/src/postgres/src/include/access/multixact.h

Source
/*
 * multixact.h
 *
 * PostgreSQL multi-transaction-log manager
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/access/multixact.h
 */
#ifndef MULTIXACT_H
#define MULTIXACT_H

#include "access/transam.h"
#include "access/xlogreader.h"
#include "lib/stringinfo.h"
#include "storage/sync.h"


/*
 * The first two MultiXactId values are reserved to store the truncation Xid
 * and epoch of the first segment, so we start assigning multixact values from
 * 2.
 */
#define InvalidMultiXactId  ((MultiXactId) 0)
#define FirstMultiXactId  ((MultiXactId) 1)
#define MaxMultiXactId    ((MultiXactId) 0xFFFFFFFF)

#define MultiXactIdIsValid(multi) ((multi) != InvalidMultiXactId)

/*
 * Decide which of two MultiXactIds is earlier.
 *
 * XXX do we need to do something special for InvalidMultiXactId?
 * (Doesn't look like it.)
 */
static inline bool
MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
{
  int32   diff = (int32) (multi1 - multi2);

  return (diff < 0);
}

/*
 * MultiXactIdPrecedesOrEquals -- is multi1 logically <= multi2?
 *
 * XXX do we need to do something special for InvalidMultiXactId?
 * (Doesn't look like it.)
 */
static inline bool
MultiXactIdPrecedesOrEquals(MultiXactId multi1, MultiXactId multi2)
{
  int32   diff = (int32) (multi1 - multi2);

  return (diff <= 0);
}

/*
 * Possible multixact lock modes ("status").  The first four modes are for
 * tuple locks (FOR KEY SHARE, FOR SHARE, FOR NO KEY UPDATE, FOR UPDATE); the
 * next two are used for update and delete modes.
 */
typedef enum
{
  MultiXactStatusForKeyShare = 0x00,
  MultiXactStatusForShare = 0x01,
  MultiXactStatusForNoKeyUpdate = 0x02,
  MultiXactStatusForUpdate = 0x03,
  /* an update that doesn't touch "key" columns */
  MultiXactStatusNoKeyUpdate = 0x04,
  /* other updates, and delete */
  MultiXactStatusUpdate = 0x05,
} MultiXactStatus;

#define MaxMultiXactStatus MultiXactStatusUpdate

/* does a status value correspond to a tuple update? */
#define ISUPDATE_from_mxstatus(status) \
      ((status) > MultiXactStatusForUpdate)


typedef struct MultiXactMember
{
  TransactionId xid;
  MultiXactStatus status;
} MultiXactMember;


/* ----------------
 *    multixact-related XLOG entries
 * ----------------
 */

#define XLOG_MULTIXACT_ZERO_OFF_PAGE  0x00
#define XLOG_MULTIXACT_ZERO_MEM_PAGE  0x10
#define XLOG_MULTIXACT_CREATE_ID    0x20
#define XLOG_MULTIXACT_TRUNCATE_ID    0x30

typedef struct xl_multixact_create
{
  MultiXactId mid;      /* new MultiXact's ID */
  MultiXactOffset moff;   /* its starting offset in members file */
  int32   nmembers;   /* number of member XIDs */
  MultiXactMember members[FLEXIBLE_ARRAY_MEMBER];
} xl_multixact_create;

#define SizeOfMultiXactCreate (offsetof(xl_multixact_create, members))

typedef struct xl_multixact_truncate
{
  Oid     oldestMultiDB;

  /* truncate multixact offsets older than this */
  MultiXactId oldestMulti;

  /* truncate multixact members older than this */
  MultiXactOffset oldestOffset;
} xl_multixact_truncate;

