PostgreSQL Source Code  git master
dsa.h File Reference
#include "port/atomics.h"
#include "storage/dsm.h"
Include dependency graph for dsa.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

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

void dsa_startup (void)
 
dsa_areadsa_create (int tranche_id)
 
dsa_areadsa_create_in_place (void *place, Size 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 limit)
 
Size dsa_minimum_size (void)
 
dsa_handle dsa_get_handle (dsa_area *area)
 
dsa_pointer dsa_allocate_extended (dsa_area *area, Size 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.

Referenced by dsa_allocate_extended(), and pagetable_allocate().

◆ DSA_ALLOC_NO_OOM

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

Definition at line 74 of file dsa.h.

Referenced by dsa_allocate_extended(), and dshash_create().

◆ DSA_ALLOC_ZERO

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

Definition at line 75 of file dsa.h.

Referenced by dsa_allocate_extended(), dshash_create(), and pagetable_allocate().

◆ dsa_allocate

◆ dsa_allocate0

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

Definition at line 88 of file dsa.h.

Referenced by ExecParallelHashJoinSetUpBatches(), resize(), and tbm_prepare_shared_iterate().

◆ dsa_pointer_atomic_compare_exchange

#define dsa_pointer_atomic_compare_exchange   pg_atomic_compare_exchange_u64

Definition at line 68 of file dsa.h.

Referenced by ExecParallelHashPushTuple().

◆ 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

◆ dsa_pointer_atomic_read

#define dsa_pointer_atomic_read   pg_atomic_read_u64

Definition at line 65 of file dsa.h.

Referenced by ExecParallelHashFirstTuple(), and ExecParallelHashPushTuple().

◆ dsa_pointer_atomic_write

#define dsa_pointer_atomic_write   pg_atomic_write_u64

Definition at line 66 of file dsa.h.

Referenced by ExecParallelHashIncreaseNumBatches().

◆ DSA_POINTER_FORMAT

#define DSA_POINTER_FORMAT   "%016" INT64_MODIFIER "x"

Definition at line 69 of file dsa.h.

Referenced by dsa_dump().

◆ DsaPointerIsValid

◆ InvalidDsaPointer

◆ SIZEOF_DSA_POINTER

#define SIZEOF_DSA_POINTER   8

Definition at line 42 of file dsa.h.

Typedef Documentation

◆ dsa_area

Definition at line 22 of file dsa.h.

◆ dsa_handle

Definition at line 100 of file dsa.h.

◆ 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  size,
int  flags 
)

Definition at line 664 of file dsa.c.

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().

