bufmgr.h File Reference

#include "port/pg_iovec.h"
#include "storage/block.h"
#include "storage/buf.h"
#include "storage/bufpage.h"
#include "storage/relfilelocator.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.

Data Structures
struct	PrefetchBufferResult
struct	BufferManagerRelation
struct	ReadBuffersOperation

Macros
#define	BMR_REL(p_rel)   ((BufferManagerRelation){.rel = p_rel})
#define	BMR_SMGR(p_smgr, p_relpersistence)   ((BufferManagerRelation){.smgr = p_smgr, .relpersistence = p_relpersistence})
#define	DEFAULT_EFFECTIVE_IO_CONCURRENCY   0
#define	DEFAULT_MAINTENANCE_IO_CONCURRENCY   0
#define	MAX_IO_COMBINE_LIMIT   PG_IOV_MAX
#define	DEFAULT_IO_COMBINE_LIMIT   Min(MAX_IO_COMBINE_LIMIT, (128 * 1024) / BLCKSZ)
#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	RelationGetNumberOfBlocks(reln)    RelationGetNumberOfBlocksInFork(reln, MAIN_FORKNUM)

Typedefs
typedef void *	Block
typedef enum BufferAccessStrategyType	BufferAccessStrategyType
typedef struct PrefetchBufferResult	PrefetchBufferResult
typedef enum ExtendBufferedFlags	ExtendBufferedFlags
typedef struct BufferManagerRelation	BufferManagerRelation
typedef enum ReadBuffersFlags	ReadBuffersFlags
typedef struct ReadBuffersOperation	ReadBuffersOperation

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 }
enum	ExtendBufferedFlags {   EB_SKIP_EXTENSION_LOCK = (1 << 0) , EB_PERFORMING_RECOVERY = (1 << 1) , EB_CREATE_FORK_IF_NEEDED = (1 << 2) , EB_LOCK_FIRST = (1 << 3) ,   EB_CLEAR_SIZE_CACHE = (1 << 4) , EB_LOCK_TARGET = (1 << 5) }
enum	ReadBuffersFlags { READ_BUFFERS_ZERO_ON_ERROR = (1 << 0) , READ_BUFFERS_ISSUE_ADVICE = (1 << 1) }

Functions
PrefetchBufferResult	PrefetchSharedBuffer (struct SMgrRelationData *smgr_reln, ForkNumber forkNum, BlockNumber blockNum)
PrefetchBufferResult	PrefetchBuffer (Relation reln, ForkNumber forkNum, BlockNumber blockNum)
bool	ReadRecentBuffer (RelFileLocator rlocator, ForkNumber forkNum, BlockNumber blockNum, Buffer recent_buffer)
Buffer	ReadBuffer (Relation reln, BlockNumber blockNum)
Buffer	ReadBufferExtended (Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
Buffer	ReadBufferWithoutRelcache (RelFileLocator rlocator, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy, bool permanent)
bool	StartReadBuffer (ReadBuffersOperation *operation, Buffer *buffer, BlockNumber blocknum, int flags)
bool	StartReadBuffers (ReadBuffersOperation *operation, Buffer *buffers, BlockNumber blocknum, int *nblocks, int flags)
void	WaitReadBuffers (ReadBuffersOperation *operation)
void	ReleaseBuffer (Buffer buffer)
void	UnlockReleaseBuffer (Buffer buffer)
bool	BufferIsExclusiveLocked (Buffer buffer)
bool	BufferIsDirty (Buffer buffer)
void	MarkBufferDirty (Buffer buffer)
void	IncrBufferRefCount (Buffer buffer)
void	CheckBufferIsPinnedOnce (Buffer buffer)
Buffer	ReleaseAndReadBuffer (Buffer buffer, Relation relation, BlockNumber blockNum)
Buffer	ExtendBufferedRel (BufferManagerRelation bmr, ForkNumber forkNum, BufferAccessStrategy strategy, uint32 flags)
BlockNumber	ExtendBufferedRelBy (BufferManagerRelation bmr, ForkNumber fork, BufferAccessStrategy strategy, uint32 flags, uint32 extend_by, Buffer *buffers, uint32 *extended_by)
Buffer	ExtendBufferedRelTo (BufferManagerRelation bmr, ForkNumber fork, BufferAccessStrategy strategy, uint32 flags, BlockNumber extend_to, ReadBufferMode mode)
void	InitBufferPoolAccess (void)
void	AtEOXact_Buffers (bool isCommit)
char *	DebugPrintBufferRefcount (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	FlushRelationsAllBuffers (struct SMgrRelationData **smgrs, int nrels)
void	CreateAndCopyRelationData (RelFileLocator src_rlocator, RelFileLocator dst_rlocator, bool permanent)
void	FlushDatabaseBuffers (Oid dbid)
void	DropRelationBuffers (struct SMgrRelationData *smgr_reln, ForkNumber *forkNum, int nforks, BlockNumber *firstDelBlock)
void	DropRelationsAllBuffers (struct SMgrRelationData **smgr_reln, int nlocators)
void	DropDatabaseBuffers (Oid dbid)
bool	BufferIsPermanent (Buffer buffer)
XLogRecPtr	BufferGetLSNAtomic (Buffer buffer)
void	BufferGetTag (Buffer buffer, RelFileLocator *rlocator, 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)
bool	BgBufferSync (struct WritebackContext *wb_context)
void	LimitAdditionalPins (uint32 *additional_pins)
void	LimitAdditionalLocalPins (uint32 *additional_pins)
bool	EvictUnpinnedBuffer (Buffer buf)
void	InitBufferPool (void)
Size	BufferShmemSize (void)
void	AtProcExit_LocalBuffers (void)
BufferAccessStrategy	GetAccessStrategy (BufferAccessStrategyType btype)
BufferAccessStrategy	GetAccessStrategyWithSize (BufferAccessStrategyType btype, int ring_size_kb)
int	GetAccessStrategyBufferCount (BufferAccessStrategy strategy)
int	GetAccessStrategyPinLimit (BufferAccessStrategy strategy)
void	FreeAccessStrategy (BufferAccessStrategy strategy)
static bool	BufferIsValid (Buffer bufnum)
static Block	BufferGetBlock (Buffer buffer)
static Size	BufferGetPageSize (Buffer buffer)
static Page	BufferGetPage (Buffer buffer)

Variables
PGDLLIMPORT int	NBuffers
PGDLLIMPORT bool	zero_damaged_pages
PGDLLIMPORT int	bgwriter_lru_maxpages
PGDLLIMPORT double	bgwriter_lru_multiplier
PGDLLIMPORT bool	track_io_timing
PGDLLIMPORT int	effective_io_concurrency
PGDLLIMPORT int	maintenance_io_concurrency
PGDLLIMPORT int	io_combine_limit
PGDLLIMPORT int	checkpoint_flush_after
PGDLLIMPORT int	backend_flush_after
PGDLLIMPORT int	bgwriter_flush_after
PGDLLIMPORT char *	BufferBlocks
PGDLLIMPORT int	NLocBuffer
PGDLLIMPORT Block *	LocalBufferBlockPointers
PGDLLIMPORT int32 *	LocalRefCount

Macro Definition Documentation

BMR_REL

#define BMR_REL

(

p_rel

)

((BufferManagerRelation){.rel = p_rel})

Definition at line 107 of file bufmgr.h.

BMR_SMGR

#define BMR_SMGR	(		p_smgr,
			p_relpersistence
	)		((BufferManagerRelation){.smgr = p_smgr, .relpersistence = p_relpersistence})

Definition at line 108 of file bufmgr.h.

BUFFER_LOCK_EXCLUSIVE

#define BUFFER_LOCK_EXCLUSIVE   2

Definition at line 199 of file bufmgr.h.

BUFFER_LOCK_SHARE

#define BUFFER_LOCK_SHARE   1

Definition at line 198 of file bufmgr.h.

BUFFER_LOCK_UNLOCK

#define BUFFER_LOCK_UNLOCK   0

Definition at line 197 of file bufmgr.h.

DEFAULT_EFFECTIVE_IO_CONCURRENCY

#define DEFAULT_EFFECTIVE_IO_CONCURRENCY   0

Definition at line 166 of file bufmgr.h.

DEFAULT_IO_COMBINE_LIMIT

#define DEFAULT_IO_COMBINE_LIMIT   Min(MAX_IO_COMBINE_LIMIT, (128 * 1024) / BLCKSZ)

Definition at line 173 of file bufmgr.h.

DEFAULT_MAINTENANCE_IO_CONCURRENCY

#define DEFAULT_MAINTENANCE_IO_CONCURRENCY   0

Definition at line 167 of file bufmgr.h.

MAX_IO_COMBINE_LIMIT

#define MAX_IO_COMBINE_LIMIT   PG_IOV_MAX

Definition at line 172 of file bufmgr.h.

MAX_IO_CONCURRENCY

#define MAX_IO_CONCURRENCY   1000

Definition at line 189 of file bufmgr.h.

P_NEW

#define P_NEW   InvalidBlockNumber /* grow the file to get a new page */

Definition at line 192 of file bufmgr.h.

RelationGetNumberOfBlocks

#define RelationGetNumberOfBlocks

(

reln

)

RelationGetNumberOfBlocksInFork(reln, MAIN_FORKNUM)

Definition at line 281 of file bufmgr.h.

Typedef Documentation

Block

typedef void* Block

Definition at line 25 of file bufmgr.h.

BufferAccessStrategyType

typedef enum BufferAccessStrategyType BufferAccessStrategyType

BufferManagerRelation

typedef struct BufferManagerRelation BufferManagerRelation

ExtendBufferedFlags

typedef enum ExtendBufferedFlags ExtendBufferedFlags

PrefetchBufferResult

typedef struct PrefetchBufferResult PrefetchBufferResult

ReadBuffersFlags

typedef enum ReadBuffersFlags ReadBuffersFlags

ReadBuffersOperation

typedef struct ReadBuffersOperation ReadBuffersOperation

Definition at line 25 of file bufmgr.h.

Enumeration Type Documentation

BufferAccessStrategyType

enum BufferAccessStrategyType

Enumerator
BAS_NORMAL
BAS_BULKREAD
BAS_BULKWRITE
BAS_VACUUM

Definition at line 33 of file bufmgr.h.

{
    BAS_NORMAL,                 /* Normal random access */
    BAS_BULKREAD,               /* Large read-only scan (hint bit updates are
                                 * ok) */
    BAS_BULKWRITE,              /* Large multi-block write (e.g. COPY IN) */
    BAS_VACUUM,                 /* VACUUM */
} BufferAccessStrategyType;

ExtendBufferedFlags

enum ExtendBufferedFlags

Enumerator
EB_SKIP_EXTENSION_LOCK
EB_PERFORMING_RECOVERY
EB_CREATE_FORK_IF_NEEDED
EB_LOCK_FIRST
EB_CLEAR_SIZE_CACHE
EB_LOCK_TARGET

Definition at line 67 of file bufmgr.h.

{
    /*
     * Don't acquire extension lock. This is safe only if the relation isn't
     * shared, an access exclusive lock is held or if this is the startup
     * process.
     */
    EB_SKIP_EXTENSION_LOCK = (1 << 0),
 
    /* Is this extension part of recovery? */
    EB_PERFORMING_RECOVERY = (1 << 1),
 
    /*
     * Should the fork be created if it does not currently exist? This likely
     * only ever makes sense for relation forks.
     */
    EB_CREATE_FORK_IF_NEEDED = (1 << 2),
 
    /* Should the first (possibly only) return buffer be returned locked? */
    EB_LOCK_FIRST = (1 << 3),
 
    /* Should the smgr size cache be cleared? */
    EB_CLEAR_SIZE_CACHE = (1 << 4),
 
    /* internal flags follow */
    EB_LOCK_TARGET = (1 << 5),
}           ExtendBufferedFlags;

ReadBufferMode

enum ReadBufferMode

Enumerator
RBM_NORMAL
RBM_ZERO_AND_LOCK
RBM_ZERO_AND_CLEANUP_LOCK
RBM_ZERO_ON_ERROR
RBM_NORMAL_NO_LOG

Definition at line 43 of file bufmgr.h.

{
    RBM_NORMAL,                 /* Normal read */
    RBM_ZERO_AND_LOCK,          /* Don't read from disk, caller will
                                 * initialize. Also locks the page. */
    RBM_ZERO_AND_CLEANUP_LOCK,  /* Like RBM_ZERO_AND_LOCK, but locks the page
                                 * in "cleanup" mode */
    RBM_ZERO_ON_ERROR,          /* Read, but return an all-zeros page on error */
    RBM_NORMAL_NO_LOG,          /* Don't log page as invalid during WAL
                                 * replay; otherwise same as RBM_NORMAL */
} ReadBufferMode;

ReadBuffersFlags

enum ReadBuffersFlags

Enumerator
READ_BUFFERS_ZERO_ON_ERROR
READ_BUFFERS_ISSUE_ADVICE

Definition at line 110 of file bufmgr.h.

{
    /* Zero out page if reading fails. */
    READ_BUFFERS_ZERO_ON_ERROR = (1 << 0),
 
    /* Call smgrprefetch() if I/O necessary. */
    READ_BUFFERS_ISSUE_ADVICE = (1 << 1),
} ReadBuffersFlags;

Function Documentation

AtEOXact_Buffers()

void AtEOXact_Buffers

(

bool

isCommit

)

Definition at line 3502 of file bufmgr.c.

{
    CheckForBufferLeaks();
 
    AtEOXact_LocalBuffers(isCommit);
 
    Assert(PrivateRefCountOverflowed == 0);
}

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

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

AtProcExit_LocalBuffers()

void AtProcExit_LocalBuffers

(

void

)

Definition at line 830 of file localbuf.c.

{
    /*
     * We shouldn't be holding any remaining pins; if we are, and assertions
     * aren't enabled, we'll fail later in DropRelationBuffers while trying to
     * drop the temp rels.
     */
    CheckForLocalBufferLeaks();
}

References CheckForLocalBufferLeaks().

Referenced by AtProcExit_Buffers().

BgBufferSync()

bool BgBufferSync

(

struct WritebackContext *

wb_context

)

Definition at line 3131 of file bufmgr.c.

