PostgreSQL Source Code  git master
bufmgr.h File Reference
#include "storage/block.h"
#include "storage/buf.h"
#include "storage/bufpage.h"
#include "storage/relfilenode.h"
#include "utils/relcache.h"
#include "utils/snapmgr.h"
Include dependency graph for bufmgr.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Macros

#define MAX_IO_CONCURRENCY   1000
 
#define P_NEW   InvalidBlockNumber /* grow the file to get a new page */
 
#define BUFFER_LOCK_UNLOCK   0
 
#define BUFFER_LOCK_SHARE   1
 
#define BUFFER_LOCK_EXCLUSIVE   2
 
#define BufferIsValid(bufnum)
 
#define BufferGetBlock(buffer)
 
#define BufferGetPageSize(buffer)
 
#define BufferGetPage(buffer)   ((Page)BufferGetBlock(buffer))
 
#define RelationGetNumberOfBlocks(reln)   RelationGetNumberOfBlocksInFork(reln, MAIN_FORKNUM)
 

Typedefs

typedef void * Block
 
typedef enum BufferAccessStrategyType BufferAccessStrategyType
 

Enumerations

enum  BufferAccessStrategyType { BAS_NORMAL, BAS_BULKREAD, BAS_BULKWRITE, BAS_VACUUM }
 
enum  ReadBufferMode {
  RBM_NORMAL, RBM_ZERO_AND_LOCK, RBM_ZERO_AND_CLEANUP_LOCK, RBM_ZERO_ON_ERROR,
  RBM_NORMAL_NO_LOG
}
 

Functions

bool ComputeIoConcurrency (int io_concurrency, double *target)
 
void PrefetchBuffer (Relation reln, ForkNumber forkNum, BlockNumber blockNum)
 
Buffer ReadBuffer (Relation reln, BlockNumber blockNum)
 
Buffer ReadBufferExtended (Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
 
Buffer ReadBufferWithoutRelcache (RelFileNode rnode, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
 
void ReleaseBuffer (Buffer buffer)
 
void UnlockReleaseBuffer (Buffer buffer)
 
void MarkBufferDirty (Buffer buffer)
 
void IncrBufferRefCount (Buffer buffer)
 
Buffer ReleaseAndReadBuffer (Buffer buffer, Relation relation, BlockNumber blockNum)
 
void InitBufferPool (void)
 
void InitBufferPoolAccess (void)
 
void InitBufferPoolBackend (void)
 
void AtEOXact_Buffers (bool isCommit)
 
void PrintBufferLeakWarning (Buffer buffer)
 
void CheckPointBuffers (int flags)
 
BlockNumber BufferGetBlockNumber (Buffer buffer)
 
BlockNumber RelationGetNumberOfBlocksInFork (Relation relation, ForkNumber forkNum)
 
void FlushOneBuffer (Buffer buffer)
 
void FlushRelationBuffers (Relation rel)
 
void FlushDatabaseBuffers (Oid dbid)
 
void DropRelFileNodeBuffers (RelFileNodeBackend rnode, ForkNumber *forkNum, int nforks, BlockNumber *firstDelBlock)
 
void DropRelFileNodesAllBuffers (RelFileNodeBackend *rnodes, int nnodes)
 
void DropDatabaseBuffers (Oid dbid)
 
bool BufferIsPermanent (Buffer buffer)
 
XLogRecPtr BufferGetLSNAtomic (Buffer buffer)
 
Size BufferShmemSize (void)
 
void BufferGetTag (Buffer buffer, RelFileNode *rnode, ForkNumber *forknum, BlockNumber *blknum)
 
void MarkBufferDirtyHint (Buffer buffer, bool buffer_std)
 
void UnlockBuffers (void)
 
void LockBuffer (Buffer buffer, int mode)
 
bool ConditionalLockBuffer (Buffer buffer)
 
void LockBufferForCleanup (Buffer buffer)
 
bool ConditionalLockBufferForCleanup (Buffer buffer)
 
bool IsBufferCleanupOK (Buffer buffer)
 
bool HoldingBufferPinThatDelaysRecovery (void)
 
void AbortBufferIO (void)
 
void BufmgrCommit (void)
 
bool BgBufferSync (struct WritebackContext *wb_context)
 
void AtProcExit_LocalBuffers (void)
 
void TestForOldSnapshot_impl (Snapshot snapshot, Relation relation)
 
BufferAccessStrategy GetAccessStrategy (BufferAccessStrategyType btype)
 
void FreeAccessStrategy (BufferAccessStrategy strategy)
 
static void TestForOldSnapshot (Snapshot snapshot, Relation relation, Page page)
 

Variables

PGDLLIMPORT int NBuffers
 
bool zero_damaged_pages
 
int bgwriter_lru_maxpages
 
double bgwriter_lru_multiplier
 
bool track_io_timing
 
int target_prefetch_pages
 
int checkpoint_flush_after
 
int backend_flush_after
 
int bgwriter_flush_after
 
PGDLLIMPORT char * BufferBlocks
 
int effective_io_concurrency
 
PGDLLIMPORT int NLocBuffer
 
PGDLLIMPORT BlockLocalBufferBlockPointers
 
PGDLLIMPORT int32LocalRefCount
 

Macro Definition Documentation

◆ BUFFER_LOCK_EXCLUSIVE

◆ BUFFER_LOCK_SHARE

◆ BUFFER_LOCK_UNLOCK

#define BUFFER_LOCK_UNLOCK   0

Definition at line 86 of file bufmgr.h.

Referenced by _bt_drop_lock_and_maybe_pin(), _bt_endpoint(), _bt_first(), _bt_getroot(), _bt_killitems(), _bt_moveright(), _bt_pagedel(), _bt_relandgetbuf(), _bt_search(), _bt_unlink_halfdead_page(), _bt_update_meta_cleanup_info(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_finish_split(), _hash_first(), _hash_freeovflpage(), _hash_getcachedmetap(), _hash_init(), _hash_kill_items(), _hash_readnext(), _hash_readpage(), _hash_readprev(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), blinsert(), BloomNewBuffer(), brin_doinsert(), brin_doupdate(), brin_evacuate_page(), brin_getinsertbuffer(), brin_page_cleanup(), bringetbitmap(), brinGetTupleForHeapBlock(), brininsert(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), brinsummarize(), btvacuumpage(), ConditionalLockBufferForCleanup(), fsm_readbuf(), fsm_search_avail(), fsm_vacuum_page(), get_raw_page_internal(), GetVisibilityMapPins(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_compute_xid_horizon_for_tuples(), heap_delete(), heap_fetch(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_page_prune_opt(), heap_update(), heap_xlog_visible(), heapam_index_build_range_scan(), heapam_index_fetch_tuple(), heapam_index_validate_scan(), heapam_relation_copy_for_cluster(), heapam_scan_bitmap_next_block(), heapam_scan_sample_next_tuple(), heapam_tuple_satisfies_snapshot(), heapgetpage(), heapgettup(), lazy_scan_heap(), LockBuffer(), LockBufferForCleanup(), pgrowlocks(), pgstat_heap(), pgstatindex_impl(), RelationGetBufferForTuple(), revmap_physical_extend(), SpGistNewBuffer(), summarize_range(), UnlockReleaseBuffer(), visibilitymap_clear(), visibilitymap_set(), vm_readbuf(), and XLogReadBufferExtended().

◆ BufferGetBlock

#define BufferGetBlock (   buffer)
Value:
( \
AssertMacro(BufferIsValid(buffer)), \
BufferIsLocal(buffer) ? \
LocalBufferBlockPointers[-(buffer) - 1] \
: \
(Block) (BufferBlocks + ((Size) ((buffer) - 1)) * BLCKSZ) \
)
PGDLLIMPORT char * BufferBlocks
Definition: buf_init.c:21
size_t Size
Definition: c.h:467
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
void * Block
Definition: bufmgr.h:24

Definition at line 126 of file bufmgr.h.

Referenced by XLogSaveBufferForHint().

◆ BufferGetPage

#define BufferGetPage (   buffer)    ((Page)BufferGetBlock(buffer))

Definition at line 159 of file bufmgr.h.

Referenced by _bt_binsrch(), _bt_binsrch_insert(), _bt_check_unique(), _bt_checkpage(), _bt_clear_incomplete_split(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_doinsert(), _bt_endpoint(), _bt_findinsertloc(), _bt_finish_split(), _bt_get_endpoint(), _bt_getbuf(), _bt_getmeta(), _bt_getroot(), _bt_getstackbuf(), _bt_gettrueroot(), _bt_insert_parent(), _bt_insertonpg(), _bt_is_page_halfdead(), _bt_killitems(), _bt_lock_branch_parent(), _bt_mark_page_halfdead(), _bt_moveright(), _bt_newroot(), _bt_pagedel(), _bt_readnextpage(), _bt_readpage(), _bt_restore_meta(), _bt_search(), _bt_split(), _bt_stepright(), _bt_unlink_halfdead_page(), _bt_update_meta_cleanup_info(), _bt_vacuum_needs_cleanup(), _bt_vacuum_one_page(), _bt_walk_left(), _hash_addovflpage(), _hash_checkpage(), _hash_doinsert(), _hash_expandtable(), _hash_finish_split(), _hash_first(), _hash_freeovflpage(), _hash_get_newblock_from_oldbucket(), _hash_get_oldblock_from_newbucket(), _hash_getbucketbuf_from_hashkey(), _hash_getcachedmetap(), _hash_getinitbuf(), _hash_getnewbuf(), _hash_init(), _hash_init_metabuffer(), _hash_initbitmapbuffer(), _hash_initbuf(), _hash_kill_items(), _hash_next(), _hash_pgaddmultitup(), _hash_pgaddtup(), _hash_readnext(), _hash_readpage(), _hash_readprev(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), allocNewBuffer(), blgetbitmap(), blinsert(), BloomNewBuffer(), blvacuumcleanup(), brin_can_do_samepage_update(), brin_doinsert(), brin_doupdate(), brin_evacuate_page(), brin_getinsertbuffer(), brin_initialize_empty_new_buffer(), brin_page_cleanup(), brin_start_evacuating_page(), brin_xlog_createidx(), brin_xlog_desummarize_page(), brin_xlog_insert_update(), brin_xlog_revmap_extend(), brin_xlog_samepage_update(), brin_xlog_update(), brinbuild(), brinbuildempty(), brinGetStats(), brinGetTupleForHeapBlock(), brininsert(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), brinSetHeapBlockItemptr(), bt_metap(), bt_page_items(), bt_rootdescend(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), btvacuumpage(), BufferGetLSNAtomic(), checkXLogConsistency(), collect_corrupt_items(), collect_visibility_data(), collectMatchBitmap(), collectMatchesForHeapRow(), count_nondeletable_pages(), createPostingTree(), dataBeginPlaceToPage(), dataBeginPlaceToPageInternal(), dataBeginPlaceToPageLeaf(), dataExecPlaceToPage(), dataExecPlaceToPageInternal(), dataLocateItem(), dataPlaceToPageLeafRecompress(), dataPrepareDownlink(), dataSplitPageInternal(), do_setval(), doPickSplit(), entryExecPlaceToPage(), entryIsEnoughSpace(), entryLoadMoreItems(), entryLocateEntry(), entryLocateLeafEntry(), entryPrepareDownlink(), entrySplitPage(), fill_seq_with_data(), FreeSpaceMapPrepareTruncateRel(), fsm_readbuf(), fsm_search(), fsm_search_avail(), fsm_set_and_search(), fsm_vacuum_page(), generic_redo(), GenericXLogFinish(), GenericXLogRegisterBuffer(), get_raw_page_internal(), GetBTPageStatistics(), GetRecordedFreeSpace(), GetVisibilityMapPins(), ginbulkdelete(), ginDeletePage(), ginEntryInsert(), ginFindLeafPage(), ginFindParents(), ginFinishSplit(), ginGetStats(), ginHeapTupleFastInsert(), GinInitBuffer(), GinInitMetabuffer(), ginInsertCleanup(), ginInsertValue(), GinNewBuffer(), ginPlaceToPage(), ginRedoClearIncompleteSplit(), ginRedoCreatePTree(), ginRedoDeleteListPages(), ginRedoDeletePage(), ginRedoInsert(), ginRedoInsertData(), ginRedoInsertEntry(), ginRedoInsertListPage(), ginRedoUpdateMetapage(), ginRedoVacuumDataLeafPage(), ginScanToDelete(), ginStepRight(), ginTraverseLock(), ginUpdateStats(), ginvacuumcleanup(), ginVacuumEntryPage(), ginVacuumPostingTreeLeaf(), ginVacuumPostingTreeLeaves(), gistBufferingFindCorrectParent(), gistbufferinginserttuples(), gistbuild(), gistcheckpage(), gistdeletepage(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistfixsplit(), gistformdownlink(), gistGetMaxLevel(), GISTInitBuffer(), gistkillitems(), gistMemorizeAllDownlinks(), gistNewBuffer(), gistplacetopage(), gistProcessItup(), gistRedoClearFollowRight(), gistRedoDeleteRecord(), gistRedoPageDelete(), gistRedoPageSplitRecord(), gistRedoPageUpdateRecord(), gistScanPage(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hash_bitmap_info(), hash_xlog_add_ovfl_page(), hash_xlog_delete(), hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), hash_xlog_insert(), hash_xlog_move_page_contents(), hash_xlog_split_allocate_page(), hash_xlog_split_cleanup(), hash_xlog_split_complete(), hash_xlog_squeeze_page(), hash_xlog_update_meta_page(), hash_xlog_vacuum_one_page(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_compute_xid_horizon_for_tuples(), heap_delete(), heap_fetch(), heap_finish_speculative(), heap_get_latest_tid(), heap_hot_search_buffer(), heap_inplace_update(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_page_is_all_visible(), heap_page_prune(), heap_page_prune_execute(), heap_page_prune_opt(), heap_prune_chain(), heap_update(), heap_xlog_clean(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_freeze_page(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_update(), heap_xlog_visible(), heapam_index_build_range_scan(), heapam_index_validate_scan(), heapam_scan_analyze_next_tuple(), heapam_scan_bitmap_next_block(), heapam_scan_bitmap_next_tuple(), heapam_scan_sample_next_tuple(), heapgetpage(), heapgettup(), heapgettup_pagemode(), index_compute_xid_horizon_for_tuples(), initBloomState(), lazy_check_needs_freeze(), lazy_scan_heap(), lazy_vacuum_heap(), lazy_vacuum_page(), log_heap_update(), log_newpage_buffer(), log_newpage_range(), log_split_page(), MarkBufferDirtyHint(), moveLeafs(), moveRightIfItNeeded(), nextval_internal(), palloc_btree_page(), pg_visibility(), pgstat_btree_page(), pgstat_gist_page(), pgstat_hash_page(), pgstat_heap(), pgstatginindex_internal(), pgstathashindex(), pgstatindex_impl(), read_seq_tuple(), RelationAddExtraBlocks(), RelationGetBufferForTuple(), RelationPutHeapTuple(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), scanPostingTree(), seq_redo(), shiftList(), spgAddNodeAction(), spgbuild(), spgdoinsert(), spgGetCache(), SpGistGetBuffer(), SpGistInitBuffer(), SpGistNewBuffer(), SpGistSetLastUsedPage(), SpGistUpdateMetaPage(), spgprocesspending(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), spgRedoSplitTuple(), spgRedoVacuumLeaf(), spgRedoVacuumRedirect(), spgRedoVacuumRoot(), spgSplitNodeAction(), spgvacuumpage(), spgWalk(), startScanEntry(), statapprox_heap(), terminate_brin_buildstate(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), visibilitymap_clear(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_prepare_truncate(), visibilitymap_set(), vm_readbuf(), writeListPage(), XLogCheckBufferNeedsBackup(), XLogReadBufferExtended(), XLogReadBufferForRedoExtended(), XLogRecordPageWithFreeSpace(), XLogRegisterBuffer(), XLogSaveBufferForHint(), and xlogVacuumPage().

◆ BufferGetPageSize

◆ BufferIsValid

#define BufferIsValid (   bufnum)
Value:
( \
AssertMacro((bufnum) <= NBuffers && (bufnum) >= -NLocBuffer), \
(bufnum) != InvalidBuffer \
)
#define InvalidBuffer
Definition: buf.h:25
PGDLLIMPORT int NLocBuffer
Definition: localbuf.c:41
PGDLLIMPORT int NBuffers
Definition: globals.c:131

Definition at line 113 of file bufmgr.h.

Referenced by _bt_clear_incomplete_split(), _bt_endpoint(), _bt_first(), _bt_get_endpoint(), _bt_insertonpg(), _bt_killitems(), _bt_readpage(), _bt_relandgetbuf(), _bt_search(), _bt_split(), _bt_unlink_halfdead_page(), _hash_addovflpage(), _hash_dropscanbuf(), _hash_freeovflpage(), _hash_getbucketbuf_from_hashkey(), _hash_getcachedmetap(), _hash_readnext(), _hash_readpage(), _hash_readprev(), autoprewarm_database_main(), brin_doinsert(), brin_doupdate(), brin_getinsertbuffer(), brin_xlog_createidx(), brin_xlog_desummarize_page(), brin_xlog_insert_update(), brin_xlog_revmap_extend(), brin_xlog_samepage_update(), brin_xlog_update(), brinGetTupleForHeapBlock(), brininsert(), brinsummarize(), bt_rootdescend(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), BufferGetLSNAtomic(), BufferIsPermanent(), CheckForSerializableConflictIn(), checkXLogConsistency(), ConditionalLockBuffer(), ConditionalLockBufferForCleanup(), doPickSplit(), entryGetItem(), entryLoadMoreItems(), ExecStoreBufferHeapTuple(), ExecStorePinnedBufferHeapTuple(), FreeSpaceMapPrepareTruncateRel(), fsm_search(), fsm_vacuum_page(), generic_redo(), GetPrivateRefCount(), GetPrivateRefCountEntry(), GetRecordedFreeSpace(), GetVisibilityMapPins(), ginPlaceToPage(), ginRedoClearIncompleteSplit(), ginRedoDeletePage(), ginRedoInsert(), ginRedoUpdateMetapage(), ginRedoVacuumDataLeafPage(), ginScanToDelete(), gistinserttuples(), gistkillitems(), gistplacetopage(), gistRedoClearFollowRight(), gistRedoDeleteRecord(), gistRedoPageDelete(), gistRedoPageUpdateRecord(), gistXLogSplit(), gistXLogUpdate(), hash_xlog_add_ovfl_page(), hash_xlog_delete(), hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), hash_xlog_insert(), hash_xlog_move_page_contents(), hash_xlog_split_allocate_page(), hash_xlog_split_cleanup(), hash_xlog_split_complete(), hash_xlog_squeeze_page(), hash_xlog_update_meta_page(), hash_xlog_vacuum_one_page(), heap_compute_xid_horizon_for_tuples(), heap_endscan(), heap_lock_tuple(), heap_rescan(), heap_update(), heap_xlog_clean(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_freeze_page(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_update(), heap_xlog_visible(), heapam_index_fetch_reset(), heapam_scan_sample_next_block(), heapam_tuple_lock(), heapam_tuple_satisfies_snapshot(), heapgetpage(), heapgettup(), heapgettup_pagemode(), IsBufferCleanupOK(), lazy_scan_heap(), lazy_vacuum_heap(), lazy_vacuum_page(), LockBuffer(), LockBufferForCleanup(), log_heap_visible(), MarkBufferDirty(), MarkBufferDirtyHint(), PrintBufferLeakWarning(), ReleaseAndReadBuffer(), ReleaseBuffer(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), spgRedoSplitTuple(), spgRedoVacuumLeaf(), spgRedoVacuumRedirect(), spgRedoVacuumRoot(), statapprox_heap(), tts_buffer_heap_clear(), tts_buffer_heap_copyslot(), tts_buffer_heap_materialize(), tts_buffer_heap_store_tuple(), visibilitymap_clear(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_pin(), visibilitymap_pin_ok(), visibilitymap_prepare_truncate(), visibilitymap_set(), and XLogReadBufferForRedoExtended().