665 {
666  uint16 size_class;
667  dsa_pointer start_pointer;
668  dsa_segment_map *segment_map;
669  dsa_pointer result;
670 
671  Assert(size > 0);
672 
673  /* Sanity check on huge individual allocation size. */
674  if (((flags & DSA_ALLOC_HUGE) != 0 && !AllocHugeSizeIsValid(size)) ||
675  ((flags & DSA_ALLOC_HUGE) == 0 && !AllocSizeIsValid(size)))
676  elog(ERROR, "invalid DSA memory alloc request size %zu", size);
677 
678  /*
679  * If bigger than the largest size class, just grab a run of pages from
680  * the free page manager, instead of allocating an object from a pool.
681  * There will still be a span, but it's a special class of span that
682  * manages this whole allocation and simply gives all pages back to the
683  * free page manager when dsa_free is called.
684  */
685  if (size > dsa_size_classes[lengthof(dsa_size_classes) - 1])
686  {
687  Size npages = fpm_size_to_pages(size);
688  Size first_page;
689  dsa_pointer span_pointer;
691 
692  /* Obtain a span object. */
693  span_pointer = alloc_object(area, DSA_SCLASS_BLOCK_OF_SPANS);
694  if (!DsaPointerIsValid(span_pointer))
695  return InvalidDsaPointer;
696 
698 
699  /* Find a segment from which to allocate. */
700  segment_map = get_best_segment(area, npages);
701  if (segment_map == NULL)
702  segment_map = make_new_segment(area, npages);
703  if (segment_map == NULL)
704  {
705  /* Can't make any more segments: game over. */
707  dsa_free(area, 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 
719  /*
720  * Ask the free page manager for a run of pages. This should always
721  * succeed, since both get_best_segment and make_new_segment should
722  * only return a non-NULL pointer if it actually contains enough
723  * contiguous freespace. If it does fail, something in our backend
724  * private state is out of whack, so use FATAL to kill the process.
725  */
726  if (!FreePageManagerGet(segment_map->fpm, npages, &first_page))
727  elog(FATAL,
728  "dsa_allocate could not find %zu free pages", npages);
730 
731  start_pointer = DSA_MAKE_POINTER(get_segment_index(area, segment_map),
732  first_page * FPM_PAGE_SIZE);
733 
734  /* Initialize span and pagemap. */
736  LW_EXCLUSIVE);
737  init_span(area, span_pointer, pool, start_pointer, npages,
739  segment_map->pagemap[first_page] = span_pointer;
741 
742  /* Zero-initialize the memory if requested. */
743  if ((flags & DSA_ALLOC_ZERO) != 0)
744  memset(dsa_get_address(area, start_pointer), 0, size);
745 
746  return start_pointer;
747  }
748 
749  /* Map allocation to a size class. */
751  {
752  int mapidx;
753 
754  /* For smaller sizes we have a lookup table... */
755  mapidx = ((size + DSA_SIZE_CLASS_MAP_QUANTUM - 1) /
756  DSA_SIZE_CLASS_MAP_QUANTUM) - 1;
757  size_class = dsa_size_class_map[mapidx];
758  }
759  else
760  {
761  uint16 min;
762  uint16 max;
763 
764  /* ... and for the rest we search by binary chop. */
766  max = lengthof(dsa_size_classes) - 1;
767 
768  while (min < max)
769  {
770  uint16 mid = (min + max) / 2;
771  uint16 class_size = dsa_size_classes[mid];
772 
773  if (class_size < size)
774  min = mid + 1;
775  else
776  max = mid;
777  }
778 
779  size_class = min;
780  }
781  Assert(size <= dsa_size_classes[size_class]);
782  Assert(size_class == 0 || size > dsa_size_classes[size_class - 1]);
783 
784  /* Attempt to allocate an object from the appropriate pool. */
785  result = alloc_object(area, size_class);
786 
787  /* Check for failure to allocate. */
788  if (!DsaPointerIsValid(result))
789  {
790  /* Raise error unless asked not to. */
791  if ((flags & DSA_ALLOC_NO_OOM) == 0)
792  {
793  ereport(ERROR,
794  (errcode(ERRCODE_OUT_OF_MEMORY),
795  errmsg("out of memory"),
796  errdetail("Failed on DSA request of size %zu.", size)));
797  }
798  return InvalidDsaPointer;
799  }
800 
801  /* Zero-initialize the memory if requested. */
802  if ((flags & DSA_ALLOC_ZERO) != 0)
803  memset(dsa_get_address(area, result), 0, size);
804 
805  return result;
806 }
#define DSA_ALLOC_NO_OOM
Definition: dsa.h:74
#define InvalidDsaPointer
Definition: dsa.h:78
#define DSA_ALLOC_ZERO
Definition: dsa.h:75
static char dsa_size_class_map[]
Definition: dsa.c:259
#define fpm_size_to_pages(sz)
Definition: freepage.h:74
int errcode(int sqlerrcode)
Definition: elog.c:575
static dsa_segment_map * get_best_segment(dsa_area *area, Size npages)
Definition: dsa.c:1942
#define lengthof(array)
Definition: c.h:629
uint64 dsa_pointer
Definition: dsa.h:62
FreePageManager * fpm
Definition: dsa.c:344
#define get_segment_index(area, segment_map_ptr)
Definition: dsa.c:381
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:924
bool FreePageManagerGet(FreePageManager *fpm, Size npages, Size *first_page)
Definition: freepage.c:210
unsigned short uint16
Definition: c.h:324
#define ERROR
Definition: elog.h:43
#define FATAL
Definition: elog.h:52
dsa_area_control * control
Definition: dsa.c:357
int errdetail(const char *fmt,...)
Definition: elog.c:873
#define ereport(elevel, rest)
Definition: elog.h:122
static const uint16 dsa_size_classes[]
Definition: dsa.c:236
#define AllocSizeIsValid(size)
Definition: memutils.h:42
static void init_span(dsa_area *area, dsa_pointer span_pointer, dsa_area_pool *pool, dsa_pointer start, Size npages, uint16 size_class)
Definition: dsa.c:1336
static dsa_segment_map * make_new_segment(dsa_area *area, Size requested_pages)
Definition: dsa.c:2033
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:144
#define DSA_SIZE_CLASS_MAP_QUANTUM
Definition: dsa.c:269
#define FPM_PAGE_SIZE
Definition: freepage.h:30
#define DSA_SCLASS_BLOCK_OF_SPANS
Definition: dsa.c:250
#define DSA_ALLOC_HUGE
Definition: dsa.h:73
#define Assert(condition)
Definition: c.h:699
#define DSA_MAKE_POINTER(segment_number, offset)
Definition: dsa.c:114
dsa_area_pool pools[DSA_NUM_SIZE_CLASSES]
Definition: dsa.c:309
size_t Size
Definition: c.h:433
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
dsa_pointer * pagemap
Definition: dsa.c:345
#define AllocHugeSizeIsValid(size)
Definition: memutils.h:46
#define DsaPointerIsValid(x)
Definition: dsa.h:81
void dsa_free(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:812
int errmsg(const char *fmt,...)
Definition: elog.c:797
static dsa_pointer alloc_object(dsa_area *area, int size_class)
Definition: dsa.c:1431
#define elog
Definition: elog.h:219
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:251

◆ dsa_attach()

dsa_area* dsa_attach ( dsa_handle  handle)

Definition at line 505 of file dsa.c.

