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Replacement of the buffer replacement strategy with an ARC

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algorithm adopted for PostgreSQL.

Jan
This commit is contained in:
Jan Wieck
2003-11-13 00:40:02 +00:00
parent 27e8ef0535
commit 48adc0b34b
9 changed files with 941 additions and 225 deletions
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26
src/backend/storage/buffer/buf_init.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/buffer/buf_init.c,v 1.54 2003/08/04 02:40:03 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/buffer/buf_init.c,v 1.55 2003/11/13 00:40:01 wieck Exp $
*
*-------------------------------------------------------------------------
*/
@ -48,9 +48,6 @@ long *CurTraceBuf;
int ShowPinTrace = 0;
int Data_Descriptors;
int Free_List_Descriptor;
int Lookup_List_Descriptor;
int Num_Descriptors;
BufferDesc *BufferDescriptors;
Block *BufferBlockPointers;
@ -133,9 +130,6 @@ InitBufferPool(void)
int i;
Data_Descriptors = NBuffers;
Free_List_Descriptor = Data_Descriptors;
Lookup_List_Descriptor = Data_Descriptors + 1;
Num_Descriptors = Data_Descriptors + 1;
/*
* It's probably not really necessary to grab the lock --- if there's
@ -156,7 +150,7 @@ InitBufferPool(void)
BufferDescriptors = (BufferDesc *)
ShmemInitStruct("Buffer Descriptors",
Num_Descriptors * sizeof(BufferDesc), &foundDescs);
Data_Descriptors * sizeof(BufferDesc), &foundDescs);
BufferBlocks = (char *)
ShmemInitStruct("Buffer Blocks",
@ -176,16 +170,14 @@ InitBufferPool(void)
block = BufferBlocks;
/*
* link the buffers into a circular, doubly-linked list to
* initialize free list, and initialize the buffer headers. Still
* don't know anything about replacement strategy in this file.
* link the buffers into a single linked list. This will become the
* LiFo list of unused buffers returned by StragegyGetBuffer().
*/
for (i = 0; i < Data_Descriptors; block += BLCKSZ, buf++, i++)
{
Assert(ShmemIsValid((unsigned long) block));
buf->freeNext = i + 1;
buf->freePrev = i - 1;
buf->bufNext = i + 1;
CLEAR_BUFFERTAG(&(buf->tag));
buf->buf_id = i;
@ -199,14 +191,12 @@ InitBufferPool(void)
buf->wait_backend_id = 0;
}
/* close the circular queue */
BufferDescriptors[0].freePrev = Data_Descriptors - 1;
BufferDescriptors[Data_Descriptors - 1].freeNext = 0;
/* Correct last entry */
BufferDescriptors[Data_Descriptors - 1].bufNext = -1;
}
/* Init other shared buffer-management stuff */
InitBufTable();
InitFreeList(!foundDescs);
StrategyInitialize(!foundDescs);
LWLockRelease(BufMgrLock);
}