◆ MAX_IO_CONCURRENCY

#define MAX_IO_CONCURRENCY   1000

Definition at line 78 of file bufmgr.h.

Referenced by ComputeIoConcurrency(), and heap_compute_xid_horizon_for_tuples().

◆ P_NEW

◆ RelationGetNumberOfBlocks

Typedef Documentation

◆ Block

typedef void* Block

Definition at line 24 of file bufmgr.h.

◆ BufferAccessStrategyType

Enumeration Type Documentation

◆ BufferAccessStrategyType

Enumerator
BAS_NORMAL 
BAS_BULKREAD 
BAS_BULKWRITE 
BAS_VACUUM 

Definition at line 27 of file bufmgr.h.

28 {
29  BAS_NORMAL, /* Normal random access */
30  BAS_BULKREAD, /* Large read-only scan (hint bit updates are
31  * ok) */
32  BAS_BULKWRITE, /* Large multi-block write (e.g. COPY IN) */
33  BAS_VACUUM /* VACUUM */
BufferAccessStrategyType
Definition: bufmgr.h:27

◆ ReadBufferMode

Enumerator
RBM_NORMAL 
RBM_ZERO_AND_LOCK 
RBM_ZERO_AND_CLEANUP_LOCK 
RBM_ZERO_ON_ERROR 
RBM_NORMAL_NO_LOG 

Definition at line 37 of file bufmgr.h.

38 {
39  RBM_NORMAL, /* Normal read */
40  RBM_ZERO_AND_LOCK, /* Don't read from disk, caller will
41  * initialize. Also locks the page. */
42  RBM_ZERO_AND_CLEANUP_LOCK, /* Like RBM_ZERO_AND_LOCK, but locks the page
43  * in "cleanup" mode */
44  RBM_ZERO_ON_ERROR, /* Read, but return an all-zeros page on error */
45  RBM_NORMAL_NO_LOG /* Don't log page as invalid during WAL
46  * replay; otherwise same as RBM_NORMAL */
ReadBufferMode
Definition: bufmgr.h:37

Function Documentation

◆ AbortBufferIO()

void AbortBufferIO ( void  )

Definition at line 4030 of file bufmgr.c.

References Assert, buftag::blockNum, BM_DIRTY, BM_IO_ERROR, BM_IO_IN_PROGRESS, BM_VALID, buf, BufferDescriptorGetIOLock, ereport, errcode(), errdetail(), errmsg(), buftag::forkNum, InProgressBuf, IsForInput, LockBufHdr(), LW_EXCLUSIVE, LWLockAcquire(), pfree(), relpathperm, buftag::rnode, BufferDesc::tag, TerminateBufferIO(), UnlockBufHdr, and WARNING.

Referenced by AbortSubTransaction(), AbortTransaction(), AtProcExit_Buffers(), AutoVacLauncherMain(), BackgroundWriterMain(), CheckpointerMain(), and WalWriterMain().

4031 {
4033 
4034  if (buf)
4035  {
4036  uint32 buf_state;
4037 
4038  /*
4039  * Since LWLockReleaseAll has already been called, we're not holding
4040  * the buffer's io_in_progress_lock. We have to re-acquire it so that
4041  * we can use TerminateBufferIO. Anyone who's executing WaitIO on the
4042  * buffer will be in a busy spin until we succeed in doing this.
4043  */
4045 
4046  buf_state = LockBufHdr(buf);
4047  Assert(buf_state & BM_IO_IN_PROGRESS);
4048  if (IsForInput)
4049  {
4050  Assert(!(buf_state & BM_DIRTY));
4051 
4052  /* We'd better not think buffer is valid yet */
4053  Assert(!(buf_state & BM_VALID));
4054  UnlockBufHdr(buf, buf_state);
4055  }
4056  else
4057  {
4058  Assert(buf_state & BM_DIRTY);
4059  UnlockBufHdr(buf, buf_state);
4060  /* Issue notice if this is not the first failure... */
4061  if (buf_state & BM_IO_ERROR)
4062  {
4063  /* Buffer is pinned, so we can read tag without spinlock */
4064  char *path;
4065 
4066  path = relpathperm(buf->tag.rnode, buf->tag.forkNum);
4067  ereport(WARNING,
4068  (errcode(ERRCODE_IO_ERROR),
4069  errmsg("could not write block %u of %s",
4070  buf->tag.blockNum, path),
4071  errdetail("Multiple failures --- write error might be permanent.")));
4072  pfree(path);
4073  }
4074  }
4075  TerminateBufferIO(buf, false, BM_IO_ERROR);
4076  }
4077 }
#define relpathperm(rnode, forknum)
Definition: relpath.h:83
ForkNumber forkNum
Definition: buf_internals.h:93
int errcode(int sqlerrcode)
Definition: elog.c:608
#define BM_DIRTY
Definition: buf_internals.h:58
#define BufferDescriptorGetIOLock(bdesc)
static BufferDesc * InProgressBuf
Definition: bufmgr.c:133
void pfree(void *pointer)
Definition: mcxt.c:1056
static char * buf
Definition: pg_test_fsync.c:67
int errdetail(const char *fmt,...)
Definition: elog.c:955
unsigned int uint32
Definition: c.h:359
static bool IsForInput
Definition: bufmgr.c:134
#define ereport(elevel, rest)
Definition: elog.h:141
#define WARNING
Definition: elog.h:40
static void TerminateBufferIO(BufferDesc *buf, bool clear_dirty, uint32 set_flag_bits)
Definition: bufmgr.c:3998
#define BM_VALID
Definition: buf_internals.h:59
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
#define Assert(condition)
Definition: c.h:739
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1122
BlockNumber blockNum
Definition: buf_internals.h:94
RelFileNode rnode
Definition: buf_internals.h:92
#define BM_IO_ERROR
Definition: buf_internals.h:62
BufferTag tag
int errmsg(const char *fmt,...)
Definition: elog.c:822
#define UnlockBufHdr(desc, s)
#define BM_IO_IN_PROGRESS
Definition: buf_internals.h:61

◆ AtEOXact_Buffers()

void AtEOXact_Buffers ( bool  isCommit)

Definition at line 2423 of file bufmgr.c.

References Assert, AtEOXact_LocalBuffers(), CheckForBufferLeaks(), and PrivateRefCountOverflowed.

Referenced by AbortTransaction(), AutoVacLauncherMain(), BackgroundWriterMain(), CheckpointerMain(), CommitTransaction(), PrepareTransaction(), and WalWriterMain().

2424 {
2426 
2427  AtEOXact_LocalBuffers(isCommit);
2428 
2430 }
static int32 PrivateRefCountOverflowed
Definition: bufmgr.c:171
#define Assert(condition)
Definition: c.h:739
static void CheckForBufferLeaks(void)
Definition: bufmgr.c:2498
void AtEOXact_LocalBuffers(bool isCommit)
Definition: localbuf.c:572

◆ AtProcExit_LocalBuffers()

void AtProcExit_LocalBuffers ( void  )

Definition at line 583 of file localbuf.c.

References CheckForLocalBufferLeaks().

Referenced by AtProcExit_Buffers().

584 {
585  /*
586  * We shouldn't be holding any remaining pins; if we are, and assertions
587  * aren't enabled, we'll fail later in DropRelFileNodeBuffers while trying
588  * to drop the temp rels.
589  */
591 }
static void CheckForLocalBufferLeaks(void)
Definition: localbuf.c:543

◆ BgBufferSync()

bool BgBufferSync ( struct WritebackContext wb_context)

Definition at line 2053 of file bufmgr.c.

References Assert, bgwriter_lru_maxpages, bgwriter_lru_multiplier, BgWriterDelay, BgWriterStats, BUF_REUSABLE, BUF_WRITTEN, CurrentResourceOwner, DEBUG1, DEBUG2, elog, PgStat_MsgBgWriter::m_buf_alloc, PgStat_MsgBgWriter::m_buf_written_clean, PgStat_MsgBgWriter::m_maxwritten_clean, NBuffers, ResourceOwnerEnlargeBuffers(), StrategySyncStart(), and SyncOneBuffer().

Referenced by BackgroundWriterMain().

2054 {
2055  /* info obtained from freelist.c */
2056  int strategy_buf_id;
2057  uint32 strategy_passes;
2058  uint32 recent_alloc;
2059 
2060  /*
2061  * Information saved between calls so we can determine the strategy
2062  * point's advance rate and avoid scanning already-cleaned buffers.
2063  */
2064  static bool saved_info_valid = false;
2065  static int prev_strategy_buf_id;
2066  static uint32 prev_strategy_passes;
2067  static int next_to_clean;
2068  static uint32 next_passes;
2069 
2070  /* Moving averages of allocation rate and clean-buffer density */
2071  static float smoothed_alloc = 0;
2072  static float smoothed_density = 10.0;
2073 
2074  /* Potentially these could be tunables, but for now, not */
2075  float smoothing_samples = 16;
2076  float scan_whole_pool_milliseconds = 120000.0;
2077 
2078  /* Used to compute how far we scan ahead */
2079  long strategy_delta;
2080  int bufs_to_lap;
2081  int bufs_ahead;
2082  float scans_per_alloc;
2083  int reusable_buffers_est;
2084  int upcoming_alloc_est;
2085  int min_scan_buffers;
2086 
2087  /* Variables for the scanning loop proper */
2088  int num_to_scan;
2089  int num_written;
2090  int reusable_buffers;
2091 
2092  /* Variables for final smoothed_density update */
2093  long new_strategy_delta;
2094  uint32 new_recent_alloc;
2095 
2096  /*
2097  * Find out where the freelist clock sweep currently is, and how many
2098  * buffer allocations have happened since our last call.
2099  */
2100  strategy_buf_id = StrategySyncStart(&strategy_passes, &recent_alloc);
2101 
2102  /* Report buffer alloc counts to pgstat */
2103  BgWriterStats.m_buf_alloc += recent_alloc;
2104 
2105  /*
2106  * If we're not running the LRU scan, just stop after doing the stats
2107  * stuff. We mark the saved state invalid so that we can recover sanely
2108  * if LRU scan is turned back on later.
2109  */
2110  if (bgwriter_lru_maxpages <= 0)
2111  {
2112  saved_info_valid = false;
2113  return true;
2114  }
2115 
2116  /*
2117  * Compute strategy_delta = how many buffers have been scanned by the
2118  * clock sweep since last time. If first time through, assume none. Then
2119  * see if we are still ahead of the clock sweep, and if so, how many
2120  * buffers we could scan before we'd catch up with it and "lap" it. Note:
2121  * weird-looking coding of xxx_passes comparisons are to avoid bogus
2122  * behavior when the passes counts wrap around.
2123  */
2124  if (saved_info_valid)
2125  {
2126  int32 passes_delta = strategy_passes - prev_strategy_passes;
2127 
2128  strategy_delta = strategy_buf_id - prev_strategy_buf_id;
2129  strategy_delta += (long) passes_delta * NBuffers;
2130 
2131  Assert(strategy_delta >= 0);
2132 
2133  if ((int32) (next_passes - strategy_passes) > 0)
2134  {
2135  /* we're one pass ahead of the strategy point */
2136  bufs_to_lap = strategy_buf_id - next_to_clean;
2137 #ifdef BGW_DEBUG
2138  elog(DEBUG2, "bgwriter ahead: bgw %u-%u strategy %u-%u delta=%ld lap=%d",
2139  next_passes, next_to_clean,
2140  strategy_passes, strategy_buf_id,
2141  strategy_delta, bufs_to_lap);
2142 #endif
2143  }
2144  else if (next_passes == strategy_passes &&
2145  next_to_clean >= strategy_buf_id)
2146  {
2147  /* on same pass, but ahead or at least not behind */
2148  bufs_to_lap = NBuffers - (next_to_clean - strategy_buf_id);
2149 #ifdef BGW_DEBUG
2150  elog(DEBUG2, "bgwriter ahead: bgw %u-%u strategy %u-%u delta=%ld lap=%d",
2151  next_passes, next_to_clean,
2152  strategy_passes, strategy_buf_id,
2153  strategy_delta, bufs_to_lap);
2154 #endif
2155  }
2156  else
2157  {
2158  /*
2159  * We're behind, so skip forward to the strategy point and start
2160  * cleaning from there.
2161  */
2162 #ifdef BGW_DEBUG
2163  elog(DEBUG2, "bgwriter behind: bgw %u-%u strategy %u-%u delta=%ld",
2164  next_passes, next_to_clean,
2165  strategy_passes, strategy_buf_id,
2166  strategy_delta);
2167 #endif
2168  next_to_clean = strategy_buf_id;
2169  next_passes = strategy_passes;
2170  bufs_to_lap = NBuffers;
2171  }
2172  }
2173  else
2174  {
2175  /*
2176  * Initializing at startup or after LRU scanning had been off. Always
2177  * start at the strategy point.
2178  */
2179 #ifdef BGW_DEBUG
2180  elog(DEBUG2, "bgwriter initializing: strategy %u-%u",
2181  strategy_passes, strategy_buf_id);
2182 #endif
2183  strategy_delta = 0;
2184  next_to_clean = strategy_buf_id;
2185  next_passes = strategy_passes;
2186  bufs_to_lap = NBuffers;
2187  }
2188 
2189  /* Update saved info for next time */
2190  prev_strategy_buf_id = strategy_buf_id;
2191  prev_strategy_passes = strategy_passes;
2192  saved_info_valid = true;
2193 
2194  /*
2195  * Compute how many buffers had to be scanned for each new allocation, ie,
2196  * 1/density of reusable buffers, and track a moving average of that.
2197  *
2198  * If the strategy point didn't move, we don't update the density estimate
2199  */
2200  if (strategy_delta > 0 && recent_alloc > 0)
2201  {
2202  scans_per_alloc = (float) strategy_delta / (float) recent_alloc;
2203  smoothed_density += (scans_per_alloc - smoothed_density) /
2204  smoothing_samples;
2205  }
2206 
2207  /*
2208  * Estimate how many reusable buffers there are between the current
2209  * strategy point and where we've scanned ahead to, based on the smoothed
2210  * density estimate.
2211  */
2212  bufs_ahead = NBuffers - bufs_to_lap;
2213  reusable_buffers_est = (float) bufs_ahead / smoothed_density;
2214 
2215  /*
2216  * Track a moving average of recent buffer allocations. Here, rather than
2217  * a true average we want a fast-attack, slow-decline behavior: we
2218  * immediately follow any increase.
2219  */
2220  if (smoothed_alloc <= (float) recent_alloc)
2221  smoothed_alloc = recent_alloc;
2222  else
2223  smoothed_alloc += ((float) recent_alloc - smoothed_alloc) /
2224  smoothing_samples;
2225 
2226  /* Scale the estimate by a GUC to allow more aggressive tuning. */
2227  upcoming_alloc_est = (int) (smoothed_alloc * bgwriter_lru_multiplier);
2228 
2229  /*
2230  * If recent_alloc remains at zero for many cycles, smoothed_alloc will
2231  * eventually underflow to zero, and the underflows produce annoying
2232  * kernel warnings on some platforms. Once upcoming_alloc_est has gone to
2233  * zero, there's no point in tracking smaller and smaller values of
2234  * smoothed_alloc, so just reset it to exactly zero to avoid this
2235  * syndrome. It will pop back up as soon as recent_alloc increases.
2236  */
2237  if (upcoming_alloc_est == 0)
2238  smoothed_alloc = 0;
2239 
2240  /*
2241  * Even in cases where there's been little or no buffer allocation
2242  * activity, we want to make a small amount of progress through the buffer
2243  * cache so that as many reusable buffers as possible are clean after an
2244  * idle period.
2245  *
2246  * (scan_whole_pool_milliseconds / BgWriterDelay) computes how many times
2247  * the BGW will be called during the scan_whole_pool time; slice the
2248  * buffer pool into that many sections.
2249  */
2250  min_scan_buffers = (int) (NBuffers / (scan_whole_pool_milliseconds / BgWriterDelay));
2251 
2252  if (upcoming_alloc_est < (min_scan_buffers + reusable_buffers_est))
2253  {
2254 #ifdef BGW_DEBUG
2255  elog(DEBUG2, "bgwriter: alloc_est=%d too small, using min=%d + reusable_est=%d",
2256  upcoming_alloc_est, min_scan_buffers, reusable_buffers_est);
2257 #endif
2258  upcoming_alloc_est = min_scan_buffers + reusable_buffers_est;
2259  }
2260 
2261  /*
2262  * Now write out dirty reusable buffers, working forward from the
2263  * next_to_clean point, until we have lapped the strategy scan, or cleaned
2264  * enough buffers to match our estimate of the next cycle's allocation
2265  * requirements, or hit the bgwriter_lru_maxpages limit.
2266  */
2267 
2268  /* Make sure we can handle the pin inside SyncOneBuffer */
2270 
2271  num_to_scan = bufs_to_lap;
2272  num_written = 0;
2273  reusable_buffers = reusable_buffers_est;
2274 
2275  /* Execute the LRU scan */
2276  while (num_to_scan > 0 && reusable_buffers < upcoming_alloc_est)
2277  {
2278  int sync_state = SyncOneBuffer(next_to_clean, true,
2279  wb_context);
2280 
2281  if (++next_to_clean >= NBuffers)
2282  {
2283  next_to_clean = 0;
2284  next_passes++;
2285  }
2286  num_to_scan--;
2287 
2288  if (sync_state & BUF_WRITTEN)
2289  {
2290  reusable_buffers++;
2291  if (++num_written >= bgwriter_lru_maxpages)
2292  {
2294  break;
2295  }
2296  }
2297  else if (sync_state & BUF_REUSABLE)
2298  reusable_buffers++;
2299  }
2300 
2301  BgWriterStats.m_buf_written_clean += num_written;
2302 
2303 #ifdef BGW_DEBUG
2304  elog(DEBUG1, "bgwriter: recent_alloc=%u smoothed=%.2f delta=%ld ahead=%d density=%.2f reusable_est=%d upcoming_est=%d scanned=%d wrote=%d reusable=%d",
2305  recent_alloc, smoothed_alloc, strategy_delta, bufs_ahead,
2306  smoothed_density, reusable_buffers_est, upcoming_alloc_est,
2307  bufs_to_lap - num_to_scan,
2308  num_written,
2309  reusable_buffers - reusable_buffers_est);
2310 #endif
2311 
2312  /*
2313  * Consider the above scan as being like a new allocation scan.
2314  * Characterize its density and update the smoothed one based on it. This
2315  * effectively halves the moving average period in cases where both the
2316  * strategy and the background writer are doing some useful scanning,
2317  * which is helpful because a long memory isn't as desirable on the
2318  * density estimates.
2319  */
2320  new_strategy_delta = bufs_to_lap - num_to_scan;
2321  new_recent_alloc = reusable_buffers - reusable_buffers_est;
2322  if (new_strategy_delta > 0 && new_recent_alloc > 0)
2323  {
2324  scans_per_alloc = (float) new_strategy_delta / (float) new_recent_alloc;
2325  smoothed_density += (scans_per_alloc - smoothed_density) /
2326  smoothing_samples;
2327 
2328 #ifdef BGW_DEBUG
2329  elog(DEBUG2, "bgwriter: cleaner density alloc=%u scan=%ld density=%.2f new smoothed=%.2f",
2330  new_recent_alloc, new_strategy_delta,
2331  scans_per_alloc, smoothed_density);
2332 #endif
2333  }
2334 
2335  /* Return true if OK to hibernate */
2336  return (bufs_to_lap == 0 && recent_alloc == 0);
2337 }
PgStat_Counter m_buf_alloc
Definition: pgstat.h:420
int StrategySyncStart(uint32 *complete_passes, uint32 *num_buf_alloc)
Definition: freelist.c:395
#define DEBUG1
Definition: elog.h:25
int BgWriterDelay
Definition: bgwriter.c:67
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
PgStat_Counter m_maxwritten_clean
Definition: pgstat.h:417
PgStat_Counter m_buf_written_clean
Definition: pgstat.h:416
PgStat_MsgBgWriter BgWriterStats
Definition: pgstat.c:141
double bgwriter_lru_multiplier
Definition: bufmgr.c:111
static int SyncOneBuffer(int buf_id, bool skip_recently_used, WritebackContext *wb_context)
Definition: bufmgr.c:2356
signed int int32
Definition: c.h:347
#define BUF_REUSABLE
Definition: bufmgr.c:67
int bgwriter_lru_maxpages
Definition: bufmgr.c:110
#define DEBUG2
Definition: elog.h:24
unsigned int uint32
Definition: c.h:359
#define BUF_WRITTEN
Definition: bufmgr.c:66
void ResourceOwnerEnlargeBuffers(ResourceOwner owner)
Definition: resowner.c:893
#define Assert(condition)
Definition: c.h:739
#define elog(elevel,...)
Definition: elog.h:228
int NBuffers
Definition: globals.c:131