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

506 {
507  dsm_segment *segment;
508  dsa_area *area;
509 
510  /*
511  * An area handle is really a DSM segment handle for the first segment, so
512  * we go ahead and attach to that.
513  */
514  segment = dsm_attach(handle);
515  if (segment == NULL)
516  ereport(ERROR,
517  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
518  errmsg("could not attach to dynamic shared area")));
519 
520  area = attach_internal(dsm_segment_address(segment), segment, handle);
521 
522  /* Clean up when the control segment detaches. */
525 
526  return area;
527 }
#define PointerGetDatum(X)
Definition: postgres.h:541
dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:548
int errcode(int sqlerrcode)
Definition: elog.c:575
static dsa_area * attach_internal(void *place, dsm_segment *segment, dsa_handle handle)
Definition: dsa.c:1285
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1024
#define ERROR
Definition: elog.h:43
#define ereport(elevel, rest)
Definition: elog.h:122
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:571
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:987
Definition: dsa.c:354
int errmsg(const char *fmt,...)
Definition: elog.c:797

◆ dsa_attach_in_place()

dsa_area* dsa_attach_in_place ( void *  place,
dsm_segment segment 
)

Definition at line 540 of file dsa.c.

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

Referenced by AttachSession(), and ParallelQueryMain().

541 {
542  dsa_area *area;
543 
544  area = attach_internal(place, NULL, DSM_HANDLE_INVALID);
545 
546  /*
547  * Clean up when the control segment detaches, if a containing DSM segment
548  * was provided.
549  */
550  if (segment != NULL)
552  PointerGetDatum(place));
553 
554  return area;
555 }
#define PointerGetDatum(X)
Definition: postgres.h:541
static dsa_area * attach_internal(void *place, dsm_segment *segment, dsa_handle handle)
Definition: dsa.c:1285
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1024
#define DSM_HANDLE_INVALID
Definition: dsm.h:23
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:571
Definition: dsa.c:354

◆ dsa_create()

dsa_area* dsa_create ( int  tranche_id)

Definition at line 419 of file dsa.c.

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.

420 {
421  dsm_segment *segment;
422  dsa_area *area;
423 
424  /*
425  * Create the DSM segment that will hold the shared control object and the
426  * first segment of usable space.
427  */
428  segment = dsm_create(DSA_INITIAL_SEGMENT_SIZE, 0);
429 
430  /*
431  * All segments backing this area are pinned, so that DSA can explicitly
432  * control their lifetime (otherwise a newly created segment belonging to
433  * this area might be freed when the only backend that happens to have it
434  * mapped in ends, corrupting the area).
435  */
436  dsm_pin_segment(segment);
437 
438  /* Create a new DSA area with the control object in this segment. */
439  area = create_internal(dsm_segment_address(segment),
441  tranche_id,
442  dsm_segment_handle(segment), segment);
443 
444  /* Clean up when the control segment detaches. */
447 
448  return area;
449 }
#define PointerGetDatum(X)
Definition: postgres.h:541
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1015
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1024
void dsm_pin_segment(dsm_segment *seg)
Definition: dsm.c:854
#define DSA_INITIAL_SEGMENT_SIZE
Definition: dsa.c:68
static dsa_area * create_internal(void *place, size_t size, int tranche_id, dsm_handle control_handle, dsm_segment *control_segment)
Definition: dsa.c:1182
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:571
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:452
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:987
Definition: dsa.c:354

◆ dsa_create_in_place()

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

Definition at line 468 of file dsa.c.

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

Referenced by ExecInitParallelPlan(), and GetSessionDsmHandle().

470 {
471  dsa_area *area;
472 
473  area = create_internal(place, size, tranche_id,
474  DSM_HANDLE_INVALID, NULL);
475 
476  /*
477  * Clean up when the control segment detaches, if a containing DSM segment
478  * was provided.
479  */
480  if (segment != NULL)
482  PointerGetDatum(place));
483 
484  return area;
485 }
#define PointerGetDatum(X)
Definition: postgres.h:541
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1024
#define DSM_HANDLE_INVALID
Definition: dsm.h:23
static dsa_area * create_internal(void *place, size_t size, int tranche_id, dsm_handle control_handle, dsm_segment *control_segment)
Definition: dsa.c:1182
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:571
Definition: dsa.c:354

◆ dsa_detach()

void dsa_detach ( dsa_area area)

Definition at line 1884 of file dsa.c.

