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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)
 
#define DSA_HANDLE_INVALID   ((dsa_handle) DSM_HANDLE_INVALID)
 

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_HANDLE_INVALID

#define DSA_HANDLE_INVALID   ((dsa_handle) DSM_HANDLE_INVALID)

Definition at line 103 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 686 of file dsa.c.

687 {
688  uint16 size_class;
689  dsa_pointer start_pointer;
690  dsa_segment_map *segment_map;
691  dsa_pointer result;
692 
693  Assert(size > 0);
694 
695  /* Sanity check on huge individual allocation size. */
696  if (((flags & DSA_ALLOC_HUGE) != 0 && !AllocHugeSizeIsValid(size)) ||
697  ((flags & DSA_ALLOC_HUGE) == 0 && !AllocSizeIsValid(size)))
698  elog(ERROR, "invalid DSA memory alloc request size %zu", size);
699 
700  /*
701  * If bigger than the largest size class, just grab a run of pages from
702  * the free page manager, instead of allocating an object from a pool.
703  * There will still be a span, but it's a special class of span that
704  * manages this whole allocation and simply gives all pages back to the
705  * free page manager when dsa_free is called.
706  */
707  if (size > dsa_size_classes[lengthof(dsa_size_classes) - 1])
708  {
709  size_t npages = fpm_size_to_pages(size);
710  size_t first_page;
711  dsa_pointer span_pointer;
713 
714  /* Obtain a span object. */
715  span_pointer = alloc_object(area, DSA_SCLASS_BLOCK_OF_SPANS);
716  if (!DsaPointerIsValid(span_pointer))
717  {
718  /* Raise error unless asked not to. */
719  if ((flags & DSA_ALLOC_NO_OOM) == 0)
720  ereport(ERROR,
721  (errcode(ERRCODE_OUT_OF_MEMORY),
722  errmsg("out of memory"),
723  errdetail("Failed on DSA request of size %zu.",
724  size)));
725  return InvalidDsaPointer;
726  }
727 
729 
730  /* Find a segment from which to allocate. */
731  segment_map = get_best_segment(area, npages);
732  if (segment_map == NULL)
733  segment_map = make_new_segment(area, npages);
734  if (segment_map == NULL)
735  {
736  /* Can't make any more segments: game over. */
738  dsa_free(area, span_pointer);
739 
740  /* Raise error unless asked not to. */
741  if ((flags & DSA_ALLOC_NO_OOM) == 0)
742  ereport(ERROR,
743  (errcode(ERRCODE_OUT_OF_MEMORY),
744  errmsg("out of memory"),
745  errdetail("Failed on DSA request of size %zu.",
746  size)));
747  return InvalidDsaPointer;
748  }
749 
750  /*
751  * Ask the free page manager for a run of pages. This should always
752  * succeed, since both get_best_segment and make_new_segment should
753  * only return a non-NULL pointer if it actually contains enough
754  * contiguous freespace. If it does fail, something in our backend
755  * private state is out of whack, so use FATAL to kill the process.
756  */
757  if (!FreePageManagerGet(segment_map->fpm, npages, &first_page))
758  elog(FATAL,
759  "dsa_allocate could not find %zu free pages", npages);
761 
762  start_pointer = DSA_MAKE_POINTER(get_segment_index(area, segment_map),
763  first_page * FPM_PAGE_SIZE);
764 
765  /* Initialize span and pagemap. */
767  LW_EXCLUSIVE);
768  init_span(area, span_pointer, pool, start_pointer, npages,
770  segment_map->pagemap[first_page] = span_pointer;
772 
773  /* Zero-initialize the memory if requested. */