◆ BufferGetBlockNumber()

BlockNumber BufferGetBlockNumber ( Buffer  buffer)

Definition at line 2613 of file bufmgr.c.

References Assert, buftag::blockNum, BufferIsLocal, BufferIsPinned, GetBufferDescriptor, GetLocalBufferDescriptor, and BufferDesc::tag.

Referenced by _bt_checkpage(), _bt_endpoint(), _bt_finish_split(), _bt_first(), _bt_getroot(), _bt_insert_parent(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_moveright(), _bt_newroot(), _bt_pagedel(), _bt_readnextpage(), _bt_readpage(), _bt_restore_meta(), _bt_search(), _bt_split(), _bt_unlink_halfdead_page(), _bt_walk_left(), _hash_addovflpage(), _hash_checkpage(), _hash_first(), _hash_freeovflpage(), _hash_getnewbuf(), _hash_readnext(), _hash_readpage(), _hash_splitbucket(), allocNewBuffer(), blinsert(), BloomInitMetapage(), brin_doinsert(), brin_doupdate(), brin_getinsertbuffer(), brin_initialize_empty_new_buffer(), brin_page_cleanup(), brin_xlog_insert_update(), brinbuild(), brinGetTupleForHeapBlock(), CheckForSerializableConflictIn(), createPostingTree(), dataBeginPlaceToPageLeaf(), dataPrepareDownlink(), doPickSplit(), entryPrepareDownlink(), fill_seq_with_data(), ginFindParents(), ginFinishSplit(), ginPlaceToPage(), ginRedoDeleteListPages(), ginRedoUpdateMetapage(), ginScanToDelete(), gistbufferinginserttuples(), gistbuild(), gistcheckpage(), gistdeletepage(), gistformdownlink(), gistMemorizeAllDownlinks(), gistplacetopage(), gistRelocateBuildBuffersOnSplit(), gistScanPage(), hash_xlog_add_ovfl_page(), heap_delete(), heap_hot_search_buffer(), heap_insert(), heap_multi_insert(), heap_page_is_all_visible(), heap_prune_chain(), heap_update(), heap_xlog_confirm(), heap_xlog_lock(), makeSublist(), moveLeafs(), moveRightIfItNeeded(), pgstathashindex(), ReadBufferBI(), RelationAddExtraBlocks(), RelationGetBufferForTuple(), RelationPutHeapTuple(), revmap_get_buffer(), revmap_physical_extend(), spgAddNodeAction(), spgbuild(), spgdoinsert(), SpGistSetLastUsedPage(), spgSplitNodeAction(), spgWalk(), startScanEntry(), terminate_brin_buildstate(), vacuumLeafPage(), visibilitymap_clear(), visibilitymap_get_status(), visibilitymap_pin(), visibilitymap_pin_ok(), visibilitymap_set(), and XLogReadBufferExtended().

2614 {
2615  BufferDesc *bufHdr;
2616 
2617  Assert(BufferIsPinned(buffer));
2618 
2619  if (BufferIsLocal(buffer))
2620  bufHdr = GetLocalBufferDescriptor(-buffer - 1);
2621  else
2622  bufHdr = GetBufferDescriptor(buffer - 1);
2623 
2624  /* pinned, so OK to read tag without spinlock */
2625  return bufHdr->tag.blockNum;
2626 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
#define GetLocalBufferDescriptor(id)
#define GetBufferDescriptor(id)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
BlockNumber blockNum
Definition: buf_internals.h:94
BufferTag tag

◆ BufferGetLSNAtomic()

XLogRecPtr BufferGetLSNAtomic ( Buffer  buffer)

Definition at line 2876 of file bufmgr.c.

References Assert, BufferGetPage, BufferIsLocal, BufferIsPinned, BufferIsValid, GetBufferDescriptor, LockBufHdr(), PageGetLSN, UnlockBufHdr, and XLogHintBitIsNeeded.

Referenced by _bt_killitems(), _bt_readpage(), gistdoinsert(), gistFindPath(), gistkillitems(), gistScanPage(), SetHintBits(), and XLogSaveBufferForHint().

2877 {
2878  BufferDesc *bufHdr = GetBufferDescriptor(buffer - 1);
2879  char *page = BufferGetPage(buffer);
2880  XLogRecPtr lsn;
2881  uint32 buf_state;
2882 
2883  /*
2884  * If we don't need locking for correctness, fastpath out.
2885  */
2886  if (!XLogHintBitIsNeeded() || BufferIsLocal(buffer))
2887  return PageGetLSN(page);
2888 
2889  /* Make sure we've got a real buffer, and that we hold a pin on it. */
2890  Assert(BufferIsValid(buffer));
2891  Assert(BufferIsPinned(buffer));
2892 
2893  buf_state = LockBufHdr(bufHdr);
2894  lsn = PageGetLSN(page);
2895  UnlockBufHdr(bufHdr, buf_state);
2896 
2897  return lsn;
2898 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
#define GetBufferDescriptor(id)
unsigned int uint32
Definition: c.h:359
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define PageGetLSN(page)
Definition: bufpage.h:366
#define UnlockBufHdr(desc, s)
#define XLogHintBitIsNeeded()
Definition: xlog.h:192

◆ BufferGetTag()

void BufferGetTag ( Buffer  buffer,
RelFileNode rnode,
ForkNumber forknum,
BlockNumber blknum 
)

Definition at line 2634 of file bufmgr.c.

References Assert, buftag::blockNum, BufferIsLocal, BufferIsPinned, buftag::forkNum, GetBufferDescriptor, GetLocalBufferDescriptor, buftag::rnode, and BufferDesc::tag.

Referenced by fsm_search_avail(), ginRedoInsertEntry(), log_newpage_buffer(), ResolveCminCmaxDuringDecoding(), XLogRegisterBuffer(), and XLogSaveBufferForHint().

2636 {
2637  BufferDesc *bufHdr;
2638 
2639  /* Do the same checks as BufferGetBlockNumber. */
2640  Assert(BufferIsPinned(buffer));
2641 
2642  if (BufferIsLocal(buffer))
2643  bufHdr = GetLocalBufferDescriptor(-buffer - 1);
2644  else
2645  bufHdr = GetBufferDescriptor(buffer - 1);
2646 
2647  /* pinned, so OK to read tag without spinlock */
2648  *rnode = bufHdr->tag.rnode;
2649  *forknum = bufHdr->tag.forkNum;
2650  *blknum = bufHdr->tag.blockNum;
2651 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
ForkNumber forkNum
Definition: buf_internals.h:93
#define GetLocalBufferDescriptor(id)
#define GetBufferDescriptor(id)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
BlockNumber blockNum
Definition: buf_internals.h:94
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag

◆ BufferIsPermanent()

bool BufferIsPermanent ( Buffer  buffer)

Definition at line 2846 of file bufmgr.c.

References Assert, BM_PERMANENT, BufferIsLocal, BufferIsPinned, BufferIsValid, GetBufferDescriptor, pg_atomic_read_u32(), and BufferDesc::state.

Referenced by SetHintBits().

2847 {
2848  BufferDesc *bufHdr;
2849 
2850  /* Local buffers are used only for temp relations. */
2851  if (BufferIsLocal(buffer))
2852  return false;
2853 
2854  /* Make sure we've got a real buffer, and that we hold a pin on it. */
2855  Assert(BufferIsValid(buffer));
2856  Assert(BufferIsPinned(buffer));
2857 
2858  /*
2859  * BM_PERMANENT can't be changed while we hold a pin on the buffer, so we
2860  * need not bother with the buffer header spinlock. Even if someone else
2861  * changes the buffer header state while we're doing this, the state is
2862  * changed atomically, so we'll read the old value or the new value, but
2863  * not random garbage.
2864  */
2865  bufHdr = GetBufferDescriptor(buffer - 1);
2866  return (pg_atomic_read_u32(&bufHdr->state) & BM_PERMANENT) != 0;
2867 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
#define BM_PERMANENT
Definition: buf_internals.h:66
#define GetBufferDescriptor(id)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
pg_atomic_uint32 state
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:241

◆ BufferShmemSize()

Size BufferShmemSize ( void  )

Definition at line 160 of file buf_init.c.

References add_size(), mul_size(), NBuffers, PG_CACHE_LINE_SIZE, and StrategyShmemSize().

Referenced by CreateSharedMemoryAndSemaphores().

161 {
162  Size size = 0;
163 
164  /* size of buffer descriptors */
165  size = add_size(size, mul_size(NBuffers, sizeof(BufferDescPadded)));
166  /* to allow aligning buffer descriptors */
167  size = add_size(size, PG_CACHE_LINE_SIZE);
168 
169  /* size of data pages */
170  size = add_size(size, mul_size(NBuffers, BLCKSZ));
171 
172  /* size of stuff controlled by freelist.c */
173  size = add_size(size, StrategyShmemSize());
174 
175  /*
176  * It would be nice to include the I/O locks in the BufferDesc, but that
177  * would increase the size of a BufferDesc to more than one cache line,
178  * and benchmarking has shown that keeping every BufferDesc aligned on a
179  * cache line boundary is important for performance. So, instead, the
180  * array of I/O locks is allocated in a separate tranche. Because those
181  * locks are not highly contended, we lay out the array with minimal
182  * padding.
183  */
184  size = add_size(size, mul_size(NBuffers, sizeof(LWLockMinimallyPadded)));
185  /* to allow aligning the above */
186  size = add_size(size, PG_CACHE_LINE_SIZE);
187 
188  /* size of checkpoint sort array in bufmgr.c */
189  size = add_size(size, mul_size(NBuffers, sizeof(CkptSortItem)));
190 
191  return size;
192 }
#define PG_CACHE_LINE_SIZE
Size mul_size(Size s1, Size s2)
Definition: shmem.c:492
Size add_size(Size s1, Size s2)
Definition: shmem.c:475
size_t Size
Definition: c.h:467
int NBuffers
Definition: globals.c:131
Size StrategyShmemSize(void)
Definition: freelist.c:454

◆ BufmgrCommit()

void BufmgrCommit ( void  )

Definition at line 2599 of file bufmgr.c.

Referenced by PrepareTransaction(), and RecordTransactionCommit().

2600 {
2601  /* Nothing to do in bufmgr anymore... */
2602 }

◆ CheckPointBuffers()

void CheckPointBuffers ( int  flags)

Definition at line 2582 of file bufmgr.c.

References BufferSync(), CheckpointStats, CheckpointStatsData::ckpt_sync_end_t, CheckpointStatsData::ckpt_sync_t, CheckpointStatsData::ckpt_write_t, GetCurrentTimestamp(), and ProcessSyncRequests().

Referenced by CheckPointGuts().

2583 {
2584  TRACE_POSTGRESQL_BUFFER_CHECKPOINT_START(flags);
2586  BufferSync(flags);
2588  TRACE_POSTGRESQL_BUFFER_CHECKPOINT_SYNC_START();
2591  TRACE_POSTGRESQL_BUFFER_CHECKPOINT_DONE();
2592 }
void ProcessSyncRequests(void)
Definition: sync.c:236
TimestampTz ckpt_sync_end_t
Definition: xlog.h:238
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1583
static void BufferSync(int flags)
Definition: bufmgr.c:1786
CheckpointStatsData CheckpointStats
Definition: xlog.c:181
TimestampTz ckpt_write_t
Definition: xlog.h:236
TimestampTz ckpt_sync_t
Definition: xlog.h:237

◆ ComputeIoConcurrency()

bool ComputeIoConcurrency ( int  io_concurrency,
double *  target 
)

Definition at line 469 of file bufmgr.c.

References i, Max, MAX_IO_CONCURRENCY, and Min.

Referenced by check_effective_io_concurrency(), and ExecInitBitmapHeapScan().

470 {
471  double new_prefetch_pages = 0.0;
472  int i;
473 
474  /*
475  * Make sure the io_concurrency value is within valid range; it may have
476  * been forced with a manual pg_tablespace update.
477  */
478  io_concurrency = Min(Max(io_concurrency, 0), MAX_IO_CONCURRENCY);
479 
480  /*----------
481  * The user-visible GUC parameter is the number of drives (spindles),
482  * which we need to translate to a number-of-pages-to-prefetch target.
483  * The target value is stashed in *extra and then assigned to the actual
484  * variable by assign_effective_io_concurrency.
485  *
486  * The expected number of prefetch pages needed to keep N drives busy is:
487  *
488  * drives | I/O requests
489  * -------+----------------
490  * 1 | 1
491  * 2 | 2/1 + 2/2 = 3
492  * 3 | 3/1 + 3/2 + 3/3 = 5 1/2
493  * 4 | 4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
494  * n | n * H(n)
495  *
496  * This is called the "coupon collector problem" and H(n) is called the
497  * harmonic series. This could be approximated by n * ln(n), but for
498  * reasonable numbers of drives we might as well just compute the series.
499  *
500  * Alternatively we could set the target to the number of pages necessary
501  * so that the expected number of active spindles is some arbitrary
502  * percentage of the total. This sounds the same but is actually slightly
503  * different. The result ends up being ln(1-P)/ln((n-1)/n) where P is
504  * that desired fraction.
505  *
506  * Experimental results show that both of these formulas aren't aggressive
507  * enough, but we don't really have any better proposals.
508  *
509  * Note that if io_concurrency = 0 (disabled), we must set target = 0.
510  *----------
511  */
512 
513  for (i = 1; i <= io_concurrency; i++)
514  new_prefetch_pages += (double) io_concurrency / (double) i;
515 
516  *target = new_prefetch_pages;
517 
518  /* This range check shouldn't fail, but let's be paranoid */
519  return (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX);
520 }
#define MAX_IO_CONCURRENCY
Definition: bufmgr.h:78
#define Min(x, y)
Definition: c.h:911
#define Max(x, y)
Definition: c.h:905
int i

◆ ConditionalLockBuffer()

bool ConditionalLockBuffer ( Buffer  buffer)

Definition at line 3628 of file bufmgr.c.

References Assert, buf, BufferDescriptorGetContentLock, BufferIsLocal, BufferIsValid, GetBufferDescriptor, LW_EXCLUSIVE, and LWLockConditionalAcquire().

Referenced by _bt_doinsert(), _bt_getbuf(), BloomNewBuffer(), ConditionalLockBufferForCleanup(), GinNewBuffer(), gistNewBuffer(), RelationGetBufferForTuple(), spgdoinsert(), SpGistGetBuffer(), SpGistNewBuffer(), and SpGistUpdateMetaPage().

3629 {
3630  BufferDesc *buf;
3631 
3632  Assert(BufferIsValid(buffer));
3633  if (BufferIsLocal(buffer))
3634  return true; /* act as though we got it */
3635 
3636  buf = GetBufferDescriptor(buffer - 1);
3637 
3639  LW_EXCLUSIVE);
3640 }
bool LWLockConditionalAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1294
static char * buf
Definition: pg_test_fsync.c:67
#define GetBufferDescriptor(id)
#define BufferDescriptorGetContentLock(bdesc)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113

◆ ConditionalLockBufferForCleanup()

bool ConditionalLockBufferForCleanup ( Buffer  buffer)

Definition at line 3774 of file bufmgr.c.

References Assert, BUF_STATE_GET_REFCOUNT, BUFFER_LOCK_UNLOCK, BufferIsLocal, BufferIsValid, ConditionalLockBuffer(), GetBufferDescriptor, GetPrivateRefCount(), LocalRefCount, LockBuffer(), LockBufHdr(), PrivateRefCountEntry::refcount, and UnlockBufHdr.

