1 /*-------------------------------------------------------------------------
2  *
3  * procarray.h
4  *	  POSTGRES process array definitions.
5  *
6  *
7  * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/storage/procarray.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef PROCARRAY_H
15 #define PROCARRAY_H
16 
17 #include "storage/lock.h"
18 #include "storage/standby.h"
19 #include "utils/relcache.h"
20 #include "utils/snapshot.h"
21 
22 
23 /*
24  * These are to implement PROCARRAY_FLAGS_XXX
25  *
26  * Note: These flags are cloned from PROC_XXX flags in src/include/storage/proc.h
27  * to avoid forcing to include proc.h when including procarray.h. So if you modify
28  * PROC_XXX flags, you need to modify these flags.
29  */
30 #define		PROCARRAY_VACUUM_FLAG			0x02	/* currently running lazy
31 													 * vacuum */
32 #define		PROCARRAY_ANALYZE_FLAG			0x04	/* currently running
33 													 * analyze */
34 #define		PROCARRAY_LOGICAL_DECODING_FLAG 0x10	/* currently doing logical
35 													 * decoding outside xact */
36 
37 #define		PROCARRAY_SLOTS_XMIN			0x20	/* replication slot xmin,
38 													 * catalog_xmin */
39 /*
40  * Only flags in PROCARRAY_PROC_FLAGS_MASK are considered when matching
41  * PGXACT->vacuumFlags. Other flags are used for different purposes and
42  * have no corresponding PROC flag equivalent.
43  */
44 #define		PROCARRAY_PROC_FLAGS_MASK	(PROCARRAY_VACUUM_FLAG | \
45 										 PROCARRAY_ANALYZE_FLAG | \
46 										 PROCARRAY_LOGICAL_DECODING_FLAG)
47 
48 /* Use the following flags as an input "flags" to GetOldestXmin function */
49 /* Consider all backends except for logical decoding ones which manage xmin separately */
50 #define		PROCARRAY_FLAGS_DEFAULT			PROCARRAY_LOGICAL_DECODING_FLAG
51 /* Ignore vacuum backends */
52 #define		PROCARRAY_FLAGS_VACUUM			PROCARRAY_FLAGS_DEFAULT | PROCARRAY_VACUUM_FLAG
53 /* Ignore analyze backends */
54 #define		PROCARRAY_FLAGS_ANALYZE			PROCARRAY_FLAGS_DEFAULT | PROCARRAY_ANALYZE_FLAG
55 /* Ignore both vacuum and analyze backends */
56 #define		PROCARRAY_FLAGS_VACUUM_ANALYZE	PROCARRAY_FLAGS_DEFAULT | PROCARRAY_VACUUM_FLAG | PROCARRAY_ANALYZE_FLAG
57 
58 extern Size ProcArrayShmemSize(void);
59 extern void CreateSharedProcArray(void);
60 extern void ProcArrayAdd(PGPROC *proc);
61 extern void ProcArrayRemove(PGPROC *proc, TransactionId latestXid);
62 
63 extern void ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid);
64 extern void ProcArrayClearTransaction(PGPROC *proc);
65 
66 extern void ProcArrayInitRecovery(TransactionId initializedUptoXID);
67 extern void ProcArrayApplyRecoveryInfo(RunningTransactions running);
68 extern void ProcArrayApplyXidAssignment(TransactionId topxid,
69 							int nsubxids, TransactionId *subxids);
70 
71 extern void RecordKnownAssignedTransactionIds(TransactionId xid);
72 extern void ExpireTreeKnownAssignedTransactionIds(TransactionId xid,
73 									  int nsubxids, TransactionId *subxids,
74 									  TransactionId max_xid);
75 extern void ExpireAllKnownAssignedTransactionIds(void);
76 extern void ExpireOldKnownAssignedTransactionIds(TransactionId xid);
77 
78 extern int	GetMaxSnapshotXidCount(void);
79 extern int	GetMaxSnapshotSubxidCount(void);
80 
81 extern Snapshot GetSnapshotData(Snapshot snapshot);
82 
83 extern bool ProcArrayInstallImportedXmin(TransactionId xmin,
84 							 VirtualTransactionId *sourcevxid);
85 extern bool ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc);
86 
87 extern RunningTransactions GetRunningTransactionData(void);
88 
89 extern bool TransactionIdIsInProgress(TransactionId xid);
90 extern bool TransactionIdIsActive(TransactionId xid);
91 extern TransactionId GetOldestXmin(Relation rel, int flags);
92 extern TransactionId GetOldestActiveTransactionId(void);
93 extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
94 
95 extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids);
96 extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids, int nvxids);
97 
98 extern PGPROC *BackendPidGetProc(int pid);
99 extern PGPROC *BackendPidGetProcWithLock(int pid);
100 extern int	BackendXidGetPid(TransactionId xid);
101 extern bool IsBackendPid(int pid);
102 
103 extern VirtualTransactionId *GetCurrentVirtualXIDs(TransactionId limitXmin,
104 					  bool excludeXmin0, bool allDbs, int excludeVacuum,
105 					  int *nvxids);
106 extern VirtualTransactionId *GetConflictingVirtualXIDs(TransactionId limitXmin, Oid dbOid);
107 extern pid_t CancelVirtualTransaction(VirtualTransactionId vxid, ProcSignalReason sigmode);
108 extern pid_t SignalVirtualTransaction(VirtualTransactionId vxid, ProcSignalReason sigmode,
109 									  bool conflictPending);
110 
111 extern bool MinimumActiveBackends(int min);
112 extern int	CountDBBackends(Oid databaseid);
113 extern int	CountDBConnections(Oid databaseid);
114 extern void CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending);
115 extern int	CountUserBackends(Oid roleid);
116 extern bool CountOtherDBBackends(Oid databaseId,
117 					 int *nbackends, int *nprepared);
118 
119 extern void XidCacheRemoveRunningXids(TransactionId xid,
120 						  int nxids, const TransactionId *xids,
121 						  TransactionId latestXid);
122 
123 extern void ProcArraySetReplicationSlotXmin(TransactionId xmin,
124 								TransactionId catalog_xmin, bool already_locked);
125 
126 extern void ProcArrayGetReplicationSlotXmin(TransactionId *xmin,
127 								TransactionId *catalog_xmin);
128 
129 #endif							/* PROCARRAY_H */
130