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

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

1885 {
1886  int i;
1887 
1888  /* Detach from all segments. */
1889  for (i = 0; i <= area->high_segment_index; ++i)
1890  if (area->segment_maps[i].segment != NULL)
1891  dsm_detach(area->segment_maps[i].segment);
1892 
1893  /*
1894  * Note that 'detaching' (= detaching from DSM segments) doesn't include
1895  * 'releasing' (= adjusting the reference count). It would be nice to
1896  * combine these operations, but client code might never get around to
1897  * calling dsa_detach because of an error path, and a detach hook on any
1898  * particular segment is too late to detach other segments in the area
1899  * without risking a 'leak' warning in the non-error path.
1900  */
1901 
1902  /* Free the backend-local area object. */
1903  pfree(area);
1904 }
dsa_segment_index high_segment_index
Definition: dsa.c:371
dsm_segment * segment
Definition: dsa.c:341
void pfree(void *pointer)
Definition: mcxt.c:1031
dsa_segment_map segment_maps[DSA_MAX_SEGMENTS]
Definition: dsa.c:368
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:713
int i

◆ dsa_dump()

void dsa_dump ( dsa_area area)

Definition at line 1057 of file dsa.c.

References 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, get_segment_by_index(), dsa_area_control::handle, dsa_segment_map::header, i, 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.

1058 {
1059  Size i,
1060  j;
1061 
1062  /*
1063  * Note: This gives an inconsistent snapshot as it acquires and releases
1064  * individual locks as it goes...
1065  */
1066 
1068  fprintf(stderr, "dsa_area handle %x:\n", area->control->handle);
1069  fprintf(stderr, " max_total_segment_size: %zu\n",
1071  fprintf(stderr, " total_segment_size: %zu\n",
1072  area->control->total_segment_size);
1073  fprintf(stderr, " refcnt: %d\n", area->control->refcnt);
1074  fprintf(stderr, " pinned: %c\n", area->control->pinned ? 't' : 'f');
1075  fprintf(stderr, " segment bins:\n");
1076  for (i = 0; i < DSA_NUM_SEGMENT_BINS; ++i)
1077  {
1078  if (area->control->segment_bins[i] != DSA_SEGMENT_INDEX_NONE)
1079  {
1080  dsa_segment_index segment_index;
1081 
1082  fprintf(stderr,
1083  " segment bin %zu (at least %d contiguous pages free):\n",
1084  i, 1 << (i - 1));
1085  segment_index = area->control->segment_bins[i];
1086  while (segment_index != DSA_SEGMENT_INDEX_NONE)
1087  {
1088  dsa_segment_map *segment_map;
1089 
1090  segment_map =
1091  get_segment_by_index(area, segment_index);
1092 
1093  fprintf(stderr,
1094  " segment index %zu, usable_pages = %zu, "
1095  "contiguous_pages = %zu, mapped at %p\n",
1096  segment_index,
1097  segment_map->header->usable_pages,
1098  fpm_largest(segment_map->fpm),
1099  segment_map->mapped_address);
1100  segment_index = segment_map->header->next;
1101  }
1102  }
1103  }
1105 
1106  fprintf(stderr, " pools:\n");
1107  for (i = 0; i < DSA_NUM_SIZE_CLASSES; ++i)
1108  {
1109  bool found = false;
1110 
1112  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1113  if (DsaPointerIsValid(area->control->pools[i].spans[j]))
1114  found = true;
1115  if (found)
1116  {
1117  if (i == DSA_SCLASS_BLOCK_OF_SPANS)
1118  fprintf(stderr, " pool for blocks of span objects:\n");
1119  else if (i == DSA_SCLASS_SPAN_LARGE)
1120  fprintf(stderr, " pool for large object spans:\n");
1121  else
1122  fprintf(stderr,
1123  " pool for size class %zu (object size %hu bytes):\n",
1124  i, dsa_size_classes[i]);
1125  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1126  {
1127  if (!DsaPointerIsValid(area->control->pools[i].spans[j]))
1128  fprintf(stderr, " fullness class %zu is empty\n", j);
1129  else
1130  {
1131  dsa_pointer span_pointer = area->control->pools[i].spans[j];
1132 
1133  fprintf(stderr, " fullness class %zu:\n", j);
1134  while (DsaPointerIsValid(span_pointer))
1135  {
1136  dsa_area_span *span;
1137 
1138  span = dsa_get_address(area, span_pointer);
1139  fprintf(stderr,
1140  " span descriptor at "
1141  DSA_POINTER_FORMAT ", superblock at "
1143  ", pages = %zu, objects free = %hu/%hu\n",
1144  span_pointer, span->start, span->npages,
1145  span->nallocatable, span->nmax);
1146  span_pointer = span->nextspan;
1147  }
1148  }
1149  }
1150  }
1151  LWLockRelease(DSA_SCLASS_LOCK(area, i));
1152  }
1153 }
uint16 nmax
Definition: dsa.c:205
dsa_segment_index segment_bins[DSA_NUM_SEGMENT_BINS]
Definition: dsa.c:307
dsa_pointer nextspan
Definition: dsa.c:198
Size max_total_segment_size
Definition: dsa.c:313
#define DSA_NUM_SIZE_CLASSES
Definition: dsa.c:247
bool pinned
Definition: dsa.c:319
#define DSA_FULLNESS_CLASSES
Definition: dsa.c:277
dsa_pointer start
Definition: dsa.c:199
uint64 dsa_pointer
Definition: dsa.h:62
FreePageManager * fpm
Definition: dsa.c:344
dsa_segment_header * header
Definition: dsa.c:343
Size total_segment_size
Definition: dsa.c:311
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:924
#define DSA_POINTER_FORMAT
Definition: dsa.h:69
int refcnt
Definition: dsa.c:317
dsa_segment_index next
Definition: dsa.c:170
dsa_area_control * control
Definition: dsa.c:357
#define DSA_NUM_SEGMENT_BINS
Definition: dsa.c:133
static const uint16 dsa_size_classes[]
Definition: dsa.c:236
Size dsa_segment_index
Definition: dsa.c:124
Size npages
Definition: dsa.c:200
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:144
#define DSA_SCLASS_BLOCK_OF_SPANS
Definition: dsa.c:250
#define fpm_largest(fpm)
Definition: freepage.h:88
#define DSA_SEGMENT_INDEX_NONE
Definition: dsa.c:127
dsa_area_pool pools[DSA_NUM_SIZE_CLASSES]
Definition: dsa.c:309
size_t Size
Definition: c.h:433
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
dsa_pointer spans[DSA_FULLNESS_CLASSES]
Definition: dsa.c:290
char * mapped_address
Definition: dsa.c:342
#define DsaPointerIsValid(x)
Definition: dsa.h:81
Size usable_pages
Definition: dsa.c:156
uint16 nallocatable
Definition: dsa.c:203
int i
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:251
dsa_handle handle
Definition: dsa.c:303
static dsa_segment_map * get_segment_by_index(dsa_area *area, dsa_segment_index index)
Definition: dsa.c:1714