{
    /* info obtained from freelist.c */
    int         strategy_buf_id;
    uint32      strategy_passes;
    uint32      recent_alloc;
 
    /*
     * Information saved between calls so we can determine the strategy
     * point's advance rate and avoid scanning already-cleaned buffers.
     */
    static bool saved_info_valid = false;
    static int  prev_strategy_buf_id;
    static uint32 prev_strategy_passes;
    static int  next_to_clean;
    static uint32 next_passes;
 
    /* Moving averages of allocation rate and clean-buffer density */
    static float smoothed_alloc = 0;
    static float smoothed_density = 10.0;
 
    /* Potentially these could be tunables, but for now, not */
    float       smoothing_samples = 16;
    float       scan_whole_pool_milliseconds = 120000.0;
 
    /* Used to compute how far we scan ahead */
    long        strategy_delta;
    int         bufs_to_lap;
    int         bufs_ahead;
    float       scans_per_alloc;
    int         reusable_buffers_est;
    int         upcoming_alloc_est;
    int         min_scan_buffers;
 
    /* Variables for the scanning loop proper */
    int         num_to_scan;
    int         num_written;
    int         reusable_buffers;
 
    /* Variables for final smoothed_density update */
    long        new_strategy_delta;
    uint32      new_recent_alloc;
 
    /*
     * Find out where the freelist clock sweep currently is, and how many
     * buffer allocations have happened since our last call.
     */
    strategy_buf_id = StrategySyncStart(&strategy_passes, &recent_alloc);
 
    /* Report buffer alloc counts to pgstat */
    PendingBgWriterStats.buf_alloc += recent_alloc;
 
    /*
     * If we're not running the LRU scan, just stop after doing the stats
     * stuff.  We mark the saved state invalid so that we can recover sanely
     * if LRU scan is turned back on later.
     */
    if (bgwriter_lru_maxpages <= 0)
    {
        saved_info_valid = false;
        return true;
    }
 
    /*
     * Compute strategy_delta = how many buffers have been scanned by the
     * clock sweep since last time.  If first time through, assume none. Then
     * see if we are still ahead of the clock sweep, and if so, how many
     * buffers we could scan before we'd catch up with it and "lap" it. Note:
     * weird-looking coding of xxx_passes comparisons are to avoid bogus
     * behavior when the passes counts wrap around.
     */
    if (saved_info_valid)
    {
        int32       passes_delta = strategy_passes - prev_strategy_passes;
 
        strategy_delta = strategy_buf_id - prev_strategy_buf_id;
        strategy_delta += (long) passes_delta * NBuffers;
 
        Assert(strategy_delta >= 0);
 
        if ((int32) (next_passes - strategy_passes) > 0)
        {
            /* we're one pass ahead of the strategy point */
            bufs_to_lap = strategy_buf_id - next_to_clean;
#ifdef BGW_DEBUG
            elog(DEBUG2, "bgwriter ahead: bgw %u-%u strategy %u-%u delta=%ld lap=%d",
                 next_passes, next_to_clean,
                 strategy_passes, strategy_buf_id,
                 strategy_delta, bufs_to_lap);
#endif
        }
        else if (next_passes == strategy_passes &&
                 next_to_clean >= strategy_buf_id)
        {
            /* on same pass, but ahead or at least not behind */
            bufs_to_lap = NBuffers - (next_to_clean - strategy_buf_id);
#ifdef BGW_DEBUG
            elog(DEBUG2, "bgwriter ahead: bgw %u-%u strategy %u-%u delta=%ld lap=%d",
                 next_passes, next_to_clean,
                 strategy_passes, strategy_buf_id,
                 strategy_delta, bufs_to_lap);
#endif
        }
        else
        {
            /*
             * We're behind, so skip forward to the strategy point and start
             * cleaning from there.
             */
#ifdef BGW_DEBUG
            elog(DEBUG2, "bgwriter behind: bgw %u-%u strategy %u-%u delta=%ld",
                 next_passes, next_to_clean,
                 strategy_passes, strategy_buf_id,
                 strategy_delta);
#endif
            next_to_clean = strategy_buf_id;
            next_passes = strategy_passes;
            bufs_to_lap = NBuffers;
        }
    }
    else
    {
        /*
         * Initializing at startup or after LRU scanning had been off. Always
         * start at the strategy point.
         */
#ifdef BGW_DEBUG
        elog(DEBUG2, "bgwriter initializing: strategy %u-%u",
             strategy_passes, strategy_buf_id);
#endif
        strategy_delta = 0;
        next_to_clean = strategy_buf_id;
        next_passes = strategy_passes;
        bufs_to_lap = NBuffers;
    }
 
    /* Update saved info for next time */
    prev_strategy_buf_id = strategy_buf_id;
    prev_strategy_passes = strategy_passes;
    saved_info_valid = true;
 
    /*
     * Compute how many buffers had to be scanned for each new allocation, ie,
     * 1/density of reusable buffers, and track a moving average of that.
     *
     * If the strategy point didn't move, we don't update the density estimate
     */
    if (strategy_delta > 0 && recent_alloc > 0)
    {
        scans_per_alloc = (float) strategy_delta / (float) recent_alloc;
        smoothed_density += (scans_per_alloc - smoothed_density) /
            smoothing_samples;
    }
 
    /*
     * Estimate how many reusable buffers there are between the current
     * strategy point and where we've scanned ahead to, based on the smoothed
     * density estimate.
     */
    bufs_ahead = NBuffers - bufs_to_lap;
    reusable_buffers_est = (float) bufs_ahead / smoothed_density;
 
    /*
     * Track a moving average of recent buffer allocations.  Here, rather than
     * a true average we want a fast-attack, slow-decline behavior: we
     * immediately follow any increase.
     */
    if (smoothed_alloc <= (float) recent_alloc)
        smoothed_alloc = recent_alloc;
    else
        smoothed_alloc += ((float) recent_alloc - smoothed_alloc) /
            smoothing_samples;
 
    /* Scale the estimate by a GUC to allow more aggressive tuning. */
    upcoming_alloc_est = (int) (smoothed_alloc * bgwriter_lru_multiplier);
 
    /*
     * If recent_alloc remains at zero for many cycles, smoothed_alloc will
     * eventually underflow to zero, and the underflows produce annoying
     * kernel warnings on some platforms.  Once upcoming_alloc_est has gone to
     * zero, there's no point in tracking smaller and smaller values of
     * smoothed_alloc, so just reset it to exactly zero to avoid this
     * syndrome.  It will pop back up as soon as recent_alloc increases.
     */
    if (upcoming_alloc_est == 0)
        smoothed_alloc = 0;
 
    /*
     * Even in cases where there's been little or no buffer allocation
     * activity, we want to make a small amount of progress through the buffer
     * cache so that as many reusable buffers as possible are clean after an
     * idle period.
     *
     * (scan_whole_pool_milliseconds / BgWriterDelay) computes how many times
     * the BGW will be called during the scan_whole_pool time; slice the
     * buffer pool into that many sections.
     */
    min_scan_buffers = (int) (NBuffers / (scan_whole_pool_milliseconds / BgWriterDelay));
 
    if (upcoming_alloc_est < (min_scan_buffers + reusable_buffers_est))
    {
#ifdef BGW_DEBUG
        elog(DEBUG2, "bgwriter: alloc_est=%d too small, using min=%d + reusable_est=%d",
             upcoming_alloc_est, min_scan_buffers, reusable_buffers_est);
#endif
        upcoming_alloc_est = min_scan_buffers + reusable_buffers_est;
    }
 
    /*
     * Now write out dirty reusable buffers, working forward from the
     * next_to_clean point, until we have lapped the strategy scan, or cleaned
     * enough buffers to match our estimate of the next cycle's allocation
     * requirements, or hit the bgwriter_lru_maxpages limit.
     */
 
    num_to_scan = bufs_to_lap;
    num_written = 0;
    reusable_buffers = reusable_buffers_est;
 
    /* Execute the LRU scan */
    while (num_to_scan > 0 && reusable_buffers < upcoming_alloc_est)
    {
        int         sync_state = SyncOneBuffer(next_to_clean, true,
                                               wb_context);
 
        if (++next_to_clean >= NBuffers)
        {
            next_to_clean = 0;
            next_passes++;
        }
        num_to_scan--;
 
        if (sync_state & BUF_WRITTEN)
        {
            reusable_buffers++;
            if (++num_written >= bgwriter_lru_maxpages)
            {
                PendingBgWriterStats.maxwritten_clean++;
                break;
            }
        }
        else if (sync_state & BUF_REUSABLE)
            reusable_buffers++;
    }
 
    PendingBgWriterStats.buf_written_clean += num_written;
 
#ifdef BGW_DEBUG
    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",
         recent_alloc, smoothed_alloc, strategy_delta, bufs_ahead,
         smoothed_density, reusable_buffers_est, upcoming_alloc_est,
         bufs_to_lap - num_to_scan,
         num_written,
         reusable_buffers - reusable_buffers_est);
#endif
 
    /*
     * Consider the above scan as being like a new allocation scan.
     * Characterize its density and update the smoothed one based on it. This
     * effectively halves the moving average period in cases where both the
     * strategy and the background writer are doing some useful scanning,
     * which is helpful because a long memory isn't as desirable on the
     * density estimates.
     */
    new_strategy_delta = bufs_to_lap - num_to_scan;
    new_recent_alloc = reusable_buffers - reusable_buffers_est;
    if (new_strategy_delta > 0 && new_recent_alloc > 0)
    {
        scans_per_alloc = (float) new_strategy_delta / (float) new_recent_alloc;
        smoothed_density += (scans_per_alloc - smoothed_density) /
            smoothing_samples;
 
#ifdef BGW_DEBUG
        elog(DEBUG2, "bgwriter: cleaner density alloc=%u scan=%ld density=%.2f new smoothed=%.2f",
             new_recent_alloc, new_strategy_delta,
             scans_per_alloc, smoothed_density);
#endif
    }
 
    /* Return true if OK to hibernate */
    return (bufs_to_lap == 0 && recent_alloc == 0);
}

References Assert, bgwriter_lru_maxpages, bgwriter_lru_multiplier, BgWriterDelay, PgStat_BgWriterStats::buf_alloc, BUF_REUSABLE, BUF_WRITTEN, PgStat_BgWriterStats::buf_written_clean, DEBUG1, DEBUG2, elog, PgStat_BgWriterStats::maxwritten_clean, NBuffers, PendingBgWriterStats, StrategySyncStart(), and SyncOneBuffer().

Referenced by BackgroundWriterMain().

BufferGetBlock()

static Block BufferGetBlock ( Buffer  buffer )

inlinestatic

Definition at line 375 of file bufmgr.h.

{
    Assert(BufferIsValid(buffer));
 
    if (BufferIsLocal(buffer))
        return LocalBufferBlockPointers[-buffer - 1];
    else
        return (Block) (BufferBlocks + ((Size) (buffer - 1)) * BLCKSZ);
}

References Assert, BufferBlocks, BufferIsLocal, BufferIsValid(), and LocalBufferBlockPointers.

Referenced by BufferGetPage(), WaitReadBuffers(), and XLogSaveBufferForHint().

BufferGetBlockNumber()

BlockNumber BufferGetBlockNumber

(

Buffer

buffer

)

Definition at line 3667 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    Assert(BufferIsPinned(buffer));
 
    if (BufferIsLocal(buffer))
        bufHdr = GetLocalBufferDescriptor(-buffer - 1);
    else
        bufHdr = GetBufferDescriptor(buffer - 1);
 
    /* pinned, so OK to read tag without spinlock */
    return bufHdr->tag.blockNum;
}

References Assert, buftag::blockNum, PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsPinned, GetBufferDescriptor(), GetLocalBufferDescriptor(), and BufferDesc::tag.

Referenced by _bt_binsrch_insert(), _bt_bottomupdel_pass(), _bt_check_unique(), _bt_checkpage(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_doinsert(), _bt_endpoint(), _bt_finish_split(), _bt_first(), _bt_getroot(), _bt_insert_parent(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_moveright(), _bt_newlevel(), _bt_pagedel(), _bt_readnextpage(), _bt_readpage(), _bt_restore_meta(), _bt_search(), _bt_simpledel_pass(), _bt_split(), _bt_unlink_halfdead_page(), _bt_walk_left(), _hash_addovflpage(), _hash_checkpage(), _hash_doinsert(), _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(), collectMatchBitmap(), createPostingTree(), dataBeginPlaceToPageLeaf(), dataPrepareDownlink(), doPickSplit(), entryPrepareDownlink(), fill_seq_fork_with_data(), ginEntryInsert(), ginFindParents(), ginFinishSplit(), ginPlaceToPage(), ginRedoDeleteListPages(), ginRedoUpdateMetapage(), ginScanToDelete(), gistbufferinginserttuples(), gistbuild(), gistcheckpage(), gistdeletepage(), gistformdownlink(), gistinserttuples(), gistMemorizeAllDownlinks(), gistplacetopage(), gistRelocateBuildBuffersOnSplit(), gistScanPage(), hash_xlog_add_ovfl_page(), heap_delete(), heap_fetch_next_buffer(), heap_hot_search_buffer(), heap_insert(), heap_multi_insert(), heap_page_is_all_visible(), heap_page_prune_and_freeze(), heap_prepare_pagescan(), heap_update(), heap_xlog_confirm(), heap_xlog_lock(), heapam_scan_analyze_next_block(), heapgettup(), heapgettup_pagemode(), index_compute_xid_horizon_for_tuples(), lazy_scan_noprune(), lazy_scan_prune(), makeSublist(), moveLeafs(), moveRightIfItNeeded(), pgstathashindex(), ReadBufferBI(), RelationAddBlocks(), RelationGetBufferForTuple(), RelationPutHeapTuple(), revmap_get_buffer(), revmap_physical_extend(), ScanSourceDatabasePgClassPage(), spgAddNodeAction(), spgbuild(), spgdoinsert(), SpGistSetLastUsedPage(), spgSplitNodeAction(), spgWalk(), startScanEntry(), terminate_brin_buildstate(), vacuumLeafPage(), visibilitymap_clear(), visibilitymap_get_status(), visibilitymap_pin(), visibilitymap_pin_ok(), visibilitymap_set(), and WaitReadBuffers().

BufferGetLSNAtomic()

XLogRecPtr BufferGetLSNAtomic

(

Buffer

buffer

)

Definition at line 3928 of file bufmgr.c.

{
    BufferDesc *bufHdr = GetBufferDescriptor(buffer - 1);
    char       *page = BufferGetPage(buffer);
    XLogRecPtr  lsn;
    uint32      buf_state;
 
    /*
     * If we don't need locking for correctness, fastpath out.
     */
    if (!XLogHintBitIsNeeded() || BufferIsLocal(buffer))
        return PageGetLSN(page);
 
    /* Make sure we've got a real buffer, and that we hold a pin on it. */
    Assert(BufferIsValid(buffer));
    Assert(BufferIsPinned(buffer));
 
    buf_state = LockBufHdr(bufHdr);
    lsn = PageGetLSN(page);
    UnlockBufHdr(bufHdr, buf_state);
 
    return lsn;
}

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

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

BufferGetPage()

static Page BufferGetPage ( Buffer  buffer )

inlinestatic

Definition at line 408 of file bufmgr.h.

{
    return (Page) BufferGetBlock(buffer);
}

References BufferGetBlock().

Referenced by _bt_allocbuf(), _bt_binsrch(), _bt_binsrch_insert(), _bt_bottomupdel_pass(), _bt_check_unique(), _bt_checkpage(), _bt_clear_incomplete_split(), _bt_conditionallockbuf(), _bt_dedup_pass(), _bt_delete_or_dedup_one_page(), _bt_delitems_delete(), _bt_delitems_delete_check(), _bt_delitems_vacuum(), _bt_endpoint(), _bt_findinsertloc(), _bt_finish_split(), _bt_get_endpoint(), _bt_getmeta(), _bt_getroot(), _bt_getstackbuf(), _bt_gettrueroot(), _bt_insert_parent(), _bt_insertonpg(), _bt_killitems(), _bt_leftsib_splitflag(), _bt_lock_subtree_parent(), _bt_lockbuf(), _bt_mark_page_halfdead(), _bt_moveright(), _bt_newlevel(), _bt_pagedel(), _bt_readnextpage(), _bt_readpage(), _bt_restore_meta(), _bt_rightsib_halfdeadflag(), _bt_search(), _bt_search_insert(), _bt_set_cleanup_info(), _bt_simpledel_pass(), _bt_split(), _bt_stepright(), _bt_unlink_halfdead_page(), _bt_unlockbuf(), _bt_upgradelockbufcleanup(), _bt_vacuum_needs_cleanup(), _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_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_internal(), bt_recheck_sibling_links(), bt_rootdescend(), btree_xlog_dedup(), 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(), 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_fork_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(), ginFinishOldSplit(), 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_delete(), heap_fetch(), heap_finish_speculative(), heap_force_common(), heap_freeze_prepared_tuples(), heap_get_latest_tid(), heap_hot_search_buffer(), heap_index_delete_tuples(), heap_inplace_update(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_page_is_all_visible(), heap_page_prune_and_freeze(), heap_page_prune_execute(), heap_page_prune_opt(), heap_pre_freeze_checks(), heap_prepare_pagescan(), heap_update(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_prune_freeze(), 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(), heapgettup_continue_page(), heapgettup_pagemode(), heapgettup_start_page(), index_compute_xid_horizon_for_tuples(), initBloomState(), lazy_scan_heap(), lazy_vacuum_heap_page(), lazy_vacuum_heap_rel(), log_heap_prune_and_freeze(), 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(), RelationAddBlocks(), RelationCopyStorageUsingBuffer(), RelationGetBufferForTuple(), RelationPutHeapTuple(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), scanPostingTree(), ScanSourceDatabasePgClass(), 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(), verify_heapam(), verifyBackupPageConsistency(), visibilitymap_clear(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_prepare_truncate(), visibilitymap_set(), vm_readbuf(), writeListPage(), XLogCheckBufferNeedsBackup(), XLogReadBufferExtended(), XLogReadBufferForRedoExtended(), XLogRecordPageWithFreeSpace(), XLogRegisterBuffer(), XLogSaveBufferForHint(), xlogVacuumPage(), and ZeroBuffer().