Referenced by _hash_finish_split(), _hash_getbuf_with_condlock_cleanup(), heap_page_prune_opt(), lazy_scan_heap(), and lazy_vacuum_heap().

3775 {
3776  BufferDesc *bufHdr;
3777  uint32 buf_state,
3778  refcount;
3779 
3780  Assert(BufferIsValid(buffer));
3781 
3782  if (BufferIsLocal(buffer))
3783  {
3784  refcount = LocalRefCount[-buffer - 1];
3785  /* There should be exactly one pin */
3786  Assert(refcount > 0);
3787  if (refcount != 1)
3788  return false;
3789  /* Nobody else to wait for */
3790  return true;
3791  }
3792 
3793  /* There should be exactly one local pin */
3794  refcount = GetPrivateRefCount(buffer);
3795  Assert(refcount);
3796  if (refcount != 1)
3797  return false;
3798 
3799  /* Try to acquire lock */
3800  if (!ConditionalLockBuffer(buffer))
3801  return false;
3802 
3803  bufHdr = GetBufferDescriptor(buffer - 1);
3804  buf_state = LockBufHdr(bufHdr);
3805  refcount = BUF_STATE_GET_REFCOUNT(buf_state);
3806 
3807  Assert(refcount > 0);
3808  if (refcount == 1)
3809  {
3810  /* Successfully acquired exclusive lock with pincount 1 */
3811  UnlockBufHdr(bufHdr, buf_state);
3812  return true;
3813  }
3814 
3815  /* Failed, so release the lock */
3816  UnlockBufHdr(bufHdr, buf_state);
3817  LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
3818  return false;
3819 }
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
#define GetBufferDescriptor(id)
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
unsigned int uint32
Definition: c.h:359
bool ConditionalLockBuffer(Buffer buffer)
Definition: bufmgr.c:3628
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define UnlockBufHdr(desc, s)
int32 * LocalRefCount
Definition: localbuf.c:45
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48

◆ DropDatabaseBuffers()

void DropDatabaseBuffers ( Oid  dbid)

Definition at line 3099 of file bufmgr.c.

References buftag::blockNum, buf, BufferDescriptorGetBuffer, RelFileNode::dbNode, elog, buftag::forkNum, BufferDesc::freeNext, GetBufferDescriptor, GetPrivateRefCount(), i, InvalidateBuffer(), InvalidBackendId, LockBufHdr(), LOG, NBuffers, relpathbackend, relpathperm, buftag::rnode, BufferDesc::tag, and UnlockBufHdr.

Referenced by dbase_redo(), dropdb(), and movedb().

3100 {
3101  int i;
3102 
3103  /*
3104  * We needn't consider local buffers, since by assumption the target
3105  * database isn't our own.
3106  */
3107 
3108  for (i = 0; i < NBuffers; i++)
3109  {
3110  BufferDesc *bufHdr = GetBufferDescriptor(i);
3111  uint32 buf_state;
3112 
3113  /*
3114  * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
3115  * and saves some cycles.
3116  */
3117  if (bufHdr->tag.rnode.dbNode != dbid)
3118  continue;
3119 
3120  buf_state = LockBufHdr(bufHdr);
3121  if (bufHdr->tag.rnode.dbNode == dbid)
3122  InvalidateBuffer(bufHdr); /* releases spinlock */
3123  else
3124  UnlockBufHdr(bufHdr, buf_state);
3125  }
3126 }
static void InvalidateBuffer(BufferDesc *buf)
Definition: bufmgr.c:1360
#define GetBufferDescriptor(id)
unsigned int uint32
Definition: c.h:359
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
#define UnlockBufHdr(desc, s)
int i
int NBuffers
Definition: globals.c:131

◆ DropRelFileNodeBuffers()

void DropRelFileNodeBuffers ( RelFileNodeBackend  rnode,
ForkNumber forkNum,
int  nforks,
BlockNumber firstDelBlock 
)

Definition at line 2927 of file bufmgr.c.

References RelFileNodeBackend::backend, buftag::blockNum, DropRelFileNodeLocalBuffers(), buftag::forkNum, GetBufferDescriptor, i, InvalidateBuffer(), LockBufHdr(), MyBackendId, NBuffers, RelFileNodeBackend::node, RelFileNodeBackendIsTemp, RelFileNodeEquals, buftag::rnode, BufferDesc::tag, and UnlockBufHdr.

Referenced by smgrtruncate().

2929 {
2930  int i;
2931  int j;
2932 
2933  /* If it's a local relation, it's localbuf.c's problem. */
2934  if (RelFileNodeBackendIsTemp(rnode))
2935  {
2936  if (rnode.backend == MyBackendId)
2937  {
2938  for (j = 0; j < nforks; j++)
2939  DropRelFileNodeLocalBuffers(rnode.node, forkNum[j],
2940  firstDelBlock[j]);
2941  }
2942  return;
2943  }
2944 
2945  for (i = 0; i < NBuffers; i++)
2946  {
2947  BufferDesc *bufHdr = GetBufferDescriptor(i);
2948  uint32 buf_state;
2949 
2950  /*
2951  * We can make this a tad faster by prechecking the buffer tag before
2952  * we attempt to lock the buffer; this saves a lot of lock
2953  * acquisitions in typical cases. It should be safe because the
2954  * caller must have AccessExclusiveLock on the relation, or some other
2955  * reason to be certain that no one is loading new pages of the rel
2956  * into the buffer pool. (Otherwise we might well miss such pages
2957  * entirely.) Therefore, while the tag might be changing while we
2958  * look at it, it can't be changing *to* a value we care about, only
2959  * *away* from such a value. So false negatives are impossible, and
2960  * false positives are safe because we'll recheck after getting the
2961  * buffer lock.
2962  *
2963  * We could check forkNum and blockNum as well as the rnode, but the
2964  * incremental win from doing so seems small.
2965  */
2966  if (!RelFileNodeEquals(bufHdr->tag.rnode, rnode.node))
2967  continue;
2968 
2969  buf_state = LockBufHdr(bufHdr);
2970 
2971  for (j = 0; j < nforks; j++)
2972  {
2973  if (RelFileNodeEquals(bufHdr->tag.rnode, rnode.node) &&
2974  bufHdr->tag.forkNum == forkNum[j] &&
2975  bufHdr->tag.blockNum >= firstDelBlock[j])
2976  {
2977  InvalidateBuffer(bufHdr); /* releases spinlock */
2978  break;
2979  }
2980  }
2981  if (j >= nforks)
2982  UnlockBufHdr(bufHdr, buf_state);
2983  }
2984 }
BackendId MyBackendId
Definition: globals.c:81
#define RelFileNodeBackendIsTemp(rnode)
Definition: relfilenode.h:78
ForkNumber forkNum
Definition: buf_internals.h:93
static void InvalidateBuffer(BufferDesc *buf)
Definition: bufmgr.c:1360
void DropRelFileNodeLocalBuffers(RelFileNode rnode, ForkNumber forkNum, BlockNumber firstDelBlock)
Definition: localbuf.c:320
#define GetBufferDescriptor(id)
unsigned int uint32
Definition: c.h:359
RelFileNode node
Definition: relfilenode.h:74
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
BackendId backend
Definition: relfilenode.h:75
BlockNumber blockNum
Definition: buf_internals.h:94
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
#define UnlockBufHdr(desc, s)
int i
int NBuffers
Definition: globals.c:131
#define RelFileNodeEquals(node1, node2)
Definition: relfilenode.h:88

◆ DropRelFileNodesAllBuffers()

void DropRelFileNodesAllBuffers ( RelFileNodeBackend rnodes,
int  nnodes 
)

Definition at line 2996 of file bufmgr.c.

References DROP_RELS_BSEARCH_THRESHOLD, DropRelFileNodeAllLocalBuffers(), GetBufferDescriptor, i, InvalidateBuffer(), LockBufHdr(), MyBackendId, NBuffers, RelFileNodeBackend::node, palloc(), pfree(), pg_qsort(), RelFileNodeBackendIsTemp, RelFileNodeEquals, buftag::rnode, rnode_comparator(), BufferDesc::tag, and UnlockBufHdr.

Referenced by smgrdounlink(), and smgrdounlinkall().

2997 {
2998  int i,
2999  n = 0;
3000  RelFileNode *nodes;
3001  bool use_bsearch;
3002 
3003  if (nnodes == 0)
3004  return;
3005 
3006  nodes = palloc(sizeof(RelFileNode) * nnodes); /* non-local relations */
3007 
3008  /* If it's a local relation, it's localbuf.c's problem. */
3009  for (i = 0; i < nnodes; i++)
3010  {
3011  if (RelFileNodeBackendIsTemp(rnodes[i]))
3012  {
3013  if (rnodes[i].backend == MyBackendId)
3014  DropRelFileNodeAllLocalBuffers(rnodes[i].node);
3015  }
3016  else
3017  nodes[n++] = rnodes[i].node;
3018  }
3019 
3020  /*
3021  * If there are no non-local relations, then we're done. Release the
3022  * memory and return.
3023  */
3024  if (n == 0)
3025  {
3026  pfree(nodes);
3027  return;
3028  }
3029 
3030  /*
3031  * For low number of relations to drop just use a simple walk through, to
3032  * save the bsearch overhead. The threshold to use is rather a guess than
3033  * an exactly determined value, as it depends on many factors (CPU and RAM
3034  * speeds, amount of shared buffers etc.).
3035  */
3036  use_bsearch = n > DROP_RELS_BSEARCH_THRESHOLD;
3037 
3038  /* sort the list of rnodes if necessary */
3039  if (use_bsearch)
3040  pg_qsort(nodes, n, sizeof(RelFileNode), rnode_comparator);
3041 
3042  for (i = 0; i < NBuffers; i++)
3043  {
3044  RelFileNode *rnode = NULL;
3045  BufferDesc *bufHdr = GetBufferDescriptor(i);
3046  uint32 buf_state;
3047 
3048  /*
3049  * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
3050  * and saves some cycles.
3051  */
3052 
3053  if (!use_bsearch)
3054  {
3055  int j;
3056 
3057  for (j = 0; j < n; j++)
3058  {
3059  if (RelFileNodeEquals(bufHdr->tag.rnode, nodes[j]))
3060  {
3061  rnode = &nodes[j];
3062  break;
3063  }
3064  }
3065  }
3066  else
3067  {
3068  rnode = bsearch((const void *) &(bufHdr->tag.rnode),
3069  nodes, n, sizeof(RelFileNode),
3071  }
3072 
3073  /* buffer doesn't belong to any of the given relfilenodes; skip it */
3074  if (rnode == NULL)
3075  continue;
3076 
3077  buf_state = LockBufHdr(bufHdr);
3078  if (RelFileNodeEquals(bufHdr->tag.rnode, (*rnode)))
3079  InvalidateBuffer(bufHdr); /* releases spinlock */
3080  else
3081  UnlockBufHdr(bufHdr, buf_state);
3082  }
3083 
3084  pfree(nodes);
3085 }
BackendId MyBackendId
Definition: globals.c:81
#define RelFileNodeBackendIsTemp(rnode)
Definition: relfilenode.h:78
static void InvalidateBuffer(BufferDesc *buf)
Definition: bufmgr.c:1360
#define DROP_RELS_BSEARCH_THRESHOLD
Definition: bufmgr.c:69
void DropRelFileNodeAllLocalBuffers(RelFileNode rnode)
Definition: localbuf.c:367
void pfree(void *pointer)
Definition: mcxt.c:1056
#define GetBufferDescriptor(id)
unsigned int uint32
Definition: c.h:359
static int rnode_comparator(const void *p1, const void *p2)
Definition: bufmgr.c:4121
RelFileNode node
Definition: relfilenode.h:74
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
void pg_qsort(void *base, size_t nel, size_t elsize, int(*cmp)(const void *, const void *))
Definition: qsort.c:113
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
void * palloc(Size size)
Definition: mcxt.c:949
#define UnlockBufHdr(desc, s)
int i
int NBuffers
Definition: globals.c:131
#define RelFileNodeEquals(node1, node2)
Definition: relfilenode.h:88

◆ FlushDatabaseBuffers()

void FlushDatabaseBuffers ( Oid  dbid)

Definition at line 3302 of file bufmgr.c.

References BM_DIRTY, BM_VALID, BufferDescriptorGetContentLock, CurrentResourceOwner, RelFileNode::dbNode, FlushBuffer(), GetBufferDescriptor, i, LockBufHdr(), LW_SHARED, LWLockAcquire(), LWLockRelease(), NBuffers, PinBuffer_Locked(), ReservePrivateRefCountEntry(), ResourceOwnerEnlargeBuffers(), buftag::rnode, BufferDesc::tag, UnlockBufHdr, and UnpinBuffer().

Referenced by dbase_redo().

3303 {
3304  int i;
3305  BufferDesc *bufHdr;
3306 
3307  /* Make sure we can handle the pin inside the loop */
3309 
3310  for (i = 0; i < NBuffers; i++)
3311  {
3312  uint32 buf_state;
3313 
3314  bufHdr = GetBufferDescriptor(i);
3315 
3316  /*
3317  * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
3318  * and saves some cycles.
3319  */
3320  if (bufHdr->tag.rnode.dbNode != dbid)
3321  continue;
3322 
3324 
3325  buf_state = LockBufHdr(bufHdr);
3326  if (bufHdr->tag.rnode.dbNode == dbid &&
3327  (buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
3328  {
3329  PinBuffer_Locked(bufHdr);
3331  FlushBuffer(bufHdr, NULL);
3333  UnpinBuffer(bufHdr, true);
3334  }
3335  else
3336  UnlockBufHdr(bufHdr, buf_state);
3337  }
3338 }
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
#define BM_DIRTY
Definition: buf_internals.h:58
static void FlushBuffer(BufferDesc *buf, SMgrRelation reln)
Definition: bufmgr.c:2673
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1726
#define GetBufferDescriptor(id)
unsigned int uint32
Definition: c.h:359
static void UnpinBuffer(BufferDesc *buf, bool fixOwner)
Definition: bufmgr.c:1702
void ResourceOwnerEnlargeBuffers(ResourceOwner owner)
Definition: resowner.c:893
#define BM_VALID
Definition: buf_internals.h:59
#define BufferDescriptorGetContentLock(bdesc)
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
static void PinBuffer_Locked(BufferDesc *buf)
Definition: bufmgr.c:1664
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1122
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
#define UnlockBufHdr(desc, s)
int i
int NBuffers
Definition: globals.c:131
static void ReservePrivateRefCountEntry(void)
Definition: bufmgr.c:187

◆ FlushOneBuffer()

void FlushOneBuffer ( Buffer  buffer)

Definition at line 3345 of file bufmgr.c.

References Assert, BufferDescriptorGetContentLock, BufferIsLocal, BufferIsPinned, FlushBuffer(), GetBufferDescriptor, and LWLockHeldByMe().

Referenced by hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), and XLogReadBufferForRedoExtended().

3346 {
3347  BufferDesc *bufHdr;
3348 
3349  /* currently not needed, but no fundamental reason not to support */
3350  Assert(!BufferIsLocal(buffer));
3351 
3352  Assert(BufferIsPinned(buffer));
3353 
3354  bufHdr = GetBufferDescriptor(buffer - 1);
3355 
3357 
3358  FlushBuffer(bufHdr, NULL);
3359 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
bool LWLockHeldByMe(LWLock *l)
Definition: lwlock.c:1842
static void FlushBuffer(BufferDesc *buf, SMgrRelation reln)
Definition: bufmgr.c:2673
#define GetBufferDescriptor(id)
#define BufferDescriptorGetContentLock(bdesc)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37

◆ FlushRelationBuffers()

void FlushRelationBuffers ( Relation  rel)

Definition at line 3204 of file bufmgr.c.

References ErrorContextCallback::arg, buftag::blockNum, BM_DIRTY, BM_JUST_DIRTIED, BM_VALID, BufferDescriptorGetContentLock, ErrorContextCallback::callback, CurrentResourceOwner, error_context_stack, FlushBuffer(), buftag::forkNum, GetBufferDescriptor, GetLocalBufferDescriptor, i, local_buffer_write_error_callback(), LocalBufHdrGetBlock, LockBufHdr(), LW_SHARED, LWLockAcquire(), LWLockRelease(), NBuffers, NLocBuffer, PageSetChecksumInplace(), pg_atomic_read_u32(), pg_atomic_unlocked_write_u32(), PinBuffer_Locked(), ErrorContextCallback::previous, RelationData::rd_node, RelationData::rd_smgr, RelationOpenSmgr, RelationUsesLocalBuffers, RelFileNodeEquals, ReservePrivateRefCountEntry(), ResourceOwnerEnlargeBuffers(), buftag::rnode, smgrwrite(), BufferDesc::state, BufferDesc::tag, UnlockBufHdr, and UnpinBuffer().

Referenced by heap_sync(), heapam_relation_copy_data(), and index_copy_data().