774  if ((flags & DSA_ALLOC_ZERO) != 0)
775  memset(dsa_get_address(area, start_pointer), 0, size);
776 
777  return start_pointer;
778  }
779 
780  /* Map allocation to a size class. */
782  {
783  int mapidx;
784 
785  /* For smaller sizes we have a lookup table... */
786  mapidx = ((size + DSA_SIZE_CLASS_MAP_QUANTUM - 1) /
788  size_class = dsa_size_class_map[mapidx];
789  }
790  else
791  {
792  uint16 min;
793  uint16 max;
794 
795  /* ... and for the rest we search by binary chop. */
797  max = lengthof(dsa_size_classes) - 1;
798 
799  while (min < max)
800  {
801  uint16 mid = (min + max) / 2;
802  uint16 class_size = dsa_size_classes[mid];
803 
804  if (class_size < size)
805  min = mid + 1;
806  else
807  max = mid;
808  }
809 
810  size_class = min;
811  }
812  Assert(size <= dsa_size_classes[size_class]);
813  Assert(size_class == 0 || size > dsa_size_classes[size_class - 1]);
814 
815  /* Attempt to allocate an object from the appropriate pool. */
816  result = alloc_object(area, size_class);
817 
818  /* Check for failure to allocate. */
819  if (!DsaPointerIsValid(result))
820  {
821  /* Raise error unless asked not to. */
822  if ((flags & DSA_ALLOC_NO_OOM) == 0)
823  ereport(ERROR,
824  (errcode(ERRCODE_OUT_OF_MEMORY),
825  errmsg("out of memory"),
826  errdetail("Failed on DSA request of size %zu.", size)));
827  return InvalidDsaPointer;
828  }
829 
830  /* Zero-initialize the memory if requested. */
831  if ((flags & DSA_ALLOC_ZERO) != 0)
832  memset(dsa_get_address(area, result), 0, size);
833 
834  return result;
835 }
unsigned short uint16
Definition: c.h:494
#define lengthof(array)
Definition: c.h:777
static const uint16 dsa_size_classes[]
Definition: dsa.c:249
#define DSA_AREA_LOCK(area)
Definition: dsa.c:156
#define DSA_MAKE_POINTER(segment_number, offset)
Definition: dsa.c:116
#define get_segment_index(area, segment_map_ptr)
Definition: dsa.c:399
static dsa_pointer alloc_object(dsa_area *area, int size_class)
Definition: dsa.c:1462
#define DSA_SIZE_CLASS_MAP_QUANTUM
Definition: dsa.c:282
static const uint8 dsa_size_class_map[]
Definition: dsa.c:272
static dsa_segment_map * make_new_segment(dsa_area *area, size_t requested_pages)
Definition: dsa.c:2071
void * dsa_get_address(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:957
#define DSA_SCLASS_LOCK(area, sclass)
Definition: dsa.c:157
#define DSA_SCLASS_BLOCK_OF_SPANS
Definition: dsa.c:263
#define DSA_SCLASS_SPAN_LARGE
Definition: dsa.c:264
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:1367
static dsa_segment_map * get_best_segment(dsa_area *area, size_t npages)
Definition: dsa.c:2000
void dsa_free(dsa_area *area, dsa_pointer dp)
Definition: dsa.c:841
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:1208
int errcode(int sqlerrcode)
Definition: elog.c:860
int errmsg(const char *fmt,...)
Definition: elog.c:1075
#define FATAL
Definition: elog.h:41
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
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:1168
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1781
@ LW_EXCLUSIVE
Definition: lwlock.h:116
#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:322
dsa_area_control * control
Definition: dsa.c:370
FreePageManager * fpm
Definition: dsa.c:357
dsa_pointer * pagemap
Definition: dsa.c:358