BufferGetPageSize()

static Size BufferGetPageSize ( Buffer  buffer )

inlinestatic

Definition at line 397 of file bufmgr.h.

{
    AssertMacro(BufferIsValid(buffer));
    return (Size) BLCKSZ;
}

References AssertMacro, and BufferIsValid().

Referenced by _bt_allocbuf(), _bt_restore_meta(), _bt_split(), _hash_freeovflpage(), _hash_getinitbuf(), _hash_getnewbuf(), _hash_init_metabuffer(), _hash_initbitmapbuffer(), _hash_initbuf(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_split(), btree_xlog_unlink_page(), fill_seq_fork_with_data(), GinInitBuffer(), GinInitMetabuffer(), hash_xlog_squeeze_page(), heap_xlog_insert(), heap_xlog_multi_insert(), heap_xlog_update(), RelationAddBlocks(), RelationGetBufferForTuple(), seq_redo(), and SpGistInitBuffer().

BufferGetTag()

void BufferGetTag	(	Buffer	buffer,
		RelFileLocator *	rlocator,
		ForkNumber *	forknum,
		BlockNumber *	blknum
	)

Definition at line 3688 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    /* Do the same checks as BufferGetBlockNumber. */
    Assert(BufferIsPinned(buffer));
 
    if (BufferIsLocal(buffer))
        bufHdr = GetLocalBufferDescriptor(-buffer - 1);
    else
        bufHdr = GetBufferDescriptor(buffer - 1);
 
    /* pinned, so OK to read tag without spinlock */
    *rlocator = BufTagGetRelFileLocator(&bufHdr->tag);
    *forknum = BufTagGetForkNum(&bufHdr->tag);
    *blknum = bufHdr->tag.blockNum;
}

References Assert, buftag::blockNum, PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsPinned, BufTagGetForkNum(), BufTagGetRelFileLocator(), GetBufferDescriptor(), GetLocalBufferDescriptor(), and BufferDesc::tag.

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

BufferIsDirty()

bool BufferIsDirty

(

Buffer

buffer

)

Definition at line 2442 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    if (BufferIsLocal(buffer))
    {
        int         bufid = -buffer - 1;
 
        bufHdr = GetLocalBufferDescriptor(bufid);
    }
    else
    {
        bufHdr = GetBufferDescriptor(buffer - 1);
    }
 
    Assert(BufferIsPinned(buffer));
    Assert(LWLockHeldByMeInMode(BufferDescriptorGetContentLock(bufHdr),
                                LW_EXCLUSIVE));
 
    return pg_atomic_read_u32(&bufHdr->state) & BM_DIRTY;
}

References Assert, BM_DIRTY, PrivateRefCountEntry::buffer, BufferDescriptorGetContentLock(), BufferIsLocal, BufferIsPinned, GetBufferDescriptor(), GetLocalBufferDescriptor(), LW_EXCLUSIVE, LWLockHeldByMeInMode(), pg_atomic_read_u32(), and BufferDesc::state.

Referenced by XLogRegisterBuffer().

BufferIsExclusiveLocked()

bool BufferIsExclusiveLocked

(

Buffer

buffer

)

Definition at line 2413 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    if (BufferIsLocal(buffer))
    {
        int         bufid = -buffer - 1;
 
        bufHdr = GetLocalBufferDescriptor(bufid);
    }
    else
    {
        bufHdr = GetBufferDescriptor(buffer - 1);
    }
 
    Assert(BufferIsPinned(buffer));
    return LWLockHeldByMeInMode(BufferDescriptorGetContentLock(bufHdr),
                                LW_EXCLUSIVE);
}

References Assert, PrivateRefCountEntry::buffer, BufferDescriptorGetContentLock(), BufferIsLocal, BufferIsPinned, GetBufferDescriptor(), GetLocalBufferDescriptor(), LW_EXCLUSIVE, and LWLockHeldByMeInMode().

Referenced by XLogRegisterBuffer().

BufferIsPermanent()

bool BufferIsPermanent

(

Buffer

buffer

)

Definition at line 3898 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    /* Local buffers are used only for temp relations. */
    if (BufferIsLocal(buffer))
        return false;
 
    /* Make sure we've got a real buffer, and that we hold a pin on it. */
    Assert(BufferIsValid(buffer));
    Assert(BufferIsPinned(buffer));
 
    /*
     * BM_PERMANENT can't be changed while we hold a pin on the buffer, so we
     * need not bother with the buffer header spinlock.  Even if someone else
     * changes the buffer header state while we're doing this, the state is
     * changed atomically, so we'll read the old value or the new value, but
     * not random garbage.
     */
    bufHdr = GetBufferDescriptor(buffer - 1);
    return (pg_atomic_read_u32(&bufHdr->state) & BM_PERMANENT) != 0;
}

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

Referenced by SetHintBits().

BufferIsValid()

static bool BufferIsValid ( Buffer  bufnum )

inlinestatic

Definition at line 359 of file bufmgr.h.

{
    Assert(bufnum <= NBuffers);
    Assert(bufnum >= -NLocBuffer);
 
    return bufnum != InvalidBuffer;
}

References Assert, InvalidBuffer, NBuffers, and NLocBuffer.

Referenced by _bt_clear_incomplete_split(), _bt_endpoint(), _bt_first(), _bt_get_endpoint(), _bt_insertonpg(), _bt_readpage(), _bt_relandgetbuf(), _bt_search(), _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_recheck_sibling_links(), bt_rootdescend(), btree_xlog_dedup(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), BufferGetBlock(), BufferGetLSNAtomic(), BufferGetPageSize(), BufferIsPermanent(), ConditionalLockBufferForCleanup(), DebugPrintBufferRefcount(), 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_endscan(), heap_fetch_next_buffer(), heap_index_delete_tuples(), heap_lock_tuple(), heap_rescan(), heap_update(), heap_vac_scan_next_block(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_prune_freeze(), heap_xlog_update(), heap_xlog_visible(), heapam_index_fetch_reset(), heapam_scan_analyze_next_block(), heapam_scan_sample_next_block(), heapam_tuple_lock(), heapam_tuple_satisfies_snapshot(), heapgettup(), heapgettup_continue_page(), heapgettup_pagemode(), heapgettup_start_page(), IsBufferCleanupOK(), lazy_scan_heap(), lazy_vacuum_heap_rel(), log_heap_visible(), MarkBufferDirty(), MarkBufferDirtyHint(), read_stream_next_buffer(), ReadRecentBuffer(), ReleaseAndReadBuffer(), ReleaseBuffer(), ResOwnerReleaseBufferPin(), 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(), verifyBackupPageConsistency(), visibilitymap_clear(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_pin(), visibilitymap_pin_ok(), visibilitymap_prepare_truncate(), visibilitymap_set(), XLogPrefetcherNextBlock(), XLogReadBufferExtended(), and XLogReadBufferForRedoExtended().

BufferShmemSize()

Size BufferShmemSize

(

void

)

Definition at line 160 of file buf_init.c.

{
    Size        size = 0;
 
    /* size of buffer descriptors */
    size = add_size(size, mul_size(NBuffers, sizeof(BufferDescPadded)));
    /* to allow aligning buffer descriptors */
    size = add_size(size, PG_CACHE_LINE_SIZE);
 
    /* size of data pages, plus alignment padding */
    size = add_size(size, PG_IO_ALIGN_SIZE);
    size = add_size(size, mul_size(NBuffers, BLCKSZ));
 
    /* size of stuff controlled by freelist.c */
    size = add_size(size, StrategyShmemSize());
 
    /* size of I/O condition variables */
    size = add_size(size, mul_size(NBuffers,
                                   sizeof(ConditionVariableMinimallyPadded)));
    /* to allow aligning the above */
    size = add_size(size, PG_CACHE_LINE_SIZE);
 
    /* size of checkpoint sort array in bufmgr.c */
    size = add_size(size, mul_size(NBuffers, sizeof(CkptSortItem)));
 
    return size;
}

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

Referenced by CalculateShmemSize().

CheckBufferIsPinnedOnce()

void CheckBufferIsPinnedOnce

(

Buffer

buffer

)

Definition at line 5132 of file bufmgr.c.

{
    if (BufferIsLocal(buffer))
    {
        if (LocalRefCount[-buffer - 1] != 1)
            elog(ERROR, "incorrect local pin count: %d",
                 LocalRefCount[-buffer - 1]);
    }
    else
    {
        if (GetPrivateRefCount(buffer) != 1)
            elog(ERROR, "incorrect local pin count: %d",
                 GetPrivateRefCount(buffer));
    }
}

References PrivateRefCountEntry::buffer, BufferIsLocal, elog, ERROR, GetPrivateRefCount(), and LocalRefCount.

Referenced by GetVictimBuffer(), and LockBufferForCleanup().

CheckPointBuffers()

void CheckPointBuffers

(

int

flags

)

Definition at line 3653 of file bufmgr.c.

{
    BufferSync(flags);
}

References BufferSync().

Referenced by CheckPointGuts().

ConditionalLockBuffer()

bool ConditionalLockBuffer

(

Buffer

buffer

)

Definition at line 5111 of file bufmgr.c.

{
    BufferDesc *buf;
 
    Assert(BufferIsPinned(buffer));
    if (BufferIsLocal(buffer))
        return true;            /* act as though we got it */
 
    buf = GetBufferDescriptor(buffer - 1);
 
    return LWLockConditionalAcquire(BufferDescriptorGetContentLock(buf),
                                    LW_EXCLUSIVE);
}

References Assert, buf, PrivateRefCountEntry::buffer, BufferDescriptorGetContentLock(), BufferIsLocal, BufferIsPinned, GetBufferDescriptor(), LW_EXCLUSIVE, and LWLockConditionalAcquire().

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

ConditionalLockBufferForCleanup()

bool ConditionalLockBufferForCleanup

(

Buffer

buffer

)

Definition at line 5326 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    uint32      buf_state,
                refcount;
 
    Assert(BufferIsValid(buffer));
 
    if (BufferIsLocal(buffer))
    {
        refcount = LocalRefCount[-buffer - 1];
        /* There should be exactly one pin */
        Assert(refcount > 0);
        if (refcount != 1)
            return false;
        /* Nobody else to wait for */
        return true;
    }
 
    /* There should be exactly one local pin */
    refcount = GetPrivateRefCount(buffer);
    Assert(refcount);
    if (refcount != 1)
        return false;
 
    /* Try to acquire lock */
    if (!ConditionalLockBuffer(buffer))
        return false;
 
    bufHdr = GetBufferDescriptor(buffer - 1);
    buf_state = LockBufHdr(bufHdr);
    refcount = BUF_STATE_GET_REFCOUNT(buf_state);
 
    Assert(refcount > 0);
    if (refcount == 1)
    {
        /* Successfully acquired exclusive lock with pincount 1 */
        UnlockBufHdr(bufHdr, buf_state);
        return true;
    }
 
    /* Failed, so release the lock */
    UnlockBufHdr(bufHdr, buf_state);
    LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
    return false;
}

References Assert, BUF_STATE_GET_REFCOUNT, PrivateRefCountEntry::buffer, 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(), and lazy_scan_heap().

CreateAndCopyRelationData()

void CreateAndCopyRelationData	(	RelFileLocator	src_rlocator,
		RelFileLocator	dst_rlocator,
		bool	permanent
	)

Definition at line 4724 of file bufmgr.c.

{
    char        relpersistence;
    SMgrRelation src_rel;
    SMgrRelation dst_rel;
 
    /* Set the relpersistence. */
    relpersistence = permanent ?
        RELPERSISTENCE_PERMANENT : RELPERSISTENCE_UNLOGGED;
 
    src_rel = smgropen(src_rlocator, INVALID_PROC_NUMBER);
    dst_rel = smgropen(dst_rlocator, INVALID_PROC_NUMBER);
 
    /*
     * Create and copy all forks of the relation.  During create database we
     * have a separate cleanup mechanism which deletes complete database
     * directory.  Therefore, each individual relation doesn't need to be
     * registered for cleanup.
     */
    RelationCreateStorage(dst_rlocator, relpersistence, false);
 
    /* copy main fork. */
    RelationCopyStorageUsingBuffer(src_rlocator, dst_rlocator, MAIN_FORKNUM,
                                   permanent);
 
    /* copy those extra forks that exist */
    for (ForkNumber forkNum = MAIN_FORKNUM + 1;
         forkNum <= MAX_FORKNUM; forkNum++)
    {
        if (smgrexists(src_rel, forkNum))
        {
            smgrcreate(dst_rel, forkNum, false);
 
            /*
             * WAL log creation if the relation is persistent, or this is the
             * init fork of an unlogged relation.
             */
            if (permanent || forkNum == INIT_FORKNUM)
                log_smgrcreate(&dst_rlocator, forkNum);
 
            /* Copy a fork's data, block by block. */
            RelationCopyStorageUsingBuffer(src_rlocator, dst_rlocator, forkNum,
                                           permanent);
        }
    }
}

References INIT_FORKNUM, INVALID_PROC_NUMBER, log_smgrcreate(), MAIN_FORKNUM, MAX_FORKNUM, RelationCopyStorageUsingBuffer(), RelationCreateStorage(), smgrcreate(), smgrexists(), and smgropen().

Referenced by CreateDatabaseUsingWalLog().

DebugPrintBufferRefcount()

char* DebugPrintBufferRefcount

(

Buffer

buffer

)

Definition at line 3608 of file bufmgr.c.

{
    BufferDesc *buf;
    int32       loccount;
    char       *path;
    char       *result;
    ProcNumber  backend;
    uint32      buf_state;
 
    Assert(BufferIsValid(buffer));
    if (BufferIsLocal(buffer))
    {
        buf = GetLocalBufferDescriptor(-buffer - 1);
        loccount = LocalRefCount[-buffer - 1];
        backend = MyProcNumber;
    }
    else
    {
        buf = GetBufferDescriptor(buffer - 1);
        loccount = GetPrivateRefCount(buffer);
        backend = INVALID_PROC_NUMBER;
    }
 
    /* theoretically we should lock the bufhdr here */
    path = relpathbackend(BufTagGetRelFileLocator(&buf->tag), backend,
                          BufTagGetForkNum(&buf->tag));
    buf_state = pg_atomic_read_u32(&buf->state);
 
    result = psprintf("[%03d] (rel=%s, blockNum=%u, flags=0x%x, refcount=%u %d)",
                      buffer, path,
                      buf->tag.blockNum, buf_state & BUF_FLAG_MASK,
                      BUF_STATE_GET_REFCOUNT(buf_state), loccount);
    pfree(path);
    return result;
}

References Assert, buf, BUF_FLAG_MASK, BUF_STATE_GET_REFCOUNT, PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsValid(), BufTagGetForkNum(), BufTagGetRelFileLocator(), GetBufferDescriptor(), GetLocalBufferDescriptor(), GetPrivateRefCount(), INVALID_PROC_NUMBER, LocalRefCount, MyProcNumber, pfree(), pg_atomic_read_u32(), psprintf(), and relpathbackend.

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

DropDatabaseBuffers()

void DropDatabaseBuffers

(

Oid

dbid

)

Definition at line 4329 of file bufmgr.c.

{
    int         i;
 
    /*
     * We needn't consider local buffers, since by assumption the target
     * database isn't our own.
     */
 
    for (i = 0; i < NBuffers; i++)
    {
        BufferDesc *bufHdr = GetBufferDescriptor(i);
        uint32      buf_state;
 
        /*
         * As in DropRelationBuffers, an unlocked precheck should be safe and
         * saves some cycles.
         */
        if (bufHdr->tag.dbOid != dbid)
            continue;
 
        buf_state = LockBufHdr(bufHdr);
        if (bufHdr->tag.dbOid == dbid)
            InvalidateBuffer(bufHdr);   /* releases spinlock */
        else
            UnlockBufHdr(bufHdr, buf_state);
    }
}

References buftag::dbOid, GetBufferDescriptor(), i, InvalidateBuffer(), LockBufHdr(), NBuffers, BufferDesc::tag, and UnlockBufHdr().