3205 {
3206  int i;
3207  BufferDesc *bufHdr;
3208 
3209  /* Open rel at the smgr level if not already done */
3210  RelationOpenSmgr(rel);
3211 
3212  if (RelationUsesLocalBuffers(rel))
3213  {
3214  for (i = 0; i < NLocBuffer; i++)
3215  {
3216  uint32 buf_state;
3217 
3218  bufHdr = GetLocalBufferDescriptor(i);
3219  if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node) &&
3220  ((buf_state = pg_atomic_read_u32(&bufHdr->state)) &
3221  (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
3222  {
3223  ErrorContextCallback errcallback;
3224  Page localpage;
3225 
3226  localpage = (char *) LocalBufHdrGetBlock(bufHdr);
3227 
3228  /* Setup error traceback support for ereport() */
3230  errcallback.arg = (void *) bufHdr;
3231  errcallback.previous = error_context_stack;
3232  error_context_stack = &errcallback;
3233 
3234  PageSetChecksumInplace(localpage, bufHdr->tag.blockNum);
3235 
3236  smgrwrite(rel->rd_smgr,
3237  bufHdr->tag.forkNum,
3238  bufHdr->tag.blockNum,
3239  localpage,
3240  false);
3241 
3242  buf_state &= ~(BM_DIRTY | BM_JUST_DIRTIED);
3243  pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
3244 
3245  /* Pop the error context stack */
3246  error_context_stack = errcallback.previous;
3247  }
3248  }
3249 
3250  return;
3251  }
3252 
3253  /* Make sure we can handle the pin inside the loop */
3255 
3256  for (i = 0; i < NBuffers; i++)
3257  {
3258  uint32 buf_state;
3259 
3260  bufHdr = GetBufferDescriptor(i);
3261 
3262  /*
3263  * As in DropRelFileNodeBuffers, an unlocked precheck should be safe
3264  * and saves some cycles.
3265  */
3266  if (!RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node))
3267  continue;
3268 
3270 
3271  buf_state = LockBufHdr(bufHdr);
3272  if (RelFileNodeEquals(bufHdr->tag.rnode, rel->rd_node) &&
3273  (buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
3274  {
3275  PinBuffer_Locked(bufHdr);
3277  FlushBuffer(bufHdr, rel->rd_smgr);
3279  UnpinBuffer(bufHdr, true);
3280  }
3281  else
3282  UnlockBufHdr(bufHdr, buf_state);
3283  }
3284 }
#define LocalBufHdrGetBlock(bufHdr)
Definition: bufmgr.c:62
ForkNumber forkNum
Definition: buf_internals.h:93
static void local_buffer_write_error_callback(void *arg)
Definition: bufmgr.c:4102
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
#define GetLocalBufferDescriptor(id)
#define BM_DIRTY
Definition: buf_internals.h:58
void(* callback)(void *arg)
Definition: elog.h:256
struct ErrorContextCallback * previous
Definition: elog.h:255
static void FlushBuffer(BufferDesc *buf, SMgrRelation reln)
Definition: bufmgr.c:2673
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1726
ErrorContextCallback * error_context_stack
Definition: elog.c:91
#define RelationOpenSmgr(relation)
Definition: rel.h:479
int NLocBuffer
Definition: localbuf.c:41
void smgrwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, char *buffer, bool skipFsync)
Definition: smgr.c:530
#define GetBufferDescriptor(id)
#define BM_JUST_DIRTIED
Definition: buf_internals.h:63
unsigned int uint32
Definition: c.h:359
static void UnpinBuffer(BufferDesc *buf, bool fixOwner)
Definition: bufmgr.c:1702
void ResourceOwnerEnlargeBuffers(ResourceOwner owner)
Definition: resowner.c:893
#define BM_VALID
Definition: buf_internals.h:59
RelFileNode rd_node
Definition: rel.h:54
#define BufferDescriptorGetContentLock(bdesc)
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
static void PinBuffer_Locked(BufferDesc *buf)
Definition: bufmgr.c:1664
void PageSetChecksumInplace(Page page, BlockNumber blkno)
Definition: bufpage.c:1198
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1122
BlockNumber blockNum
Definition: buf_internals.h:94
RelFileNode rnode
Definition: buf_internals.h:92
#define RelationUsesLocalBuffers(relation)
Definition: rel.h:531
BufferTag tag
#define UnlockBufHdr(desc, s)
int i
int NBuffers
Definition: globals.c:131
static void pg_atomic_unlocked_write_u32(volatile pg_atomic_uint32 *ptr, uint32 val)
Definition: atomics.h:277
static void ReservePrivateRefCountEntry(void)
Definition: bufmgr.c:187
pg_atomic_uint32 state
Pointer Page
Definition: bufpage.h:78
#define RelFileNodeEquals(node1, node2)
Definition: relfilenode.h:88
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:241

◆ FreeAccessStrategy()

void FreeAccessStrategy ( BufferAccessStrategy  strategy)

Definition at line 597 of file freelist.c.

References pfree().

Referenced by blgetbitmap(), FreeBulkInsertState(), heap_endscan(), and initscan().

598 {
599  /* don't crash if called on a "default" strategy */
600  if (strategy != NULL)
601  pfree(strategy);
602 }
void pfree(void *pointer)
Definition: mcxt.c:1056

◆ GetAccessStrategy()

BufferAccessStrategy GetAccessStrategy ( BufferAccessStrategyType  btype)

Definition at line 542 of file freelist.c.

References BAS_BULKREAD, BAS_BULKWRITE, BAS_NORMAL, BAS_VACUUM, BufferAccessStrategyData::btype, BufferAccessStrategyData::buffers, elog, ERROR, Min, NBuffers, offsetof, palloc0(), and BufferAccessStrategyData::ring_size.

Referenced by blgetbitmap(), bt_check_every_level(), collect_corrupt_items(), collect_visibility_data(), do_autovacuum(), GetBulkInsertState(), initscan(), pgstat_index(), pgstathashindex(), pgstatindex_impl(), statapprox_heap(), and vacuum().

543 {
544  BufferAccessStrategy strategy;
545  int ring_size;
546 
547  /*
548  * Select ring size to use. See buffer/README for rationales.
549  *
550  * Note: if you change the ring size for BAS_BULKREAD, see also
551  * SYNC_SCAN_REPORT_INTERVAL in access/heap/syncscan.c.
552  */
553  switch (btype)
554  {
555  case BAS_NORMAL:
556  /* if someone asks for NORMAL, just give 'em a "default" object */
557  return NULL;
558 
559  case BAS_BULKREAD:
560  ring_size = 256 * 1024 / BLCKSZ;
561  break;
562  case BAS_BULKWRITE:
563  ring_size = 16 * 1024 * 1024 / BLCKSZ;
564  break;
565  case BAS_VACUUM:
566  ring_size = 256 * 1024 / BLCKSZ;
567  break;
568 
569  default:
570  elog(ERROR, "unrecognized buffer access strategy: %d",
571  (int) btype);
572  return NULL; /* keep compiler quiet */
573  }
574 
575  /* Make sure ring isn't an undue fraction of shared buffers */
576  ring_size = Min(NBuffers / 8, ring_size);
577 
578  /* Allocate the object and initialize all elements to zeroes */
579  strategy = (BufferAccessStrategy)
581  ring_size * sizeof(Buffer));
582 
583  /* Set fields that don't start out zero */
584  strategy->btype = btype;
585  strategy->ring_size = ring_size;
586 
587  return strategy;
588 }
struct BufferAccessStrategyData * BufferAccessStrategy
Definition: buf.h:44
#define Min(x, y)
Definition: c.h:911
#define ERROR
Definition: elog.h:43
BufferAccessStrategyType btype
Definition: freelist.c:74
void * palloc0(Size size)
Definition: mcxt.c:980
#define elog(elevel,...)
Definition: elog.h:228
int NBuffers
Definition: globals.c:131
int Buffer
Definition: buf.h:23
#define offsetof(type, field)
Definition: c.h:662

◆ HoldingBufferPinThatDelaysRecovery()

bool HoldingBufferPinThatDelaysRecovery ( void  )

Definition at line 3748 of file bufmgr.c.

References GetPrivateRefCount(), and GetStartupBufferPinWaitBufId().

Referenced by CheckRecoveryConflictDeadlock(), and RecoveryConflictInterrupt().

3749 {
3750  int bufid = GetStartupBufferPinWaitBufId();
3751 
3752  /*
3753  * If we get woken slowly then it's possible that the Startup process was
3754  * already woken by other backends before we got here. Also possible that
3755  * we get here by multiple interrupts or interrupts at inappropriate
3756  * times, so make sure we do nothing if the bufid is not set.
3757  */
3758  if (bufid < 0)
3759  return false;
3760 
3761  if (GetPrivateRefCount(bufid + 1) > 0)
3762  return true;
3763 
3764  return false;
3765 }
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
int GetStartupBufferPinWaitBufId(void)
Definition: proc.c:657

◆ IncrBufferRefCount()

void IncrBufferRefCount ( Buffer  buffer)

Definition at line 3403 of file bufmgr.c.

References Assert, BufferIsLocal, BufferIsPinned, CurrentResourceOwner, GetPrivateRefCountEntry(), LocalRefCount, PrivateRefCountEntry::refcount, ResourceOwnerEnlargeBuffers(), and ResourceOwnerRememberBuffer().

Referenced by _bt_steppage(), btrestrpos(), entryLoadMoreItems(), ReadBufferBI(), scanPostingTree(), startScanEntry(), and tts_buffer_heap_store_tuple().

3404 {
3405  Assert(BufferIsPinned(buffer));
3407  if (BufferIsLocal(buffer))
3408  LocalRefCount[-buffer - 1]++;
3409  else
3410  {
3411  PrivateRefCountEntry *ref;
3412 
3413  ref = GetPrivateRefCountEntry(buffer, true);
3414  Assert(ref != NULL);
3415  ref->refcount++;
3416  }
3418 }
static PrivateRefCountEntry * GetPrivateRefCountEntry(Buffer buffer, bool do_move)
Definition: bufmgr.c:279
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
void ResourceOwnerRememberBuffer(ResourceOwner owner, Buffer buffer)
Definition: resowner.c:906
void ResourceOwnerEnlargeBuffers(ResourceOwner owner)
Definition: resowner.c:893
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
int32 * LocalRefCount
Definition: localbuf.c:45

◆ InitBufferPool()

void InitBufferPool ( void  )

Definition at line 67 of file buf_init.c.

References Assert, backend_flush_after, buf, BufferDesc::buf_id, BufferBlocks, BufferDescriptorGetContentLock, BufferDescriptorGetIOLock, CLEAR_BUFFERTAG, BufferDesc::freeNext, FREENEXT_END_OF_LIST, GetBufferDescriptor, i, LWLockInitialize(), LWLockRegisterTranche(), LWTRANCHE_BUFFER_CONTENT, LWTRANCHE_BUFFER_IO_IN_PROGRESS, NBuffers, pg_atomic_init_u32(), ShmemInitStruct(), BufferDesc::state, StrategyInitialize(), BufferDesc::tag, BufferDesc::wait_backend_pid, and WritebackContextInit().

Referenced by CreateSharedMemoryAndSemaphores().

68 {
69  bool foundBufs,
70  foundDescs,
71  foundIOLocks,
72  foundBufCkpt;
73 
74  /* Align descriptors to a cacheline boundary. */
76  ShmemInitStruct("Buffer Descriptors",
77  NBuffers * sizeof(BufferDescPadded),
78  &foundDescs);
79 
80  BufferBlocks = (char *)
81  ShmemInitStruct("Buffer Blocks",
82  NBuffers * (Size) BLCKSZ, &foundBufs);
83 
84  /* Align lwlocks to cacheline boundary */
86  ShmemInitStruct("Buffer IO Locks",
88  &foundIOLocks);
89 
92 
93  /*
94  * The array used to sort to-be-checkpointed buffer ids is located in
95  * shared memory, to avoid having to allocate significant amounts of
96  * memory at runtime. As that'd be in the middle of a checkpoint, or when
97  * the checkpointer is restarted, memory allocation failures would be
98  * painful.
99  */
101  ShmemInitStruct("Checkpoint BufferIds",
102  NBuffers * sizeof(CkptSortItem), &foundBufCkpt);
103 
104  if (foundDescs || foundBufs || foundIOLocks || foundBufCkpt)
105  {
106  /* should find all of these, or none of them */
107  Assert(foundDescs && foundBufs && foundIOLocks && foundBufCkpt);
108  /* note: this path is only taken in EXEC_BACKEND case */
109  }
110  else
111  {
112  int i;
113 
114  /*
115  * Initialize all the buffer headers.
116  */
117  for (i = 0; i < NBuffers; i++)
118  {
120 
121  CLEAR_BUFFERTAG(buf->tag);
122 
123  pg_atomic_init_u32(&buf->state, 0);
124  buf->wait_backend_pid = 0;
125 
126  buf->buf_id = i;
127 
128  /*
129  * Initially link all the buffers together as unused. Subsequent
130  * management of this list is done by freelist.c.
131  */
132  buf->freeNext = i + 1;
133 
136 
139  }
140 
141  /* Correct last entry of linked list */
142  GetBufferDescriptor(NBuffers - 1)->freeNext = FREENEXT_END_OF_LIST;
143  }
144 
145  /* Init other shared buffer-management stuff */
146  StrategyInitialize(!foundDescs);
147 
148  /* Initialize per-backend file flush context */
151 }
#define FREENEXT_END_OF_LIST
LWLockMinimallyPadded * BufferIOLWLockArray
Definition: buf_init.c:22
int wait_backend_pid
int backend_flush_after
Definition: bufmgr.c:121
#define BufferDescriptorGetIOLock(bdesc)
void StrategyInitialize(bool init)
Definition: freelist.c:475
void WritebackContextInit(WritebackContext *context, int *max_pending)
Definition: bufmgr.c:4288
void LWLockRegisterTranche(int tranche_id, const char *tranche_name)
Definition: lwlock.c:603
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:372
WritebackContext BackendWritebackContext
Definition: buf_init.c:23
static char * buf
Definition: pg_test_fsync.c:67
BufferDescPadded * BufferDescriptors
Definition: buf_init.c:20
#define GetBufferDescriptor(id)
union LWLockMinimallyPadded LWLockMinimallyPadded
void LWLockInitialize(LWLock *lock, int tranche_id)
Definition: lwlock.c:678
#define BufferDescriptorGetContentLock(bdesc)
#define Assert(condition)
Definition: c.h:739
#define CLEAR_BUFFERTAG(a)
Definition: buf_internals.h:97
CkptSortItem * CkptBufferIds
Definition: buf_init.c:24
size_t Size
Definition: c.h:467
BufferTag tag
int i
int NBuffers
Definition: globals.c:131
pg_atomic_uint32 state
static void pg_atomic_init_u32(volatile pg_atomic_uint32 *ptr, uint32 val)
Definition: atomics.h:223
char * BufferBlocks
Definition: buf_init.c:21

◆ InitBufferPoolAccess()

void InitBufferPoolAccess ( void  )

Definition at line 2445 of file bufmgr.c.

References HASHCTL::entrysize, HASH_BLOBS, hash_create(), HASH_ELEM, HASHCTL::keysize, MemSet, and PrivateRefCountArray.

Referenced by BaseInit().

2446 {
2447  HASHCTL hash_ctl;
2448 
2449  memset(&PrivateRefCountArray, 0, sizeof(PrivateRefCountArray));
2450 
2451  MemSet(&hash_ctl, 0, sizeof(hash_ctl));
2452  hash_ctl.keysize = sizeof(int32);
2453  hash_ctl.entrysize = sizeof(PrivateRefCountEntry);
2454 
2455  PrivateRefCountHash = hash_create("PrivateRefCount", 100, &hash_ctl,
2456  HASH_ELEM | HASH_BLOBS);
2457 }
struct PrivateRefCountEntry PrivateRefCountEntry
#define HASH_ELEM
Definition: hsearch.h:87
Size entrysize
Definition: hsearch.h:73
#define MemSet(start, val, len)
Definition: c.h:962
signed int int32
Definition: c.h:347
static struct PrivateRefCountEntry PrivateRefCountArray[REFCOUNT_ARRAY_ENTRIES]
Definition: bufmgr.c:169
#define HASH_BLOBS
Definition: hsearch.h:88
HTAB * hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
Definition: dynahash.c:316
Size keysize
Definition: hsearch.h:72
static HTAB * PrivateRefCountHash
Definition: bufmgr.c:170

◆ InitBufferPoolBackend()

void InitBufferPoolBackend ( void  )

Definition at line 2469 of file bufmgr.c.

References AtProcExit_Buffers(), and on_shmem_exit().

Referenced by AuxiliaryProcessMain(), and InitPostgres().

2470 {
2472 }
void on_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:361
static void AtProcExit_Buffers(int code, Datum arg)
Definition: bufmgr.c:2479

◆ IsBufferCleanupOK()

bool IsBufferCleanupOK ( Buffer  buffer)

Definition at line 3830 of file bufmgr.c.

References Assert, BUF_STATE_GET_REFCOUNT, BufferDescriptorGetContentLock, BufferIsLocal, BufferIsValid, GetBufferDescriptor, GetPrivateRefCount(), LocalRefCount, LockBufHdr(), LW_EXCLUSIVE, LWLockHeldByMeInMode(), and UnlockBufHdr.

Referenced by _hash_doinsert(), _hash_expandtable(), _hash_splitbucket(), hash_xlog_split_allocate_page(), and hashbucketcleanup().

3831 {
3832  BufferDesc *bufHdr;
3833  uint32 buf_state;
3834 
3835  Assert(BufferIsValid(buffer));
3836 
3837  if (BufferIsLocal(buffer))
3838  {
3839  /* There should be exactly one pin */
3840  if (LocalRefCount[-buffer - 1] != 1)
3841  return false;
3842  /* Nobody else to wait for */
3843  return true;
3844  }
3845 
3846  /* There should be exactly one local pin */
3847  if (GetPrivateRefCount(buffer) != 1)
3848  return false;
3849 
3850  bufHdr = GetBufferDescriptor(buffer - 1);
3851 
3852  /* caller must hold exclusive lock on buffer */
3854  LW_EXCLUSIVE));
3855 
3856  buf_state = LockBufHdr(bufHdr);
3857 
3858  Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
3859  if (BUF_STATE_GET_REFCOUNT(buf_state) == 1)
3860  {
3861  /* pincount is OK. */
3862  UnlockBufHdr(bufHdr, buf_state);
3863  return true;
3864  }
3865 
3866  UnlockBufHdr(bufHdr, buf_state);
3867  return false;
3868 }
bool LWLockHeldByMeInMode(LWLock *l, LWLockMode mode)
Definition: lwlock.c:1860
#define GetBufferDescriptor(id)
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
unsigned int uint32
Definition: c.h:359
#define BufferDescriptorGetContentLock(bdesc)
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define UnlockBufHdr(desc, s)
int32 * LocalRefCount
Definition: localbuf.c:45
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48

◆ LockBuffer()

void LockBuffer ( Buffer  buffer,
int  mode 
)

Definition at line 3602 of file bufmgr.c.

References Assert, buf, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferDescriptorGetContentLock, BufferIsLocal, BufferIsValid, elog, ERROR, GetBufferDescriptor, LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), and LWLockRelease().