◆ dsa_free()

void dsa_free ( dsa_area area,
dsa_pointer  dp 
)

Definition at line 812 of file dsa.c.

References add_span_to_fullness_class(), Assert, check_for_freed_segments(), destroy_superblock(), DSA_AREA_LOCK, DSA_EXTRACT_OFFSET, DSA_EXTRACT_SEGMENT_NUMBER, dsa_free(), 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(), dsa_free(), dshash_create(), dshash_destroy(), ensure_active_superblock(), ExecHashTableDetach(), ExecHashTableDetachBatch(), ExecParallelCleanup(), ExecParallelHashIncreaseNumBatches(), ExecParallelHashIncreaseNumBuckets(), ExecParallelHashRepartitionFirst(), ExecParallelReinitialize(), find_or_make_matching_shared_tupledesc(), pagetable_free(), resize(), and tbm_free_shared_area().

813 {
814  dsa_segment_map *segment_map;
815  int pageno;
816  dsa_pointer span_pointer;
817  dsa_area_span *span;
818  char *superblock;
819  char *object;
820  Size size;
821  int size_class;
822 
823  /* Make sure we don't have a stale segment in the slot 'dp' refers to. */
825 
826  /* Locate the object, span and pool. */
827  segment_map = get_segment_by_index(area, DSA_EXTRACT_SEGMENT_NUMBER(dp));
828  pageno = DSA_EXTRACT_OFFSET(dp) / FPM_PAGE_SIZE;
829  span_pointer = segment_map->pagemap[pageno];
830  span = dsa_get_address(area, span_pointer);
831  superblock = dsa_get_address(area, span->start);
832  object = dsa_get_address(area, dp);
833  size_class = span->size_class;
834  size = dsa_size_classes[size_class];
835 
836  /*
837  * Special case for large objects that live in a special span: we return
838  * those pages directly to the free page manager and free the span.
839  */
840  if (span->size_class == DSA_SCLASS_SPAN_LARGE)
841  {
842 
843 #ifdef CLOBBER_FREED_MEMORY
844  memset(object, 0x7f, span->npages * FPM_PAGE_SIZE);
845 #endif
846 
847  /* Give pages back to free page manager. */
849  FreePageManagerPut(segment_map->fpm,
851  span->npages);
853  /* Unlink span. */
855  LW_EXCLUSIVE);
856  unlink_span(area, span);
858  /* Free the span object so it can be reused. */
859  dsa_free(area, span_pointer);
860  return;
861  }
862 
863 #ifdef CLOBBER_FREED_MEMORY
864  memset(object, 0x7f, size);
865 #endif
866 
867  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
868 
869  /* Put the object on the span's freelist. */
870  Assert(object >= superblock);
871  Assert(object < superblock + DSA_SUPERBLOCK_SIZE);
872  Assert((object - superblock) % size == 0);
873  NextFreeObjectIndex(object) = span->firstfree;
874  span->firstfree = (object - superblock) / size;
875  ++span->nallocatable;
876 
877  /*
878  * See if the span needs to moved to a different fullness class, or be
879  * freed so its pages can be given back to the segment.
880  */
881  if (span->nallocatable == 1 && span->fclass == DSA_FULLNESS_CLASSES - 1)
882  {
883  /*
884  * The block was completely full and is located in the
885  * highest-numbered fullness class, which is never scanned for free
886  * chunks. We must move it to the next-lower fullness class.
887  */
888  unlink_span(area, span);
889  add_span_to_fullness_class(area, span, span_pointer,
891 
892  /*
893  * If this is the only span, and there is no active span, then we
894  * should probably move this span to fullness class 1. (Otherwise if
895  * you allocate exactly all the objects in the only span, it moves to
896  * class 3, then you free them all, it moves to 2, and then is given
897  * back, leaving no active span).
898  */
899  }
900  else if (span->nallocatable == span->nmax &&
901  (span->fclass != 1 || span->prevspan != InvalidDsaPointer))
902  {
903  /*
904  * This entire block is free, and it's not the active block for this
905  * size class. Return the memory to the free page manager. We don't
906  * do this for the active block to prevent hysteresis: if we
