postgresql/src/include/access/clog.h
Tom Lane 499abb0c0f Implement new 'lightweight lock manager' that's intermediate between
existing lock manager and spinlocks: it understands exclusive vs shared
lock but has few other fancy features.  Replace most uses of spinlocks
with lightweight locks.  All remaining uses of spinlocks have very short
lock hold times (a few dozen instructions), so tweak spinlock backoff
code to work efficiently given this assumption.  All per my proposal on
pghackers 26-Sep-01.
2001-09-29 04:02:27 +00:00

51 lines
1.4 KiB
C

/*
* clog.h
*
* PostgreSQL transaction-commit-log manager
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: clog.h,v 1.2 2001/09/29 04:02:26 tgl Exp $
*/
#ifndef CLOG_H
#define CLOG_H
#include "access/xlog.h"
/*
* Possible transaction statuses --- note that all-zeroes is the initial
* state.
*/
typedef int XidStatus;
#define TRANSACTION_STATUS_IN_PROGRESS 0x00
#define TRANSACTION_STATUS_COMMITTED 0x01
#define TRANSACTION_STATUS_ABORTED 0x02
/* 0x03 is available without changing commit log space allocation */
/* exported because lwlock.c needs it */
#define NUM_CLOG_BUFFERS 8
extern void TransactionIdSetStatus(TransactionId xid, XidStatus status);
extern XidStatus TransactionIdGetStatus(TransactionId xid);
extern int CLOGShmemSize(void);
extern void CLOGShmemInit(void);
extern void BootStrapCLOG(void);
extern void StartupCLOG(void);
extern void ShutdownCLOG(void);
extern void CheckPointCLOG(void);
extern void ExtendCLOG(TransactionId newestXact);
extern void TruncateCLOG(TransactionId oldestXact);
/* XLOG stuff */
#define CLOG_ZEROPAGE 0x00
extern void clog_redo(XLogRecPtr lsn, XLogRecord *record);
extern void clog_undo(XLogRecPtr lsn, XLogRecord *record);
extern void clog_desc(char *buf, uint8 xl_info, char *rec);
#endif /* CLOG_H */