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 525 of file dsa.c.

526 {
527  dsm_segment *segment;
528  dsa_area *area;
529 
530  /*
531  * An area handle is really a DSM segment handle for the first segment, so
532  * we go ahead and attach to that.
533  */
534  segment = dsm_attach(handle);
535  if (segment == NULL)
536  ereport(ERROR,
537  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
538  errmsg("could not attach to dynamic shared area")));
539 
540  area = attach_internal(dsm_segment_address(segment), segment, handle);
541 
542  /* Clean up when the control segment detaches. */
545 
546  return area;
547 }
void dsa_on_dsm_detach_release_in_place(dsm_segment *segment, Datum place)
Definition: dsa.c:591
static dsa_area * attach_internal(void *place, dsm_segment *segment, dsa_handle handle)
Definition: dsa.c:1316
void * dsm_segment_address(dsm_segment *seg)
Definition: dsm.c:1096
void on_dsm_detach(dsm_segment *seg, on_dsm_detach_callback function, Datum arg)
Definition: dsm.c:1133
dsm_segment * dsm_attach(dsm_handle h)
Definition: dsm.c:666
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:322
Definition: dsa.c:368

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

Referenced by init_dsm_registry(), and logicalrep_launcher_attach_dshmem().

◆ dsa_attach_in_place()

dsa_area* dsa_attach_in_place ( void *  place,
dsm_segment segment 
)

Definition at line 560 of file dsa.c.

561 {
562  dsa_area *area;
563 
564  area = attach_internal(place, NULL, DSA_HANDLE_INVALID);
565 
566  /*
567  * Clean up when the control segment detaches, if a containing DSM segment
568  * was provided.
569  */
570  if (segment != NULL)
572  PointerGetDatum(place));
573 
574  return area;
575 }
#define DSA_HANDLE_INVALID
Definition: dsa.h:103

References attach_internal(), DSA_HANDLE_INVALID, dsa_on_dsm_detach_release_in_place(), 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 439 of file dsa.c.

440 {
441  dsm_segment *segment;
442  dsa_area *area;
443 
444  /*
445  * Create the DSM segment that will hold the shared control object and the
446  * first segment of usable space.
447  */
448  segment = dsm_create(DSA_INITIAL_SEGMENT_SIZE, 0);
449 
450  /*
451  * All segments backing this area are pinned, so that DSA can explicitly
452  * control their lifetime (otherwise a newly created segment belonging to
453  * this area might be freed when the only backend that happens to have it
454  * mapped in ends, corrupting the area).
455  */
456  dsm_pin_segment(segment);
457 
458  /* Create a new DSA area with the control object in this segment. */
459  area = create_internal(dsm_segment_address(segment),
461  tranche_id,
462  dsm_segment_handle(segment), segment);
463 
464  /* Clean up when the control segment detaches. */
467 
468  return area;
469 }
#define DSA_INITIAL_SEGMENT_SIZE
Definition: dsa.c:70
static dsa_area * create_internal(void *place, size_t size, int tranche_id, dsm_handle control_handle, dsm_segment *control_segment)
Definition: dsa.c:1216
dsm_handle dsm_segment_handle(dsm_segment *seg)
Definition: dsm.c:1124
dsm_segment * dsm_create(Size size, int flags)
Definition: dsm.c:517
void dsm_pin_segment(dsm_segment *seg)
Definition: dsm.c:956

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().

Referenced by init_dsm_registry(), logicalrep_launcher_attach_dshmem(), test_dsa_basic(), and test_dsa_resowners().

◆ dsa_create_in_place()

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

Definition at line 488 of file dsa.c.

490 {
491  dsa_area *area;
492 
493  area = create_internal(place, size, tranche_id,
494  DSM_HANDLE_INVALID, NULL);
495 
496  /*
497  * Clean up when the control segment detaches, if a containing DSM segment
498  * was provided.
499  */
500  if (segment != NULL)
502  PointerGetDatum(place));
503 
504  return area;
505 }
#define DSM_HANDLE_INVALID
Definition: dsm_impl.h:58

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 1942 of file dsa.c.

1943 {
1944  int i;
1945 
1946  /* Detach from all segments. */
1947  for (i = 0; i <= area->high_segment_index; ++i)
1948  if (area->segment_maps[i].segment != NULL)
1949  dsm_detach(area->segment_maps[i].segment);
1950 
1951  /*
1952  * Note that 'detaching' (= detaching from DSM segments) doesn't include
1953  * 'releasing' (= adjusting the reference count). It would be nice to
1954  * combine these operations, but client code might never get around to
1955  * calling dsa_detach because of an error path, and a detach hook on any
1956  * particular segment is too late to detach other segments in the area
1957  * without risking a 'leak' warning in the non-error path.
1958  */
1959 
1960  /* Free the backend-local area object. */
1961  pfree(area);
1962 }
void dsm_detach(dsm_segment *seg)
Definition: dsm.c:804
int i
Definition: isn.c:73
void pfree(void *pointer)
Definition: mcxt.c:1431
dsa_segment_map segment_maps[DSA_MAX_SEGMENTS]
Definition: dsa.c:386
dsa_segment_index high_segment_index
Definition: dsa.c:389
dsm_segment * segment
Definition: dsa.c:354

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(), StatsShmemInit(), test_dsa_basic(), and test_dsa_resowners().