907  * repeatedly allocate and free the only chunk in the active block, it
908  * will be very inefficient if we deallocate and reallocate the block
909  * every time.
910  */
911  destroy_superblock(area, span_pointer);
912  }
913 
914  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
915 }
uint16 nmax
Definition: dsa.c:205
#define DSA_SUPERBLOCK_SIZE
Definition: dsa.c:378
#define InvalidDsaPointer
Definition: dsa.h:78
#define DSA_FULLNESS_CLASSES
Definition: dsa.c:277
dsa_pointer start
Definition: dsa.c:199
uint64 dsa_pointer
Definition: dsa.h:62
void FreePageManagerPut(FreePageManager *fpm, Size first_page, Size npages)
Definition: freepage.c:379
FreePageManager * fpm
Definition: dsa.c:344
uint16 fclass
Definition: dsa.c:206
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:924
uint16 size_class
Definition: dsa.c:201
static const uint16 dsa_size_classes[]
Definition: dsa.c:236
static void unlink_span(dsa_area *area, dsa_area_span *span)
Definition: dsa.c:1838
Size npages
Definition: dsa.c:200
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:144
dsa_pointer prevspan
Definition: dsa.c:197
#define FPM_PAGE_SIZE
Definition: freepage.h:30
static void add_span_to_fullness_class(dsa_area *area, dsa_area_span *span, dsa_pointer span_pointer, int fclass)
Definition: dsa.c:1861
#define DSA_EXTRACT_SEGMENT_NUMBER(dp)
Definition: dsa.c:118
#define Assert(condition)
Definition: c.h:699
#define DSA_EXTRACT_OFFSET(dp)
Definition: dsa.c:121
size_t Size
Definition: c.h:433
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
dsa_pointer * pagemap
Definition: dsa.c:345
static void destroy_superblock(dsa_area *area, dsa_pointer span_pointer)
Definition: dsa.c:1775
void dsa_free(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:812
uint16 nallocatable
Definition: dsa.c:203
static void check_for_freed_segments(dsa_area *area)
Definition: dsa.c:2202
uint16 firstfree
Definition: dsa.c:204
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:251
#define NextFreeObjectIndex(object)
Definition: dsa.c:213
static dsa_segment_map * get_segment_by_index(dsa_area *area, dsa_segment_index index)
Definition: dsa.c:1714

◆ dsa_get_address()

void* dsa_get_address ( dsa_area area,
dsa_pointer  dp 
)

Definition at line 924 of file dsa.c.

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(), 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(), 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().

925 {
927  Size offset;
928 
929  /* Convert InvalidDsaPointer to NULL. */
930  if (!DsaPointerIsValid(dp))
931  return NULL;
932 
933  /* Process any requests to detach from freed segments. */
935 
936  /* Break the dsa_pointer into its components. */
937  index = DSA_EXTRACT_SEGMENT_NUMBER(dp);
938  offset = DSA_EXTRACT_OFFSET(dp);
939  Assert(index < DSA_MAX_SEGMENTS);
940 
941  /* Check if we need to cause this segment to be mapped in. */
942  if (unlikely(area->segment_maps[index].mapped_address == NULL))
943  {
944  /* Call for effect (we don't need the result). */
945  get_segment_by_index(area, index);
946  }
947 
948  return area->segment_maps[index].mapped_address + offset;
949 }
Definition: type.h:89
Size dsa_segment_index
Definition: dsa.c:124
#define DSA_EXTRACT_SEGMENT_NUMBER(dp)
Definition: dsa.c:118
#define Assert(condition)
Definition: c.h:699
#define DSA_EXTRACT_OFFSET(dp)
Definition: dsa.c:121
size_t Size
Definition: c.h:433
char * mapped_address
Definition: dsa.c:342
#define DSA_MAX_SEGMENTS
Definition: dsa.c:94
#define DsaPointerIsValid(x)
Definition: dsa.h:81
dsa_segment_map segment_maps[DSA_MAX_SEGMENTS]
Definition: dsa.c:368
static void check_for_freed_segments(dsa_area *area)
Definition: dsa.c:2202
#define unlikely(x)
Definition: c.h:208
static dsa_segment_map * get_segment_by_index(dsa_area *area, dsa_segment_index index)
Definition: dsa.c:1714