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

DropRelationBuffers()

void DropRelationBuffers	(	struct SMgrRelationData *	smgr_reln,
		ForkNumber *	forkNum,
		int	nforks,
		BlockNumber *	firstDelBlock
	)

DropRelationsAllBuffers()

void DropRelationsAllBuffers	(	struct SMgrRelationData **	smgr_reln,
		int	nlocators
	)

EvictUnpinnedBuffer()

bool EvictUnpinnedBuffer

(

Buffer

buf

)

Definition at line 6023 of file bufmgr.c.

{
    BufferDesc *desc;
    uint32      buf_state;
    bool        result;
 
    /* Make sure we can pin the buffer. */
    ResourceOwnerEnlarge(CurrentResourceOwner);
    ReservePrivateRefCountEntry();
 
    Assert(!BufferIsLocal(buf));
    desc = GetBufferDescriptor(buf - 1);
 
    /* Lock the header and check if it's valid. */
    buf_state = LockBufHdr(desc);
    if ((buf_state & BM_VALID) == 0)
    {
        UnlockBufHdr(desc, buf_state);
        return false;
    }
 
    /* Check that it's not pinned already. */
    if (BUF_STATE_GET_REFCOUNT(buf_state) > 0)
    {
        UnlockBufHdr(desc, buf_state);
        return false;
    }
 
    PinBuffer_Locked(desc);     /* releases spinlock */
 
    /* If it was dirty, try to clean it once. */
    if (buf_state & BM_DIRTY)
    {
        LWLockAcquire(BufferDescriptorGetContentLock(desc), LW_SHARED);
        FlushBuffer(desc, NULL, IOOBJECT_RELATION, IOCONTEXT_NORMAL);
        LWLockRelease(BufferDescriptorGetContentLock(desc));
    }
 
    /* This will return false if it becomes dirty or someone else pins it. */
    result = InvalidateVictimBuffer(desc);
 
    UnpinBuffer(desc);
 
    return result;
}

References Assert, BM_DIRTY, BM_VALID, buf, BUF_STATE_GET_REFCOUNT, BufferDescriptorGetContentLock(), BufferIsLocal, CurrentResourceOwner, FlushBuffer(), GetBufferDescriptor(), InvalidateVictimBuffer(), IOCONTEXT_NORMAL, IOOBJECT_RELATION, LockBufHdr(), LW_SHARED, LWLockAcquire(), LWLockRelease(), PinBuffer_Locked(), ReservePrivateRefCountEntry(), ResourceOwnerEnlarge(), UnlockBufHdr(), and UnpinBuffer().

Referenced by pg_buffercache_evict().

ExtendBufferedRel()

Buffer ExtendBufferedRel	(	BufferManagerRelation	bmr,
		ForkNumber	forkNum,
		BufferAccessStrategy	strategy,
		uint32	flags
	)

Definition at line 845 of file bufmgr.c.

{
    Buffer      buf;
    uint32      extend_by = 1;
 
    ExtendBufferedRelBy(bmr, forkNum, strategy, flags, extend_by,
                        &buf, &extend_by);
 
    return buf;
}

References buf, and ExtendBufferedRelBy().

Referenced by _bt_allocbuf(), _hash_getnewbuf(), BloomNewBuffer(), brinbuild(), brinbuildempty(), fill_seq_fork_with_data(), ginbuildempty(), GinNewBuffer(), gistbuildempty(), gistNewBuffer(), ReadBuffer_common(), revmap_physical_extend(), and SpGistNewBuffer().

ExtendBufferedRelBy()

BlockNumber ExtendBufferedRelBy	(	BufferManagerRelation	bmr,
		ForkNumber	fork,
		BufferAccessStrategy	strategy,
		uint32	flags,
		uint32	extend_by,
		Buffer *	buffers,
		uint32 *	extended_by
	)

Definition at line 877 of file bufmgr.c.

{
    Assert((bmr.rel != NULL) != (bmr.smgr != NULL));
    Assert(bmr.smgr == NULL || bmr.relpersistence != 0);
    Assert(extend_by > 0);
 
    if (bmr.smgr == NULL)
    {
        bmr.smgr = RelationGetSmgr(bmr.rel);
        bmr.relpersistence = bmr.rel->rd_rel->relpersistence;
    }
 
    return ExtendBufferedRelCommon(bmr, fork, strategy, flags,
                                   extend_by, InvalidBlockNumber,
                                   buffers, extended_by);
}

References Assert, ExtendBufferedRelCommon(), InvalidBlockNumber, RelationData::rd_rel, BufferManagerRelation::rel, RelationGetSmgr(), BufferManagerRelation::relpersistence, and BufferManagerRelation::smgr.

Referenced by ExtendBufferedRel(), and RelationAddBlocks().

ExtendBufferedRelTo()

Buffer ExtendBufferedRelTo	(	BufferManagerRelation	bmr,
		ForkNumber	fork,
		BufferAccessStrategy	strategy,
		uint32	flags,
		BlockNumber	extend_to,
		ReadBufferMode	mode
	)

Definition at line 909 of file bufmgr.c.

{
    BlockNumber current_size;
    uint32      extended_by = 0;
    Buffer      buffer = InvalidBuffer;
    Buffer      buffers[64];
 
    Assert((bmr.rel != NULL) != (bmr.smgr != NULL));
    Assert(bmr.smgr == NULL || bmr.relpersistence != 0);
    Assert(extend_to != InvalidBlockNumber && extend_to > 0);
 
    if (bmr.smgr == NULL)
    {
        bmr.smgr = RelationGetSmgr(bmr.rel);
        bmr.relpersistence = bmr.rel->rd_rel->relpersistence;
    }
 
    /*
     * If desired, create the file if it doesn't exist.  If
     * smgr_cached_nblocks[fork] is positive then it must exist, no need for
     * an smgrexists call.
     */
    if ((flags & EB_CREATE_FORK_IF_NEEDED) &&
        (bmr.smgr->smgr_cached_nblocks[fork] == 0 ||
         bmr.smgr->smgr_cached_nblocks[fork] == InvalidBlockNumber) &&
        !smgrexists(bmr.smgr, fork))
    {
        LockRelationForExtension(bmr.rel, ExclusiveLock);
 
        /* recheck, fork might have been created concurrently */
        if (!smgrexists(bmr.smgr, fork))
            smgrcreate(bmr.smgr, fork, flags & EB_PERFORMING_RECOVERY);
 
        UnlockRelationForExtension(bmr.rel, ExclusiveLock);
    }
 
    /*
     * If requested, invalidate size cache, so that smgrnblocks asks the
     * kernel.
     */
    if (flags & EB_CLEAR_SIZE_CACHE)
        bmr.smgr->smgr_cached_nblocks[fork] = InvalidBlockNumber;
 
    /*
     * Estimate how many pages we'll need to extend by. This avoids acquiring
     * unnecessarily many victim buffers.
     */
    current_size = smgrnblocks(bmr.smgr, fork);
 
    /*
     * Since no-one else can be looking at the page contents yet, there is no
     * difference between an exclusive lock and a cleanup-strength lock. Note
     * that we pass the original mode to ReadBuffer_common() below, when
     * falling back to reading the buffer to a concurrent relation extension.
     */
    if (mode == RBM_ZERO_AND_LOCK || mode == RBM_ZERO_AND_CLEANUP_LOCK)
        flags |= EB_LOCK_TARGET;
 
    while (current_size < extend_to)
    {
        uint32      num_pages = lengthof(buffers);
        BlockNumber first_block;
 
        if ((uint64) current_size + num_pages > extend_to)
            num_pages = extend_to - current_size;
 
        first_block = ExtendBufferedRelCommon(bmr, fork, strategy, flags,
                                              num_pages, extend_to,
                                              buffers, &extended_by);
 
        current_size = first_block + extended_by;
        Assert(num_pages != 0 || current_size >= extend_to);
 
        for (uint32 i = 0; i < extended_by; i++)
        {
            if (first_block + i != extend_to - 1)
                ReleaseBuffer(buffers[i]);
            else
                buffer = buffers[i];
        }
    }
 
    /*
     * It's possible that another backend concurrently extended the relation.
     * In that case read the buffer.
     *
     * XXX: Should we control this via a flag?
     */
    if (buffer == InvalidBuffer)
    {
        Assert(extended_by == 0);
        buffer = ReadBuffer_common(bmr.rel, bmr.smgr, 0,
                                   fork, extend_to - 1, mode, strategy);
    }
 
    return buffer;
}

References Assert, PrivateRefCountEntry::buffer, current_size, EB_CLEAR_SIZE_CACHE, EB_CREATE_FORK_IF_NEEDED, EB_LOCK_TARGET, EB_PERFORMING_RECOVERY, ExclusiveLock, ExtendBufferedRelCommon(), i, InvalidBlockNumber, InvalidBuffer, lengthof, LockRelationForExtension(), mode, RBM_ZERO_AND_CLEANUP_LOCK, RBM_ZERO_AND_LOCK, RelationData::rd_rel, ReadBuffer_common(), BufferManagerRelation::rel, RelationGetSmgr(), ReleaseBuffer(), BufferManagerRelation::relpersistence, BufferManagerRelation::smgr, SMgrRelationData::smgr_cached_nblocks, smgrcreate(), smgrexists(), smgrnblocks(), and UnlockRelationForExtension().

Referenced by fsm_extend(), vm_extend(), and XLogReadBufferExtended().

FlushDatabaseBuffers()

void FlushDatabaseBuffers

(

Oid

dbid

)

Definition at line 4788 of file bufmgr.c.

{
    int         i;
    BufferDesc *bufHdr;
 
    for (i = 0; i < NBuffers; i++)
    {
        uint32      buf_state;
 
        bufHdr = GetBufferDescriptor(i);
 
        /*
         * As in DropRelationBuffers, an unlocked precheck should be safe and
         * saves some cycles.
         */
        if (bufHdr->tag.dbOid != dbid)
            continue;
 
        /* Make sure we can handle the pin */
        ReservePrivateRefCountEntry();
        ResourceOwnerEnlarge(CurrentResourceOwner);
 
        buf_state = LockBufHdr(bufHdr);
        if (bufHdr->tag.dbOid == dbid &&
            (buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
        {
            PinBuffer_Locked(bufHdr);
            LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
            FlushBuffer(bufHdr, NULL, IOOBJECT_RELATION, IOCONTEXT_NORMAL);
            LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
            UnpinBuffer(bufHdr);
        }
        else
            UnlockBufHdr(bufHdr, buf_state);
    }
}

References BM_DIRTY, BM_VALID, BufferDescriptorGetContentLock(), CurrentResourceOwner, buftag::dbOid, FlushBuffer(), GetBufferDescriptor(), i, IOCONTEXT_NORMAL, IOOBJECT_RELATION, LockBufHdr(), LW_SHARED, LWLockAcquire(), LWLockRelease(), NBuffers, PinBuffer_Locked(), ReservePrivateRefCountEntry(), ResourceOwnerEnlarge(), BufferDesc::tag, UnlockBufHdr(), and UnpinBuffer().

Referenced by dbase_redo().

FlushOneBuffer()

void FlushOneBuffer

(

Buffer

buffer

)

Definition at line 4830 of file bufmgr.c.

{
    BufferDesc *bufHdr;
 
    /* currently not needed, but no fundamental reason not to support */
    Assert(!BufferIsLocal(buffer));
 
    Assert(BufferIsPinned(buffer));
 
    bufHdr = GetBufferDescriptor(buffer - 1);
 
    Assert(LWLockHeldByMe(BufferDescriptorGetContentLock(bufHdr)));
 
    FlushBuffer(bufHdr, NULL, IOOBJECT_RELATION, IOCONTEXT_NORMAL);
}

References Assert, PrivateRefCountEntry::buffer, BufferDescriptorGetContentLock(), BufferIsLocal, BufferIsPinned, FlushBuffer(), GetBufferDescriptor(), IOCONTEXT_NORMAL, IOOBJECT_RELATION, and LWLockHeldByMe().

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

FlushRelationBuffers()

void FlushRelationBuffers

(

Relation

rel

)

Definition at line 4435 of file bufmgr.c.

{
    int         i;
    BufferDesc *bufHdr;
    SMgrRelation srel = RelationGetSmgr(rel);
 
    if (RelationUsesLocalBuffers(rel))
    {
        for (i = 0; i < NLocBuffer; i++)
        {
            uint32      buf_state;
            instr_time  io_start;
 
            bufHdr = GetLocalBufferDescriptor(i);
            if (BufTagMatchesRelFileLocator(&bufHdr->tag, &rel->rd_locator) &&
                ((buf_state = pg_atomic_read_u32(&bufHdr->state)) &
                 (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
            {
                ErrorContextCallback errcallback;
                Page        localpage;
 
                localpage = (char *) LocalBufHdrGetBlock(bufHdr);
 
                /* Setup error traceback support for ereport() */
                errcallback.callback = local_buffer_write_error_callback;
                errcallback.arg = (void *) bufHdr;
                errcallback.previous = error_context_stack;
                error_context_stack = &errcallback;
 
                PageSetChecksumInplace(localpage, bufHdr->tag.blockNum);
 
                io_start = pgstat_prepare_io_time(track_io_timing);
 
                smgrwrite(srel,
                          BufTagGetForkNum(&bufHdr->tag),
                          bufHdr->tag.blockNum,
                          localpage,
                          false);
 
                pgstat_count_io_op_time(IOOBJECT_TEMP_RELATION,
                                        IOCONTEXT_NORMAL, IOOP_WRITE,
                                        io_start, 1);
 
                buf_state &= ~(BM_DIRTY | BM_JUST_DIRTIED);
                pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
 
                pgBufferUsage.local_blks_written++;
 
                /* Pop the error context stack */
                error_context_stack = errcallback.previous;
            }
        }
 
        return;
    }
 
    for (i = 0; i < NBuffers; i++)
    {
        uint32      buf_state;
 
        bufHdr = GetBufferDescriptor(i);
 
        /*
         * As in DropRelationBuffers, an unlocked precheck should be safe and
         * saves some cycles.
         */
        if (!BufTagMatchesRelFileLocator(&bufHdr->tag, &rel->rd_locator))
            continue;
 
        /* Make sure we can handle the pin */
        ReservePrivateRefCountEntry();
        ResourceOwnerEnlarge(CurrentResourceOwner);
 
        buf_state = LockBufHdr(bufHdr);
        if (BufTagMatchesRelFileLocator(&bufHdr->tag, &rel->rd_locator) &&
            (buf_state & (BM_VALID | BM_DIRTY)) == (BM_VALID | BM_DIRTY))
        {
            PinBuffer_Locked(bufHdr);
            LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_SHARED);
            FlushBuffer(bufHdr, srel, IOOBJECT_RELATION, IOCONTEXT_NORMAL);
            LWLockRelease(BufferDescriptorGetContentLock(bufHdr));
            UnpinBuffer(bufHdr);
        }
        else
            UnlockBufHdr(bufHdr, buf_state);
    }
}

References ErrorContextCallback::arg, buftag::blockNum, BM_DIRTY, BM_JUST_DIRTIED, BM_VALID, BufferDescriptorGetContentLock(), BufTagGetForkNum(), BufTagMatchesRelFileLocator(), ErrorContextCallback::callback, CurrentResourceOwner, error_context_stack, FlushBuffer(), GetBufferDescriptor(), GetLocalBufferDescriptor(), i, IOCONTEXT_NORMAL, IOOBJECT_RELATION, IOOBJECT_TEMP_RELATION, IOOP_WRITE, BufferUsage::local_blks_written, local_buffer_write_error_callback(), LocalBufHdrGetBlock, LockBufHdr(), LW_SHARED, LWLockAcquire(), LWLockRelease(), NBuffers, NLocBuffer, PageSetChecksumInplace(), pg_atomic_read_u32(), pg_atomic_unlocked_write_u32(), pgBufferUsage, pgstat_count_io_op_time(), pgstat_prepare_io_time(), PinBuffer_Locked(), ErrorContextCallback::previous, RelationData::rd_locator, RelationGetSmgr(), RelationUsesLocalBuffers, ReservePrivateRefCountEntry(), ResourceOwnerEnlarge(), smgrwrite(), BufferDesc::state, BufferDesc::tag, track_io_timing, UnlockBufHdr(), and UnpinBuffer().