Referenced by _bt_drop_lock_and_maybe_pin(), _bt_endpoint(), _bt_first(), _bt_getbuf(), _bt_getroot(), _bt_killitems(), _bt_moveright(), _bt_pagedel(), _bt_readnextpage(), _bt_relandgetbuf(), _bt_search(), _bt_unlink_halfdead_page(), _bt_update_meta_cleanup_info(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_finish_split(), _hash_first(), _hash_freeovflpage(), _hash_getbuf(), _hash_getbuf_with_strategy(), _hash_getcachedmetap(), _hash_getnewbuf(), _hash_init(), _hash_kill_items(), _hash_readnext(), _hash_readpage(), _hash_readprev(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), blbulkdelete(), blgetbitmap(), blinsert(), BloomNewBuffer(), blvacuumcleanup(), brin_doinsert(), brin_doupdate(), brin_evacuate_page(), brin_getinsertbuffer(), brin_page_cleanup(), brinbuild(), brinbuildempty(), bringetbitmap(), brinGetStats(), brinGetTupleForHeapBlock(), brininsert(), brinLockRevmapPageForUpdate(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), brinsummarize(), bt_metap(), bt_page_items(), bt_page_stats(), btvacuumpage(), checkXLogConsistency(), collect_corrupt_items(), collect_visibility_data(), collectMatchBitmap(), ConditionalLockBufferForCleanup(), count_nondeletable_pages(), entryLoadMoreItems(), fill_seq_with_data(), FreeSpaceMapPrepareTruncateRel(), fsm_readbuf(), fsm_search(), fsm_search_avail(), fsm_set_and_search(), fsm_vacuum_page(), get_raw_page_internal(), GetVisibilityMapPins(), ginbuildempty(), ginbulkdelete(), ginEntryInsert(), ginFindLeafPage(), ginFindParents(), ginFinishSplit(), ginGetStats(), ginHeapTupleFastInsert(), ginInsertCleanup(), ginInsertValue(), GinNewBuffer(), ginScanToDelete(), ginStepRight(), ginTraverseLock(), ginUpdateStats(), ginvacuumcleanup(), ginVacuumPostingTreeLeaves(), gistBufferingFindCorrectParent(), gistbufferinginserttuples(), gistbuildempty(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistfinishsplit(), gistfixsplit(), gistformdownlink(), gistGetMaxLevel(), gistinserttuples(), gistkillitems(), gistNewBuffer(), gistProcessItup(), gistScanPage(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_compute_xid_horizon_for_tuples(), heap_delete(), heap_fetch(), heap_finish_speculative(), heap_get_latest_tid(), heap_inplace_update(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_page_prune_opt(), heap_update(), heap_xlog_visible(), heapam_index_build_range_scan(), heapam_index_fetch_tuple(), heapam_index_validate_scan(), heapam_relation_copy_for_cluster(), heapam_scan_analyze_next_block(), heapam_scan_bitmap_next_block(), heapam_scan_sample_next_tuple(), heapam_tuple_satisfies_snapshot(), heapgetpage(), heapgettup(), initBloomState(), lazy_scan_heap(), LockBufferForCleanup(), log_newpage_range(), palloc_btree_page(), pg_visibility(), pgrowlocks(), pgstat_btree_page(), pgstat_gist_page(), pgstat_heap(), pgstatginindex_internal(), pgstathashindex(), pgstatindex_impl(), read_seq_tuple(), RelationGetBufferForTuple(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), shiftList(), spgdoinsert(), spgGetCache(), SpGistNewBuffer(), spgprocesspending(), spgvacuumpage(), spgWalk(), startScanEntry(), statapprox_heap(), summarize_range(), UnlockReleaseBuffer(), visibilitymap_clear(), visibilitymap_prepare_truncate(), visibilitymap_set(), vm_readbuf(), XLogReadBufferExtended(), XLogReadBufferForRedoExtended(), and XLogRecordPageWithFreeSpace().

3603 {
3604  BufferDesc *buf;
3605 
3606  Assert(BufferIsValid(buffer));
3607  if (BufferIsLocal(buffer))
3608  return; /* local buffers need no lock */
3609 
3610  buf = GetBufferDescriptor(buffer - 1);
3611 
3612  if (mode == BUFFER_LOCK_UNLOCK)
3614  else if (mode == BUFFER_LOCK_SHARE)
3616  else if (mode == BUFFER_LOCK_EXCLUSIVE)
3618  else
3619  elog(ERROR, "unrecognized buffer lock mode: %d", mode);
3620 }
static PgChecksumMode mode
Definition: pg_checksums.c:61
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1726
#define ERROR
Definition: elog.h:43
static char * buf
Definition: pg_test_fsync.c:67
#define GetBufferDescriptor(id)
#define BufferDescriptorGetContentLock(bdesc)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1122
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define elog(elevel,...)
Definition: elog.h:228
#define BUFFER_LOCK_SHARE
Definition: bufmgr.h:87

◆ LockBufferForCleanup()

void LockBufferForCleanup ( Buffer  buffer)

Definition at line 3659 of file bufmgr.c.

References Assert, BM_PIN_COUNT_WAITER, BUF_STATE_GET_REFCOUNT, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferIsLocal, BufferIsValid, elog, ERROR, GetBufferDescriptor, GetPrivateRefCount(), InHotStandby, LocalRefCount, LockBuffer(), LockBufHdr(), MyProcPid, PG_WAIT_BUFFER_PIN, ProcWaitForSignal(), ResolveRecoveryConflictWithBufferPin(), SetStartupBufferPinWaitBufId(), UnlockBufHdr, and BufferDesc::wait_backend_pid.

Referenced by btree_xlog_vacuum(), btvacuumpage(), btvacuumscan(), ginVacuumPostingTree(), hashbulkdelete(), lazy_scan_heap(), ReadBuffer_common(), and XLogReadBufferForRedoExtended().

3660 {
3661  BufferDesc *bufHdr;
3662 
3663  Assert(BufferIsValid(buffer));
3664  Assert(PinCountWaitBuf == NULL);
3665 
3666  if (BufferIsLocal(buffer))
3667  {
3668  /* There should be exactly one pin */
3669  if (LocalRefCount[-buffer - 1] != 1)
3670  elog(ERROR, "incorrect local pin count: %d",
3671  LocalRefCount[-buffer - 1]);
3672  /* Nobody else to wait for */
3673  return;
3674  }
3675 
3676  /* There should be exactly one local pin */
3677  if (GetPrivateRefCount(buffer) != 1)
3678  elog(ERROR, "incorrect local pin count: %d",
3679  GetPrivateRefCount(buffer));
3680 
3681  bufHdr = GetBufferDescriptor(buffer - 1);
3682 
3683  for (;;)
3684  {
3685  uint32 buf_state;
3686 
3687  /* Try to acquire lock */
3689  buf_state = LockBufHdr(bufHdr);
3690 
3691  Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
3692  if (BUF_STATE_GET_REFCOUNT(buf_state) == 1)
3693  {
3694  /* Successfully acquired exclusive lock with pincount 1 */
3695  UnlockBufHdr(bufHdr, buf_state);
3696  return;
3697  }
3698  /* Failed, so mark myself as waiting for pincount 1 */
3699  if (buf_state & BM_PIN_COUNT_WAITER)
3700  {
3701  UnlockBufHdr(bufHdr, buf_state);
3702  LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
3703  elog(ERROR, "multiple backends attempting to wait for pincount 1");
3704  }
3705  bufHdr->wait_backend_pid = MyProcPid;
3706  PinCountWaitBuf = bufHdr;
3707  buf_state |= BM_PIN_COUNT_WAITER;
3708  UnlockBufHdr(bufHdr, buf_state);
3709  LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
3710 
3711  /* Wait to be signaled by UnpinBuffer() */
3712  if (InHotStandby)
3713  {
3714  /* Publish the bufid that Startup process waits on */
3715  SetStartupBufferPinWaitBufId(buffer - 1);
3716  /* Set alarm and then wait to be signaled by UnpinBuffer() */
3718  /* Reset the published bufid */
3720  }
3721  else
3723 
3724  /*
3725  * Remove flag marking us as waiter. Normally this will not be set
3726  * anymore, but ProcWaitForSignal() can return for other signals as
3727  * well. We take care to only reset the flag if we're the waiter, as
3728  * theoretically another backend could have started waiting. That's
3729  * impossible with the current usages due to table level locking, but
3730  * better be safe.
3731  */
3732  buf_state = LockBufHdr(bufHdr);
3733  if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
3734  bufHdr->wait_backend_pid == MyProcPid)
3735  buf_state &= ~BM_PIN_COUNT_WAITER;
3736  UnlockBufHdr(bufHdr, buf_state);
3737 
3738  PinCountWaitBuf = NULL;
3739  /* Loop back and try again */
3740  }
3741 }
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
int MyProcPid
Definition: globals.c:40
int wait_backend_pid
#define InHotStandby
Definition: xlog.h:74
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:88
#define ERROR
Definition: elog.h:43
void ResolveRecoveryConflictWithBufferPin(void)
Definition: standby.c:461
void SetStartupBufferPinWaitBufId(int bufid)
Definition: proc.c:645
#define GetBufferDescriptor(id)
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
unsigned int uint32
Definition: c.h:359
void ProcWaitForSignal(uint32 wait_event_info)
Definition: proc.c:1798
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602
#define PG_WAIT_BUFFER_PIN
Definition: pgstat.h:756
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define UnlockBufHdr(desc, s)
#define elog(elevel,...)
Definition: elog.h:228
static BufferDesc * PinCountWaitBuf
Definition: bufmgr.c:137
int32 * LocalRefCount
Definition: localbuf.c:45
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48
#define BM_PIN_COUNT_WAITER
Definition: buf_internals.h:64

◆ MarkBufferDirty()

void MarkBufferDirty ( Buffer  buffer)

Definition at line 1458 of file bufmgr.c.

References Assert, BM_DIRTY, BM_JUST_DIRTIED, BM_LOCKED, BUF_STATE_GET_REFCOUNT, BufferDescriptorGetContentLock, BufferIsLocal, BufferIsPinned, BufferIsValid, elog, ERROR, GetBufferDescriptor, LW_EXCLUSIVE, LWLockHeldByMeInMode(), MarkLocalBufferDirty(), pg_atomic_compare_exchange_u32(), pg_atomic_read_u32(), pgBufferUsage, BufferUsage::shared_blks_dirtied, BufferDesc::state, VacuumCostActive, VacuumCostBalance, VacuumCostPageDirty, VacuumPageDirty, and WaitBufHdrUnlocked().

Referenced by _bt_clear_incomplete_split(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newroot(), _bt_restore_meta(), _bt_split(), _bt_unlink_halfdead_page(), _bt_update_meta_cleanup_info(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_freeovflpage(), _hash_init(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), addLeafTuple(), brin_doinsert(), brin_doupdate(), brin_initialize_empty_new_buffer(), brin_xlog_createidx(), brin_xlog_desummarize_page(), brin_xlog_insert_update(), brin_xlog_revmap_extend(), brin_xlog_samepage_update(), brin_xlog_update(), brinbuild(), brinbuildempty(), brinRevmapDesummarizeRange(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), createPostingTree(), do_setval(), doPickSplit(), fill_seq_with_data(), FreeSpaceMapPrepareTruncateRel(), generic_redo(), GenericXLogFinish(), ginbuild(), ginbuildempty(), ginbulkdelete(), ginDeletePage(), ginHeapTupleFastInsert(), ginPlaceToPage(), ginRedoClearIncompleteSplit(), ginRedoCreatePTree(), ginRedoDeleteListPages(), ginRedoDeletePage(), ginRedoInsert(), ginRedoInsertListPage(), ginRedoUpdateMetapage(), ginRedoVacuumDataLeafPage(), ginUpdateStats(), ginVacuumPostingTreeLeaf(), gistbuild(), gistbuildempty(), gistdeletepage(), gistplacetopage(), gistprunepage(), gistRedoClearFollowRight(), gistRedoDeleteRecord(), gistRedoPageDelete(), gistRedoPageSplitRecord(), gistRedoPageUpdateRecord(), gistvacuumpage(), hash_xlog_add_ovfl_page(), hash_xlog_delete(), hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), hash_xlog_insert(), hash_xlog_move_page_contents(), hash_xlog_split_allocate_page(), hash_xlog_split_cleanup(), hash_xlog_split_complete(), hash_xlog_squeeze_page(), hash_xlog_update_meta_page(), hash_xlog_vacuum_one_page(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_finish_speculative(), heap_inplace_update(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_page_prune(), heap_update(), heap_xlog_clean(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_freeze_page(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_update(), heap_xlog_visible(), lazy_scan_heap(), lazy_vacuum_page(), log_newpage_range(), moveLeafs(), nextval_internal(), RelationGetBufferForTuple(), revmap_physical_extend(), saveNodeLink(), seq_redo(), shiftList(), spgAddNodeAction(), spgbuild(), SpGistUpdateMetaPage(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), spgRedoSplitTuple(), spgRedoVacuumLeaf(), spgRedoVacuumRedirect(), spgRedoVacuumRoot(), spgSplitNodeAction(), vacuumLeafPage(), vacuumLeafRoot(), vacuumRedirectAndPlaceholder(), visibilitymap_clear(), visibilitymap_prepare_truncate(), visibilitymap_set(), writeListPage(), and XLogReadBufferForRedoExtended().

1459 {
1460  BufferDesc *bufHdr;
1461  uint32 buf_state;
1462  uint32 old_buf_state;
1463 
1464  if (!BufferIsValid(buffer))
1465  elog(ERROR, "bad buffer ID: %d", buffer);
1466 
1467  if (BufferIsLocal(buffer))
1468  {
1469  MarkLocalBufferDirty(buffer);
1470  return;
1471  }
1472 
1473  bufHdr = GetBufferDescriptor(buffer - 1);
1474 
1475  Assert(BufferIsPinned(buffer));
1477  LW_EXCLUSIVE));
1478 
1479  old_buf_state = pg_atomic_read_u32(&bufHdr->state);
1480  for (;;)
1481  {
1482  if (old_buf_state & BM_LOCKED)
1483  old_buf_state = WaitBufHdrUnlocked(bufHdr);
1484 
1485  buf_state = old_buf_state;
1486 
1487  Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
1488  buf_state |= BM_DIRTY | BM_JUST_DIRTIED;
1489 
1490  if (pg_atomic_compare_exchange_u32(&bufHdr->state, &old_buf_state,
1491  buf_state))
1492  break;
1493  }
1494 
1495  /*
1496  * If the buffer was not dirty already, do vacuum accounting.
1497  */
1498  if (!(old_buf_state & BM_DIRTY))
1499  {
1500  VacuumPageDirty++;
1502  if (VacuumCostActive)
1504  }
1505 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
bool LWLockHeldByMeInMode(LWLock *l, LWLockMode mode)
Definition: lwlock.c:1860
int VacuumCostBalance
Definition: globals.c:147
static bool pg_atomic_compare_exchange_u32(volatile pg_atomic_uint32 *ptr, uint32 *expected, uint32 newval)
Definition: atomics.h:311
#define BM_DIRTY
Definition: buf_internals.h:58
int VacuumCostPageDirty
Definition: globals.c:139
#define ERROR
Definition: elog.h:43
#define GetBufferDescriptor(id)
#define BM_JUST_DIRTIED
Definition: buf_internals.h:63
long shared_blks_dirtied
Definition: instrument.h:23
unsigned int uint32
Definition: c.h:359
void MarkLocalBufferDirty(Buffer buffer)
Definition: localbuf.c:280
#define BM_LOCKED
Definition: buf_internals.h:57
int VacuumPageDirty
Definition: globals.c:145
#define BufferDescriptorGetContentLock(bdesc)
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
static uint32 WaitBufHdrUnlocked(BufferDesc *buf)
Definition: bufmgr.c:4176
#define elog(elevel,...)
Definition: elog.h:228
pg_atomic_uint32 state
BufferUsage pgBufferUsage
Definition: instrument.c:20
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48
bool VacuumCostActive
Definition: globals.c:148
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:241

◆ MarkBufferDirtyHint()

void MarkBufferDirtyHint ( Buffer  buffer,
bool  buffer_std 
)

Definition at line 3435 of file bufmgr.c.

References Assert, BM_DIRTY, BM_JUST_DIRTIED, BM_PERMANENT, BUF_STATE_GET_REFCOUNT, BufferDescriptorGetContentLock, BufferGetPage, BufferIsLocal, BufferIsValid, PGXACT::delayChkpt, elog, ERROR, GetBufferDescriptor, GetPrivateRefCount(), InvalidXLogRecPtr, LockBufHdr(), LWLockHeldByMe(), MarkLocalBufferDirty(), MyPgXact, PageSetLSN, pg_atomic_read_u32(), pgBufferUsage, RecoveryInProgress(), BufferUsage::shared_blks_dirtied, BufferDesc::state, UnlockBufHdr, VacuumCostActive, VacuumCostBalance, VacuumCostPageDirty, VacuumPageDirty, XLogHintBitIsNeeded, XLogRecPtrIsInvalid, and XLogSaveBufferForHint().

Referenced by _bt_check_unique(), _bt_killitems(), _hash_kill_items(), brin_start_evacuating_page(), btvacuumpage(), fsm_search_avail(), fsm_set_and_search(), fsm_vacuum_page(), gistkillitems(), heap_page_prune(), read_seq_tuple(), SetHintBits(), and XLogRecordPageWithFreeSpace().

