buf_init.c File Reference

#include "postgres.h"
#include "storage/bufmgr.h"
#include "storage/buf_internals.h"

Include dependency graph for buf_init.c:

Go to the source code of this file.

Functions
void	InitBufferPool (void)
void	InitBufferPoolAccess (void)
Size	BufferShmemSize (void)
Variables
BufferDesc *	BufferDescriptors
char *	BufferBlocks
int32 *	PrivateRefCount

---

Function Documentation

Size BufferShmemSize

(

void

)

Definition at line 164 of file buf_init.c.

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

Referenced by CreateSharedMemoryAndSemaphores().

{
    Size        size = 0;

    /* size of buffer descriptors */
    size = add_size(size, mul_size(NBuffers, sizeof(BufferDesc)));

    /* size of data pages */
    size = add_size(size, mul_size(NBuffers, BLCKSZ));

    /* size of stuff controlled by freelist.c */
    size = add_size(size, StrategyShmemSize());

    return size;
}

void InitBufferPool

(

void

)

Definition at line 73 of file buf_init.c.

References Assert, buf, sbufdesc::buf_hdr_lock, sbufdesc::buf_id, BufferBlocks, CLEAR_BUFFERTAG, sbufdesc::content_lock, sbufdesc::flags, sbufdesc::freeNext, i, sbufdesc::io_in_progress_lock, LWLockAssign(), NBuffers, sbufdesc::refcount, ShmemInitStruct(), SpinLockInit, StrategyInitialize(), sbufdesc::tag, sbufdesc::usage_count, and sbufdesc::wait_backend_pid.

Referenced by CreateSharedMemoryAndSemaphores().

{
    bool        foundBufs,
                foundDescs;

    BufferDescriptors = (BufferDesc *)
        ShmemInitStruct("Buffer Descriptors",
                        NBuffers * sizeof(BufferDesc), &foundDescs);

    BufferBlocks = (char *)
        ShmemInitStruct("Buffer Blocks",
                        NBuffers * (Size) BLCKSZ, &foundBufs);

    if (foundDescs || foundBufs)
    {
        /* both should be present or neither */
        Assert(foundDescs && foundBufs);
        /* note: this path is only taken in EXEC_BACKEND case */
    }
    else
    {
        BufferDesc *buf;
        int         i;

        buf = BufferDescriptors;

        /*
         * Initialize all the buffer headers.
         */
        for (i = 0; i < NBuffers; buf++, i++)
        {
            CLEAR_BUFFERTAG(buf->tag);
            buf->flags = 0;
            buf->usage_count = 0;
            buf->refcount = 0;
            buf->wait_backend_pid = 0;

            SpinLockInit(&buf->buf_hdr_lock);

            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;

            buf->io_in_progress_lock = LWLockAssign();
            buf->content_lock = LWLockAssign();
        }

        /* Correct last entry of linked list */
        BufferDescriptors[NBuffers - 1].freeNext = FREENEXT_END_OF_LIST;
    }

    /* Init other shared buffer-management stuff */
    StrategyInitialize(!foundDescs);
}

void InitBufferPoolAccess

(

void

)

Definition at line 145 of file buf_init.c.

References calloc, ereport, errcode(), errmsg(), FATAL, NBuffers, and PrivateRefCount.

Referenced by BaseInit().

{
    /*
     * Allocate and zero local arrays of per-buffer info.
     */
    PrivateRefCount = (int32 *) calloc(NBuffers, sizeof(int32));
    if (!PrivateRefCount)
        ereport(FATAL,
                (errcode(ERRCODE_OUT_OF_MEMORY),
                 errmsg("out of memory")));
}

---

Variable Documentation

char* BufferBlocks

Definition at line 22 of file buf_init.c.

Referenced by InitBufferPool().

BufferDesc* BufferDescriptors

Definition at line 21 of file buf_init.c.

Referenced by BufferAlloc(), BufferGetBlockNumber(), BufferGetLSNAtomic(), BufferGetTag(), BufferIsPermanent(), BufferSync(), ConditionalLockBuffer(), ConditionalLockBufferForCleanup(), DropDatabaseBuffers(), DropRelFileNodeBuffers(), DropRelFileNodesAllBuffers(), FlushDatabaseBuffers(), FlushRelationBuffers(), GetBufferFromRing(), LockBuffer(), LockBufferForCleanup(), MarkBufferDirty(), MarkBufferDirtyHint(), pg_buffercache_pages(), PrintBufferLeakWarning(), ReleaseAndReadBuffer(), ReleaseBuffer(), StrategyGetBuffer(), and SyncOneBuffer().

int32* PrivateRefCount

Definition at line 23 of file buf_init.c.

Referenced by AtEOXact_Buffers(), AtProcExit_Buffers(), ConditionalLockBufferForCleanup(), HoldingBufferPinThatDelaysRecovery(), IncrBufferRefCount(), InitBufferPoolAccess(), InvalidateBuffer(), LockBufferForCleanup(), MarkBufferDirty(), MarkBufferDirtyHint(), PinBuffer(), PinBuffer_Locked(), PrintBufferLeakWarning(), ReleaseAndReadBuffer(), ReleaseBuffer(), and UnpinBuffer().