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

FlushRelationsAllBuffers()

void FlushRelationsAllBuffers	(	struct SMgrRelationData **	smgrs,
		int	nrels
	)

FreeAccessStrategy()

void FreeAccessStrategy

(

BufferAccessStrategy

strategy

)

Definition at line 681 of file freelist.c.

{
    /* don't crash if called on a "default" strategy */
    if (strategy != NULL)
        pfree(strategy);
}

References pfree().

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

GetAccessStrategy()

BufferAccessStrategy GetAccessStrategy

(

BufferAccessStrategyType

btype

)

Definition at line 541 of file freelist.c.

{
    int         ring_size_kb;
 
    /*
     * Select ring size to use.  See buffer/README for rationales.
     *
     * Note: if you change the ring size for BAS_BULKREAD, see also
     * SYNC_SCAN_REPORT_INTERVAL in access/heap/syncscan.c.
     */
    switch (btype)
    {
        case BAS_NORMAL:
            /* if someone asks for NORMAL, just give 'em a "default" object */
            return NULL;
 
        case BAS_BULKREAD:
            ring_size_kb = 256;
            break;
        case BAS_BULKWRITE:
            ring_size_kb = 16 * 1024;
            break;
        case BAS_VACUUM:
            ring_size_kb = 2048;
            break;
 
        default:
            elog(ERROR, "unrecognized buffer access strategy: %d",
                 (int) btype);
            return NULL;        /* keep compiler quiet */
    }
 
    return GetAccessStrategyWithSize(btype, ring_size_kb);
}

References BAS_BULKREAD, BAS_BULKWRITE, BAS_NORMAL, BAS_VACUUM, elog, ERROR, and GetAccessStrategyWithSize().

Referenced by blgetbitmap(), bt_check_every_level(), collect_corrupt_items(), collect_visibility_data(), GetBulkInsertState(), initscan(), pgstat_index(), pgstathashindex(), pgstatindex_impl(), RelationCopyStorageUsingBuffer(), ScanSourceDatabasePgClass(), statapprox_heap(), and verify_heapam().

GetAccessStrategyBufferCount()

int GetAccessStrategyBufferCount

(

BufferAccessStrategy

strategy

)

Definition at line 624 of file freelist.c.

{
    if (strategy == NULL)
        return 0;
 
    return strategy->nbuffers;
}

References BufferAccessStrategyData::nbuffers.

Referenced by parallel_vacuum_init().

GetAccessStrategyPinLimit()

int GetAccessStrategyPinLimit

(

BufferAccessStrategy

strategy

)

Definition at line 647 of file freelist.c.

{
    if (strategy == NULL)
        return NBuffers;
 
    switch (strategy->btype)
    {
        case BAS_BULKREAD:
 
            /*
             * Since BAS_BULKREAD uses StrategyRejectBuffer(), dirty buffers
             * shouldn't be a problem and the caller is free to pin up to the
             * entire ring at once.
             */
            return strategy->nbuffers;
 
        default:
 
            /*
             * Tell caller not to pin more than half the buffers in the ring.
             * This is a trade-off between look ahead distance and deferring
             * writeback and associated WAL traffic.
             */
            return strategy->nbuffers / 2;
    }
}

References BAS_BULKREAD, BufferAccessStrategyData::btype, BufferAccessStrategyData::nbuffers, and NBuffers.

Referenced by read_stream_begin_relation().

GetAccessStrategyWithSize()

BufferAccessStrategy GetAccessStrategyWithSize	(	BufferAccessStrategyType	btype,
		int	ring_size_kb
	)

Definition at line 584 of file freelist.c.

{
    int         ring_buffers;
    BufferAccessStrategy strategy;
 
    Assert(ring_size_kb >= 0);
 
    /* Figure out how many buffers ring_size_kb is */
    ring_buffers = ring_size_kb / (BLCKSZ / 1024);
 
    /* 0 means unlimited, so no BufferAccessStrategy required */
    if (ring_buffers == 0)
        return NULL;
 
    /* Cap to 1/8th of shared_buffers */
    ring_buffers = Min(NBuffers / 8, ring_buffers);
 
    /* NBuffers should never be less than 16, so this shouldn't happen */
    Assert(ring_buffers > 0);
 
    /* Allocate the object and initialize all elements to zeroes */
    strategy = (BufferAccessStrategy)
        palloc0(offsetof(BufferAccessStrategyData, buffers) +
                ring_buffers * sizeof(Buffer));
 
    /* Set fields that don't start out zero */
    strategy->btype = btype;
    strategy->nbuffers = ring_buffers;
 
    return strategy;
}

References Assert, BufferAccessStrategyData::btype, Min, BufferAccessStrategyData::nbuffers, NBuffers, and palloc0().

Referenced by do_autovacuum(), ExecVacuum(), GetAccessStrategy(), and parallel_vacuum_main().

HoldingBufferPinThatDelaysRecovery()

bool HoldingBufferPinThatDelaysRecovery

(

void

)

Definition at line 5300 of file bufmgr.c.

{
    int         bufid = GetStartupBufferPinWaitBufId();
 
    /*
     * If we get woken slowly then it's possible that the Startup process was
     * already woken by other backends before we got here. Also possible that
     * we get here by multiple interrupts or interrupts at inappropriate
     * times, so make sure we do nothing if the bufid is not set.
     */
    if (bufid < 0)
        return false;
 
    if (GetPrivateRefCount(bufid + 1) > 0)
        return true;
 
    return false;
}

References GetPrivateRefCount(), and GetStartupBufferPinWaitBufId().

Referenced by CheckRecoveryConflictDeadlock(), and ProcessRecoveryConflictInterrupt().

IncrBufferRefCount()

void IncrBufferRefCount

(

Buffer

buffer

)

Definition at line 4882 of file bufmgr.c.

{
    Assert(BufferIsPinned(buffer));
    ResourceOwnerEnlarge(CurrentResourceOwner);
    if (BufferIsLocal(buffer))
        LocalRefCount[-buffer - 1]++;
    else
    {
        PrivateRefCountEntry *ref;
 
        ref = GetPrivateRefCountEntry(buffer, true);
        Assert(ref != NULL);
        ref->refcount++;
    }
    ResourceOwnerRememberBuffer(CurrentResourceOwner, buffer);
}

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

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

InitBufferPool()

void InitBufferPool

(

void

)

Definition at line 68 of file buf_init.c.

{
    bool        foundBufs,
                foundDescs,
                foundIOCV,
                foundBufCkpt;
 
    /* Align descriptors to a cacheline boundary. */
    BufferDescriptors = (BufferDescPadded *)
        ShmemInitStruct("Buffer Descriptors",
                        NBuffers * sizeof(BufferDescPadded),
                        &foundDescs);
 
    /* Align buffer pool on IO page size boundary. */
    BufferBlocks = (char *)
        TYPEALIGN(PG_IO_ALIGN_SIZE,
                  ShmemInitStruct("Buffer Blocks",
                                  NBuffers * (Size) BLCKSZ + PG_IO_ALIGN_SIZE,
                                  &foundBufs));
 
    /* Align condition variables to cacheline boundary. */
    BufferIOCVArray = (ConditionVariableMinimallyPadded *)
        ShmemInitStruct("Buffer IO Condition Variables",
                        NBuffers * sizeof(ConditionVariableMinimallyPadded),
                        &foundIOCV);
 
    /*
     * The array used to sort to-be-checkpointed buffer ids is located in
     * shared memory, to avoid having to allocate significant amounts of
     * memory at runtime. As that'd be in the middle of a checkpoint, or when
     * the checkpointer is restarted, memory allocation failures would be
     * painful.
     */
    CkptBufferIds = (CkptSortItem *)
        ShmemInitStruct("Checkpoint BufferIds",
                        NBuffers * sizeof(CkptSortItem), &foundBufCkpt);
 
    if (foundDescs || foundBufs || foundIOCV || foundBufCkpt)
    {
        /* should find all of these, or none of them */
        Assert(foundDescs && foundBufs && foundIOCV && foundBufCkpt);
        /* note: this path is only taken in EXEC_BACKEND case */
    }
    else
    {
        int         i;
 
        /*
         * Initialize all the buffer headers.
         */
        for (i = 0; i < NBuffers; i++)
        {
            BufferDesc *buf = GetBufferDescriptor(i);
 
            ClearBufferTag(&buf->tag);
 
            pg_atomic_init_u32(&buf->state, 0);
            buf->wait_backend_pgprocno = INVALID_PROC_NUMBER;
 
            buf->buf_id = i;
 
            /*
             * Initially link all the buffers together as unused. Subsequent
             * management of this list is done by freelist.c.
             */
            buf->freeNext = i + 1;
 
            LWLockInitialize(BufferDescriptorGetContentLock(buf),
                             LWTRANCHE_BUFFER_CONTENT);
 
            ConditionVariableInit(BufferDescriptorGetIOCV(buf));
        }
 
        /* Correct last entry of linked list */
        GetBufferDescriptor(NBuffers - 1)->freeNext = FREENEXT_END_OF_LIST;
    }
 
    /* Init other shared buffer-management stuff */
    StrategyInitialize(!foundDescs);
 
    /* Initialize per-backend file flush context */
    WritebackContextInit(&BackendWritebackContext,
                         &backend_flush_after);
}

References Assert, backend_flush_after, BackendWritebackContext, buf, BufferBlocks, BufferDescriptorGetContentLock(), BufferDescriptorGetIOCV(), BufferDescriptors, BufferIOCVArray, CkptBufferIds, ClearBufferTag(), ConditionVariableInit(), BufferDesc::freeNext, FREENEXT_END_OF_LIST, GetBufferDescriptor(), i, INVALID_PROC_NUMBER, LWLockInitialize(), LWTRANCHE_BUFFER_CONTENT, NBuffers, pg_atomic_init_u32(), PG_IO_ALIGN_SIZE, ShmemInitStruct(), StrategyInitialize(), TYPEALIGN, and WritebackContextInit().

Referenced by CreateOrAttachShmemStructs().

InitBufferPoolAccess()

void InitBufferPoolAccess

(

void

)

Definition at line 3519 of file bufmgr.c.

{
    HASHCTL     hash_ctl;
 
    memset(&PrivateRefCountArray, 0, sizeof(PrivateRefCountArray));
 
    hash_ctl.keysize = sizeof(int32);
    hash_ctl.entrysize = sizeof(PrivateRefCountEntry);
 
    PrivateRefCountHash = hash_create("PrivateRefCount", 100, &hash_ctl,
                                      HASH_ELEM | HASH_BLOBS);
 
    /*
     * AtProcExit_Buffers needs LWLock access, and thereby has to be called at
     * the corresponding phase of backend shutdown.
     */
    Assert(MyProc != NULL);
    on_shmem_exit(AtProcExit_Buffers, 0);
}

References Assert, AtProcExit_Buffers(), HASHCTL::entrysize, HASH_BLOBS, hash_create(), HASH_ELEM, HASHCTL::keysize, MyProc, on_shmem_exit(), PrivateRefCountArray, and PrivateRefCountHash.

Referenced by BaseInit().

IsBufferCleanupOK()

bool IsBufferCleanupOK

(

Buffer

buffer

)

Definition at line 5382 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    uint32      buf_state;
 
    Assert(BufferIsValid(buffer));
 
    if (BufferIsLocal(buffer))
    {
        /* There should be exactly one pin */
        if (LocalRefCount[-buffer - 1] != 1)
            return false;
        /* Nobody else to wait for */
        return true;
    }
 
    /* There should be exactly one local pin */
    if (GetPrivateRefCount(buffer) != 1)
        return false;
 
    bufHdr = GetBufferDescriptor(buffer - 1);
 
    /* caller must hold exclusive lock on buffer */
    Assert(LWLockHeldByMeInMode(BufferDescriptorGetContentLock(bufHdr),
                                LW_EXCLUSIVE));
 
    buf_state = LockBufHdr(bufHdr);
 
    Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
    if (BUF_STATE_GET_REFCOUNT(buf_state) == 1)
    {
        /* pincount is OK. */
        UnlockBufHdr(bufHdr, buf_state);
        return true;
    }
 
    UnlockBufHdr(bufHdr, buf_state);
    return false;
}

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

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

LimitAdditionalLocalPins()

void LimitAdditionalLocalPins

(

uint32 *

additional_pins

)

Definition at line 290 of file localbuf.c.

{
    uint32      max_pins;
 
    if (*additional_pins <= 1)
        return;
 
    /*
     * In contrast to LimitAdditionalPins() other backends don't play a role
     * here. We can allow up to NLocBuffer pins in total, but it might not be
     * initialized yet so read num_temp_buffers.
     */
    max_pins = (num_temp_buffers - NLocalPinnedBuffers);
 
    if (*additional_pins >= max_pins)
        *additional_pins = max_pins;
}

References NLocalPinnedBuffers, and num_temp_buffers.

Referenced by ExtendBufferedRelLocal(), and read_stream_begin_relation().

LimitAdditionalPins()

void LimitAdditionalPins

(

uint32 *

additional_pins

)

Definition at line 2058 of file bufmgr.c.

{
    uint32      max_backends;
    int         max_proportional_pins;
 
    if (*additional_pins <= 1)
        return;
 
    max_backends = MaxBackends + NUM_AUXILIARY_PROCS;
    max_proportional_pins = NBuffers / max_backends;
 
    /*
     * Subtract the approximate number of buffers already pinned by this
     * backend. We get the number of "overflowed" pins for free, but don't
     * know the number of pins in PrivateRefCountArray. The cost of
     * calculating that exactly doesn't seem worth it, so just assume the max.
     */
    max_proportional_pins -= PrivateRefCountOverflowed + REFCOUNT_ARRAY_ENTRIES;
 
    if (max_proportional_pins <= 0)
        max_proportional_pins = 1;
 
    if (*additional_pins > max_proportional_pins)
        *additional_pins = max_proportional_pins;
}

References MaxBackends, NBuffers, NUM_AUXILIARY_PROCS, PrivateRefCountOverflowed, and REFCOUNT_ARRAY_ENTRIES.

Referenced by ExtendBufferedRelShared(), and read_stream_begin_relation().

LockBuffer()

void LockBuffer	(	Buffer	buffer,
		int	mode
	)

Definition at line 5085 of file bufmgr.c.

{
    BufferDesc *buf;
 
    Assert(BufferIsPinned(buffer));
    if (BufferIsLocal(buffer))
        return;                 /* local buffers need no lock */
 
    buf = GetBufferDescriptor(buffer - 1);
 
    if (mode == BUFFER_LOCK_UNLOCK)
        LWLockRelease(BufferDescriptorGetContentLock(buf));
    else if (mode == BUFFER_LOCK_SHARE)
        LWLockAcquire(BufferDescriptorGetContentLock(buf), LW_SHARED);
    else if (mode == BUFFER_LOCK_EXCLUSIVE)
        LWLockAcquire(BufferDescriptorGetContentLock(buf), LW_EXCLUSIVE);
    else
        elog(ERROR, "unrecognized buffer lock mode: %d", mode);
}

References Assert, buf, PrivateRefCountEntry::buffer, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_SHARE, BUFFER_LOCK_UNLOCK, BufferDescriptorGetContentLock(), BufferIsLocal, BufferIsPinned, elog, ERROR, GetBufferDescriptor(), LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), and mode.

