Quelle  procarray.h

/*-------------------------------------------------------------------------
 *
 * procarray.h
 *   POSTGRES process array definitions.
 *
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/storage/procarray.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PROCARRAY_H
#define PROCARRAY_H

#include "storage/lock.h"
#include "storage/standby.h"
#include "utils/relcache.h"
#include "utils/snapshot.h"


extern Size ProcArrayShmemSize(void);
extern void ProcArrayShmemInit(void);
extern void ProcArrayAdd(PGPROC *proc);
extern void ProcArrayRemove(PGPROC *proc, TransactionId latestXid);

extern void ProcArrayEndTransaction(PGPROC *proc, TransactionId latestXid);
extern void ProcArrayClearTransaction(PGPROC *proc);

extern void ProcArrayInitRecovery(TransactionId initializedUptoXID);
extern void ProcArrayApplyRecoveryInfo(RunningTransactions running);
extern void ProcArrayApplyXidAssignment(TransactionId topxid,
          int nsubxids, TransactionId *subxids);

extern void RecordKnownAssignedTransactionIds(TransactionId xid);
extern void ExpireTreeKnownAssignedTransactionIds(TransactionId xid,
              int nsubxids, TransactionId *subxids,
              TransactionId max_xid);
extern void ExpireAllKnownAssignedTransactionIds(void);
extern void ExpireOldKnownAssignedTransactionIds(TransactionId xid);
extern void KnownAssignedTransactionIdsIdleMaintenance(void);

extern int GetMaxSnapshotXidCount(void);
extern int GetMaxSnapshotSubxidCount(void);

extern Snapshot GetSnapshotData(Snapshot snapshot);

extern bool ProcArrayInstallImportedXmin(TransactionId xmin,
           VirtualTransactionId *sourcevxid);
extern bool ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc);

extern RunningTransactions GetRunningTransactionData(void);

extern bool TransactionIdIsInProgress(TransactionId xid);
extern bool TransactionIdIsActive(TransactionId xid);
extern TransactionId GetOldestNonRemovableTransactionId(Relation rel);
extern TransactionId GetOldestTransactionIdConsideredRunning(void);
extern TransactionId GetOldestActiveTransactionId(void);
extern TransactionId GetOldestSafeDecodingTransactionId(bool catalogOnly);
extern void GetReplicationHorizons(TransactionId *xmin, TransactionId *catalog_xmin);

extern VirtualTransactionId *GetVirtualXIDsDelayingChkpt(int *nvxids, int type);
extern bool HaveVirtualXIDsDelayingChkpt(VirtualTransactionId *vxids,
           int nvxids, int type);

extern PGPROC *ProcNumberGetProc(int procNumber);
extern void ProcNumberGetTransactionIds(int procNumber, TransactionId *xid,
          TransactionId *xmin, int *nsubxid,
          bool *overflowed);
extern PGPROC *BackendPidGetProc(int pid);
extern PGPROC *BackendPidGetProcWithLock(int pid);
extern int BackendXidGetPid(TransactionId xid);
extern bool IsBackendPid(int pid);

extern VirtualTransactionId *GetCurrentVirtualXIDs(TransactionId limitXmin,
               bool excludeXmin0, bool allDbs, int excludeVacuum,
               int *nvxids);
extern VirtualTransactionId *GetConflictingVirtualXIDs(TransactionId limitXmin, Oid dbOid);
extern pid_t CancelVirtualTransaction(VirtualTransactionId vxid, ProcSignalReason sigmode);
extern pid_t SignalVirtualTransaction(VirtualTransactionId vxid, ProcSignalReason sigmode,
           bool conflictPending);

extern bool MinimumActiveBackends(int min);
extern int CountDBBackends(Oid databaseid);
extern int CountDBConnections(Oid databaseid);
extern void CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending);
extern int CountUserBackends(Oid roleid);
extern bool CountOtherDBBackends(Oid databaseId,
         int *nbackends, int *nprepared);
extern void TerminateOtherDBBackends(Oid databaseId);

extern void XidCacheRemoveRunningXids(TransactionId xid,
           int nxids, const TransactionId *xids,
           TransactionId latestXid);

extern void ProcArraySetReplicationSlotXmin(TransactionId xmin,
           TransactionId catalog_xmin, bool already_locked);

extern void ProcArrayGetReplicationSlotXmin(TransactionId *xmin,
           TransactionId *catalog_xmin);

#endif       /* PROCARRAY_H */