◆ dsa_dump()

void dsa_dump ( dsa_area area)

Definition at line 1090 of file dsa.c.

1091 {
1092  size_t i,
1093  j;
1094 
1095  /*
1096  * Note: This gives an inconsistent snapshot as it acquires and releases
1097  * individual locks as it goes...
1098  */
1099 
1102  fprintf(stderr, "dsa_area handle %x:\n", area->control->handle);
1103  fprintf(stderr, " max_total_segment_size: %zu\n",
1105  fprintf(stderr, " total_segment_size: %zu\n",
1106  area->control->total_segment_size);
1107  fprintf(stderr, " refcnt: %d\n", area->control->refcnt);
1108  fprintf(stderr, " pinned: %c\n", area->control->pinned ? 't' : 'f');
1109  fprintf(stderr, " segment bins:\n");
1110  for (i = 0; i < DSA_NUM_SEGMENT_BINS; ++i)
1111  {
1113  {
1114  dsa_segment_index segment_index;
1115 
1116  fprintf(stderr,
1117  " segment bin %zu (at least %d contiguous pages free):\n",
1118  i, 1 << (i - 1));
1119  segment_index = area->control->segment_bins[i];
1120  while (segment_index != DSA_SEGMENT_INDEX_NONE)
1121  {
1122  dsa_segment_map *segment_map;
1123 
1124  segment_map =
1125  get_segment_by_index(area, segment_index);
1126 
1127  fprintf(stderr,
1128  " segment index %zu, usable_pages = %zu, "
1129  "contiguous_pages = %zu, mapped at %p\n",
1130  segment_index,
1131  segment_map->header->usable_pages,
1132  fpm_largest(segment_map->fpm),
1133  segment_map->mapped_address);
1134  segment_index = segment_map->header->next;
1135  }
1136  }
1137  }
1139 
1140  fprintf(stderr, " pools:\n");
1141  for (i = 0; i < DSA_NUM_SIZE_CLASSES; ++i)
1142  {
1143  bool found = false;
1144 
1146  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1147  if (DsaPointerIsValid(area->control->pools[i].spans[j]))
1148  found = true;
1149  if (found)
1150  {
1152  fprintf(stderr, " pool for blocks of span objects:\n");
1153  else if (i == DSA_SCLASS_SPAN_LARGE)
1154  fprintf(stderr, " pool for large object spans:\n");
1155  else
1156  fprintf(stderr,
1157  " pool for size class %zu (object size %hu bytes):\n",
1158  i, dsa_size_classes[i]);
1159  for (j = 0; j < DSA_FULLNESS_CLASSES; ++j)
1160  {
1161  if (!DsaPointerIsValid(area->control->pools[i].spans[j]))
1162  fprintf(stderr, " fullness class %zu is empty\n", j);
1163  else
1164  {
1165  dsa_pointer span_pointer = area->control->pools[i].spans[j];
1166 
1167  fprintf(stderr, " fullness class %zu:\n", j);
1168  while (DsaPointerIsValid(span_pointer))
1169  {
1170  dsa_area_span *span;
1171 
1172  span = dsa_get_address(area, span_pointer);
1173  fprintf(stderr,
1174  " span descriptor at "
1175  DSA_POINTER_FORMAT ", superblock at "
1177  ", pages = %zu, objects free = %hu/%hu\n",
1178  span_pointer, span->start, span->npages,
1179  span->nallocatable, span->nmax);
1180  span_pointer = span->nextspan;
1181  }
1182  }
1183  }
1184  }
1186  }
1187 }
#define DSA_SEGMENT_INDEX_NONE
Definition: dsa.c:129
static void check_for_freed_segments_locked(dsa_area *area)
Definition: dsa.c:2278
size_t dsa_segment_index
Definition: dsa.c:126
static dsa_segment_map * get_segment_by_index(dsa_area *area, dsa_segment_index index)
Definition: dsa.c:1747
#define DSA_NUM_SIZE_CLASSES
Definition: dsa.c:260
#define DSA_FULLNESS_CLASSES
Definition: dsa.c:290
#define DSA_NUM_SEGMENT_BINS
Definition: dsa.c:135
#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:324
bool pinned
Definition: dsa.c:332
size_t max_total_segment_size
Definition: dsa.c:326
dsa_segment_index segment_bins[DSA_NUM_SEGMENT_BINS]
Definition: dsa.c:320
int refcnt
Definition: dsa.c:330
dsa_handle handle
Definition: dsa.c:316
dsa_pointer spans[DSA_FULLNESS_CLASSES]
Definition: dsa.c:303
dsa_pointer nextspan
Definition: dsa.c:211
dsa_pointer start
Definition: dsa.c:212
uint16 nallocatable
Definition: dsa.c:216
uint16 nmax
Definition: dsa.c:218
size_t npages
Definition: dsa.c:213
dsa_segment_index next
Definition: dsa.c:183
size_t usable_pages
Definition: dsa.c:169
dsa_segment_header * header
Definition: dsa.c:356
char * mapped_address
Definition: dsa.c:355

