsa_set_size_limit ( dsa_area area,
size_t  limit 
)

◆ dsa_trim()

void dsa_trim ( dsa_area area)

Definition at line 1032 of file dsa.c.

1033 {
1034  int size_class;
1035 
1036  /*
1037  * Trim in reverse pool order so we get to the spans-of-spans last, just
1038  * in case any become entirely free while processing all the other pools.
1039  */
1040  for (size_class = DSA_NUM_SIZE_CLASSES - 1; size_class >= 0; --size_class)
1041  {
1042  dsa_area_pool *pool = &area->control->pools[size_class];
1043  dsa_pointer span_pointer;
1044 
1045  if (size_class == DSA_SCLASS_SPAN_LARGE)
1046  {
1047  /* Large object frees give back segments aggressively already. */
1048  continue;
1049  }
1050 
1051  /*
1052  * Search fullness class 1 only. That is where we expect to find an
1053  * entirely empty superblock (entirely empty superblocks in other
1054  * fullness classes are returned to the free page map by dsa_free).
1055  */
1056  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
1057  span_pointer = pool->spans[1];
1058  while (DsaPointerIsValid(span_pointer))
1059  {
1060  dsa_area_span *span = dsa_get_address(area, span_pointer);
1061  dsa_pointer next = span->nextspan;
1062 
1063  if (span->nallocatable == span->nmax)
1064  destroy_superblock(area, span_pointer);
1065 
1066  span_pointer = next;
1067  }
1068  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
1069  }
1070 }
static int32 next
Definition: blutils.c:219

References dsa_area::control, destroy_superblock(), dsa_get_address(), DSA_NUM_SIZE_CLASSES, DSA_SCLASS_LOCK, DSA_SCLASS_SPAN_LARGE, DsaPointerIsValid, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_area_span::nallocatable, next, dsa_area_span::nextspan, dsa_area_span::nmax, dsa_area_control::pools, and dsa_area_pool::spans.

◆ dsa_unpin()

void dsa_unpin ( dsa_area area)

Definition at line 996 of file dsa.c.

997 {
999  Assert(area->control->refcnt > 1);
1000  if (!area->control->pinned)
1001  {
1003  elog(ERROR, "dsa_area not pinned");
1004  }
1005  area->control->pinned = false;
1006  --area->control->refcnt;
1008 }

References Assert(), dsa_area::control, DSA_AREA_LOCK, elog(), ERROR, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), dsa_area_control::pinned, and dsa_area_control::refcnt.