Referenced by _bt_lockbuf(), _bt_unlockbuf(), _bt_upgradelockbufcleanup(), _hash_addovflpage(), _hash_doinsert(), _hash_expandtable(), _hash_finish_split(), _hash_first(), _hash_freeovflpage(), _hash_getbuf(), _hash_getbuf_with_strategy(), _hash_getcachedmetap(), _hash_init(), _hash_kill_items(), _hash_readnext(), _hash_readpage(), _hash_readprev(), _hash_splitbucket(), _hash_squeezebucket(), _hash_vacuum_one_page(), blbulkdelete(), blgetbitmap(), blinsert(), BloomInitMetapage(), BloomNewBuffer(), blvacuumcleanup(), brin_doinsert(), brin_doupdate(), brin_evacuate_page(), brin_getinsertbuffer(), brin_page_cleanup(), bringetbitmap(), brinGetStats(), brinGetTupleForHeapBlock(), brininsert(), brinLockRevmapPageForUpdate(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), brinsummarize(), bt_metap(), bt_multi_page_stats(), bt_page_items_internal(), bt_page_stats_internal(), bt_recheck_sibling_links(), collect_corrupt_items(), collect_visibility_data(), collectMatchBitmap(), ConditionalLockBufferForCleanup(), count_nondeletable_pages(), entryLoadMoreItems(), FreeSpaceMapPrepareTruncateRel(), fsm_readbuf(), fsm_search(), fsm_search_avail(), fsm_set_and_search(), fsm_vacuum_page(), get_raw_page_internal(), GetVisibilityMapPins(), ginbulkdelete(), ginEntryInsert(), ginFindLeafPage(), ginFindParents(), ginFinishOldSplit(), ginFinishSplit(), ginGetStats(), ginHeapTupleFastInsert(), ginInsertCleanup(), ginInsertValue(), GinNewBuffer(), ginScanToDelete(), ginStepRight(), ginTraverseLock(), ginUpdateStats(), ginvacuumcleanup(), ginVacuumPostingTreeLeaves(), gistBufferingFindCorrectParent(), gistbufferinginserttuples(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistfinishsplit(), gistfixsplit(), gistformdownlink(), gistGetMaxLevel(), gistinserttuples(), gistkillitems(), gistNewBuffer(), gistProcessItup(), gistScanPage(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hashbucketcleanup(), hashbulkdelete(), heap_abort_speculative(), heap_delete(), heap_fetch(), heap_finish_speculative(), heap_get_latest_tid(), heap_index_delete_tuples(), heap_inplace_update(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_page_prune_opt(), heap_prepare_pagescan(), 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(), heapgettup(), initBloomState(), lazy_scan_heap(), lazy_scan_new_or_empty(), lazy_vacuum_heap_rel(), 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(), RelationAddBlocks(), RelationCopyStorageUsingBuffer(), RelationGetBufferForTuple(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), ScanSourceDatabasePgClass(), shiftList(), spgdoinsert(), spgGetCache(), SpGistNewBuffer(), spgprocesspending(), spgvacuumpage(), spgWalk(), startScanEntry(), statapprox_heap(), summarize_range(), UnlockReleaseBuffer(), verify_heapam(), verifyBackupPageConsistency(), visibilitymap_clear(), visibilitymap_prepare_truncate(), visibilitymap_set(), vm_readbuf(), XLogReadBufferForRedoExtended(), XLogRecordPageWithFreeSpace(), and ZeroBuffer().

LockBufferForCleanup()

void LockBufferForCleanup

(

Buffer

buffer

)

Definition at line 5165 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    TimestampTz waitStart = 0;
    bool        waiting = false;
    bool        logged_recovery_conflict = false;
 
    Assert(BufferIsPinned(buffer));
    Assert(PinCountWaitBuf == NULL);
 
    CheckBufferIsPinnedOnce(buffer);
 
    /* Nobody else to wait for */
    if (BufferIsLocal(buffer))
        return;
 
    bufHdr = GetBufferDescriptor(buffer - 1);
 
    for (;;)
    {
        uint32      buf_state;
 
        /* Try to acquire lock */
        LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
        buf_state = LockBufHdr(bufHdr);
 
        Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
        if (BUF_STATE_GET_REFCOUNT(buf_state) == 1)
        {
            /* Successfully acquired exclusive lock with pincount 1 */
            UnlockBufHdr(bufHdr, buf_state);
 
            /*
             * Emit the log message if recovery conflict on buffer pin was
             * resolved but the startup process waited longer than
             * deadlock_timeout for it.
             */
            if (logged_recovery_conflict)
                LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN,
                                    waitStart, GetCurrentTimestamp(),
                                    NULL, false);
 
            if (waiting)
            {
                /* reset ps display to remove the suffix if we added one */
                set_ps_display_remove_suffix();
                waiting = false;
            }
            return;
        }
        /* Failed, so mark myself as waiting for pincount 1 */
        if (buf_state & BM_PIN_COUNT_WAITER)
        {
            UnlockBufHdr(bufHdr, buf_state);
            LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
            elog(ERROR, "multiple backends attempting to wait for pincount 1");
        }
        bufHdr->wait_backend_pgprocno = MyProcNumber;
        PinCountWaitBuf = bufHdr;
        buf_state |= BM_PIN_COUNT_WAITER;
        UnlockBufHdr(bufHdr, buf_state);
        LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
 
        /* Wait to be signaled by UnpinBuffer() */
        if (InHotStandby)
        {
            if (!waiting)
            {
                /* adjust the process title to indicate that it's waiting */
                set_ps_display_suffix("waiting");
                waiting = true;
            }
 
            /*
             * Emit the log message if the startup process is waiting longer
             * than deadlock_timeout for recovery conflict on buffer pin.
             *
             * Skip this if first time through because the startup process has
             * not started waiting yet in this case. So, the wait start
             * timestamp is set after this logic.
             */
            if (waitStart != 0 && !logged_recovery_conflict)
            {
                TimestampTz now = GetCurrentTimestamp();
 
                if (TimestampDifferenceExceeds(waitStart, now,
                                               DeadlockTimeout))
                {
                    LogRecoveryConflict(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN,
                                        waitStart, now, NULL, true);
                    logged_recovery_conflict = true;
                }
            }
 
            /*
             * Set the wait start timestamp if logging is enabled and first
             * time through.
             */
            if (log_recovery_conflict_waits && waitStart == 0)
                waitStart = GetCurrentTimestamp();
 
            /* Publish the bufid that Startup process waits on */
            SetStartupBufferPinWaitBufId(buffer - 1);
            /* Set alarm and then wait to be signaled by UnpinBuffer() */
            ResolveRecoveryConflictWithBufferPin();
            /* Reset the published bufid */
            SetStartupBufferPinWaitBufId(-1);
        }
        else
            ProcWaitForSignal(WAIT_EVENT_BUFFER_PIN);
 
        /*
         * Remove flag marking us as waiter. Normally this will not be set
         * anymore, but ProcWaitForSignal() can return for other signals as
         * well.  We take care to only reset the flag if we're the waiter, as
         * theoretically another backend could have started waiting. That's
         * impossible with the current usages due to table level locking, but
         * better be safe.
         */
        buf_state = LockBufHdr(bufHdr);
        if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
            bufHdr->wait_backend_pgprocno == MyProcNumber)
            buf_state &= ~BM_PIN_COUNT_WAITER;
        UnlockBufHdr(bufHdr, buf_state);
 
        PinCountWaitBuf = NULL;
        /* Loop back and try again */
    }
}

References Assert, BM_PIN_COUNT_WAITER, BUF_STATE_GET_REFCOUNT, PrivateRefCountEntry::buffer, BUFFER_LOCK_EXCLUSIVE, BUFFER_LOCK_UNLOCK, BufferIsLocal, BufferIsPinned, CheckBufferIsPinnedOnce(), DeadlockTimeout, elog, ERROR, GetBufferDescriptor(), GetCurrentTimestamp(), InHotStandby, LockBuffer(), LockBufHdr(), log_recovery_conflict_waits, LogRecoveryConflict(), MyProcNumber, now(), PinCountWaitBuf, PROCSIG_RECOVERY_CONFLICT_BUFFERPIN, ProcWaitForSignal(), ResolveRecoveryConflictWithBufferPin(), set_ps_display_remove_suffix(), set_ps_display_suffix(), SetStartupBufferPinWaitBufId(), TimestampDifferenceExceeds(), UnlockBufHdr(), BufferDesc::wait_backend_pgprocno, and waiting.

Referenced by _bt_upgradelockbufcleanup(), ginVacuumPostingTree(), hashbulkdelete(), heap_force_common(), lazy_scan_heap(), XLogReadBufferForRedoExtended(), and ZeroBuffer().

MarkBufferDirty()

void MarkBufferDirty

(

Buffer

buffer

)

Definition at line 2474 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    uint32      buf_state;
    uint32      old_buf_state;
 
    if (!BufferIsValid(buffer))
        elog(ERROR, "bad buffer ID: %d", buffer);
 
    if (BufferIsLocal(buffer))
    {
        MarkLocalBufferDirty(buffer);
        return;
    }
 
    bufHdr = GetBufferDescriptor(buffer - 1);
 
    Assert(BufferIsPinned(buffer));
    Assert(LWLockHeldByMeInMode(BufferDescriptorGetContentLock(bufHdr),
                                LW_EXCLUSIVE));
 
    old_buf_state = pg_atomic_read_u32(&bufHdr->state);
    for (;;)
    {
        if (old_buf_state & BM_LOCKED)
            old_buf_state = WaitBufHdrUnlocked(bufHdr);
 
        buf_state = old_buf_state;
 
        Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
        buf_state |= BM_DIRTY | BM_JUST_DIRTIED;
 
        if (pg_atomic_compare_exchange_u32(&bufHdr->state, &old_buf_state,
                                           buf_state))
            break;
    }
 
    /*
     * If the buffer was not dirty already, do vacuum accounting.
     */
    if (!(old_buf_state & BM_DIRTY))
    {
        VacuumPageDirty++;
        pgBufferUsage.shared_blks_dirtied++;
        if (VacuumCostActive)
            VacuumCostBalance += VacuumCostPageDirty;
    }
}

References Assert, BM_DIRTY, BM_JUST_DIRTIED, BM_LOCKED, BUF_STATE_GET_REFCOUNT, PrivateRefCountEntry::buffer, 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_dedup_pass(), _bt_delitems_delete(), _bt_delitems_vacuum(), _bt_getroot(), _bt_insertonpg(), _bt_mark_page_halfdead(), _bt_newlevel(), _bt_restore_meta(), _bt_set_cleanup_info(), _bt_split(), _bt_unlink_halfdead_page(), _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_dedup(), 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(), dataExecPlaceToPageInternal(), dataExecPlaceToPageLeaf(), do_setval(), doPickSplit(), entryExecPlaceToPage(), fill_seq_fork_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_force_common(), heap_inplace_update(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_page_prune_and_freeze(), heap_update(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_prune_freeze(), heap_xlog_update(), heap_xlog_visible(), lazy_scan_new_or_empty(), lazy_scan_prune(), lazy_vacuum_heap_page(), log_newpage_range(), moveLeafs(), nextval_internal(), RelationAddBlocks(), RelationCopyStorageUsingBuffer(), 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().

MarkBufferDirtyHint()

void MarkBufferDirtyHint	(	Buffer	buffer,
		bool	buffer_std
	)

Definition at line 4914 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    Page        page = BufferGetPage(buffer);
 
    if (!BufferIsValid(buffer))
        elog(ERROR, "bad buffer ID: %d", buffer);
 
    if (BufferIsLocal(buffer))
    {
        MarkLocalBufferDirty(buffer);
        return;
    }
 
    bufHdr = GetBufferDescriptor(buffer - 1);
 
    Assert(GetPrivateRefCount(buffer) > 0);
    /* here, either share or exclusive lock is OK */
    Assert(LWLockHeldByMe(BufferDescriptorGetContentLock(bufHdr)));
 
    /*
     * This routine might get called many times on the same page, if we are
     * making the first scan after commit of an xact that added/deleted many
     * tuples. So, be as quick as we can if the buffer is already dirty.  We
     * do this by not acquiring spinlock if it looks like the status bits are
     * already set.  Since we make this test unlocked, there's a chance we
     * might fail to notice that the flags have just been cleared, and failed
     * to reset them, due to memory-ordering issues.  But since this function
     * is only intended to be used in cases where failing to write out the
     * data would be harmless anyway, it doesn't really matter.
     */
    if ((pg_atomic_read_u32(&bufHdr->state) & (BM_DIRTY | BM_JUST_DIRTIED)) !=
        (BM_DIRTY | BM_JUST_DIRTIED))
    {
        XLogRecPtr  lsn = InvalidXLogRecPtr;
        bool        dirtied = false;
        bool        delayChkptFlags = false;
        uint32      buf_state;
 
        /*
         * If we need to protect hint bit updates from torn writes, WAL-log a
         * full page image of the page. This full page image is only necessary
         * if the hint bit update is the first change to the page since the
         * last checkpoint.
         *
         * We don't check full_page_writes here because that logic is included
         * when we call XLogInsert() since the value changes dynamically.
         */
        if (XLogHintBitIsNeeded() &&
            (pg_atomic_read_u32(&bufHdr->state) & BM_PERMANENT))
        {
            /*
             * If we must not write WAL, due to a relfilelocator-specific
             * condition or being in recovery, don't dirty the page.  We can
             * set the hint, just not dirty the page as a result so the hint
             * is lost when we evict the page or shutdown.
             *
             * See src/backend/storage/page/README for longer discussion.
             */
            if (RecoveryInProgress() ||
                RelFileLocatorSkippingWAL(BufTagGetRelFileLocator(&bufHdr->tag)))
                return;
 
            /*
             * If the block is already dirty because we either made a change
             * or set a hint already, then we don't need to write a full page
             * image.  Note that aggressive cleaning of blocks dirtied by hint
             * bit setting would increase the call rate. Bulk setting of hint
             * bits would reduce the call rate...
             *
             * We must issue the WAL record before we mark the buffer dirty.
             * Otherwise we might write the page before we write the WAL. That
             * causes a race condition, since a checkpoint might occur between
             * writing the WAL record and marking the buffer dirty. We solve
             * that with a kluge, but one that is already in use during
             * transaction commit to prevent race conditions. Basically, we
             * simply prevent the checkpoint WAL record from being written
             * until we have marked the buffer dirty. We don't start the
             * checkpoint flush until we have marked dirty, so our checkpoint
             * must flush the change to disk successfully or the checkpoint
             * never gets written, so crash recovery will fix.
             *
             * It's possible we may enter here without an xid, so it is
             * essential that CreateCheckPoint waits for virtual transactions
             * rather than full transactionids.
             */
            Assert((MyProc->delayChkptFlags & DELAY_CHKPT_START) == 0);
            MyProc->delayChkptFlags |= DELAY_CHKPT_START;
            delayChkptFlags = true;
            lsn = XLogSaveBufferForHint(buffer, buffer_std);
        }
 
        buf_state = LockBufHdr(bufHdr);
 
        Assert(BUF_STATE_GET_REFCOUNT(buf_state) > 0);
 
        if (!(buf_state & BM_DIRTY))
        {
            dirtied = true;     /* Means "will be dirtied by this action" */
 
            /*
             * Set the page LSN if we wrote a backup block. We aren't supposed
             * to set this when only holding a share lock but as long as we
             * serialise it somehow we're OK. We choose to set LSN while
             * holding the buffer header lock, which causes any reader of an
             * LSN who holds only a share lock to also obtain a buffer header
             * lock before using PageGetLSN(), which is enforced in
             * BufferGetLSNAtomic().
             *
             * If checksums are enabled, you might think we should reset the
             * checksum here. That will happen when the page is written
             * sometime later in this checkpoint cycle.
             */
            if (!XLogRecPtrIsInvalid(lsn))
                PageSetLSN(page, lsn);
        }
 
        buf_state |= BM_DIRTY | BM_JUST_DIRTIED;
        UnlockBufHdr(bufHdr, buf_state);
 
        if (delayChkptFlags)
            MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
 
        if (dirtied)
        {
            VacuumPageDirty++;
            pgBufferUsage.shared_blks_dirtied++;
            if (VacuumCostActive)
                VacuumCostBalance += VacuumCostPageDirty;
        }
    }
}

References Assert, BM_DIRTY, BM_JUST_DIRTIED, BM_PERMANENT, BUF_STATE_GET_REFCOUNT, PrivateRefCountEntry::buffer, BufferDescriptorGetContentLock(), BufferGetPage(), BufferIsLocal, BufferIsValid(), BufTagGetRelFileLocator(), DELAY_CHKPT_START, PGPROC::delayChkptFlags, elog, ERROR, GetBufferDescriptor(), GetPrivateRefCount(), InvalidXLogRecPtr, LockBufHdr(), LWLockHeldByMe(), MarkLocalBufferDirty(), MyProc, PageSetLSN(), pg_atomic_read_u32(), pgBufferUsage, RecoveryInProgress(), RelFileLocatorSkippingWAL(), BufferUsage::shared_blks_dirtied, BufferDesc::state, BufferDesc::tag, 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(), fsm_search_avail(), fsm_set_and_search(), fsm_vacuum_page(), gistkillitems(), heap_page_prune_and_freeze(), read_seq_tuple(), SetHintBits(), and XLogRecordPageWithFreeSpace().

