rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
postgresql/src/include/access/slru.h

66 lines
1.9 KiB
C
Raw Normal View History

This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
/*
* slru.h
*
* Simple LRU
*
* Portions Copyright (c) 2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
2004-05-28 07:13:32 +02:00
* $PostgreSQL: pgsql/src/include/access/slru.h,v 1.5 2004/05/28 05:13:17 tgl Exp $
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
*/
#ifndef SLRU_H
#define SLRU_H
#include "access/xlog.h"
/* exported because lwlock.c needs it */
#define NUM_CLOG_BUFFERS 8
Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
2004-05-28 07:13:32 +02:00
/*
* Note: the separation between SlruLockData and SlruSharedData is purely
* historical; the structs could be combined.
*/
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
typedef struct SlruLockData
{
pgindent run.
2003-08-04 02:43:34 +02:00
LWLockId ControlLock;
LWLockId BufferLocks[NUM_CLOG_BUFFERS]; /* Per-buffer I/O locks */
Another pgindent run with updated typedefs.
2003-08-08 23:42:59 +02:00
} SlruLockData;
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
typedef SlruLockData *SlruLock;
Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
2004-05-28 07:13:32 +02:00
/*
* SlruCtlData is an unshared structure that points to the active information
* in shared memory.
*/
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
typedef struct SlruCtlData
{
pgindent run.
2003-08-04 02:43:34 +02:00
void *shared; /* pointer to SlruSharedData */
SlruLock locks;
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
2004-05-28 07:13:32 +02:00
/*
* Dir is set during SimpleLruShmemInit and does not change thereafter.
* The value is automatically inherited by backends via fork, and
* doesn't need to be in shared memory.
*/
pgindent run.
2003-08-04 02:43:34 +02:00
char Dir[MAXPGPATH];
Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
2004-05-28 07:13:32 +02:00
/*
* Decide which of two page numbers is "older" for truncation purposes.
* We need to use comparison of TransactionIds here in order to do the
* right thing with wraparound XID arithmetic.
*/
pgindent run.
2003-08-04 02:43:34 +02:00
bool (*PagePrecedes) (int, int);
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
Another pgindent run with updated typedefs.
2003-08-08 23:42:59 +02:00
} SlruCtlData;
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
typedef SlruCtlData *SlruCtl;
extern int SimpleLruShmemSize(void);
extern void SimpleLruInit(SlruCtl ctl, const char *name, const char *subdir);
extern int SimpleLruZeroPage(SlruCtl ctl, int pageno);
pgindent run.
2003-08-04 02:43:34 +02:00
extern char *SimpleLruReadPage(SlruCtl ctl, int pageno, TransactionId xid, bool forwrite);
This patch extracts page buffer pooling and the simple least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-06-12 00:37:46 +02:00
extern void SimpleLruWritePage(SlruCtl ctl, int slotno);
extern void SimpleLruSetLatestPage(SlruCtl ctl, int pageno);
extern void SimpleLruFlush(SlruCtl ctl, bool checkpoint);
extern void SimpleLruTruncate(SlruCtl ctl, int cutoffPage);
#endif /* SLRU_H */