3436 {
3437  BufferDesc *bufHdr;
3438  Page page = BufferGetPage(buffer);
3439 
3440  if (!BufferIsValid(buffer))
3441  elog(ERROR, "bad buffer ID: %d", buffer);
3442 
3443  if (BufferIsLocal(buffer))
3444  {
3445  MarkLocalBufferDirty(buffer);
3446  return;
3447  }
3448 
3449  bufHdr = GetBufferDescriptor(buffer - 1);
3450 
3451  Assert(GetPrivateRefCount(buffer) > 0);
3452  /* here, either share or exclusive lock is OK */
3454 
3455  /*
3456  * This routine might get called many times on the same page, if we are
3457  * making the first scan after commit of an xact that added/deleted many
3458  * tuples. So, be as quick as we can if the buffer is already dirty. We
3459  * do this by not acquiring spinlock if it looks like the status bits are
3460  * already set. Since we make this test unlocked, there's a chance we
3461  * might fail to notice that the flags have just been cleared, and failed
3462  * to reset them, due to memory-ordering issues. But since this function
3463  * is only intended to be used in cases where failing to write out the
3464  * data would be harmless anyway, it doesn't really matter.
3465  */
3466  if ((pg_atomic_read_u32(&bufHdr->state) & (BM_DIRTY | BM_JUST_DIRTIED)) !=
3468  {
3470  bool dirtied = false;
3471  bool delayChkpt = false;
3472  uint32 buf_state;
3473 
3474  /*
3475  * If we need to protect hint bit updates from torn writes, WAL-log a
3476  * full page image of the page. This full page image is only necessary
3477  * if the hint bit update is the first change to the page since the
3478  * last checkpoint.
3479  *
3480  * We don't check full_page_writes here because that logic is included
3481  * when we call XLogInsert() since the value changes dynamically.
3482  */
3483  if (XLogHintBitIsNeeded() &&
3484  (pg_atomic_read_u32(&bufHdr->state) & BM_PERMANENT))
3485  {
3486  /*
3487  * If we're in recovery we cannot dirty a page because of a hint.
3488  * We can set the hint, just not dirty the page as a result so the
3489  * hint is lost when we evict the page or shutdown.
3490  *
3491  * See src/backend/storage/page/README for longer discussion.
3492  */
3493  if (RecoveryInProgress())
3494  return;
3495 
3496  /*
3497  * If the block is already dirty because we either made a change
3498  * or set a hint already, then we don't need to write a full page
3499  * image. Note that aggressive cleaning of blocks dirtied by hint
3500  * bit setting would increase the call rate. Bulk setting of hint
3501  * bits would reduce the call rate...
3502  *
3503  * We must issue the WAL record before we mark the buffer dirty.
3504  * Otherwise we might write the page before we write the WAL. That
3505  * causes a race condition, since a checkpoint might occur between
3506  * writing the WAL record and marking the buffer dirty. We solve
3507  * that with a kluge, but one that is already in use during
3508  * transaction commit to prevent race conditions. Basically, we
3509  * simply prevent the checkpoint WAL record from being written
3510  * until we have marked the buffer dirty. We don't start the
3511  * checkpoint flush until we have marked dirty, so our checkpoint
3512  * must flush the change to disk successfully or the checkpoint
3513  * never gets written, so crash recovery will fix.
3514  *
3515  * It's possible we may enter here without an xid, so it is
3516  * essential that CreateCheckpoint waits for virtual transactions
3517  * rather than full transactionids.
3518  */
3519  MyPgXact->delayChkpt = delayChkpt = true;
3520  lsn = XLogSaveBufferForHint(buffer, buffer_std);
3521  }
3522 
3523  buf_state = LockBufHdr(bufHdr);
3524 
3525  Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
3526 
3527  if (!(buf_state & BM_DIRTY))
3528  {
3529  dirtied = true; /* Means "will be dirtied by this action" */
3530 
3531  /*
3532  * Set the page LSN if we wrote a backup block. We aren't supposed
3533  * to set this when only holding a share lock but as long as we
3534  * serialise it somehow we're OK. We choose to set LSN while
3535  * holding the buffer header lock, which causes any reader of an
3536  * LSN who holds only a share lock to also obtain a buffer header
3537  * lock before using PageGetLSN(), which is enforced in
3538  * BufferGetLSNAtomic().
3539  *
3540  * If checksums are enabled, you might think we should reset the
3541  * checksum here. That will happen when the page is written
3542  * sometime later in this checkpoint cycle.
3543  */
3544  if (!XLogRecPtrIsInvalid(lsn))
3545  PageSetLSN(page, lsn);
3546  }
3547 
3548  buf_state |= BM_DIRTY | BM_JUST_DIRTIED;
3549  UnlockBufHdr(bufHdr, buf_state);
3550 
3551  if (delayChkpt)
3552  MyPgXact->delayChkpt = false;
3553 
3554  if (dirtied)
3555  {
3556  VacuumPageDirty++;
3558  if (VacuumCostActive)
3560  }
3561  }
3562 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
#define BM_PERMANENT
Definition: buf_internals.h:66
int VacuumCostBalance
Definition: globals.c:147
bool LWLockHeldByMe(LWLock *l)
Definition: lwlock.c:1842
XLogRecPtr XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
Definition: xloginsert.c:893
bool RecoveryInProgress(void)
Definition: xlog.c:7935
#define BM_DIRTY
Definition: buf_internals.h:58
int VacuumCostPageDirty
Definition: globals.c:139
PGXACT * MyPgXact
Definition: proc.c:68
#define ERROR
Definition: elog.h:43
#define GetBufferDescriptor(id)
#define BM_JUST_DIRTIED
Definition: buf_internals.h:63
long shared_blks_dirtied
Definition: instrument.h:23
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
unsigned int uint32
Definition: c.h:359
#define BufferGetPage(buffer)
Definition: bufmgr.h:159
bool delayChkpt
Definition: proc.h:235
void MarkLocalBufferDirty(Buffer buffer)
Definition: localbuf.c:280
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
int VacuumPageDirty
Definition: globals.c:145
#define BufferDescriptorGetContentLock(bdesc)
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define UnlockBufHdr(desc, s)
#define elog(elevel,...)
Definition: elog.h:228
pg_atomic_uint32 state
#define PageSetLSN(page, lsn)
Definition: bufpage.h:368
#define XLogHintBitIsNeeded()
Definition: xlog.h:192
Pointer Page
Definition: bufpage.h:78
BufferUsage pgBufferUsage
Definition: instrument.c:20
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48
bool VacuumCostActive
Definition: globals.c:148
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:241

◆ PrefetchBuffer()

void PrefetchBuffer ( Relation  reln,
ForkNumber  forkNum,
BlockNumber  blockNum 
)

Definition at line 531 of file bufmgr.c.

References Assert, BlockNumberIsValid, BufMappingPartitionLock, BufTableHashCode(), BufTableLookup(), ereport, errcode(), errmsg(), ERROR, INIT_BUFFERTAG, LocalPrefetchBuffer(), LW_SHARED, LWLockAcquire(), LWLockRelease(), RelFileNodeBackend::node, RelationData::rd_smgr, RELATION_IS_OTHER_TEMP, RelationIsValid, RelationOpenSmgr, RelationUsesLocalBuffers, SMgrRelationData::smgr_rnode, and smgrprefetch().

Referenced by BitmapPrefetch(), count_nondeletable_pages(), HeapTupleHeaderAdvanceLatestRemovedXid(), and pg_prewarm().

532 {
533 #ifdef USE_PREFETCH
534  Assert(RelationIsValid(reln));
535  Assert(BlockNumberIsValid(blockNum));
536 
537  /* Open it at the smgr level if not already done */
538  RelationOpenSmgr(reln);
539 
540  if (RelationUsesLocalBuffers(reln))
541  {
542  /* see comments in ReadBufferExtended */
543  if (RELATION_IS_OTHER_TEMP(reln))
544  ereport(ERROR,
545  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
546  errmsg("cannot access temporary tables of other sessions")));
547 
548  /* pass it off to localbuf.c */
549  LocalPrefetchBuffer(reln->rd_smgr, forkNum, blockNum);
550  }
551  else
552  {
553  BufferTag newTag; /* identity of requested block */
554  uint32 newHash; /* hash value for newTag */
555  LWLock *newPartitionLock; /* buffer partition lock for it */
556  int buf_id;
557 
558  /* create a tag so we can lookup the buffer */
559  INIT_BUFFERTAG(newTag, reln->rd_smgr->smgr_rnode.node,
560  forkNum, blockNum);
561 
562  /* determine its hash code and partition lock ID */
563  newHash = BufTableHashCode(&newTag);
564  newPartitionLock = BufMappingPartitionLock(newHash);
565 
566  /* see if the block is in the buffer pool already */
567  LWLockAcquire(newPartitionLock, LW_SHARED);
568  buf_id = BufTableLookup(&newTag, newHash);
569  LWLockRelease(newPartitionLock);
570 
571  /* If not in buffers, initiate prefetch */
572  if (buf_id < 0)
573  smgrprefetch(reln->rd_smgr, forkNum, blockNum);
574 
575  /*
576  * If the block *is* in buffers, we do nothing. This is not really
577  * ideal: the block might be just about to be evicted, which would be
578  * stupid since we know we are going to need it soon. But the only
579  * easy answer is to bump the usage_count, which does not seem like a
580  * great solution: when the caller does ultimately touch the block,
581  * usage_count would get bumped again, resulting in too much
582  * favoritism for blocks that are involved in a prefetch sequence. A
583  * real fix would involve some additional per-buffer state, and it's
584  * not clear that there's enough of a problem to justify that.
585  */
586  }
587 #endif /* USE_PREFETCH */
588 }
Definition: lwlock.h:32
#define BufMappingPartitionLock(hashcode)
void LocalPrefetchBuffer(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum)
Definition: localbuf.c:64
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
uint32 BufTableHashCode(BufferTag *tagPtr)
Definition: buf_table.c:79
int errcode(int sqlerrcode)
Definition: elog.c:608
int BufTableLookup(BufferTag *tagPtr, uint32 hashcode)
Definition: buf_table.c:91
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1726
#define RelationOpenSmgr(relation)
Definition: rel.h:479
#define ERROR
Definition: elog.h:43
#define RelationIsValid(relation)
Definition: rel.h:395
RelFileNodeBackend smgr_rnode
Definition: smgr.h:42
unsigned int uint32
Definition: c.h:359
#define ereport(elevel, rest)
Definition: elog.h:141
#define BlockNumberIsValid(blockNumber)
Definition: block.h:70
RelFileNode node
Definition: relfilenode.h:74
#define Assert(condition)
Definition: c.h:739
#define RELATION_IS_OTHER_TEMP(relation)
Definition: rel.h:552
#define INIT_BUFFERTAG(a, xx_rnode, xx_forkNum, xx_blockNum)
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1122
#define RelationUsesLocalBuffers(relation)
Definition: rel.h:531
int errmsg(const char *fmt,...)
Definition: elog.c:822
void smgrprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum)
Definition: smgr.c:494

◆ PrintBufferLeakWarning()

void PrintBufferLeakWarning ( Buffer  buffer)

Definition at line 2539 of file bufmgr.c.

References Assert, buftag::blockNum, buf, BUF_FLAG_MASK, BUF_STATE_GET_REFCOUNT, BufferIsLocal, BufferIsValid, elog, buftag::forkNum, GetBufferDescriptor, GetLocalBufferDescriptor, GetPrivateRefCount(), InvalidBackendId, LocalRefCount, MyBackendId, pfree(), pg_atomic_read_u32(), relpathbackend, buftag::rnode, BufferDesc::state, BufferDesc::tag, and WARNING.

Referenced by CheckForBufferLeaks(), CheckForLocalBufferLeaks(), and ResourceOwnerReleaseInternal().

2540 {
2541  BufferDesc *buf;
2542  int32 loccount;
2543  char *path;
2544  BackendId backend;
2545  uint32 buf_state;
2546 
2547  Assert(BufferIsValid(buffer));
2548  if (BufferIsLocal(buffer))
2549  {
2550  buf = GetLocalBufferDescriptor(-buffer - 1);
2551  loccount = LocalRefCount[-buffer - 1];
2552  backend = MyBackendId;
2553  }
2554  else
2555  {
2556  buf = GetBufferDescriptor(buffer - 1);
2557  loccount = GetPrivateRefCount(buffer);
2558  backend = InvalidBackendId;
2559  }
2560 
2561  /* theoretically we should lock the bufhdr here */
2562  path = relpathbackend(buf->tag.rnode, backend, buf->tag.forkNum);
2563  buf_state = pg_atomic_read_u32(&buf->state);
2564  elog(WARNING,
2565  "buffer refcount leak: [%03d] "
2566  "(rel=%s, blockNum=%u, flags=0x%x, refcount=%u %d)",
2567  buffer, path,
2568  buf->tag.blockNum, buf_state & BUF_FLAG_MASK,
2569  BUF_STATE_GET_REFCOUNT(buf_state), loccount);
2570  pfree(path);
2571 }
BackendId MyBackendId
Definition: globals.c:81
ForkNumber forkNum
Definition: buf_internals.h:93
#define GetLocalBufferDescriptor(id)
signed int int32
Definition: c.h:347
void pfree(void *pointer)
Definition: mcxt.c:1056
#define BUF_FLAG_MASK
Definition: buf_internals.h:45
static char * buf
Definition: pg_test_fsync.c:67
#define GetBufferDescriptor(id)
static int32 GetPrivateRefCount(Buffer buffer)
Definition: bufmgr.c:359
unsigned int uint32
Definition: c.h:359
#define WARNING
Definition: elog.h:40
#define InvalidBackendId
Definition: backendid.h:23
int BackendId
Definition: backendid.h:21
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
BlockNumber blockNum
Definition: buf_internals.h:94
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
#define elog(elevel,...)
Definition: elog.h:228
pg_atomic_uint32 state
#define relpathbackend(rnode, backend, forknum)
Definition: relpath.h:78
int32 * LocalRefCount
Definition: localbuf.c:45
#define BUF_STATE_GET_REFCOUNT(state)
Definition: buf_internals.h:48
static uint32 pg_atomic_read_u32(volatile pg_atomic_uint32 *ptr)
Definition: atomics.h:241

◆ ReadBuffer()

Buffer ReadBuffer ( Relation  reln,
BlockNumber  blockNum 
)

Definition at line 596 of file bufmgr.c.

References MAIN_FORKNUM, RBM_NORMAL, and ReadBufferExtended().

Referenced by _bt_doinsert(), _bt_getbuf(), _hash_getbuf(), _hash_getbuf_with_condlock_cleanup(), blbulkdelete(), blinsert(), BloomNewBuffer(), brin_getinsertbuffer(), brinbuild(), brinGetStats(), brinGetTupleForHeapBlock(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), bt_metap(), bt_page_items(), bt_page_stats(), fill_seq_with_data(), ginFindLeafPage(), ginFindParents(), ginGetStats(), ginHeapTupleFastInsert(), ginInsertCleanup(), GinNewBuffer(), ginStepRight(), ginUpdateStats(), gistBufferingFindCorrectParent(), gistbufferinginserttuples(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistfixsplit(), gistGetMaxLevel(), gistkillitems(), gistNewBuffer(), gistProcessItup(), gistScanPage(), heap_abort_speculative(), heap_compute_xid_horizon_for_tuples(), heap_delete(), heap_fetch(), heap_finish_speculative(), heap_get_latest_tid(), heap_inplace_update(), heap_lock_tuple(), heap_update(), initBloomState(), log_newpage_range(), pg_visibility(), pgstatginindex_internal(), read_seq_tuple(), RelationGetBufferForTuple(), ReleaseAndReadBuffer(), revmap_get_buffer(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), shiftList(), spgdoinsert(), spgGetCache(), SpGistGetBuffer(), SpGistNewBuffer(), SpGistUpdateMetaPage(), and spgWalk().

597 {
598  return ReadBufferExtended(reln, MAIN_FORKNUM, blockNum, RBM_NORMAL, NULL);
599 }
Buffer ReadBufferExtended(Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
Definition: bufmgr.c:642

◆ ReadBufferExtended()

Buffer ReadBufferExtended ( Relation  reln,
ForkNumber  forkNum,
BlockNumber  blockNum,
ReadBufferMode  mode,
BufferAccessStrategy  strategy 
)

Definition at line 642 of file bufmgr.c.

References buf, ereport, errcode(), errmsg(), ERROR, pgstat_count_buffer_hit, pgstat_count_buffer_read, RelationData::rd_rel, RelationData::rd_smgr, ReadBuffer_common(), RELATION_IS_OTHER_TEMP, and RelationOpenSmgr.

Referenced by _hash_getbuf_with_strategy(), _hash_getinitbuf(), _hash_getnewbuf(), autoprewarm_database_main(), blbulkdelete(), blgetbitmap(), blvacuumcleanup(), brin_vacuum_scan(), brinbuildempty(), btvacuumpage(), btvacuumscan(), collect_corrupt_items(), collect_visibility_data(), count_nondeletable_pages(), fsm_readbuf(), get_raw_page_internal(), ginbuildempty(), ginbulkdelete(), ginDeletePage(), ginScanToDelete(), ginvacuumcleanup(), ginVacuumPostingTree(), ginVacuumPostingTreeLeaves(), gistbuildempty(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hashbulkdelete(), heapam_scan_analyze_next_block(), heapgetpage(), lazy_scan_heap(), lazy_vacuum_heap(), palloc_btree_page(), pg_prewarm(), pgstat_btree_page(), pgstat_gist_page(), pgstat_heap(), pgstathashindex(), pgstatindex_impl(), ReadBuffer(), ReadBufferBI(), spgprocesspending(), spgvacuumpage(), statapprox_heap(), and vm_readbuf().

644 {
645  bool hit;
646  Buffer buf;
647 
648  /* Open it at the smgr level if not already done */
649  RelationOpenSmgr(reln);
650 
651  /*
652  * Reject attempts to read non-local temporary relations; we would be
653  * likely to get wrong data since we have no visibility into the owning
654  * session's local buffers.
655  */
656  if (RELATION_IS_OTHER_TEMP(reln))
657  ereport(ERROR,
658  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
659  errmsg("cannot access temporary tables of other sessions")));
660 
661  /*
662  * Read the buffer, and update pgstat counters to reflect a cache hit or
663  * miss.
664  */
666  buf = ReadBuffer_common(reln->rd_smgr, reln->rd_rel->relpersistence,
667  forkNum, blockNum, mode, strategy, &hit);
668  if (hit)
670  return buf;
671 }
static PgChecksumMode mode
Definition: pg_checksums.c:61
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
int errcode(int sqlerrcode)
Definition: elog.c:608
Form_pg_class rd_rel
Definition: rel.h:83
#define RelationOpenSmgr(relation)
Definition: rel.h:479
#define ERROR
Definition: elog.h:43
#define pgstat_count_buffer_read(rel)
Definition: pgstat.h:1383
static char * buf
Definition: pg_test_fsync.c:67
#define ereport(elevel, rest)
Definition: elog.h:141
#define pgstat_count_buffer_hit(rel)
Definition: pgstat.h:1388
static Buffer ReadBuffer_common(SMgrRelation reln, char relpersistence, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy, bool *hit)
Definition: bufmgr.c:705
#define RELATION_IS_OTHER_TEMP(relation)
Definition: rel.h:552
int errmsg(const char *fmt,...)
Definition: elog.c:822
int Buffer
Definition: buf.h:23

◆ ReadBufferWithoutRelcache()

Buffer ReadBufferWithoutRelcache ( RelFileNode  rnode,
ForkNumber  forkNum,
BlockNumber  blockNum,
ReadBufferMode  mode,
BufferAccessStrategy  strategy 
)

Definition at line 684 of file bufmgr.c.

References Assert, InRecovery, InvalidBackendId, ReadBuffer_common(), and smgropen().

Referenced by XLogReadBufferExtended().

687 {
688  bool hit;
689 
690  SMgrRelation smgr = smgropen(rnode, InvalidBackendId);
691 
693 
694  return ReadBuffer_common(smgr, RELPERSISTENCE_PERMANENT, forkNum, blockNum,
695  mode, strategy, &hit);
696 }
static PgChecksumMode mode
Definition: pg_checksums.c:61
bool InRecovery
Definition: xlog.c:200
SMgrRelation smgropen(RelFileNode rnode, BackendId backend)
Definition: smgr.c:145
#define InvalidBackendId
Definition: backendid.h:23
static Buffer ReadBuffer_common(SMgrRelation reln, char relpersistence, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy, bool *hit)
Definition: bufmgr.c:705
#define Assert(condition)
Definition: c.h:739

◆ RelationGetNumberOfBlocksInFork()

BlockNumber RelationGetNumberOfBlocksInFork ( Relation  relation,
ForkNumber  forkNum 
)

Definition at line 2800 of file bufmgr.c.

References Assert, RelationData::rd_rel, RelationData::rd_smgr, RelationOpenSmgr, smgrnblocks(), and table_relation_size().

Referenced by _hash_getnewbuf(), _hash_init(), autoprewarm_database_main(), get_raw_page_internal(), and pg_prewarm().