PrefetchBuffer()

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

Definition at line 638 of file bufmgr.c.

{
    Assert(RelationIsValid(reln));
    Assert(BlockNumberIsValid(blockNum));
 
    if (RelationUsesLocalBuffers(reln))
    {
        /* see comments in ReadBufferExtended */
        if (RELATION_IS_OTHER_TEMP(reln))
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("cannot access temporary tables of other sessions")));
 
        /* pass it off to localbuf.c */
        return PrefetchLocalBuffer(RelationGetSmgr(reln), forkNum, blockNum);
    }
    else
    {
        /* pass it to the shared buffer version */
        return PrefetchSharedBuffer(RelationGetSmgr(reln), forkNum, blockNum);
    }
}

References Assert, BlockNumberIsValid(), ereport, errcode(), errmsg(), ERROR, PrefetchLocalBuffer(), PrefetchSharedBuffer(), RELATION_IS_OTHER_TEMP, RelationGetSmgr(), RelationIsValid, and RelationUsesLocalBuffers.

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

PrefetchSharedBuffer()

PrefetchBufferResult PrefetchSharedBuffer	(	struct SMgrRelationData *	smgr_reln,
		ForkNumber	forkNum,
		BlockNumber	blockNum
	)

ReadBuffer()

Buffer ReadBuffer	(	Relation	reln,
		BlockNumber	blockNum
	)

Definition at line 745 of file bufmgr.c.

{
    return ReadBufferExtended(reln, MAIN_FORKNUM, blockNum, RBM_NORMAL, NULL);
}

References MAIN_FORKNUM, RBM_NORMAL, and ReadBufferExtended().

Referenced by _bt_allocbuf(), _bt_getbuf(), _bt_search_insert(), _hash_getbuf(), _hash_getbuf_with_condlock_cleanup(), blbulkdelete(), blinsert(), BloomNewBuffer(), brin_getinsertbuffer(), brinGetStats(), brinGetTupleForHeapBlock(), brinRevmapDesummarizeRange(), brinRevmapInitialize(), bt_metap(), bt_multi_page_stats(), bt_page_items_internal(), bt_page_stats_internal(), ginFindLeafPage(), ginFindParents(), ginGetStats(), ginHeapTupleFastInsert(), ginInsertCleanup(), GinNewBuffer(), ginStepRight(), ginUpdateStats(), gistBufferingFindCorrectParent(), gistbufferinginserttuples(), gistdoinsert(), gistFindCorrectParent(), gistFindPath(), gistfixsplit(), gistGetMaxLevel(), gistkillitems(), gistNewBuffer(), gistProcessItup(), gistScanPage(), heap_abort_speculative(), heap_delete(), heap_fetch(), heap_finish_speculative(), heap_force_common(), heap_get_latest_tid(), heap_index_delete_tuples(), heap_inplace_update(), heap_lock_tuple(), heap_update(), initBloomState(), 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().

ReadBufferExtended()

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

inline

Definition at line 792 of file bufmgr.c.

{
    Buffer      buf;
 
    /*
     * Reject attempts to read non-local temporary relations; we would be
     * likely to get wrong data since we have no visibility into the owning
     * session's local buffers.
     */
    if (RELATION_IS_OTHER_TEMP(reln))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("cannot access temporary tables of other sessions")));
 
    /*
     * Read the buffer, and update pgstat counters to reflect a cache hit or
     * miss.
     */
    buf = ReadBuffer_common(reln, RelationGetSmgr(reln), 0,
                            forkNum, blockNum, mode, strategy);
 
    return buf;
}

References buf, ereport, errcode(), errmsg(), ERROR, mode, ReadBuffer_common(), RELATION_IS_OTHER_TEMP, and RelationGetSmgr().

Referenced by _hash_getbuf_with_strategy(), _hash_getinitbuf(), _hash_getnewbuf(), autoprewarm_database_main(), blbulkdelete(), blgetbitmap(), BloomInitMetapage(), blvacuumcleanup(), brin_vacuum_scan(), bt_recheck_sibling_links(), btvacuumpage(), collect_corrupt_items(), collect_visibility_data(), count_nondeletable_pages(), fsm_readbuf(), get_raw_page_internal(), ginbulkdelete(), ginDeletePage(), ginScanToDelete(), ginvacuumcleanup(), ginVacuumPostingTree(), ginVacuumPostingTreeLeaves(), gistvacuum_delete_empty_pages(), gistvacuumpage(), hashbulkdelete(), heapam_scan_sample_next_block(), lazy_scan_heap(), lazy_vacuum_heap_rel(), log_newpage_range(), palloc_btree_page(), pgstat_btree_page(), pgstat_gist_page(), pgstat_heap(), pgstathashindex(), pgstatindex_impl(), ReadBuffer(), ReadBufferBI(), spgprocesspending(), spgvacuumpage(), statapprox_heap(), verify_heapam(), and vm_readbuf().

ReadBufferWithoutRelcache()

Buffer ReadBufferWithoutRelcache	(	RelFileLocator	rlocator,
		ForkNumber	forkNum,
		BlockNumber	blockNum,
		ReadBufferMode	mode,
		BufferAccessStrategy	strategy,
		bool	permanent
	)

Definition at line 829 of file bufmgr.c.

{
    SMgrRelation smgr = smgropen(rlocator, INVALID_PROC_NUMBER);
 
    return ReadBuffer_common(NULL, smgr,
                             permanent ? RELPERSISTENCE_PERMANENT : RELPERSISTENCE_UNLOGGED,
                             forkNum, blockNum,
                             mode, strategy);
}

References INVALID_PROC_NUMBER, mode, ReadBuffer_common(), and smgropen().

Referenced by RelationCopyStorageUsingBuffer(), ScanSourceDatabasePgClass(), and XLogReadBufferExtended().

ReadRecentBuffer()

bool ReadRecentBuffer	(	RelFileLocator	rlocator,
		ForkNumber	forkNum,
		BlockNumber	blockNum,
		Buffer	recent_buffer
	)

Definition at line 669 of file bufmgr.c.

{
    BufferDesc *bufHdr;
    BufferTag   tag;
    uint32      buf_state;
    bool        have_private_ref;
 
    Assert(BufferIsValid(recent_buffer));
 
    ResourceOwnerEnlarge(CurrentResourceOwner);
    ReservePrivateRefCountEntry();
    InitBufferTag(&tag, &rlocator, forkNum, blockNum);
 
    if (BufferIsLocal(recent_buffer))
    {
        int         b = -recent_buffer - 1;
 
        bufHdr = GetLocalBufferDescriptor(b);
        buf_state = pg_atomic_read_u32(&bufHdr->state);
 
        /* Is it still valid and holding the right tag? */
        if ((buf_state & BM_VALID) && BufferTagsEqual(&tag, &bufHdr->tag))
        {
            PinLocalBuffer(bufHdr, true);
 
            pgBufferUsage.local_blks_hit++;
 
            return true;
        }
    }
    else
    {
        bufHdr = GetBufferDescriptor(recent_buffer - 1);
        have_private_ref = GetPrivateRefCount(recent_buffer) > 0;
 
        /*
         * Do we already have this buffer pinned with a private reference?  If
         * so, it must be valid and it is safe to check the tag without
         * locking.  If not, we have to lock the header first and then check.
         */
        if (have_private_ref)
            buf_state = pg_atomic_read_u32(&bufHdr->state);
        else
            buf_state = LockBufHdr(bufHdr);
 
        if ((buf_state & BM_VALID) && BufferTagsEqual(&tag, &bufHdr->tag))
        {
            /*
             * It's now safe to pin the buffer.  We can't pin first and ask
             * questions later, because it might confuse code paths like
             * InvalidateBuffer() if we pinned a random non-matching buffer.
             */
            if (have_private_ref)
                PinBuffer(bufHdr, NULL);    /* bump pin count */
            else
                PinBuffer_Locked(bufHdr);   /* pin for first time */
 
            pgBufferUsage.shared_blks_hit++;
 
            return true;
        }
 
        /* If we locked the header above, now unlock. */
        if (!have_private_ref)
            UnlockBufHdr(bufHdr, buf_state);
    }
 
    return false;
}

References Assert, b, BM_VALID, BufferIsLocal, BufferIsValid(), BufferTagsEqual(), CurrentResourceOwner, GetBufferDescriptor(), GetLocalBufferDescriptor(), GetPrivateRefCount(), InitBufferTag(), BufferUsage::local_blks_hit, LockBufHdr(), pg_atomic_read_u32(), pgBufferUsage, PinBuffer(), PinBuffer_Locked(), PinLocalBuffer(), ReservePrivateRefCountEntry(), ResourceOwnerEnlarge(), BufferUsage::shared_blks_hit, BufferDesc::state, BufferDesc::tag, and UnlockBufHdr().

Referenced by XLogReadBufferExtended().

RelationGetNumberOfBlocksInFork()

BlockNumber RelationGetNumberOfBlocksInFork	(	Relation	relation,
		ForkNumber	forkNum
	)

Definition at line 3866 of file bufmgr.c.

{
    if (RELKIND_HAS_TABLE_AM(relation->rd_rel->relkind))
    {
        /*
         * Not every table AM uses BLCKSZ wide fixed size blocks. Therefore
         * tableam returns the size in bytes - but for the purpose of this
         * routine, we want the number of blocks. Therefore divide, rounding
         * up.
         */
        uint64      szbytes;
 
        szbytes = table_relation_size(relation, forkNum);
 
        return (szbytes + (BLCKSZ - 1)) / BLCKSZ;
    }
    else if (RELKIND_HAS_STORAGE(relation->rd_rel->relkind))
    {
        return smgrnblocks(RelationGetSmgr(relation), forkNum);
    }
    else
        Assert(false);
 
    return 0;                   /* keep compiler quiet */
}

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

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

ReleaseAndReadBuffer()

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

Definition at line 2537 of file bufmgr.c.

{
    ForkNumber  forkNum = MAIN_FORKNUM;
    BufferDesc *bufHdr;
 
    if (BufferIsValid(buffer))
    {
        Assert(BufferIsPinned(buffer));
        if (BufferIsLocal(buffer))
        {
            bufHdr = GetLocalBufferDescriptor(-buffer - 1);
            if (bufHdr->tag.blockNum == blockNum &&
                BufTagMatchesRelFileLocator(&bufHdr->tag, &relation->rd_locator) &&
                BufTagGetForkNum(&bufHdr->tag) == forkNum)
                return buffer;
            UnpinLocalBuffer(buffer);
        }
        else
        {
            bufHdr = GetBufferDescriptor(buffer - 1);
            /* we have pin, so it's ok to examine tag without spinlock */
            if (bufHdr->tag.blockNum == blockNum &&
                BufTagMatchesRelFileLocator(&bufHdr->tag, &relation->rd_locator) &&
                BufTagGetForkNum(&bufHdr->tag) == forkNum)
                return buffer;
            UnpinBuffer(bufHdr);
        }
    }
 
    return ReadBuffer(relation, blockNum);
}

References Assert, buftag::blockNum, PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsPinned, BufferIsValid(), BufTagGetForkNum(), BufTagMatchesRelFileLocator(), GetBufferDescriptor(), GetLocalBufferDescriptor(), MAIN_FORKNUM, RelationData::rd_locator, ReadBuffer(), BufferDesc::tag, UnpinBuffer(), and UnpinLocalBuffer().

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

ReleaseBuffer()

void ReleaseBuffer

(

Buffer

buffer

)

Definition at line 4850 of file bufmgr.c.

{
    if (!BufferIsValid(buffer))
        elog(ERROR, "bad buffer ID: %d", buffer);
 
    if (BufferIsLocal(buffer))
        UnpinLocalBuffer(buffer);
    else
        UnpinBuffer(GetBufferDescriptor(buffer - 1));
}

References PrivateRefCountEntry::buffer, BufferIsLocal, BufferIsValid(), elog, ERROR, GetBufferDescriptor(), UnpinBuffer(), and UnpinLocalBuffer().

Referenced by _bt_allocbuf(), _bt_drop_lock_and_maybe_pin(), _bt_pagedel(), _bt_relbuf(), _bt_search_insert(), _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(), ExtendBufferedRelTo(), FreeBulkInsertState(), freeGinBtreeStack(), fsm_search(), 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_delete(), heap_endscan(), heap_fetch(), heap_fetch_next_buffer(), heap_force_common(), heap_insert(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_rescan(), heap_update(), heap_vac_scan_next_block(), 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(), heapgettup(), heapgettup_pagemode(), lazy_scan_heap(), lazy_vacuum_heap_rel(), pg_prewarm(), pg_visibility(), pg_visibility_map(), pg_visibility_map_summary(), pgstatindex_impl(), read_stream_reset(), ReadBufferBI(), RelationAddBlocks(), RelationGetBufferForTuple(), ReleaseBulkInsertStatePin(), revmap_get_buffer(), 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(), verify_heapam(), visibilitymap_count(), visibilitymap_get_status(), visibilitymap_pin(), and XLogReadBufferExtended().

StartReadBuffer()

bool StartReadBuffer	(	ReadBuffersOperation *	operation,
		Buffer *	buffer,
		BlockNumber	blocknum,
		int	flags
	)

Definition at line 1321 of file bufmgr.c.

{
    int         nblocks = 1;
    bool        result;
 
    result = StartReadBuffersImpl(operation, buffer, blocknum, &nblocks, flags);
    Assert(nblocks == 1);       /* single block can't be short */
 
    return result;
}

References Assert, PrivateRefCountEntry::buffer, and StartReadBuffersImpl().

Referenced by read_stream_next_buffer(), and ReadBuffer_common().

StartReadBuffers()

bool StartReadBuffers	(	ReadBuffersOperation *	operation,
		Buffer *	buffers,
		BlockNumber	blocknum,
		int *	nblocks,
		int	flags
	)

Definition at line 1306 of file bufmgr.c.

{
    return StartReadBuffersImpl(operation, buffers, blockNum, nblocks, flags);
}

References StartReadBuffersImpl().

Referenced by read_stream_start_pending_read().

UnlockBuffers()

void UnlockBuffers

(

void

)

Definition at line 5057 of file bufmgr.c.

{
    BufferDesc *buf = PinCountWaitBuf;
 
    if (buf)
    {
        uint32      buf_state;
 
        buf_state = LockBufHdr(buf);
 
        /*
         * Don't complain if flag bit not set; it could have been reset but we
         * got a cancel/die interrupt before getting the signal.
         */
        if ((buf_state & BM_PIN_COUNT_WAITER) != 0 &&
            buf->wait_backend_pgprocno == MyProcNumber)
            buf_state &= ~BM_PIN_COUNT_WAITER;
 
        UnlockBufHdr(buf, buf_state);
 
        PinCountWaitBuf = NULL;
    }
}

References BM_PIN_COUNT_WAITER, buf, LockBufHdr(), MyProcNumber, PinCountWaitBuf, and UnlockBufHdr().

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

UnlockReleaseBuffer()

void UnlockReleaseBuffer

(

Buffer

buffer

)

Definition at line 4867 of file bufmgr.c.

{
    LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
    ReleaseBuffer(buffer);
}

References PrivateRefCountEntry::buffer, BUFFER_LOCK_UNLOCK, LockBuffer(), and ReleaseBuffer().