◆ dsa_get_handle()

dsa_handle dsa_get_handle ( dsa_area area)

Definition at line 493 of file dsa.c.

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

494 {
496  return area->control->handle;
497 }
#define DSM_HANDLE_INVALID
Definition: dsm.h:23
dsa_area_control * control
Definition: dsa.c:357
#define Assert(condition)
Definition: c.h:699
dsa_handle handle
Definition: dsa.c:303

◆ dsa_minimum_size()

Size dsa_minimum_size ( void  )

Definition at line 1160 of file dsa.c.

References FPM_PAGE_SIZE, and MAXALIGN.

Referenced by create_internal(), and ExecInitParallelPlan().

1161 {
1162  Size size;
1163  int pages = 0;
1164 
1165  size = MAXALIGN(sizeof(dsa_area_control)) +
1166  MAXALIGN(sizeof(FreePageManager));
1167 
1168  /* Figure out how many pages we need, including the page map... */
1169  while (((size + FPM_PAGE_SIZE - 1) / FPM_PAGE_SIZE) > pages)
1170  {
1171  ++pages;
1172  size += sizeof(dsa_pointer);
1173  }
1174 
1175  return pages * FPM_PAGE_SIZE;
1176 }
uint64 dsa_pointer
Definition: dsa.h:62
#define FPM_PAGE_SIZE
Definition: freepage.h:30
size_t Size
Definition: c.h:433
#define MAXALIGN(LEN)
Definition: c.h:652

◆ dsa_on_dsm_detach_release_in_place()

void dsa_on_dsm_detach_release_in_place ( dsm_segment ,
Datum   
)

Definition at line 571 of file dsa.c.

References DatumGetPointer, and dsa_release_in_place().

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

572 {
574 }
void dsa_release_in_place(void *place)
Definition: dsa.c:600
#define DatumGetPointer(X)
Definition: postgres.h:534

◆ dsa_on_shmem_exit_release_in_place()

void dsa_on_shmem_exit_release_in_place ( int  ,
Datum   
)

Definition at line 585 of file dsa.c.

References DatumGetPointer, and dsa_release_in_place().

586 {
588 }
void dsa_release_in_place(void *place)
Definition: dsa.c:600
#define DatumGetPointer(X)
Definition: postgres.h:534

◆ dsa_pin()

void dsa_pin ( dsa_area area)

Definition at line 957 of file dsa.c.

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

958 {
960  if (area->control->pinned)
961  {
963  elog(ERROR, "dsa_area already pinned");
964  }
965  area->control->pinned = true;
966  ++area->control->refcnt;
968 }
bool pinned
Definition: dsa.c:319
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
int refcnt
Definition: dsa.c:317
#define ERROR
Definition: elog.h:43
dsa_area_control * control
Definition: dsa.c:357
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
#define elog
Definition: elog.h:219
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143

◆ dsa_pin_mapping()

void dsa_pin_mapping ( dsa_area area)

Definition at line 630 of file dsa.c.

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(), and GetSessionDsmHandle().

631 {
632  int i;
633 
634  Assert(!area->mapping_pinned);
635  area->mapping_pinned = true;
636 
637  for (i = 0; i <= area->high_segment_index; ++i)
638  if (area->segment_maps[i].segment != NULL)
640 }
bool mapping_pinned
Definition: dsa.c:360
dsa_segment_index high_segment_index
Definition: dsa.c:371
dsm_segment * segment
Definition: dsa.c:341
void dsm_pin_mapping(dsm_segment *seg)
Definition: dsm.c:814
#define Assert(condition)
Definition: c.h:699
dsa_segment_map segment_maps[DSA_MAX_SEGMENTS]
Definition: dsa.c:368
int i

◆ dsa_release_in_place()

void dsa_release_in_place ( void *  place)

Definition at line 600 of file dsa.c.

References Assert, dsa_area::control, 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().

