init
This commit is contained in:
blue-lemon0104
172
pg_include/access/transam.h
Executable file
172
pg_include/access/transam.h
Executable file
@@ -0,0 +1,172 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* transam.h
|
||||
* postgres transaction access method support code
|
||||
*
|
||||
*
|
||||
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* src/include/access/transam.h
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
#ifndef TRANSAM_H
|
||||
#define TRANSAM_H
|
||||
|
||||
#include "access/xlogdefs.h"
|
||||
|
||||
|
||||
/* ----------------
|
||||
* Special transaction ID values
|
||||
*
|
||||
* BootstrapTransactionId is the XID for "bootstrap" operations, and
|
||||
* FrozenTransactionId is used for very old tuples. Both should
|
||||
* always be considered valid.
|
||||
*
|
||||
* FirstNormalTransactionId is the first "normal" transaction id.
|
||||
* Note: if you need to change it, you must change pg_class.h as well.
|
||||
* ----------------
|
||||
*/
|
||||
#define InvalidTransactionId ((TransactionId) 0)
|
||||
#define BootstrapTransactionId ((TransactionId) 1)
|
||||
#define FrozenTransactionId ((TransactionId) 2)
|
||||
#define FirstNormalTransactionId ((TransactionId) 3)
|
||||
#define MaxTransactionId ((TransactionId) 0xFFFFFFFF)
|
||||
|
||||
/* ----------------
|
||||
* transaction ID manipulation macros
|
||||
* ----------------
|
||||
*/
|
||||
#define TransactionIdIsValid(xid) ((xid) != InvalidTransactionId)
|
||||
#define TransactionIdIsNormal(xid) ((xid) >= FirstNormalTransactionId)
|
||||
#define TransactionIdEquals(id1, id2) ((id1) == (id2))
|
||||
#define TransactionIdStore(xid, dest) (*(dest) = (xid))
|
||||
#define StoreInvalidTransactionId(dest) (*(dest) = InvalidTransactionId)
|
||||
|
||||
/* advance a transaction ID variable, handling wraparound correctly */
|
||||
#define TransactionIdAdvance(dest) \
|
||||
do { \
|
||||
(dest)++; \
|
||||
if ((dest) < FirstNormalTransactionId) \
|
||||
(dest) = FirstNormalTransactionId; \
|
||||
} while(0)
|
||||
|
||||
/* back up a transaction ID variable, handling wraparound correctly */
|
||||
#define TransactionIdRetreat(dest) \
|
||||
do { \
|
||||
(dest)--; \
|
||||
} while ((dest) < FirstNormalTransactionId)
|
||||
|
||||
/* compare two XIDs already known to be normal; this is a macro for speed */
|
||||
#define NormalTransactionIdPrecedes(id1, id2) \
|
||||
(AssertMacro(TransactionIdIsNormal(id1) && TransactionIdIsNormal(id2)), \
|
||||
(int32) ((id1) - (id2)) < 0)
|
||||
|
||||
/* ----------
|
||||
* Object ID (OID) zero is InvalidOid.
|
||||
*
|
||||
* OIDs 1-9999 are reserved for manual assignment (see the files
|
||||
* in src/include/catalog/).
|
||||
*
|
||||
* OIDS 10000-16383 are reserved for assignment during initdb
|
||||
* using the OID generator. (We start the generator at 10000.)
|
||||
*
|
||||
* OIDs beginning at 16384 are assigned from the OID generator
|
||||
* during normal multiuser operation. (We force the generator up to
|
||||
* 16384 as soon as we are in normal operation.)
|
||||
*
|
||||
* The choices of 10000 and 16384 are completely arbitrary, and can be moved
|
||||
* if we run low on OIDs in either category. Changing the macros below
|
||||
* should be sufficient to do this.
|
||||
*
|
||||
* NOTE: if the OID generator wraps around, we skip over OIDs 0-16383
|
||||
* and resume with 16384. This minimizes the odds of OID conflict, by not
|
||||
* reassigning OIDs that might have been assigned during initdb.
|
||||
* ----------
|
||||
*/
|
||||
#define FirstBootstrapObjectId 10000
|
||||
#define FirstNormalObjectId 16384
|
||||
|
||||
/*
|
||||
* VariableCache is a data structure in shared memory that is used to track
|
||||
* OID and XID assignment state. For largely historical reasons, there is
|
||||
* just one struct with different fields that are protected by different
|
||||
* LWLocks.