2801 {
2802  switch (relation->rd_rel->relkind)
2803  {
2804  case RELKIND_SEQUENCE:
2805  case RELKIND_INDEX:
2806  case RELKIND_PARTITIONED_INDEX:
2807  /* Open it at the smgr level if not already done */
2808  RelationOpenSmgr(relation);
2809 
2810  return smgrnblocks(relation->rd_smgr, forkNum);
2811 
2812  case RELKIND_RELATION:
2813  case RELKIND_TOASTVALUE:
2814  case RELKIND_MATVIEW:
2815  {
2816  /*
2817  * Not every table AM uses BLCKSZ wide fixed size blocks.
2818  * Therefore tableam returns the size in bytes - but for the
2819  * purpose of this routine, we want the number of blocks.
2820  * Therefore divide, rounding up.
2821  */
2822  uint64 szbytes;
2823 
2824  szbytes = table_relation_size(relation, forkNum);
2825 
2826  return (szbytes + (BLCKSZ - 1)) / BLCKSZ;
2827  }
2828  case RELKIND_VIEW:
2829  case RELKIND_COMPOSITE_TYPE:
2830  case RELKIND_FOREIGN_TABLE:
2831  case RELKIND_PARTITIONED_TABLE:
2832  default:
2833  Assert(false);
2834  break;
2835  }
2836 
2837  return 0; /* keep compiler quiet */
2838 }
struct SMgrRelationData * rd_smgr
Definition: rel.h:56
Form_pg_class rd_rel
Definition: rel.h:83
#define RelationOpenSmgr(relation)
Definition: rel.h:479
static uint64 table_relation_size(Relation rel, ForkNumber forkNumber)
Definition: tableam.h:1592
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:555
#define Assert(condition)
Definition: c.h:739

◆ ReleaseAndReadBuffer()

Buffer ReleaseAndReadBuffer ( Buffer  buffer,
Relation  relation,
BlockNumber  blockNum 
)

Definition at line 1521 of file bufmgr.c.

References Assert, buftag::blockNum, PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsPinned, BufferIsValid, CurrentResourceOwner, buftag::forkNum, GetBufferDescriptor, GetLocalBufferDescriptor, LocalRefCount, MAIN_FORKNUM, RelationData::rd_node, ReadBuffer(), RelFileNodeEquals, ResourceOwnerForgetBuffer(), buftag::rnode, BufferDesc::tag, and UnpinBuffer().

Referenced by _bt_relandgetbuf(), ginFindLeafPage(), heapam_index_fetch_tuple(), and heapam_scan_bitmap_next_block().

1524 {
1525  ForkNumber forkNum = MAIN_FORKNUM;
1526  BufferDesc *bufHdr;
1527 
1528  if (BufferIsValid(buffer))
1529  {
1530  Assert(BufferIsPinned(buffer));
1531  if (BufferIsLocal(buffer))
1532  {
1533  bufHdr = GetLocalBufferDescriptor(-buffer - 1);
1534  if (bufHdr->tag.blockNum == blockNum &&
1535  RelFileNodeEquals(bufHdr->tag.rnode, relation->rd_node) &&
1536  bufHdr->tag.forkNum == forkNum)
1537  return buffer;
1539  LocalRefCount[-buffer - 1]--;
1540  }
1541  else
1542  {
1543  bufHdr = GetBufferDescriptor(buffer - 1);
1544  /* we have pin, so it's ok to examine tag without spinlock */
1545  if (bufHdr->tag.blockNum == blockNum &&
1546  RelFileNodeEquals(bufHdr->tag.rnode, relation->rd_node) &&
1547  bufHdr->tag.forkNum == forkNum)
1548  return buffer;
1549  UnpinBuffer(bufHdr, true);
1550  }
1551  }
1552 
1553  return ReadBuffer(relation, blockNum);
1554 }
#define BufferIsPinned(bufnum)
Definition: bufmgr.c:420
ForkNumber forkNum
Definition: buf_internals.h:93
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
#define GetLocalBufferDescriptor(id)
#define GetBufferDescriptor(id)
ForkNumber
Definition: relpath.h:40
static void UnpinBuffer(BufferDesc *buf, bool fixOwner)
Definition: bufmgr.c:1702
RelFileNode rd_node
Definition: rel.h:54
#define Assert(condition)
Definition: c.h:739
Buffer ReadBuffer(Relation reln, BlockNumber blockNum)
Definition: bufmgr.c:596
#define BufferIsLocal(buffer)
Definition: buf.h:37
BlockNumber blockNum
Definition: buf_internals.h:94
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
RelFileNode rnode
Definition: buf_internals.h:92
BufferTag tag
int32 * LocalRefCount
Definition: localbuf.c:45
#define RelFileNodeEquals(node1, node2)
Definition: relfilenode.h:88
void ResourceOwnerForgetBuffer(ResourceOwner owner, Buffer buffer)
Definition: resowner.c:915

◆ ReleaseBuffer()

void ReleaseBuffer ( Buffer  buffer)

Definition at line 3365 of file bufmgr.c.

References Assert, BufferIsLocal, BufferIsValid, CurrentResourceOwner, elog, ERROR, GetBufferDescriptor, LocalRefCount, ResourceOwnerForgetBuffer(), and UnpinBuffer().

Referenced by _bt_doinsert(), _bt_drop_lock_and_maybe_pin(), _bt_getbuf(), _bt_pagedel(), _bt_unlink_halfdead_page(), _hash_dropbuf(), _hash_getbuf_with_condlock_cleanup(), autoprewarm_database_main(), blinsert(), BloomNewBuffer(), brin_getinsertbuffer(), brin_vacuum_scan(), bringetbitmap(), brinGetTupleForHeapBlock(), brininsert(), brinRevmapTerminate(), brinsummarize(), collect_corrupt_items(), collect_visibility_data(), entryLoadMoreItems(), ExecEndBitmapHeapScan(), ExecEndIndexOnlyScan(), ExecReScanBitmapHeapScan(), FreeBulkInsertState(), freeGinBtreeStack(), fsm_vacuum_page(), get_actual_variable_endpoint(), get_raw_page_internal(), GetRecordedFreeSpace(), ginDeletePage(), ginFindParents(), ginFinishSplit(), ginFreeScanKeys(), ginInsertCleanup(), GinNewBuffer(), ginScanToDelete(), gistdoinsert(), gistFindCorrectParent(), gistNewBuffer(), gistvacuum_delete_empty_pages(), heap_abort_speculative(), heap_compute_xid_horizon_for_tuples(), heap_delete(), heap_endscan(), heap_fetch(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_rescan(), heap_update(), heap_xlog_delete(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_update(), heap_xlog_visible(), heapam_index_fetch_reset(), heapam_scan_sample_next_block(), heapam_tuple_lock(), heapgetpage(), heapgettup(), heapgettup_pagemode(), lazy_scan_heap(), lazy_vacuum_heap(), pg_prewarm(), pg_visibility(), pg_visibility_map(), pg_visibility_map_summary(), pgstatindex_impl(), ReadBufferBI(), RelationGetBufferForTuple(), ReleaseBulkInsertStatePin(), ResourceOwnerReleaseInternal(), revmap_get_buffer(), revmap_physical_extend(), spgdoinsert(), SpGistGetBuffer(), SpGistNewBuffer(), SpGistUpdateMetaPage(), statapprox_heap(), summarize_range(), terminate_brin_buildstate(), tts_buffer_heap_clear(), tts_buffer_heap_materialize(), tts_buffer_heap_store_tuple(), UnlockReleaseBuffer(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_pin(), and XLogReadBufferExtended().

3366 {
3367  if (!BufferIsValid(buffer))
3368  elog(ERROR, "bad buffer ID: %d", buffer);
3369 
3370  if (BufferIsLocal(buffer))
3371  {
3373 
3374  Assert(LocalRefCount[-buffer - 1] > 0);
3375  LocalRefCount[-buffer - 1]--;
3376  return;
3377  }
3378 
3379  UnpinBuffer(GetBufferDescriptor(buffer - 1), true);
3380 }
ResourceOwner CurrentResourceOwner
Definition: resowner.c:142
#define ERROR
Definition: elog.h:43
#define GetBufferDescriptor(id)
static void UnpinBuffer(BufferDesc *buf, bool fixOwner)
Definition: bufmgr.c:1702
#define Assert(condition)
Definition: c.h:739
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define BufferIsValid(bufnum)
Definition: bufmgr.h:113
#define elog(elevel,...)
Definition: elog.h:228
int32 * LocalRefCount
Definition: localbuf.c:45
void ResourceOwnerForgetBuffer(ResourceOwner owner, Buffer buffer)
Definition: resowner.c:915

◆ TestForOldSnapshot()

static void TestForOldSnapshot ( Snapshot  snapshot,
Relation  relation,
Page  page 
)
inlinestatic

Definition at line 264 of file bufmgr.h.

References Assert, old_snapshot_threshold, PageGetLSN, SNAPSHOT_MVCC, SNAPSHOT_TOAST, TestForOldSnapshot_impl(), and XLogRecPtrIsInvalid.

Referenced by _bt_get_endpoint(), _bt_moveright(), _bt_readnextpage(), _bt_walk_left(), _hash_first(), _hash_next(), _hash_readnext(), _hash_readprev(), blgetbitmap(), brinGetTupleForHeapBlock(), brinRevmapInitialize(), collectMatchBitmap(), collectMatchesForHeapRow(), ginFindLeafPage(), gistScanPage(), heap_fetch(), heap_get_latest_tid(), heapgetpage(), heapgettup(), heapgettup_pagemode(), scanGetCandidate(), scanPendingInsert(), and spgWalk().

265 {
266  Assert(relation != NULL);
267 
268  if (old_snapshot_threshold >= 0
269  && (snapshot) != NULL
270  && ((snapshot)->snapshot_type == SNAPSHOT_MVCC
271  || (snapshot)->snapshot_type == SNAPSHOT_TOAST)
272  && !XLogRecPtrIsInvalid((snapshot)->lsn)
273  && PageGetLSN(page) > (snapshot)->lsn)
274  TestForOldSnapshot_impl(snapshot, relation);
275 }
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
#define Assert(condition)
Definition: c.h:739
#define PageGetLSN(page)
Definition: bufpage.h:366
int old_snapshot_threshold
Definition: snapmgr.c:75
void TestForOldSnapshot_impl(Snapshot snapshot, Relation relation)
Definition: bufmgr.c:4408

◆ TestForOldSnapshot_impl()

void TestForOldSnapshot_impl ( Snapshot  snapshot,
Relation  relation 
)

Definition at line 4408 of file bufmgr.c.

References ereport, errcode(), errmsg(), ERROR, GetOldSnapshotThresholdTimestamp(), and RelationAllowsEarlyPruning.

Referenced by TestForOldSnapshot().

4409 {
4410  if (RelationAllowsEarlyPruning(relation)
4411  && (snapshot)->whenTaken < GetOldSnapshotThresholdTimestamp())
4412  ereport(ERROR,
4413  (errcode(ERRCODE_SNAPSHOT_TOO_OLD),
4414  errmsg("snapshot too old")));
4415 }
TimestampTz GetOldSnapshotThresholdTimestamp(void)
Definition: snapmgr.c:1745
#define RelationAllowsEarlyPruning(rel)
Definition: snapmgr.h:38
int errcode(int sqlerrcode)
Definition: elog.c:608
#define ERROR
Definition: elog.h:43
#define ereport(elevel, rest)
Definition: elog.h:141
int errmsg(const char *fmt,...)
Definition: elog.c:822

◆ UnlockBuffers()

void UnlockBuffers ( void  )

Definition at line 3574 of file bufmgr.c.

References BM_PIN_COUNT_WAITER, buf, LockBufHdr(), MyProcPid, PinCountWaitBuf, UnlockBufHdr, and BufferDesc::wait_backend_pid.

Referenced by AbortSubTransaction(), AbortTransaction(), AtProcExit_Buffers(), AutoVacLauncherMain(), BackgroundWriterMain(), CheckpointerMain(), and WalWriterMain().

3575 {
3577 
3578  if (buf)
3579  {
3580  uint32 buf_state;
3581 
3582  buf_state = LockBufHdr(buf);
3583 
3584  /*
3585  * Don't complain if flag bit not set; it could have been reset but we
3586  * got a cancel/die interrupt before getting the signal.
3587  */
3588  if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
3589  buf->wait_backend_pid == MyProcPid)
3590  buf_state &= ~BM_PIN_COUNT_WAITER;
3591 
3592  UnlockBufHdr(buf, buf_state);
3593 
3594  PinCountWaitBuf = NULL;
3595  }
3596 }
int MyProcPid
Definition: globals.c:40
int wait_backend_pid
static char * buf
Definition: pg_test_fsync.c:67
unsigned int uint32
Definition: c.h:359
uint32 LockBufHdr(BufferDesc *desc)
Definition: bufmgr.c:4148
#define UnlockBufHdr(desc, s)
static BufferDesc * PinCountWaitBuf
Definition: bufmgr.c:137
#define BM_PIN_COUNT_WAITER
Definition: buf_internals.h:64

◆ UnlockReleaseBuffer()

void UnlockReleaseBuffer ( Buffer  buffer)

Definition at line 3388 of file bufmgr.c.

References BUFFER_LOCK_UNLOCK, LockBuffer(), and ReleaseBuffer().

Referenced by _bt_clear_incomplete_split(), _bt_relbuf(), _bt_restore_meta(), _hash_relbuf(), allocNewBuffer(), AlterSequence(), blbulkdelete(), blgetbitmap(), blinsert(), BloomInitMetapage(), blvacuumcleanup(), brin_doinsert(), brin_doupdate(), brin_evacuate_page(), brin_getinsertbuffer(), brin_xlog_createidx(), brin_xlog_desummarize_page(), brin_xlog_insert_update(), brin_xlog_revmap_extend(), brin_xlog_samepage_update(), brin_xlog_update(), brinbuild(), brinbuildempty(), brinGetStats(), brinRevmapDesummarizeRange(), bt_metap(), bt_page_items(), bt_page_stats(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), checkXLogConsistency(), collect_corrupt_items(), collect_visibility_data(), count_nondeletable_pages(), createPostingTree(), do_setval(), doPickSplit(), entryLoadMoreItems(), fill_seq_with_data(), flushCachedPage(), FreeSpaceMapPrepareTruncateRel(), fsm_search(), fsm_set_and_search(), generic_redo(), ginbuild(), ginbuildempty(), ginbulkdelete(), ginFindParents(), ginGetStats(), ginHeapTupleFastInsert(), ginInsertCleanup(), ginPlaceToPage(), ginRedoClearIncompleteSplit(), ginRedoCreatePTree(), ginRedoDeleteListPages(), ginRedoDeletePage(), ginRedoInsert(), ginRedoInsertListPage(), ginRedoSplit(), ginRedoUpdateMetapage(), ginRedoVacuumDataLeafPage(), ginRedoVacuumPage(), ginScanToDelete(), ginStepRight(), ginUpdateStats(), ginvacuumcleanup(), ginVacuumPostingTree(), ginVacuumPostingTreeLeaves(), gistbufferinginserttuples(), gistbuild(), gistbuildempty(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistGetMaxLevel(), gistinserttuples(), gistkillitems(), gistplacetopage(), gistProcessItup(), gistRedoClearFollowRight(), gistRedoDeleteRecord(), gistRedoPageDelete(), gistRedoPageSplitRecord(), gistRedoPageUpdateRecord(), gistScanPage(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hash_xlog_add_ovfl_page(), hash_xlog_delete(), hash_xlog_init_bitmap_page(), hash_xlog_init_meta_page(), hash_xlog_insert(), hash_xlog_move_page_contents(), hash_xlog_split_allocate_page(), hash_xlog_split_cleanup(), hash_xlog_split_complete(), hash_xlog_split_page(), hash_xlog_squeeze_page(), hash_xlog_update_meta_page(), hash_xlog_vacuum_one_page(), heap_delete(), heap_finish_speculative(), heap_get_latest_tid(), heap_inplace_update(), heap_insert(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), heap_xlog_clean(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_freeze_page(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_update(), heap_xlog_visible(), heapam_scan_analyze_next_tuple(), initBloomState(), lazy_scan_heap(), lazy_vacuum_heap(), log_newpage_range(), moveLeafs(), nextval_internal(), palloc_btree_page(), pg_sequence_last_value(), pg_visibility(), pgstat_gist_page(), pgstat_heap(), pgstatginindex_internal(), pgstathashindex(), RelationAddExtraBlocks(), RelationGetBufferForTuple(), ResetSequence(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), scanPostingTree(), seq_redo(), shiftList(), spgAddNodeAction(), spgbuild(), spgdoinsert(), spgGetCache(), SpGistGetBuffer(), SpGistUpdateMetaPage(), spgMatchNodeAction(), spgprocesspending(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), spgRedoSplitTuple(), spgRedoVacuumLeaf(), spgRedoVacuumRedirect(), spgRedoVacuumRoot(), spgSplitNodeAction(), spgvacuumpage(), spgWalk(), statapprox_heap(), visibilitymap_prepare_truncate(), writeListPage(), xlog_redo(), and XLogRecordPageWithFreeSpace().

3389 {
3390  LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
3391  ReleaseBuffer(buffer);
3392 }
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:86
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3365
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:3602

Variable Documentation

◆ backend_flush_after

int backend_flush_after

Definition at line 121 of file bufmgr.c.

Referenced by InitBufferPool().

◆ bgwriter_flush_after

int bgwriter_flush_after

Definition at line 120 of file bufmgr.c.

Referenced by BackgroundWriterMain().

◆ bgwriter_lru_maxpages

int bgwriter_lru_maxpages

Definition at line 110 of file bufmgr.c.

Referenced by BgBufferSync().

◆ bgwriter_lru_multiplier

double bgwriter_lru_multiplier

Definition at line 111 of file bufmgr.c.

Referenced by BgBufferSync().

◆ BufferBlocks

PGDLLIMPORT char* BufferBlocks

Definition at line 21 of file buf_init.c.

Referenced by InitBufferPool().

◆ checkpoint_flush_after

int checkpoint_flush_after

Definition at line 119 of file bufmgr.c.

Referenced by BufferSync().

◆ effective_io_concurrency

int effective_io_concurrency

◆ LocalBufferBlockPointers

PGDLLIMPORT Block* LocalBufferBlockPointers

Definition at line 44 of file localbuf.c.

Referenced by InitLocalBuffers().

◆ LocalRefCount

◆ NBuffers

◆ NLocBuffer

◆ target_prefetch_pages

int target_prefetch_pages

Definition at line 130 of file bufmgr.c.

Referenced by assign_effective_io_concurrency(), and ExecInitBitmapHeapScan().

◆ track_io_timing

bool track_io_timing

Definition at line 112 of file bufmgr.c.

Referenced by FlushBuffer(), ReadBuffer_common(), and show_buffer_usage().

◆ zero_damaged_pages

bool zero_damaged_pages

Definition at line 109 of file bufmgr.c.

Referenced by mdread(), and ReadBuffer_common().