#define SizeOfMultiXactTruncate (sizeof(xl_multixact_truncate))


extern MultiXactId MultiXactIdCreate(TransactionId xid1,
                   MultiXactStatus status1, TransactionId xid2,
                   MultiXactStatus status2);
extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid,
                   MultiXactStatus status);
extern MultiXactId MultiXactIdCreateFromMembers(int nmembers,
                        MultiXactMember *members);

extern MultiXactId ReadNextMultiXactId(void);
extern void ReadMultiXactIdRange(MultiXactId *oldest, MultiXactId *next);
extern bool MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly);
extern void MultiXactIdSetOldestMember(void);
extern int  GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members,
                  bool from_pgupgrade, bool isLockOnly);
extern void GetMultiXactInfo(uint32 *multixacts, MultiXactOffset *nextOffset,
               MultiXactId *oldestMultiXactId,
               MultiXactOffset *oldestOffset);

extern int  multixactoffsetssyncfiletag(const FileTag *ftag, char *path);
extern int  multixactmemberssyncfiletag(const FileTag *ftag, char *path);

extern void AtEOXact_MultiXact(void);
extern void AtPrepare_MultiXact(void);
extern void PostPrepare_MultiXact(FullTransactionId fxid);

extern void BootStrapMultiXact(void);
extern void StartupMultiXact(void);
extern void TrimMultiXact(void);
extern void SetMultiXactIdLimit(MultiXactId oldest_datminmxid,
                Oid oldest_datoid);
extern void MultiXactGetCheckptMulti(bool is_shutdown,
                   MultiXactId *nextMulti,
                   MultiXactOffset *nextMultiOffset,
                   MultiXactId *oldestMulti,
                   Oid *oldestMultiDB);
extern void CheckPointMultiXact(void);
extern MultiXactId GetOldestMultiXactId(void);
extern void TruncateMultiXact(MultiXactId newOldestMulti,
                Oid newOldestMultiDB);
extern void MultiXactSetNextMXact(MultiXactId nextMulti,
                  MultiXactOffset nextMultiOffset);
extern void MultiXactAdvanceNextMXact(MultiXactId minMulti,
                    MultiXactOffset minMultiOffset);
extern void MultiXactAdvanceOldest(MultiXactId oldestMulti, Oid oldestMultiDB);
extern int  MultiXactMemberFreezeThreshold(void);

extern void multixact_twophase_recover(FullTransactionId fxid, uint16 info,
                     void *recdata, uint32 len);
extern void multixact_twophase_postcommit(FullTransactionId fxid, uint16 info,
                      void *recdata, uint32 len);
extern void multixact_twophase_postabort(FullTransactionId fxid, uint16 info,
                     void *recdata, uint32 len);

extern void multixact_redo(XLogReaderState *record);
extern void multixact_desc(StringInfo buf, XLogReaderState *record);
extern const char *multixact_identify(uint8 info);
extern char *mxid_to_string(MultiXactId multi, int nmembers,
              MultiXactMember *members);
extern char *mxstatus_to_string(MultiXactStatus status);