|
||||
*
|
||||
* Note: xidWrapLimit and oldestXidDB are not "active" values, but are
|
||||
* used just to generate useful messages when xidWarnLimit or xidStopLimit
|
||||
* are exceeded.
|
||||
*/
|
||||
typedef struct VariableCacheData
|
||||
{
|
||||
/*
|
||||
* These fields are protected by OidGenLock.
|
||||
*/
|
||||
Oid nextOid; /* next OID to assign */
|
||||
uint32 oidCount; /* OIDs available before must do XLOG work */
|
||||
|
||||
/*
|
||||
* These fields are protected by XidGenLock.
|
||||
*/
|
||||
TransactionId nextXid; /* next XID to assign */
|
||||
|
||||
TransactionId oldestXid; /* cluster-wide minimum datfrozenxid */
|
||||
TransactionId xidVacLimit; /* start forcing autovacuums here */
|
||||
TransactionId xidWarnLimit; /* start complaining here */
|
||||
TransactionId xidStopLimit; /* refuse to advance nextXid beyond here */
|
||||
TransactionId xidWrapLimit; /* where the world ends */
|
||||
Oid oldestXidDB; /* database with minimum datfrozenxid */
|
||||
|
||||
/*
|
||||
* These fields are protected by ProcArrayLock.
|
||||
*/
|
||||
TransactionId latestCompletedXid; /* newest XID that has committed or
|
||||
* aborted */
|
||||
} VariableCacheData;
|
||||
|
||||
typedef VariableCacheData *VariableCache;
|
||||
|
||||
|
||||
/* ----------------
|
||||
* extern declarations
|
||||
* ----------------
|
||||
*/
|
||||
|
||||
/* in transam/xact.c */
|
||||
extern bool TransactionStartedDuringRecovery(void);
|
||||
|
||||
/* in transam/varsup.c */
|
||||
extern PGDLLIMPORT VariableCache ShmemVariableCache;
|
||||
|
||||
/* in transam/transam.c */
|
||||
extern const XLogRecPtr InvalidXLogRecPtr;
|
||||
|
||||
|
||||
/*
|
||||
* prototypes for functions in transam/transam.c
|
||||
*/
|
||||
extern bool TransactionIdDidCommit(TransactionId transactionId);
|
||||
extern bool TransactionIdDidAbort(TransactionId transactionId);
|
||||
extern bool TransactionIdIsKnownCompleted(TransactionId transactionId);
|
||||
extern void TransactionIdAbort(TransactionId transactionId);
|
||||
extern void TransactionIdCommitTree(TransactionId xid, int nxids, TransactionId *xids);
|
||||
extern void TransactionIdAsyncCommitTree(TransactionId xid, int nxids, TransactionId *xids, XLogRecPtr lsn);
|
||||
extern void TransactionIdAbortTree(TransactionId xid, int nxids, TransactionId *xids);
|
||||
extern bool TransactionIdPrecedes(TransactionId id1, TransactionId id2);
|
||||
extern bool TransactionIdPrecedesOrEquals(TransactionId id1, TransactionId id2);
|
||||
extern bool TransactionIdFollows(TransactionId id1, TransactionId id2);
|
||||
extern bool TransactionIdFollowsOrEquals(TransactionId id1, TransactionId id2);
|
||||
extern TransactionId TransactionIdLatest(TransactionId mainxid,
|
||||
int nxids, const TransactionId *xids);
|
||||
extern XLogRecPtr TransactionIdGetCommitLSN(TransactionId xid);
|
||||
|
||||
/* in transam/varsup.c */
|
||||
extern TransactionId GetNewTransactionId(bool isSubXact);
|
||||
extern TransactionId ReadNewTransactionId(void);
|
||||
extern void SetTransactionIdLimit(TransactionId oldest_datfrozenxid,
|
||||
Oid oldest_datoid);
|
||||
extern bool ForceTransactionIdLimitUpdate(void);
|
||||
extern Oid GetNewObjectId(void);
|
||||
|
||||
#endif /* TRAMSAM_H */
|
||||
Reference in New Issue
Block a user