601 {
602  dsa_area_control *control = (dsa_area_control *) place;
603  int i;
604 
605  LWLockAcquire(&control->lock, LW_EXCLUSIVE);
606  Assert(control->segment_header.magic ==
607  (DSA_SEGMENT_HEADER_MAGIC ^ control->handle ^ 0));
608  Assert(control->refcnt > 0);
609  if (--control->refcnt == 0)
610  {
611  for (i = 0; i <= control->high_segment_index; ++i)
612  {
613  dsm_handle handle;
614 
615  handle = control->segment_handles[i];
616  if (handle != DSM_HANDLE_INVALID)
617  dsm_unpin_segment(handle);
618  }
619  }
620  LWLockRelease(&control->lock);
621 }
uint32 dsm_handle
Definition: dsm_impl.h:55
dsa_segment_index high_segment_index
Definition: dsa.c:315
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
#define DSM_HANDLE_INVALID
Definition: dsm.h:23
LWLock lock
Definition: dsa.c:325
int refcnt
Definition: dsa.c:317
void dsm_unpin_segment(dsm_handle handle)
Definition: dsm.c:886
dsa_segment_header segment_header
Definition: dsa.c:301
#define Assert(condition)
Definition: c.h:699
dsm_handle segment_handles[DSA_MAX_SEGMENTS]
Definition: dsa.c:305
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
int i
#define DSA_SEGMENT_HEADER_MAGIC
Definition: dsa.c:111
uint32 magic
Definition: dsa.c:154
dsa_handle handle
Definition: dsa.c:303

◆ dsa_set_size_limit()

void dsa_set_size_limit ( dsa_area area,
Size  limit 
)

Definition at line 1000 of file dsa.c.

References dsa_area::control, DSA_AREA_LOCK, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), and dsa_area_control::max_total_segment_size.

1001 {
1003  area->control->max_total_segment_size = limit;
1005 }
Size max_total_segment_size
Definition: dsa.c:313
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
dsa_area_control * control
Definition: dsa.c:357
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143

◆ dsa_startup()

void dsa_startup ( void  )

◆ dsa_trim()

void dsa_trim ( dsa_area area)

Definition at line 1012 of file dsa.c.

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.

1013 {
1014  int size_class;
1015 
1016  /*
1017  * Trim in reverse pool order so we get to the spans-of-spans last, just
1018  * in case any become entirely free while processing all the other pools.
1019  */
1020  for (size_class = DSA_NUM_SIZE_CLASSES - 1; size_class >= 0; --size_class)
1021  {
1022  dsa_area_pool *pool = &area->control->pools[size_class];
1023  dsa_pointer span_pointer;
1024 
1025  if (size_class == DSA_SCLASS_SPAN_LARGE)
1026  {
1027  /* Large object frees give back segments aggressively already. */
1028  continue;
1029  }
1030 
1031  /*
1032  * Search fullness class 1 only. That is where we expect to find an
1033  * entirely empty superblock (entirely empty superblocks in other
1034  * fullness classes are returned to the free page map by dsa_free).
1035  */
1036  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
1037  span_pointer = pool->spans[1];
1038  while (DsaPointerIsValid(span_pointer))
1039  {
1040  dsa_area_span *span = dsa_get_address(area, span_pointer);
1041  dsa_pointer next = span->nextspan;
1042 
1043  if (span->nallocatable == span->nmax)
1044  destroy_superblock(area, span_pointer);
1045 
1046  span_pointer = next;
1047  }
1048  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
1049  }
1050 }
uint16 nmax
Definition: dsa.c:205
dsa_pointer nextspan
Definition: dsa.c:198
static int32 next
Definition: blutils.c:211
#define DSA_NUM_SIZE_CLASSES
Definition: dsa.c:247
uint64 dsa_pointer
Definition: dsa.h:62
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:924
dsa_area_control * control
Definition: dsa.c:357
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:144
dsa_area_pool pools[DSA_NUM_SIZE_CLASSES]
Definition: dsa.c:309
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
dsa_pointer spans[DSA_FULLNESS_CLASSES]
Definition: dsa.c:290
#define DsaPointerIsValid(x)
Definition: dsa.h:81
static void destroy_superblock(dsa_area *area, dsa_pointer span_pointer)
Definition: dsa.c:1775
uint16 nallocatable
Definition: dsa.c:203
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:251

◆ dsa_unpin()

void dsa_unpin ( dsa_area area)

Definition at line 976 of file dsa.c.

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

977 {
979  Assert(area->control->refcnt > 1);
980  if (!area->control->pinned)
981  {
983  elog(ERROR, "dsa_area not pinned");
984  }
985  area->control->pinned = false;
986  --area->control->refcnt;
988 }
bool pinned
Definition: dsa.c:319
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1725
int refcnt
Definition: dsa.c:317
#define ERROR
Definition: elog.h:43
dsa_area_control * control
Definition: dsa.c:357
#define Assert(condition)
Definition: c.h:699
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1121
#define elog
Definition: elog.h:219
#define DSA_AREA_LOCK(area)
Definition: dsa.c:143