#endif              /* MULTIXACT_H */

Line	Count	Source
1		/*
2		* multixact.h
3		*
4		* PostgreSQL multi-transaction-log manager
5		*
6		* Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7		* Portions Copyright (c) 1994, Regents of the University of California
8		*
9		* src/include/access/multixact.h
10		*/
11		#ifndef MULTIXACT_H
12		#define MULTIXACT_H
13
14		#include "access/transam.h"
15		#include "access/xlogreader.h"
16		#include "lib/stringinfo.h"
17		#include "storage/sync.h"
18
19
20		/*
21		* The first two MultiXactId values are reserved to store the truncation Xid
22		* and epoch of the first segment, so we start assigning multixact values from
23		* 2.
24		*/
25	0	#define InvalidMultiXactId ((MultiXactId) 0)
26	0	#define FirstMultiXactId ((MultiXactId) 1)
27	0	#define MaxMultiXactId ((MultiXactId) 0xFFFFFFFF)
28
29	0	#define MultiXactIdIsValid(multi) ((multi) != InvalidMultiXactId)
30
31		/*
32		* Decide which of two MultiXactIds is earlier.
33		*
34		* XXX do we need to do something special for InvalidMultiXactId?
35		* (Doesn't look like it.)
36		*/
37		static inline bool
38		MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
39	0	{
40	0	int32 diff = (int32) (multi1 - multi2);
41
42	0	return (diff < 0);
43	0	} Unexecuted instantiation: heapam.c:MultiXactIdPrecedes Unexecuted instantiation: heapam_handler.c:MultiXactIdPrecedes Unexecuted instantiation: heapam_visibility.c:MultiXactIdPrecedes Unexecuted instantiation: pruneheap.c:MultiXactIdPrecedes Unexecuted instantiation: vacuumlazy.c:MultiXactIdPrecedes Unexecuted instantiation: mxactdesc.c:MultiXactIdPrecedes Unexecuted instantiation: multixact.c:MultiXactIdPrecedes Unexecuted instantiation: rmgr.c:MultiXactIdPrecedes Unexecuted instantiation: twophase_rmgr.c:MultiXactIdPrecedes Unexecuted instantiation: xact.c:MultiXactIdPrecedes Unexecuted instantiation: xlog.c:MultiXactIdPrecedes Unexecuted instantiation: heap.c:MultiXactIdPrecedes Unexecuted instantiation: index.c:MultiXactIdPrecedes Unexecuted instantiation: analyze.c:MultiXactIdPrecedes Unexecuted instantiation: dbcommands.c:MultiXactIdPrecedes Unexecuted instantiation: matview.c:MultiXactIdPrecedes Unexecuted instantiation: repack.c:MultiXactIdPrecedes Unexecuted instantiation: sequence.c:MultiXactIdPrecedes Unexecuted instantiation: tablecmds.c:MultiXactIdPrecedes Unexecuted instantiation: vacuum.c:MultiXactIdPrecedes Unexecuted instantiation: autovacuum.c:MultiXactIdPrecedes Unexecuted instantiation: sync.c:MultiXactIdPrecedes Unexecuted instantiation: multixactfuncs.c:MultiXactIdPrecedes Unexecuted instantiation: xid.c:MultiXactIdPrecedes Unexecuted instantiation: relcache.c:MultiXactIdPrecedes
44
45		/*
46		* MultiXactIdPrecedesOrEquals -- is multi1 logically <= multi2?
47		*
48		* XXX do we need to do something special for InvalidMultiXactId?
49		* (Doesn't look like it.)
50		*/
51		static inline bool
52		MultiXactIdPrecedesOrEquals(MultiXactId multi1, MultiXactId multi2)
53	0	{
54	0	int32 diff = (int32) (multi1 - multi2);
55
56	0	return (diff <= 0);
57	0	} Unexecuted instantiation: heapam.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: heapam_handler.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: heapam_visibility.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: pruneheap.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: vacuumlazy.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: mxactdesc.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: multixact.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: rmgr.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: twophase_rmgr.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: xact.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: xlog.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: heap.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: index.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: analyze.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: dbcommands.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: matview.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: repack.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: sequence.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: tablecmds.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: vacuum.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: autovacuum.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: sync.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: multixactfuncs.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: xid.c:MultiXactIdPrecedesOrEquals Unexecuted instantiation: relcache.c:MultiXactIdPrecedesOrEquals
58
59		/*
60		* Possible multixact lock modes ("status"). The first four modes are for