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 841 of file dsa.c.

842 {
843  dsa_segment_map *segment_map;
844  int pageno;
845  dsa_pointer span_pointer;
846  dsa_area_span *span;
847  char *superblock;
848  char *object;
849  size_t size;
850  int size_class;
851 
852  /* Make sure we don't have a stale segment in the slot 'dp' refers to. */
854 
855  /* Locate the object, span and pool. */
856  segment_map = get_segment_by_index(area, DSA_EXTRACT_SEGMENT_NUMBER(dp));
857  pageno = DSA_EXTRACT_OFFSET(dp) / FPM_PAGE_SIZE;
858  span_pointer = segment_map->pagemap[pageno];
859  span = dsa_get_address(area, span_pointer);
860  superblock = dsa_get_address(area, span->start);
861  object = dsa_get_address(area, dp);
862  size_class = span->size_class;
863  size = dsa_size_classes[size_class];
864 
865  /*
866  * Special case for large objects that live in a special span: we return
867  * those pages directly to the free page manager and free the span.
868  */
869  if (span->size_class == DSA_SCLASS_SPAN_LARGE)
870  {
871 
872 #ifdef CLOBBER_FREED_MEMORY
873  memset(object, 0x7f, span->npages * FPM_PAGE_SIZE);
874 #endif
875 
876  /* Give pages back to free page manager. */
878  FreePageManagerPut(segment_map->fpm,
880  span->npages);
881 
882  /* Move segment to appropriate bin if necessary. */
883  rebin_segment(area, segment_map);
885 
886  /* Unlink span. */
888  LW_EXCLUSIVE);
889  unlink_span(area, span);
891  /* Free the span object so it can be reused. */
892  dsa_free(area, span_pointer);
893  return;
894  }
895 
896 #ifdef CLOBBER_FREED_MEMORY
897  memset(object, 0x7f, size);
898 #endif
899 
900  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
901 
902  /* Put the object on the span's freelist. */
903  Assert(object >= superblock);
904  Assert(object < superblock + DSA_SUPERBLOCK_SIZE);
905  Assert((object - superblock) % size == 0);
906  NextFreeObjectIndex(object) = span->firstfree;
907  span->firstfree = (object - superblock) / size;
908  ++span->nallocatable;
909 
910  /*
911  * See if the span needs to moved to a different fullness class, or be
912  * freed so its pages can be given back to the segment.
913  */
914  if (span->nallocatable == 1 && span->fclass == DSA_FULLNESS_CLASSES - 1)
915  {
916  /*
917  * The block was completely full and is located in the
918  * highest-numbered fullness class, which is never scanned for free
919  * chunks. We must move it to the next-lower fullness class.
920  */
921  unlink_span(area, span);
922  add_span_to_fullness_class(area, span, span_pointer,
924 
925  /*
926  * If this is the only span, and there is no active span, then we
927  * should probably move this span to fullness class 1. (Otherwise if
928  * you allocate exactly all the objects in the only span, it moves to
929  * class 3, then you free them all, it moves to 2, and then is given
930  * back, leaving no active span).
931  */
932  }
933  else if (span->nallocatable == span->nmax &&
934  (span->fclass != 1 || span->prevspan != InvalidDsaPointer))
935  {
936  /*
937  * This entire block is free, and it's not the active block for this
938  * size class. Return the memory to the free page manager. We don't
939  * do this for the active block to prevent hysteresis: if we
940  * repeatedly allocate and free the only chunk in the active block, it
941  * will be very inefficient if we deallocate and reallocate the block
942  * every time.
943  */
944  destroy_superblock(area, span_pointer);
945  }
946 
947  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
948 }
static void check_for_freed_segments(dsa_area *area)
Definition: dsa.c:2242
#define DSA_EXTRACT_SEGMENT_NUMBER(dp)
Definition: dsa.c:120
static void add_span_to_fullness_class(dsa_area *area, dsa_area_span *span, dsa_pointer span_pointer, int fclass)
Definition: dsa.c:1919
#define DSA_SUPERBLOCK_SIZE
Definition: dsa.c:396
#define DSA_EXTRACT_OFFSET(dp)
Definition: dsa.c:123
static void destroy_superblock(dsa_area *area, dsa_pointer span_pointer)
Definition: dsa.c:1827
static void rebin_segment(dsa_area *area, dsa_segment_map *segment_map)
Definition: dsa.c:2306
static void unlink_span(dsa_area *area, dsa_area_span *span)
Definition: dsa.c:1896
#define NextFreeObjectIndex(object)
Definition: dsa.c:226
void FreePageManagerPut(FreePageManager *fpm, Size first_page, Size npages)
Definition: freepage.c:379
uint16 fclass
Definition: dsa.c:219
dsa_pointer prevspan
Definition: dsa.c:210
uint16 size_class
Definition: dsa.c:214
uint16 firstfree
Definition: dsa.c:217

