4 * PostgreSQL multi-transaction-log manager
6 * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
9 * $PostgreSQL: pgsql/src/include/access/multixact.h,v 1.16 2010/01/02 16:58:00 momjian Exp $
14 #include "access/xlog.h"
16 #define InvalidMultiXactId ((MultiXactId) 0)
17 #define FirstMultiXactId ((MultiXactId) 1)
19 #define MultiXactIdIsValid(multi) ((multi) != InvalidMultiXactId)
21 /* Number of SLRU buffers to use for multixact */
22 #define NUM_MXACTOFFSET_BUFFERS 8
23 #define NUM_MXACTMEMBER_BUFFERS 16
26 * multixact-related XLOG entries
30 #define XLOG_MULTIXACT_ZERO_OFF_PAGE 0x00
31 #define XLOG_MULTIXACT_ZERO_MEM_PAGE 0x10
32 #define XLOG_MULTIXACT_CREATE_ID 0x20
34 typedef struct xl_multixact_create
36 MultiXactId mid; /* new MultiXact's ID */
37 MultiXactOffset moff; /* its starting offset in members file */
38 int32 nxids; /* number of member XIDs */
39 TransactionId xids[1]; /* VARIABLE LENGTH ARRAY */
40 } xl_multixact_create;
42 #define MinSizeOfMultiXactCreate offsetof(xl_multixact_create, xids)
45 extern MultiXactId MultiXactIdCreate(TransactionId xid1, TransactionId xid2);
46 extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid);
47 extern bool MultiXactIdIsRunning(MultiXactId multi);
48 extern bool MultiXactIdIsCurrent(MultiXactId multi);
49 extern void MultiXactIdWait(MultiXactId multi);
50 extern bool ConditionalMultiXactIdWait(MultiXactId multi);
51 extern void MultiXactIdSetOldestMember(void);
52 extern int GetMultiXactIdMembers(MultiXactId multi, TransactionId **xids);
54 extern void AtEOXact_MultiXact(void);
55 extern void AtPrepare_MultiXact(void);
56 extern void PostPrepare_MultiXact(TransactionId xid);
58 extern Size MultiXactShmemSize(void);
59 extern void MultiXactShmemInit(void);
60 extern void BootStrapMultiXact(void);
61 extern void StartupMultiXact(void);
62 extern void ShutdownMultiXact(void);
63 extern void MultiXactGetCheckptMulti(bool is_shutdown,
64 MultiXactId *nextMulti,
65 MultiXactOffset *nextMultiOffset);
66 extern void CheckPointMultiXact(void);
67 extern void MultiXactSetNextMXact(MultiXactId nextMulti,
68 MultiXactOffset nextMultiOffset);
69 extern void MultiXactAdvanceNextMXact(MultiXactId minMulti,
70 MultiXactOffset minMultiOffset);
72 extern void multixact_twophase_recover(TransactionId xid, uint16 info,
73 void *recdata, uint32 len);
74 extern void multixact_twophase_postcommit(TransactionId xid, uint16 info,
75 void *recdata, uint32 len);
76 extern void multixact_twophase_postabort(TransactionId xid, uint16 info,
77 void *recdata, uint32 len);
79 extern void multixact_redo(XLogRecPtr lsn, XLogRecord *record);
80 extern void multixact_desc(StringInfo buf, uint8 xl_info, char *rec);
82 #endif /* MULTIXACT_H */