61		* tuple locks (FOR KEY SHARE, FOR SHARE, FOR NO KEY UPDATE, FOR UPDATE); the
62		* next two are used for update and delete modes.
63		*/
64		typedef enum
65		{
66		MultiXactStatusForKeyShare = 0x00,
67		MultiXactStatusForShare = 0x01,
68		MultiXactStatusForNoKeyUpdate = 0x02,
69		MultiXactStatusForUpdate = 0x03,
70		/* an update that doesn't touch "key" columns */
71		MultiXactStatusNoKeyUpdate = 0x04,
72		/* other updates, and delete */
73		MultiXactStatusUpdate = 0x05,
74		} MultiXactStatus;
75
76		#define MaxMultiXactStatus MultiXactStatusUpdate
77
78		/* does a status value correspond to a tuple update? */
79		#define ISUPDATE_from_mxstatus(status) \
80	0	((status) > MultiXactStatusForUpdate)
81
82
83		typedef struct MultiXactMember
84		{
85		TransactionId xid;
86		MultiXactStatus status;
87		} MultiXactMember;
88
89
90		/* ----------------
91		* multixact-related XLOG entries
92		* ----------------
93		*/
94
95	0	#define XLOG_MULTIXACT_ZERO_OFF_PAGE 0x00
96	0	#define XLOG_MULTIXACT_ZERO_MEM_PAGE 0x10
97	0	#define XLOG_MULTIXACT_CREATE_ID 0x20
98	0	#define XLOG_MULTIXACT_TRUNCATE_ID 0x30
99
100		typedef struct xl_multixact_create
101		{
102		MultiXactId mid; /* new MultiXact's ID */
103		MultiXactOffset moff; /* its starting offset in members file */
104		int32 nmembers; /* number of member XIDs */
105		MultiXactMember members[FLEXIBLE_ARRAY_MEMBER];
106		} xl_multixact_create;
107
108	0	#define SizeOfMultiXactCreate (offsetof(xl_multixact_create, members))
109
110		typedef struct xl_multixact_truncate
111		{
112		Oid oldestMultiDB;
113
114		/* truncate multixact offsets older than this */
115		MultiXactId oldestMulti;
116
117		/* truncate multixact members older than this */
118		MultiXactOffset oldestOffset;
119		} xl_multixact_truncate;
120
121	0	#define SizeOfMultiXactTruncate (sizeof(xl_multixact_truncate))
122
123
124		extern MultiXactId MultiXactIdCreate(TransactionId xid1,
125		MultiXactStatus status1, TransactionId xid2,
126		MultiXactStatus status2);
127		extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid,
128		MultiXactStatus status);
129		extern MultiXactId MultiXactIdCreateFromMembers(int nmembers,
130		MultiXactMember *members);
131
132		extern MultiXactId ReadNextMultiXactId(void);
133		extern void ReadMultiXactIdRange(MultiXactId oldest, MultiXactId next);
134		extern bool MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly);
135		extern void MultiXactIdSetOldestMember(void);
136		extern int GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members,
137		bool from_pgupgrade, bool isLockOnly);
138		extern void GetMultiXactInfo(uint32 multixacts, MultiXactOffset nextOffset,
139		MultiXactId *oldestMultiXactId,
140		MultiXactOffset *oldestOffset);
141
142		extern int multixactoffsetssyncfiletag(const FileTag ftag, char path);
143		extern int multixactmemberssyncfiletag(const FileTag ftag, char path);
144
145		extern void AtEOXact_MultiXact(void);
146		extern void AtPrepare_MultiXact(void);
147		extern void PostPrepare_MultiXact(FullTransactionId fxid);
148
149		extern void BootStrapMultiXact(void);
150		extern void StartupMultiXact(void);
151		extern void TrimMultiXact(void);
152		extern void SetMultiXactIdLimit(MultiXactId oldest_datminmxid,
153		Oid oldest_datoid);
154		extern void MultiXactGetCheckptMulti(bool is_shutdown,
155		MultiXactId *nextMulti,
156		MultiXactOffset *nextMultiOffset,
157		MultiXactId *oldestMulti,
158		Oid *oldestMultiDB);
159		extern void CheckPointMultiXact(void);
160		extern MultiXactId GetOldestMultiXactId(void);
161		extern void TruncateMultiXact(MultiXactId newOldestMulti,
162		Oid newOldestMultiDB);
163		extern void MultiXactSetNextMXact(MultiXactId nextMulti,
164		MultiXactOffset nextMultiOffset);
165		extern void MultiXactAdvanceNextMXact(MultiXactId minMulti,
166		MultiXactOffset minMultiOffset);
167		extern void MultiXactAdvanceOldest(MultiXactId oldestMulti, Oid oldestMultiDB);
168		extern int MultiXactMemberFreezeThreshold(void);
169
170		extern void multixact_twophase_recover(FullTransactionId fxid, uint16 info,
171		void *recdata, uint32 len);
172		extern void multixact_twophase_postcommit(FullTransactionId fxid, uint16 info,
173		void *recdata, uint32 len);
174		extern void multixact_twophase_postabort(FullTransactionId fxid, uint16 info,
175		void *recdata, uint32 len);
176
177		extern void multixact_redo(XLogReaderState *record);
178		extern void multixact_desc(StringInfo buf, XLogReaderState *record);
179		extern const char *multixact_identify(uint8 info);
180		extern char *mxid_to_string(MultiXactId multi, int nmembers,
181		MultiXactMember *members);
182		extern char *mxstatus_to_string(MultiXactStatus status);
183
184		#endif /* MULTIXACT_H */

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Created: 2026-10-16 06:48