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, rebin_segment(), 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(), tbm_free_shared_area(), test_dsa_basic(), and test_dsa_resowners().

◆ dsa_get_address()

void* dsa_get_address ( dsa_area area,
dsa_pointer  dp 
)

Definition at line 957 of file dsa.c.

958 {
960  size_t offset;
961 
962  /* Convert InvalidDsaPointer to NULL. */
963  if (!DsaPointerIsValid(dp))
964  return NULL;
965 
966  /* Process any requests to detach from freed segments. */
968 
969  /* Break the dsa_pointer into its components. */
971  offset = DSA_EXTRACT_OFFSET(dp);
973 
974  /* Check if we need to cause this segment to be mapped in. */
975  if (unlikely(area->segment_maps[index].mapped_address == NULL))
976  {
977  /* Call for effect (we don't need the result). */
979  }
980 
981  return area->segment_maps[index].mapped_address + offset;
982 }
#define unlikely(x)
Definition: c.h:300
#define DSA_MAX_SEGMENTS
Definition: dsa.c:96
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(), test_dsa_basic(), test_dsa_resowners(), transfer_first_span(), and unlink_span().

◆ dsa_get_handle()

dsa_handle dsa_get_handle ( dsa_area area)

Definition at line 513 of file dsa.c.

514 {
516  return area->control->handle;
517 }

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

Referenced by init_dsm_registry(), and logicalrep_launcher_attach_dshmem().

◆ dsa_minimum_size()

size_t dsa_minimum_size ( void  )

Definition at line 1194 of file dsa.c.

1195 {
1196  size_t size;
1197  int pages = 0;
1198 
1199  size = MAXALIGN(sizeof(dsa_area_control)) +
1200  MAXALIGN(sizeof(FreePageManager));
1201 
1202  /* Figure out how many pages we need, including the page map... */
1203  while (((size + FPM_PAGE_SIZE - 1) / FPM_PAGE_SIZE) > pages)
1204  {
1205  ++pages;
1206  size += sizeof(dsa_pointer);
1207  }
1208 
1209  return pages * FPM_PAGE_SIZE;
1210 }
#define MAXALIGN(LEN)
Definition: c.h:800

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 591 of file dsa.c.

592 {
594 }
void dsa_release_in_place(void *place)
Definition: dsa.c:620
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:312

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 605 of file dsa.c.

606 {
608 }

References DatumGetPointer(), and dsa_release_in_place().

◆ dsa_pin()

void dsa_pin ( dsa_area area)

Definition at line 990 of file dsa.c.

