citus/src/include/distributed/backend_data.h

83 lines
2.9 KiB
C

/*
* backend_data.h
*
* Data structure definition for managing backend data and related function
* declarations.
*
* Copyright (c) Citus Data, Inc.
*
*-------------------------------------------------------------------------
*/
#ifndef BACKEND_DATA_H
#define BACKEND_DATA_H
#include "access/twophase.h"
#include "datatype/timestamp.h"
#include "distributed/transaction_identifier.h"
#include "nodes/pg_list.h"
#include "storage/lwlock.h"
#include "storage/proc.h"
#include "storage/s_lock.h"
/*
* Each backend's active distributed transaction information is tracked via
* BackendData in shared memory.
*
* DistributedTransactionId already has the same fields that CitusInitiatedBackend
* has. However, we prefer to keep them seperate since CitusInitiatedBackend is a
* broader concept which covers the backends that are not initiated via a distributed
* transaction as well. In other words, we could have backends that
* CitusInitiatedBackend is set but DistributedTransactionId is not set such as an
* "INSERT" query which is not inside a transaction block.
*/
typedef struct BackendData
{
Oid databaseId;
Oid userId;
slock_t mutex;
bool cancelledDueToDeadlock;
uint64 globalPID;
bool distributedCommandOriginator;
DistributedTransactionId transactionId;
} BackendData;
extern void BackendManagementShmemInit(void);
extern size_t BackendManagementShmemSize(void);
extern void InitializeBackendManagement(void);
extern int TotalProcCount(void);
extern void InitializeBackendData(void);
extern void LockBackendSharedMemory(LWLockMode lockMode);
extern void UnlockBackendSharedMemory(void);
extern void UnSetDistributedTransactionId(void);
extern void UnSetGlobalPID(void);
extern void AssignDistributedTransactionId(void);
extern void AssignGlobalPID(void);
extern uint64 GetGlobalPID(void);
extern void SetBackendDataDistributedCommandOriginator(bool
distributedCommandOriginator);
extern uint64 ExtractGlobalPID(char *applicationName);
extern int ExtractNodeIdFromGlobalPID(uint64 globalPID, bool missingOk);
extern int ExtractProcessIdFromGlobalPID(uint64 globalPID);
extern void GetBackendDataForProc(PGPROC *proc, BackendData *result);
extern void CancelTransactionDueToDeadlock(PGPROC *proc);
extern bool MyBackendGotCancelledDueToDeadlock(bool clearState);
extern bool MyBackendIsInDisributedTransaction(void);
extern List * ActiveDistributedTransactionNumbers(void);
extern LocalTransactionId GetMyProcLocalTransactionId(void);
extern int GetExternalClientBackendCount(void);
extern uint32 IncrementExternalClientBackendCounter(void);
extern void DecrementExternalClientBackendCounter(void);
extern bool IsCitusInternalBackend(void);
extern bool IsRebalancerInternalBackend(void);
extern bool IsCitusRunCommandBackend(void);
extern void ResetCitusBackendType(void);
#define INVALID_CITUS_INTERNAL_BACKEND_GPID 0
#define GLOBAL_PID_NODE_ID_FOR_NODES_NOT_IN_METADATA 99999999
#endif /* BACKEND_DATA_H */