Referenced by _bt_clear_incomplete_split(), _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_multi_page_stats(), bt_page_items_internal(), bt_page_stats_internal(), bt_recheck_sibling_links(), btree_xlog_dedup(), btree_xlog_delete(), btree_xlog_insert(), btree_xlog_mark_page_halfdead(), btree_xlog_newroot(), btree_xlog_split(), btree_xlog_unlink_page(), btree_xlog_vacuum(), collect_corrupt_items(), collect_visibility_data(), count_nondeletable_pages(), createPostingTree(), do_setval(), doPickSplit(), entryLoadMoreItems(), fill_seq_fork_with_data(), flushCachedPage(), FreeSpaceMapPrepareTruncateRel(), fsm_search(), fsm_set_and_search(), generic_redo(), ginbuild(), ginbuildempty(), ginbulkdelete(), 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_force_common(), heap_get_latest_tid(), heap_index_delete_tuples(), heap_inplace_update(), heap_insert(), heap_lock_updated_tuple_rec(), heap_multi_insert(), heap_update(), heap_xlog_confirm(), heap_xlog_delete(), heap_xlog_inplace(), heap_xlog_insert(), heap_xlog_lock(), heap_xlog_lock_updated(), heap_xlog_multi_insert(), heap_xlog_prune_freeze(), heap_xlog_update(), heap_xlog_visible(), heapam_scan_analyze_next_tuple(), initBloomState(), lazy_scan_heap(), lazy_scan_new_or_empty(), lazy_vacuum_heap_rel(), log_newpage_range(), moveLeafs(), nextval_internal(), palloc_btree_page(), pg_sequence_last_value(), pg_visibility(), pgstat_gist_page(), pgstat_heap(), pgstatginindex_internal(), pgstathashindex(), RelationCopyStorageUsingBuffer(), RelationGetBufferForTuple(), ResetSequence(), revmap_physical_extend(), scanGetCandidate(), scanPendingInsert(), scanPostingTree(), ScanSourceDatabasePgClass(), seq_redo(), SequenceChangePersistence(), shiftList(), spgAddNodeAction(), spgbuild(), spgdoinsert(), spgGetCache(), SpGistGetBuffer(), SpGistUpdateMetaPage(), spgMatchNodeAction(), spgprocesspending(), spgRedoAddLeaf(), spgRedoAddNode(), spgRedoMoveLeafs(), spgRedoPickSplit(), spgRedoSplitTuple(), spgRedoVacuumLeaf(), spgRedoVacuumRedirect(), spgRedoVacuumRoot(), spgSplitNodeAction(), spgvacuumpage(), spgWalk(), statapprox_heap(), verify_heapam(), verifyBackupPageConsistency(), visibilitymap_prepare_truncate(), writeListPage(), xlog_redo(), and XLogRecordPageWithFreeSpace().

WaitReadBuffers()

void WaitReadBuffers

(

ReadBuffersOperation *

operation

)

Definition at line 1349 of file bufmgr.c.

{
    Buffer     *buffers;
    int         nblocks;
    BlockNumber blocknum;
    ForkNumber  forknum;
    IOContext   io_context;
    IOObject    io_object;
    char        persistence;
 
    /*
     * Currently operations are only allowed to include a read of some range,
     * with an optional extra buffer that is already pinned at the end.  So
     * nblocks can be at most one more than io_buffers_len.
     */
    Assert((operation->nblocks == operation->io_buffers_len) ||
           (operation->nblocks == operation->io_buffers_len + 1));
 
    /* Find the range of the physical read we need to perform. */
    nblocks = operation->io_buffers_len;
    if (nblocks == 0)
        return;                 /* nothing to do */
 
    buffers = &operation->buffers[0];
    blocknum = operation->blocknum;
    forknum = operation->forknum;
 
    persistence = operation->rel
        ? operation->rel->rd_rel->relpersistence
        : RELPERSISTENCE_PERMANENT;
    if (persistence == RELPERSISTENCE_TEMP)
    {
        io_context = IOCONTEXT_NORMAL;
        io_object = IOOBJECT_TEMP_RELATION;
    }
    else
    {
        io_context = IOContextForStrategy(operation->strategy);
        io_object = IOOBJECT_RELATION;
    }
 
    /*
     * We count all these blocks as read by this backend.  This is traditional
     * behavior, but might turn out to be not true if we find that someone
     * else has beaten us and completed the read of some of these blocks.  In
     * that case the system globally double-counts, but we traditionally don't
     * count this as a "hit", and we don't have a separate counter for "miss,
     * but another backend completed the read".
     */
    if (persistence == RELPERSISTENCE_TEMP)
        pgBufferUsage.local_blks_read += nblocks;
    else
        pgBufferUsage.shared_blks_read += nblocks;
 
    for (int i = 0; i < nblocks; ++i)
    {
        int         io_buffers_len;
        Buffer      io_buffers[MAX_IO_COMBINE_LIMIT];
        void       *io_pages[MAX_IO_COMBINE_LIMIT];
        instr_time  io_start;
        BlockNumber io_first_block;
 
        /*
         * Skip this block if someone else has already completed it.  If an
         * I/O is already in progress in another backend, this will wait for
         * the outcome: either done, or something went wrong and we will
         * retry.
         */
        if (!WaitReadBuffersCanStartIO(buffers[i], false))
        {
            /*
             * Report this as a 'hit' for this backend, even though it must
             * have started out as a miss in PinBufferForBlock().
             */
            TRACE_POSTGRESQL_BUFFER_READ_DONE(forknum, blocknum + i,
                                              operation->smgr->smgr_rlocator.locator.spcOid,
                                              operation->smgr->smgr_rlocator.locator.dbOid,
                                              operation->smgr->smgr_rlocator.locator.relNumber,
                                              operation->smgr->smgr_rlocator.backend,
                                              true);
            continue;
        }
 
        /* We found a buffer that we need to read in. */
        io_buffers[0] = buffers[i];
        io_pages[0] = BufferGetBlock(buffers[i]);
        io_first_block = blocknum + i;
        io_buffers_len = 1;
 
        /*
         * How many neighboring-on-disk blocks can we can scatter-read into
         * other buffers at the same time?  In this case we don't wait if we
         * see an I/O already in progress.  We already hold BM_IO_IN_PROGRESS
         * for the head block, so we should get on with that I/O as soon as
         * possible.  We'll come back to this block again, above.
         */
        while ((i + 1) < nblocks &&
               WaitReadBuffersCanStartIO(buffers[i + 1], true))
        {
            /* Must be consecutive block numbers. */
            Assert(BufferGetBlockNumber(buffers[i + 1]) ==
                   BufferGetBlockNumber(buffers[i]) + 1);
 
            io_buffers[io_buffers_len] = buffers[++i];
            io_pages[io_buffers_len++] = BufferGetBlock(buffers[i]);
        }
 
        io_start = pgstat_prepare_io_time(track_io_timing);
        smgrreadv(operation->smgr, forknum, io_first_block, io_pages, io_buffers_len);
        pgstat_count_io_op_time(io_object, io_context, IOOP_READ, io_start,
                                io_buffers_len);
 
        /* Verify each block we read, and terminate the I/O. */
        for (int j = 0; j < io_buffers_len; ++j)
        {
            BufferDesc *bufHdr;
            Block       bufBlock;
 
            if (persistence == RELPERSISTENCE_TEMP)
            {
                bufHdr = GetLocalBufferDescriptor(-io_buffers[j] - 1);
                bufBlock = LocalBufHdrGetBlock(bufHdr);
            }
            else
            {
                bufHdr = GetBufferDescriptor(io_buffers[j] - 1);
                bufBlock = BufHdrGetBlock(bufHdr);
            }
 
            /* check for garbage data */
            if (!PageIsVerifiedExtended((Page) bufBlock, io_first_block + j,
                                        PIV_LOG_WARNING | PIV_REPORT_STAT))
            {
                if ((operation->flags & READ_BUFFERS_ZERO_ON_ERROR) || zero_damaged_pages)
                {
                    ereport(WARNING,
                            (errcode(ERRCODE_DATA_CORRUPTED),
                             errmsg("invalid page in block %u of relation %s; zeroing out page",
                                    io_first_block + j,
                                    relpath(operation->smgr->smgr_rlocator, forknum))));
                    memset(bufBlock, 0, BLCKSZ);
                }
                else
                    ereport(ERROR,
                            (errcode(ERRCODE_DATA_CORRUPTED),
                             errmsg("invalid page in block %u of relation %s",
                                    io_first_block + j,
                                    relpath(operation->smgr->smgr_rlocator, forknum))));
            }
 
            /* Terminate I/O and set BM_VALID. */
            if (persistence == RELPERSISTENCE_TEMP)
            {
                uint32      buf_state = pg_atomic_read_u32(&bufHdr->state);
 
                buf_state |= BM_VALID;
                pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
            }
            else
            {
                /* Set BM_VALID, terminate IO, and wake up any waiters */
                TerminateBufferIO(bufHdr, false, BM_VALID, true);
            }
 
            /* Report I/Os as completing individually. */
            TRACE_POSTGRESQL_BUFFER_READ_DONE(forknum, io_first_block + j,
                                              operation->smgr->smgr_rlocator.locator.spcOid,
                                              operation->smgr->smgr_rlocator.locator.dbOid,
                                              operation->smgr->smgr_rlocator.locator.relNumber,
                                              operation->smgr->smgr_rlocator.backend,
                                              false);
        }
 
        VacuumPageMiss += io_buffers_len;
        if (VacuumCostActive)
            VacuumCostBalance += VacuumCostPageMiss * io_buffers_len;
    }
}

References Assert, RelFileLocatorBackend::backend, ReadBuffersOperation::blocknum, BM_VALID, BufferGetBlock(), BufferGetBlockNumber(), ReadBuffersOperation::buffers, BufHdrGetBlock, RelFileLocator::dbOid, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errmsg(), ERROR, ReadBuffersOperation::flags, ReadBuffersOperation::forknum, GetBufferDescriptor(), GetLocalBufferDescriptor(), i, ReadBuffersOperation::io_buffers_len, IOCONTEXT_NORMAL, IOContextForStrategy(), IOOBJECT_RELATION, IOOBJECT_TEMP_RELATION, IOOP_READ, j, BufferUsage::local_blks_read, LocalBufHdrGetBlock, RelFileLocatorBackend::locator, MAX_IO_COMBINE_LIMIT, ReadBuffersOperation::nblocks, PageIsVerifiedExtended(), pg_atomic_read_u32(), pg_atomic_unlocked_write_u32(), pgBufferUsage, pgstat_count_io_op_time(), pgstat_prepare_io_time(), PIV_LOG_WARNING, PIV_REPORT_STAT, RelationData::rd_rel, READ_BUFFERS_ZERO_ON_ERROR, ReadBuffersOperation::rel, RelFileLocator::relNumber, relpath, BufferUsage::shared_blks_read, ReadBuffersOperation::smgr, SMgrRelationData::smgr_rlocator, smgrreadv(), RelFileLocator::spcOid, BufferDesc::state, ReadBuffersOperation::strategy, TerminateBufferIO(), track_io_timing, VacuumCostActive, VacuumCostBalance, VacuumCostPageMiss, VacuumPageMiss, WaitReadBuffersCanStartIO(), WARNING, and zero_damaged_pages.

Referenced by read_stream_next_buffer(), and ReadBuffer_common().

Variable Documentation

backend_flush_after

PGDLLIMPORT int backend_flush_after

extern

Definition at line 172 of file bufmgr.c.

Referenced by InitBufferPool().

bgwriter_flush_after

PGDLLIMPORT int bgwriter_flush_after

extern

Definition at line 171 of file bufmgr.c.

Referenced by BackgroundWriterMain().

bgwriter_lru_maxpages

PGDLLIMPORT int bgwriter_lru_maxpages

extern

Definition at line 140 of file bufmgr.c.

Referenced by BgBufferSync().

bgwriter_lru_multiplier

PGDLLIMPORT double bgwriter_lru_multiplier

extern

Definition at line 141 of file bufmgr.c.

Referenced by BgBufferSync().

BufferBlocks

PGDLLIMPORT char* BufferBlocks

extern

Definition at line 22 of file buf_init.c.

Referenced by BufferGetBlock(), and InitBufferPool().

checkpoint_flush_after

PGDLLIMPORT int checkpoint_flush_after

extern

Definition at line 170 of file bufmgr.c.

Referenced by BufferSync().

effective_io_concurrency

PGDLLIMPORT int effective_io_concurrency

extern

Definition at line 150 of file bufmgr.c.

Referenced by get_tablespace_io_concurrency(), read_stream_begin_relation(), and tablespace_reloptions().

io_combine_limit

PGDLLIMPORT int io_combine_limit

extern

Definition at line 164 of file bufmgr.c.

Referenced by read_stream_begin_relation(), read_stream_look_ahead(), read_stream_next_buffer(), and read_stream_start_pending_read().

LocalBufferBlockPointers

PGDLLIMPORT Block* LocalBufferBlockPointers

extern

Definition at line 45 of file localbuf.c.

Referenced by BufferGetBlock(), and InitLocalBuffers().

LocalRefCount

PGDLLIMPORT int32* LocalRefCount

extern

Definition at line 46 of file localbuf.c.

Referenced by CheckBufferIsPinnedOnce(), CheckForLocalBufferLeaks(), ConditionalLockBufferForCleanup(), DebugPrintBufferRefcount(), DropRelationAllLocalBuffers(), DropRelationLocalBuffers(), GetLocalVictimBuffer(), IncrBufferRefCount(), InitLocalBuffers(), IsBufferCleanupOK(), MarkLocalBufferDirty(), PinLocalBuffer(), and UnpinLocalBufferNoOwner().

maintenance_io_concurrency

PGDLLIMPORT int maintenance_io_concurrency

extern

Definition at line 157 of file bufmgr.c.

Referenced by assign_maintenance_io_concurrency(), get_tablespace_maintenance_io_concurrency(), heap_index_delete_tuples(), tablespace_reloptions(), and XLogPrefetcherReadRecord().

NBuffers

PGDLLIMPORT int NBuffers

extern

Definition at line 139 of file globals.c.

Referenced by apw_dump_now(), BgBufferSync(), BufferIsValid(), BufferShmemSize(), BufferSync(), CheckpointerShmemInit(), CheckpointerShmemSize(), ClockSweepTick(), CreateCheckPoint(), DropDatabaseBuffers(), DropRelationBuffers(), DropRelationsAllBuffers(), FlushDatabaseBuffers(), FlushRelationBuffers(), FlushRelationsAllBuffers(), GetAccessStrategyPinLimit(), GetAccessStrategyWithSize(), hashbuild(), InitBufferPool(), initscan(), LimitAdditionalPins(), LogCheckpointEnd(), pg_buffercache_evict(), pg_buffercache_pages(), pg_buffercache_summary(), SimpleLruAutotuneBuffers(), StrategyGetBuffer(), StrategyInitialize(), StrategyShmemSize(), StrategySyncStart(), table_block_parallelscan_initialize(), and XLOGChooseNumBuffers().

NLocBuffer

PGDLLIMPORT int NLocBuffer

extern

Definition at line 42 of file localbuf.c.

Referenced by BufferIsValid(), check_temp_buffers(), CheckForLocalBufferLeaks(), DropRelationAllLocalBuffers(), DropRelationLocalBuffers(), FlushRelationBuffers(), GetLocalBufferStorage(), GetLocalVictimBuffer(), hashbuild(), and InitLocalBuffers().

track_io_timing

PGDLLIMPORT bool track_io_timing

extern

Definition at line 142 of file bufmgr.c.

Referenced by BufFileDumpBuffer(), BufFileLoadBuffer(), do_analyze_rel(), ExtendBufferedRelLocal(), ExtendBufferedRelShared(), FlushBuffer(), FlushRelationBuffers(), GetLocalVictimBuffer(), heap_vacuum_rel(), IssuePendingWritebacks(), mdsyncfiletag(), pgstat_count_io_op_time(), register_dirty_segment(), show_buffer_usage(), and WaitReadBuffers().

zero_damaged_pages

PGDLLIMPORT bool zero_damaged_pages

extern

Definition at line 139 of file bufmgr.c.

Referenced by mdreadv(), and WaitReadBuffers().