991 {
993  if (area->control->pinned)
994  {
996  elog(ERROR, "dsa_area already pinned");
997  }
998  area->control->pinned = true;
999  ++area->control->refcnt;
1001 }

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

Referenced by init_dsm_registry(), logicalrep_launcher_attach_dshmem(), and StatsShmemInit().

◆ dsa_pin_mapping()

void dsa_pin_mapping ( dsa_area area)

Definition at line 650 of file dsa.c.

651 {
652  int i;
653 
654  if (area->resowner != NULL)
655  {
656  area->resowner = NULL;
657 
658  for (i = 0; i <= area->high_segment_index; ++i)
659  if (area->segment_maps[i].segment != NULL)
661  }
662 }
void dsm_pin_mapping(dsm_segment *seg)
Definition: dsm.c:916
ResourceOwner resowner
Definition: dsa.c:378

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

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

◆ dsa_release_in_place()

void dsa_release_in_place ( void *  place)

Definition at line 620 of file dsa.c.

621 {
622  dsa_area_control *control = (dsa_area_control *) place;
623  int i;
624 
625  LWLockAcquire(&control->lock, LW_EXCLUSIVE);
626  Assert(control->segment_header.magic ==
627  (DSA_SEGMENT_HEADER_MAGIC ^ control->handle ^ 0));
628  Assert(control->refcnt > 0);
629  if (--control->refcnt == 0)
630  {
631  for (i = 0; i <= control->high_segment_index; ++i)
632  {
633  dsm_handle handle;
634 
635  handle = control->segment_handles[i];
636  if (handle != DSM_HANDLE_INVALID)
637  dsm_unpin_segment(handle);
638  }
639  }
640  LWLockRelease(&control->lock);
641 }
#define DSA_SEGMENT_HEADER_MAGIC
Definition: dsa.c:113
void dsm_unpin_segment(dsm_handle handle)
Definition: dsm.c:989
uint32 dsm_handle
Definition: dsm_impl.h:55
dsa_segment_header segment_header
Definition: dsa.c:314
dsa_segment_index high_segment_index
Definition: dsa.c:328
LWLock lock
Definition: dsa.c:338
dsm_handle segment_handles[DSA_MAX_SEGMENTS]
Definition: dsa.c:318
uint32 magic
Definition: dsa.c:167

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 1045 of file dsa.c.

1046 {
1047  int size_class;
1048 
1049  /*
1050  * Trim in reverse pool order so we get to the spans-of-spans last, just
1051  * in case any become entirely free while processing all the other pools.
1052  */
1053  for (size_class = DSA_NUM_SIZE_CLASSES - 1; size_class >= 0; --size_class)
1054  {
1055  dsa_area_pool *pool = &area->control->pools[size_class];
1056  dsa_pointer span_pointer;
1057 
1058  if (size_class == DSA_SCLASS_SPAN_LARGE)
1059  {
1060  /* Large object frees give back segments aggressively already. */
1061  continue;
1062  }
1063 
1064  /*
1065  * Search fullness class 1 only. That is where we expect to find an
1066  * entirely empty superblock (entirely empty superblocks in other
1067  * fullness classes are returned to the free page map by dsa_free).
1068  */
1069  LWLockAcquire(DSA_SCLASS_LOCK(area, size_class), LW_EXCLUSIVE);
1070  span_pointer = pool->spans[1];
1071  while (DsaPointerIsValid(span_pointer))
1072  {
1073  dsa_area_span *span = dsa_get_address(area, span_pointer);
1074  dsa_pointer next = span->nextspan;
1075 
1076  if (span->nallocatable == span->nmax)
1077  destroy_superblock(area, span_pointer);
1078 
1079  span_pointer = next;
1080  }
1081  LWLockRelease(DSA_SCLASS_LOCK(area, size_class));
1082  }
1083 }
static int32 next
Definition: blutils.c:221

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 1009 of file dsa.c.

1010 {
1012  Assert(area->control->refcnt > 1);
1013  if (!area->control->pinned)
1014  {
1016  elog(ERROR, "dsa_area not pinned");
1017  }
1018  area->control->pinned = false;
1019  --area->control->refcnt;
1021 }

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